# Calendar

A month grid for picking a single date, several dates or a date range.

Calendar is an open-source mobile component from suiss/uim for React Native and Expo, with SwiftUI and Jetpack Compose versions built from the same design tokens. The @esuiss/uim CLI copies its source into your project, so you own the code.

Source: https://uim.suiss.app/docs/components/calendar

![Preview](https://uim.suiss.app/previews/components-calendar--default.light.webp)

```tsx
import * as React from "react"
import { Calendar } from "@/components/ui/calendar"

type CalendarProps = React.ComponentProps<typeof Calendar>

function SingleCalendar(
  props: Omit<CalendarProps, "mode" | "selected" | "onSelect">
) {
  const today = new Date()
  const [date, setDate] = React.useState<Date | undefined>(
    new Date(today.getFullYear(), today.getMonth(), today.getDate() + 3)
  )
  return (
    <Calendar
      {...props}
      mode="single"
      selected={date}
      onSelect={setDate}
      className="rounded-2xl border border-separator"
    />
  )
}

export function CalendarExample() {
  return (
    <SingleCalendar />
  )
}
```

```swift
import EsuissUI
import SwiftUI

enum CalendarDates {
  static func day(_ offset: Int) -> Date {
    let calendar = Foundation.Calendar.current
    let start = calendar.startOfDay(for: Date())
    return calendar.date(byAdding: .day, value: offset, to: start) ?? start
  }

  static func dayOfMonth(_ day: Int) -> Date {
    let calendar = Foundation.Calendar.current
    var components = calendar.dateComponents([.year, .month], from: Date())
    components.day = day
    return calendar.date(from: components) ?? Date()
  }
}

struct CalendarBordered: ViewModifier {
  func body(content: Content) -> some View {
    content
      .clipShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
      .overlay {
        RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).strokeBorder(Color.separator)
      }
  }
}

struct CalendarSingleDemo: View {
  var size: DateCalendar.Size = .default
  var buttonVariant: VariantButtonStyle.Variant = .plain
  var captionLayout: DateCalendar.CaptionLayout = .label
  var showOutsideDays = false
  var showWeekNumber = false
  var weekendsDisabled = false

  @State private var date: Date? = CalendarDates.day(3)

  var body: some View {
    DateCalendar(
      selection: $date,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      isDisabled: { day in
        guard weekendsDisabled else { return false }
        let weekday = Foundation.Calendar.current.component(.weekday, from: day)
        return weekday == 1 || weekday == 7
      }
    )
    .modifier(CalendarBordered())
  }
}

func day(_ offset: Int) -> Date {
  let calendar = Foundation.Calendar.current
  let start = calendar.startOfDay(for: Date())
  return calendar.date(byAdding: .day, value: offset, to: start) ?? start
}

func dayOfMonth(_ day: Int) -> Date {
  let calendar = Foundation.Calendar.current
  var components = calendar.dateComponents([.year, .month], from: Date())
  components.day = day
  return calendar.date(from: components) ?? Date()
}
```

```kotlin
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Calendar
import com.esuiss.ui.components.CalendarCaptionLayout
import com.esuiss.ui.components.CalendarSize
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import java.util.Date
import java.util.GregorianCalendar
import java.util.Locale

fun calendarDay(offsetDays: Int = 0, dayOfMonth: Int? = null): Date {
    val now = GregorianCalendar()
    val result = GregorianCalendar(now.get(GregorianCalendar.YEAR), now.get(GregorianCalendar.MONTH), now.get(GregorianCalendar.DAY_OF_MONTH))
    if (dayOfMonth != null) result.set(GregorianCalendar.DAY_OF_MONTH, dayOfMonth)
    result.add(GregorianCalendar.DAY_OF_MONTH, offsetDays)
    return result.time
}

fun calendarIsWeekend(date: Date): Boolean {
    val day = GregorianCalendar().apply { time = date }.get(GregorianCalendar.DAY_OF_WEEK)
    return day == GregorianCalendar.SATURDAY || day == GregorianCalendar.SUNDAY
}

@Composable
fun CalendarFrame(content: @Composable () -> Unit) {
    Box(
        Modifier
            .border(1.dp, EsuissTheme.colors.separator, RoundedCornerShape(Radius.xl2))
            .padding(1.dp),
    ) {
        content()
    }
}

@Composable
fun CalendarSingle(
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    showWeekNumber: Boolean = false,
    showOutsideDays: Boolean = false,
    weekendsDisabled: Boolean = false,
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    locale: Locale = Locale.getDefault(),
    key: String = "",
) {
    var date by rememberSaveable(key) { mutableStateOf<Date?>(calendarDay(offsetDays = 3)) }
    CalendarFrame {
        Calendar(
            selected = date,
            onSelect = { date = it },
            size = size,
            captionLayout = captionLayout,
            showWeekNumber = showWeekNumber,
            showOutsideDays = showOutsideDays,
            disabled = { weekendsDisabled && calendarIsWeekend(it) },
            buttonVariant = buttonVariant,
            locale = locale,
        )
    }
}
```

`Calendar` renders one or more month grids with a caption, previous and next buttons, weekday headers and pressable day cells. Selection mode is set with `mode`: `single`, `multiple` or `range`. Ranges are drawn as a continuous shaded band with filled start and end days.

Three sizes are available: `sm`, `default` and `lg`. The caption can be a plain label or month and year dropdowns built on Select, which suits birth dates and other dates far from today.

## Installation

```bash title="Terminal"
npx @esuiss/uim@latest add calendar
```

```bash title="Terminal"
npx @esuiss/uim@latest add calendar --platform swift
```

```bash title="Terminal"
npx @esuiss/uim@latest add calendar --platform kotlin
```

The CLI also adds what it builds on: [Button](/docs/components/button), [Icon](/docs/components/icon), [Select](/docs/components/select), [Text](/docs/components/text).

### Manual

**Uniwind**

1. Install the dependencies:

```bash title="Terminal"
npx expo install cn phosphor-react-native react-native-svg
```

2. Add the pieces it builds on: [Button](/docs/components/button), [Icon](/docs/components/icon), [Select](/docs/components/select), [Text](/docs/components/text), and the primitives `components/primitives/calendar.tsx`, `components/primitives/use-render.tsx`.

3. Copy the source into `components/ui/calendar.tsx`:

```tsx title="uniwind/components/ui/calendar.tsx"
import { cn } from "cn"
import { CaretLeftIcon, CaretRightIcon } from "phosphor-react-native"
import * as React from "react"
import { I18nManager, ScrollView, View } from "react-native"
import * as CalendarPrimitive from "@/components/primitives/calendar"
import { resolveClassName } from "@/components/primitives/use-render"
import { Button, type ButtonProps } from "@/components/ui/button"
import { Icon } from "@/components/ui/icon"
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select"
import { Text, TextClassContext } from "@/components/ui/text"

type CalendarSize = "sm" | "default" | "lg"

type CaptionLayout = "label" | "dropdown" | "dropdown-months" | "dropdown-years"

const CELL: Record<CalendarSize, string> = {
  sm: "size-6",
  default: "size-8",
  lg: "size-10",
}

const CELL_WIDTH: Record<CalendarSize, string> = {
  sm: "w-6",
  default: "w-8",
  lg: "w-10",
}

const CELL_HEIGHT: Record<CalendarSize, string> = {
  sm: "h-6",
  default: "h-8",
  lg: "h-10",
}

const PADDING: Record<CalendarSize, string> = {
  sm: "p-2",
  default: "p-3",
  lg: "p-4",
}

const CAPTION_TEXT: Record<CalendarSize, string> = {
  sm: "text-xs",
  default: "text-sm",
  lg: "text-base",
}

const DAY_TEXT: Record<CalendarSize, string> = {
  sm: "text-3xs",
  default: "text-sm",
  lg: "text-lg",
}

const WEEKDAY_TEXT: Record<CalendarSize, string> = {
  sm: "text-3xs",
  default: "text-3xs uppercase",
  lg: "text-xs uppercase",
}

const CalendarContext = React.createContext<{ size: CalendarSize }>({
  size: "default",
})

type DropdownOption = {
  value: string
  label: string
  disabled?: boolean
}

function CalendarDropdown({
  value,
  options,
  label,
  onChange,
}: {
  value: string
  options: DropdownOption[]
  label: string
  onChange: (value: string) => void
}) {
  const { size } = React.useContext(CalendarContext)
  return (
    <Select
      items={options}
      value={value}
      onValueChange={(next) => {
        if (typeof next === "string") onChange(next)
      }}
    >
      <SelectTrigger
        size="sm"
        accessibilityLabel={label}
        className="h-auto gap-1 rounded-full bg-transparent px-1.5 py-0.5"
      >
        <SelectValue
          className={cn("flex-none font-semibold", CAPTION_TEXT[size])}
        />
      </SelectTrigger>
      <SelectContent>
        <ScrollView className="max-h-72">
          {options.map((option) => (
            <SelectItem
              key={option.value}
              value={option.value}
              label={option.label}
              disabled={option.disabled}
            >
              {option.label}
            </SelectItem>
          ))}
        </ScrollView>
      </SelectContent>
    </Select>
  )
}

function CalendarCaption({
  month,
  captionLayout,
}: {
  month: Date
  captionLayout: CaptionLayout
}) {
  const { size } = React.useContext(CalendarContext)
  const calendar = CalendarPrimitive.useRootContext()
  const year = month.getFullYear()

  if (captionLayout === "label") {
    return (
      <Text className={cn("font-semibold text-label", CAPTION_TEXT[size])}>
        {calendar.formatCaption(month)}
      </Text>
    )
  }

  const firstYear = calendar.startMonth?.getFullYear() ?? year
  const lastYear = calendar.endMonth?.getFullYear() ?? year
  const outOfRange = (target: Date) =>
    (calendar.startMonth !== undefined &&
      target.getTime() < calendar.startMonth.getTime()) ||
    (calendar.endMonth !== undefined &&
      target.getTime() > calendar.endMonth.getTime())

  const months = Array.from({ length: 12 }, (_, index) => {
    const date = new Date(year, index, 1)
    return {
      value: String(index),
      label: calendar.formatMonth(date, "short"),
      disabled: outOfRange(date),
    }
  })
  const years = Array.from(
    { length: Math.max(lastYear - firstYear + 1, 1) },
    (_, index) => ({
      value: String(firstYear + index),
      label: String(firstYear + index),
    })
  )
  const captionText = cn("font-semibold text-label", CAPTION_TEXT[size])

  return (
    <View className="flex-row items-center gap-1.5">
      {captionLayout === "dropdown-years" ? (
        <Text className={captionText}>
          {calendar.formatMonth(month, "long")}
        </Text>
      ) : (
        <CalendarDropdown
          label="Choose the Month"
          value={String(month.getMonth())}
          options={months}
          onChange={(next) =>
            calendar.goToMonth(
              new Date(year, Number(next), 1),
              CalendarPrimitive.CALENDAR_REASONS.monthSelect
            )
          }
        />
      )}
      {captionLayout === "dropdown-months" ? (
        <Text className={captionText}>{year}</Text>
      ) : (
        <CalendarDropdown
          label="Choose the Year"
          value={String(year)}
          options={years}
          onChange={(next) =>
            calendar.goToMonth(
              new Date(Number(next), month.getMonth(), 1),
              CalendarPrimitive.CALENDAR_REASONS.yearSelect
            )
          }
        />
      )}
    </View>
  )
}

function CalendarNav({
  buttonVariant,
}: {
  buttonVariant: ButtonProps["variant"]
}) {
  const { size } = React.useContext(CalendarContext)
  const calendar = CalendarPrimitive.useRootContext()
  const rtl = I18nManager.isRTL
  return (
    <View className="flex-row items-center gap-0.5">
      <CalendarPrimitive.Previous
        render={
          <Button
            variant={buttonVariant}
            size="icon"
            className={cn("p-0", CELL[size])}
          />
        }
      >
        <Icon
          as={rtl ? CaretRightIcon : CaretLeftIcon}
          className={cn(
            "size-4",
            !calendar.previousMonth && "text-label-quaternary"
          )}
        />
      </CalendarPrimitive.Previous>
      <CalendarPrimitive.Next
        render={
          <Button
            variant={buttonVariant}
            size="icon"
            className={cn("p-0", CELL[size])}
          />
        }
      >
        <Icon
          as={rtl ? CaretLeftIcon : CaretRightIcon}
          className={cn(
            "size-4",
            !calendar.nextMonth && "text-label-quaternary"
          )}
        />
      </CalendarPrimitive.Next>
    </View>
  )
}

function CalendarDayButton({
  className,
  day,
  children,
  ...props
}: React.ComponentProps<typeof CalendarPrimitive.DayButton>) {
  const { size } = React.useContext(CalendarContext)
  const modifiers = day.modifiers
  const single =
    modifiers.selected &&
    !modifiers.rangeStart &&
    !modifiers.rangeEnd &&
    !modifiers.rangeMiddle
  const filled =
    (single && modifiers.today) || modifiers.rangeStart || modifiers.rangeEnd
  return (
    <TextClassContext.Provider
      value={cn(
        "text-label",
        DAY_TEXT[size],
        modifiers.outside && "text-label-secondary",
        (modifiers.today || single) && "font-semibold text-link",
        modifiers.rangeMiddle && "text-label",
        filled && "text-on-accent",
        modifiers.disabled && "text-label-quaternary"
      )}
    >
      <CalendarPrimitive.DayButton
        day={day}
        className={(state) =>
          cn(
            "items-center justify-center rounded-full active:bg-item-pressed",
            CELL[size],
            single && "bg-accent-surface active:bg-accent-surface-pressed",
            filled && "bg-accent active:bg-accent-pressed",
            modifiers.rangeMiddle && "rounded-none",
            resolveClassName(className, state)
          )
        }
        {...props}
      >
        {children ?? <Text>{day.date.getDate()}</Text>}
      </CalendarPrimitive.DayButton>
    </TextClassContext.Provider>
  )
}

function CalendarMonth({
  month,
  index,
  buttonVariant,
  captionLayout,
  showWeekNumber,
}: {
  month: Date
  index: number
  buttonVariant: ButtonProps["variant"]
  captionLayout: CaptionLayout
  showWeekNumber: boolean
}) {
  const { size } = React.useContext(CalendarContext)
  const calendar = CalendarPrimitive.useRootContext()
  return (
    <View className="gap-4">
      <View className={cn("flex-row items-center", CELL_HEIGHT[size])}>
        <View className="flex-1 flex-row items-center ps-1.5">
          <CalendarCaption month={month} captionLayout={captionLayout} />
        </View>
        {index === 0 ? <CalendarNav buttonVariant={buttonVariant} /> : null}
      </View>
      <View role="grid" accessibilityLabel={calendar.formatCaption(month)}>
        <View className="flex-row">
          {showWeekNumber ? <View className={CELL_WIDTH[size]} /> : null}
          {calendar.weekdays.map((weekday) => (
            <View
              key={weekday.getDay()}
              accessibilityLabel={calendar.formatWeekday(weekday, "long")}
              className={cn("items-center", CELL_WIDTH[size])}
            >
              <Text
                className={cn(
                  "font-semibold text-label-secondary",
                  WEEKDAY_TEXT[size]
                )}
              >
                {calendar.formatWeekday(weekday, "short")}
              </Text>
            </View>
          ))}
        </View>
        {calendar.getWeeks(month).map((week) => (
          <View key={week.days[0]?.date.getTime()} className="mt-2 flex-row">
            {showWeekNumber ? (
              <View className={cn("items-center justify-center", CELL[size])}>
                <Text className="text-xs text-label-secondary">
                  {week.number}
                </Text>
              </View>
            ) : null}
            {week.days.map((day, dayIndex) => {
              const modifiers = day.modifiers
              const shaded =
                modifiers.rangeMiddle ||
                modifiers.rangeStart !== modifiers.rangeEnd
              return (
                <View
                  key={day.date.getTime()}
                  className={cn(
                    CELL[size],
                    !day.hidden && shaded && "bg-surface-secondary",
                    modifiers.rangeStart && "rounded-l-full",
                    modifiers.rangeEnd && "rounded-r-full",
                    modifiers.rangeMiddle && dayIndex === 0 && "rounded-l-full",
                    modifiers.rangeMiddle && dayIndex === 6 && "rounded-r-full"
                  )}
                >
                  {day.hidden ? null : <CalendarDayButton day={day} />}
                </View>
              )
            })}
          </View>
        ))}
      </View>
    </View>
  )
}

function CalendarMonths({
  buttonVariant,
  captionLayout,
  showWeekNumber,
}: {
  buttonVariant: ButtonProps["variant"]
  captionLayout: CaptionLayout
  showWeekNumber: boolean
}) {
  const calendar = CalendarPrimitive.useRootContext()
  return (
    <View className="gap-4">
      {calendar.months.map((month, index) => (
        <CalendarMonth
          key={month.getTime()}
          month={month}
          index={index}
          buttonVariant={buttonVariant}
          captionLayout={captionLayout}
          showWeekNumber={showWeekNumber}
        />
      ))}
    </View>
  )
}

function Calendar({
  className,
  size = "default",
  buttonVariant = "plain",
  captionLayout = "label",
  showWeekNumber = false,
  startMonth,
  endMonth,
  ...props
}: React.ComponentProps<typeof CalendarPrimitive.Root> & {
  buttonVariant?: ButtonProps["variant"]
  size?: CalendarSize
  captionLayout?: CaptionLayout
  showWeekNumber?: boolean
}) {
  const yearDropdown =
    captionLayout === "dropdown" || captionLayout === "dropdown-years"
  const thisYear = new Date().getFullYear()
  const context = React.useMemo(() => ({ size }), [size])
  return (
    <CalendarContext.Provider value={context}>
      <CalendarPrimitive.Root
        startMonth={
          startMonth ?? (yearDropdown ? new Date(thisYear - 100, 0) : undefined)
        }
        endMonth={
          endMonth ?? (yearDropdown ? new Date(thisYear, 11) : undefined)
        }
        className={(state) =>
          cn(
            "self-start bg-surface",
            PADDING[size],
            resolveClassName(className, state)
          )
        }
        {...props}
      >
        <CalendarMonths
          buttonVariant={buttonVariant}
          captionLayout={captionLayout}
          showWeekNumber={showWeekNumber}
        />
      </CalendarPrimitive.Root>
    </CalendarContext.Provider>
  )
}

export { Calendar, CalendarDayButton }
```

4. Update the import paths to match your project.

**NativeWind**

1. Install the dependencies:

```bash title="Terminal"
npx expo install cn phosphor-react-native react-native-svg
```

2. Add the pieces it builds on: [Button](/docs/components/button), [Icon](/docs/components/icon), [Select](/docs/components/select), [Text](/docs/components/text), and the primitives `components/primitives/calendar.tsx`, `components/primitives/use-render.tsx`.

3. Copy the source into `components/ui/calendar.tsx`:

```tsx title="nativewind/components/ui/calendar.tsx"
import { cn } from "cn"
import { CaretLeftIcon, CaretRightIcon } from "phosphor-react-native"
import * as React from "react"
import { I18nManager, ScrollView, View } from "react-native"
import * as CalendarPrimitive from "@/components/primitives/calendar"
import { resolveClassName } from "@/components/primitives/use-render"
import { Button, type ButtonProps } from "@/components/ui/button"
import { Icon } from "@/components/ui/icon"
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select"
import { Text, TextClassContext } from "@/components/ui/text"

type CalendarSize = "sm" | "default" | "lg"

type CaptionLayout = "label" | "dropdown" | "dropdown-months" | "dropdown-years"

const CELL: Record<CalendarSize, string> = {
  sm: "size-6",
  default: "size-8",
  lg: "size-10",
}

const CELL_WIDTH: Record<CalendarSize, string> = {
  sm: "w-6",
  default: "w-8",
  lg: "w-10",
}

const CELL_HEIGHT: Record<CalendarSize, string> = {
  sm: "h-6",
  default: "h-8",
  lg: "h-10",
}

const PADDING: Record<CalendarSize, string> = {
  sm: "p-2",
  default: "p-3",
  lg: "p-4",
}

const CAPTION_TEXT: Record<CalendarSize, string> = {
  sm: "text-xs",
  default: "text-sm",
  lg: "text-base",
}

const DAY_TEXT: Record<CalendarSize, string> = {
  sm: "text-3xs",
  default: "text-sm",
  lg: "text-lg",
}

const WEEKDAY_TEXT: Record<CalendarSize, string> = {
  sm: "text-3xs",
  default: "text-3xs uppercase",
  lg: "text-xs uppercase",
}

const CalendarContext = React.createContext<{ size: CalendarSize }>({
  size: "default",
})

type DropdownOption = {
  value: string
  label: string
  disabled?: boolean
}

function CalendarDropdown({
  value,
  options,
  label,
  onChange,
}: {
  value: string
  options: DropdownOption[]
  label: string
  onChange: (value: string) => void
}) {
  const { size } = React.useContext(CalendarContext)
  return (
    <Select
      items={options}
      value={value}
      onValueChange={(next) => {
        if (typeof next === "string") onChange(next)
      }}
    >
      <SelectTrigger
        size="sm"
        accessibilityLabel={label}
        className="h-auto gap-1 rounded-full bg-transparent px-1.5 py-0.5"
      >
        <SelectValue
          className={cn("flex-none font-semibold", CAPTION_TEXT[size])}
        />
      </SelectTrigger>
      <SelectContent>
        <ScrollView className="max-h-72">
          {options.map((option) => (
            <SelectItem
              key={option.value}
              value={option.value}
              label={option.label}
              disabled={option.disabled}
            >
              {option.label}
            </SelectItem>
          ))}
        </ScrollView>
      </SelectContent>
    </Select>
  )
}

function CalendarCaption({
  month,
  captionLayout,
}: {
  month: Date
  captionLayout: CaptionLayout
}) {
  const { size } = React.useContext(CalendarContext)
  const calendar = CalendarPrimitive.useRootContext()
  const year = month.getFullYear()

  if (captionLayout === "label") {
    return (
      <Text className={cn("font-semibold text-label", CAPTION_TEXT[size])}>
        {calendar.formatCaption(month)}
      </Text>
    )
  }

  const firstYear = calendar.startMonth?.getFullYear() ?? year
  const lastYear = calendar.endMonth?.getFullYear() ?? year
  const outOfRange = (target: Date) =>
    (calendar.startMonth !== undefined &&
      target.getTime() < calendar.startMonth.getTime()) ||
    (calendar.endMonth !== undefined &&
      target.getTime() > calendar.endMonth.getTime())

  const months = Array.from({ length: 12 }, (_, index) => {
    const date = new Date(year, index, 1)
    return {
      value: String(index),
      label: calendar.formatMonth(date, "short"),
      disabled: outOfRange(date),
    }
  })
  const years = Array.from(
    { length: Math.max(lastYear - firstYear + 1, 1) },
    (_, index) => ({
      value: String(firstYear + index),
      label: String(firstYear + index),
    })
  )
  const captionText = cn("font-semibold text-label", CAPTION_TEXT[size])

  return (
    <View className="flex-row items-center gap-1.5">
      {captionLayout === "dropdown-years" ? (
        <Text className={captionText}>
          {calendar.formatMonth(month, "long")}
        </Text>
      ) : (
        <CalendarDropdown
          label="Choose the Month"
          value={String(month.getMonth())}
          options={months}
          onChange={(next) =>
            calendar.goToMonth(
              new Date(year, Number(next), 1),
              CalendarPrimitive.CALENDAR_REASONS.monthSelect
            )
          }
        />
      )}
      {captionLayout === "dropdown-months" ? (
        <Text className={captionText}>{year}</Text>
      ) : (
        <CalendarDropdown
          label="Choose the Year"
          value={String(year)}
          options={years}
          onChange={(next) =>
            calendar.goToMonth(
              new Date(Number(next), month.getMonth(), 1),
              CalendarPrimitive.CALENDAR_REASONS.yearSelect
            )
          }
        />
      )}
    </View>
  )
}

function CalendarNav({
  buttonVariant,
}: {
  buttonVariant: ButtonProps["variant"]
}) {
  const { size } = React.useContext(CalendarContext)
  const calendar = CalendarPrimitive.useRootContext()
  const rtl = I18nManager.isRTL
  return (
    <View className="flex-row items-center gap-0.5">
      <CalendarPrimitive.Previous
        render={
          <Button
            variant={buttonVariant}
            size="icon"
            className={cn("p-0", CELL[size])}
          />
        }
      >
        <Icon
          as={rtl ? CaretRightIcon : CaretLeftIcon}
          className={cn(
            "size-4",
            !calendar.previousMonth && "text-label-quaternary"
          )}
        />
      </CalendarPrimitive.Previous>
      <CalendarPrimitive.Next
        render={
          <Button
            variant={buttonVariant}
            size="icon"
            className={cn("p-0", CELL[size])}
          />
        }
      >
        <Icon
          as={rtl ? CaretLeftIcon : CaretRightIcon}
          className={cn(
            "size-4",
            !calendar.nextMonth && "text-label-quaternary"
          )}
        />
      </CalendarPrimitive.Next>
    </View>
  )
}

function CalendarDayButton({
  className,
  day,
  children,
  ...props
}: React.ComponentProps<typeof CalendarPrimitive.DayButton>) {
  const { size } = React.useContext(CalendarContext)
  const modifiers = day.modifiers
  const single =
    modifiers.selected &&
    !modifiers.rangeStart &&
    !modifiers.rangeEnd &&
    !modifiers.rangeMiddle
  const filled =
    (single && modifiers.today) || modifiers.rangeStart || modifiers.rangeEnd
  return (
    <TextClassContext.Provider
      value={cn(
        "text-label",
        DAY_TEXT[size],
        modifiers.outside && "text-label-secondary",
        (modifiers.today || single) && "font-semibold text-link",
        modifiers.rangeMiddle && "text-label",
        filled && "text-on-accent",
        modifiers.disabled && "text-label-quaternary"
      )}
    >
      <CalendarPrimitive.DayButton
        day={day}
        className={(state) =>
          cn(
            "items-center justify-center rounded-full active:bg-item-pressed",
            CELL[size],
            single && "bg-accent-surface active:bg-accent-surface-pressed",
            filled && "bg-accent active:bg-accent-pressed",
            modifiers.rangeMiddle && "rounded-none",
            resolveClassName(className, state)
          )
        }
        {...props}
      >
        {children ?? <Text>{day.date.getDate()}</Text>}
      </CalendarPrimitive.DayButton>
    </TextClassContext.Provider>
  )
}

function CalendarMonth({
  month,
  index,
  buttonVariant,
  captionLayout,
  showWeekNumber,
}: {
  month: Date
  index: number
  buttonVariant: ButtonProps["variant"]
  captionLayout: CaptionLayout
  showWeekNumber: boolean
}) {
  const { size } = React.useContext(CalendarContext)
  const calendar = CalendarPrimitive.useRootContext()
  return (
    <View className="gap-4">
      <View className={cn("flex-row items-center", CELL_HEIGHT[size])}>
        <View className="flex-1 flex-row items-center ps-1.5">
          <CalendarCaption month={month} captionLayout={captionLayout} />
        </View>
        {index === 0 ? <CalendarNav buttonVariant={buttonVariant} /> : null}
      </View>
      <View role="grid" accessibilityLabel={calendar.formatCaption(month)}>
        <View className="flex-row">
          {showWeekNumber ? <View className={CELL_WIDTH[size]} /> : null}
          {calendar.weekdays.map((weekday) => (
            <View
              key={weekday.getDay()}
              accessibilityLabel={calendar.formatWeekday(weekday, "long")}
              className={cn("items-center", CELL_WIDTH[size])}
            >
              <Text
                className={cn(
                  "font-semibold text-label-secondary",
                  WEEKDAY_TEXT[size]
                )}
              >
                {calendar.formatWeekday(weekday, "short")}
              </Text>
            </View>
          ))}
        </View>
        {calendar.getWeeks(month).map((week) => (
          <View key={week.days[0]?.date.getTime()} className="mt-2 flex-row">
            {showWeekNumber ? (
              <View className={cn("items-center justify-center", CELL[size])}>
                <Text className="text-xs text-label-secondary">
                  {week.number}
                </Text>
              </View>
            ) : null}
            {week.days.map((day, dayIndex) => {
              const modifiers = day.modifiers
              const shaded =
                modifiers.rangeMiddle ||
                modifiers.rangeStart !== modifiers.rangeEnd
              return (
                <View
                  key={day.date.getTime()}
                  className={cn(
                    CELL[size],
                    !day.hidden && shaded && "bg-surface-secondary",
                    modifiers.rangeStart && "rounded-l-full",
                    modifiers.rangeEnd && "rounded-r-full",
                    modifiers.rangeMiddle && dayIndex === 0 && "rounded-l-full",
                    modifiers.rangeMiddle && dayIndex === 6 && "rounded-r-full"
                  )}
                >
                  {day.hidden ? null : <CalendarDayButton day={day} />}
                </View>
              )
            })}
          </View>
        ))}
      </View>
    </View>
  )
}

function CalendarMonths({
  buttonVariant,
  captionLayout,
  showWeekNumber,
}: {
  buttonVariant: ButtonProps["variant"]
  captionLayout: CaptionLayout
  showWeekNumber: boolean
}) {
  const calendar = CalendarPrimitive.useRootContext()
  return (
    <View className="gap-4">
      {calendar.months.map((month, index) => (
        <CalendarMonth
          key={month.getTime()}
          month={month}
          index={index}
          buttonVariant={buttonVariant}
          captionLayout={captionLayout}
          showWeekNumber={showWeekNumber}
        />
      ))}
    </View>
  )
}

function Calendar({
  className,
  size = "default",
  buttonVariant = "plain",
  captionLayout = "label",
  showWeekNumber = false,
  startMonth,
  endMonth,
  ...props
}: React.ComponentProps<typeof CalendarPrimitive.Root> & {
  buttonVariant?: ButtonProps["variant"]
  size?: CalendarSize
  captionLayout?: CaptionLayout
  showWeekNumber?: boolean
}) {
  const yearDropdown =
    captionLayout === "dropdown" || captionLayout === "dropdown-years"
  const thisYear = new Date().getFullYear()
  const context = React.useMemo(() => ({ size }), [size])
  return (
    <CalendarContext.Provider value={context}>
      <CalendarPrimitive.Root
        startMonth={
          startMonth ?? (yearDropdown ? new Date(thisYear - 100, 0) : undefined)
        }
        endMonth={
          endMonth ?? (yearDropdown ? new Date(thisYear, 11) : undefined)
        }
        className={(state) =>
          cn(
            "self-start bg-surface",
            PADDING[size],
            resolveClassName(className, state)
          )
        }
        {...props}
      >
        <CalendarMonths
          buttonVariant={buttonVariant}
          captionLayout={captionLayout}
          showWeekNumber={showWeekNumber}
        />
      </CalendarPrimitive.Root>
    </CalendarContext.Provider>
  )
}

export { Calendar, CalendarDayButton }
```

4. Update the import paths to match your project.

**StyleSheet**

1. Install the dependencies:

```bash title="Terminal"
npx expo install phosphor-react-native react-native-svg
```

2. Add the pieces it builds on: [Button](/docs/components/button), [Icon](/docs/components/icon), [Select](/docs/components/select), [Text](/docs/components/text), and the primitives `components/primitives/calendar.tsx`, `components/primitives/use-render.tsx`.

3. Copy the source into `components/ui/calendar.tsx`:

```tsx title="stylesheet/components/ui/calendar.tsx"
import { CaretLeftIcon, CaretRightIcon } from "phosphor-react-native"
import * as React from "react"
import {
  I18nManager,
  Pressable,
  ScrollView,
  type StyleProp,
  StyleSheet,
  type TextStyle,
  View,
  type ViewStyle,
} from "react-native"
import * as CalendarPrimitive from "@/components/primitives/calendar"
import { resolveStyle } from "@/components/primitives/use-render"
import { Button, type ButtonProps } from "@/components/ui/button"
import { Icon } from "@/components/ui/icon"
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select"
import { Text, TextStyleContext } from "@/components/ui/text"
import {
  fontSize,
  radius,
  type ThemeColors,
  useTheme,
} from "@/components/ui/theme"

type CalendarSize = "sm" | "default" | "lg"

type CaptionLayout = "label" | "dropdown" | "dropdown-months" | "dropdown-years"

const CELL: Record<CalendarSize, number> = { sm: 24, default: 32, lg: 40 }

const PADDING: Record<CalendarSize, number> = { sm: 8, default: 12, lg: 16 }

const CAPTION_TEXT: Record<CalendarSize, TextStyle> = {
  sm: fontSize.xs,
  default: fontSize.sm,
  lg: fontSize.base,
}

const DAY_TEXT: Record<CalendarSize, TextStyle> = {
  sm: fontSize["3xs"],
  default: fontSize.sm,
  lg: fontSize.lg,
}

const WEEKDAY_TEXT: Record<CalendarSize, TextStyle> = {
  sm: fontSize["3xs"],
  default: { ...fontSize["3xs"], textTransform: "uppercase" },
  lg: { ...fontSize.xs, textTransform: "uppercase" },
}

const styles = StyleSheet.create({
  root: { alignSelf: "flex-start" },
  months: { gap: 16 },
  month: { gap: 16 },
  header: { flexDirection: "row", alignItems: "center" },
  caption: {
    flex: 1,
    flexDirection: "row",
    alignItems: "center",
    paddingStart: 6,
  },
  dropdowns: { flexDirection: "row", alignItems: "center", gap: 6 },
  dropdownTrigger: {
    height: "auto",
    gap: 4,
    borderRadius: radius.full,
    backgroundColor: "transparent",
    paddingHorizontal: 6,
    paddingVertical: 2,
  },
  dropdownValue: { flex: 0, fontWeight: "600" },
  dropdownList: { maxHeight: 288 },
  captionText: { fontWeight: "600" },
  nav: { flexDirection: "row", alignItems: "center", gap: 2 },
  navButton: { padding: 0 },
  row: { flexDirection: "row" },
  week: { marginTop: 8, flexDirection: "row" },
  weekday: { alignItems: "center" },
  weekdayText: { fontWeight: "600" },
  center: { alignItems: "center", justifyContent: "center" },
  day: {
    alignItems: "center",
    justifyContent: "center",
    borderRadius: radius.full,
  },
})

const CalendarContext = React.createContext<{ size: CalendarSize }>({
  size: "default",
})

type DropdownOption = {
  value: string
  label: string
  disabled?: boolean
}

function CalendarDropdown({
  value,
  options,
  label,
  onChange,
}: {
  value: string
  options: DropdownOption[]
  label: string
  onChange: (value: string) => void
}) {
  const { size } = React.useContext(CalendarContext)
  return (
    <Select
      items={options}
      value={value}
      onValueChange={(next) => {
        if (typeof next === "string") onChange(next)
      }}
    >
      <SelectTrigger
        size="sm"
        accessibilityLabel={label}
        style={styles.dropdownTrigger}
      >
        <SelectValue style={[styles.dropdownValue, CAPTION_TEXT[size]]} />
      </SelectTrigger>
      <SelectContent>
        <ScrollView style={styles.dropdownList}>
          {options.map((option) => (
            <SelectItem
              key={option.value}
              value={option.value}
              label={option.label}
              disabled={option.disabled}
            >
              {option.label}
            </SelectItem>
          ))}
        </ScrollView>
      </SelectContent>
    </Select>
  )
}

function CalendarCaption({
  month,
  captionLayout,
}: {
  month: Date
  captionLayout: CaptionLayout
}) {
  const { size } = React.useContext(CalendarContext)
  const { colors } = useTheme()
  const calendar = CalendarPrimitive.useRootContext()
  const year = month.getFullYear()
  const captionText = [
    styles.captionText,
    CAPTION_TEXT[size],
    { color: colors.label },
  ]

  if (captionLayout === "label") {
    return <Text style={captionText}>{calendar.formatCaption(month)}</Text>
  }

  const firstYear = calendar.startMonth?.getFullYear() ?? year
  const lastYear = calendar.endMonth?.getFullYear() ?? year
  const outOfRange = (target: Date) =>
    (calendar.startMonth !== undefined &&
      target.getTime() < calendar.startMonth.getTime()) ||
    (calendar.endMonth !== undefined &&
      target.getTime() > calendar.endMonth.getTime())

  const months = Array.from({ length: 12 }, (_, index) => {
    const date = new Date(year, index, 1)
    return {
      value: String(index),
      label: calendar.formatMonth(date, "short"),
      disabled: outOfRange(date),
    }
  })
  const years = Array.from(
    { length: Math.max(lastYear - firstYear + 1, 1) },
    (_, index) => ({
      value: String(firstYear + index),
      label: String(firstYear + index),
    })
  )

  return (
    <View style={styles.dropdowns}>
      {captionLayout === "dropdown-years" ? (
        <Text style={captionText}>{calendar.formatMonth(month, "long")}</Text>
      ) : (
        <CalendarDropdown
          label="Choose the Month"
          value={String(month.getMonth())}
          options={months}
          onChange={(next) =>
            calendar.goToMonth(
              new Date(year, Number(next), 1),
              CalendarPrimitive.CALENDAR_REASONS.monthSelect
            )
          }
        />
      )}
      {captionLayout === "dropdown-months" ? (
        <Text style={captionText}>{year}</Text>
      ) : (
        <CalendarDropdown
          label="Choose the Year"
          value={String(year)}
          options={years}
          onChange={(next) =>
            calendar.goToMonth(
              new Date(Number(next), month.getMonth(), 1),
              CalendarPrimitive.CALENDAR_REASONS.yearSelect
            )
          }
        />
      )}
    </View>
  )
}

function CalendarNav({
  buttonVariant,
}: {
  buttonVariant: ButtonProps["variant"]
}) {
  const { size } = React.useContext(CalendarContext)
  const { colors } = useTheme()
  const calendar = CalendarPrimitive.useRootContext()
  const rtl = I18nManager.isRTL
  const buttonStyle = [
    styles.navButton,
    { width: CELL[size], height: CELL[size] },
  ]
  return (
    <View style={styles.nav}>
      <CalendarPrimitive.Previous
        render={
          <Button variant={buttonVariant} size="icon" style={buttonStyle} />
        }
      >
        <Icon
          as={rtl ? CaretRightIcon : CaretLeftIcon}
          size={16}
          color={calendar.previousMonth ? undefined : colors.labelQuaternary}
        />
      </CalendarPrimitive.Previous>
      <CalendarPrimitive.Next
        render={
          <Button variant={buttonVariant} size="icon" style={buttonStyle} />
        }
      >
        <Icon
          as={rtl ? CaretLeftIcon : CaretRightIcon}
          size={16}
          color={calendar.nextMonth ? undefined : colors.labelQuaternary}
        />
      </CalendarPrimitive.Next>
    </View>
  )
}

function dayColors(
  modifiers: CalendarPrimitive.DayModifiers,
  colors: ThemeColors,
  pressed: boolean
) {
  const single =
    modifiers.selected &&
    !modifiers.rangeStart &&
    !modifiers.rangeEnd &&
    !modifiers.rangeMiddle
  const filled =
    (single && modifiers.today) || modifiers.rangeStart || modifiers.rangeEnd
  let text = colors.label
  if (modifiers.outside) text = colors.labelSecondary
  if (modifiers.today || single) text = colors.link
  if (modifiers.rangeMiddle) text = colors.label
  if (filled) text = colors.onAccent
  if (modifiers.disabled) text = colors.labelQuaternary
  let background = pressed ? colors.itemPressed : "transparent"
  if (single) {
    background = pressed ? colors.accentSurfacePressed : colors.accentSurface
  }
  if (filled) background = pressed ? colors.accentPressed : colors.accent
  return {
    text,
    background,
    bold: modifiers.today || single,
  }
}

function CalendarDayButton({
  style,
  day,
  children,
  ...props
}: React.ComponentProps<typeof CalendarPrimitive.DayButton>) {
  const { size } = React.useContext(CalendarContext)
  const { colors } = useTheme()
  const modifiers = day.modifiers
  const idle = dayColors(modifiers, colors, false)
  return (
    <TextStyleContext.Provider
      value={{
        ...DAY_TEXT[size],
        color: idle.text,
        fontWeight: idle.bold ? "600" : "400",
      }}
    >
      <CalendarPrimitive.DayButton
        day={day}
        render={(renderProps, state) => (
          <Pressable
            {...renderProps}
            style={({ pressed }) => [
              styles.day,
              { width: CELL[size], height: CELL[size] },
              {
                backgroundColor: dayColors(modifiers, colors, pressed)
                  .background,
              },
              modifiers.rangeMiddle && { borderRadius: 0 },
              resolveStyle(style, state) as StyleProp<ViewStyle>,
            ]}
          />
        )}
        {...props}
      >
        {children ?? <Text>{day.date.getDate()}</Text>}
      </CalendarPrimitive.DayButton>
    </TextStyleContext.Provider>
  )
}

function CalendarMonth({
  month,
  index,
  buttonVariant,
  captionLayout,
  showWeekNumber,
}: {
  month: Date
  index: number
  buttonVariant: ButtonProps["variant"]
  captionLayout: CaptionLayout
  showWeekNumber: boolean
}) {
  const { size } = React.useContext(CalendarContext)
  const { colors } = useTheme()
  const calendar = CalendarPrimitive.useRootContext()
  const cell = CELL[size]
  return (
    <View style={styles.month}>
      <View style={[styles.header, { height: cell }]}>
        <View style={styles.caption}>
          <CalendarCaption month={month} captionLayout={captionLayout} />
        </View>
        {index === 0 ? <CalendarNav buttonVariant={buttonVariant} /> : null}
      </View>
      <View role="grid" accessibilityLabel={calendar.formatCaption(month)}>
        <View style={styles.row}>
          {showWeekNumber ? <View style={{ width: cell }} /> : null}
          {calendar.weekdays.map((weekday) => (
            <View
              key={weekday.getDay()}
              accessibilityLabel={calendar.formatWeekday(weekday, "long")}
              style={[styles.weekday, { width: cell }]}
            >
              <Text
                style={[
                  styles.weekdayText,
                  WEEKDAY_TEXT[size],
                  { color: colors.labelSecondary },
                ]}
              >
                {calendar.formatWeekday(weekday, "short")}
              </Text>
            </View>
          ))}
        </View>
        {calendar.getWeeks(month).map((week) => (
          <View key={week.days[0]?.date.getTime()} style={styles.week}>
            {showWeekNumber ? (
              <View style={[styles.center, { width: cell, height: cell }]}>
                <Text style={[fontSize.xs, { color: colors.labelSecondary }]}>
                  {week.number}
                </Text>
              </View>
            ) : null}
            {week.days.map((day, dayIndex) => {
              const modifiers = day.modifiers
              const shaded =
                modifiers.rangeMiddle ||
                modifiers.rangeStart !== modifiers.rangeEnd
              const rounded = radius.full
              return (
                <View
                  key={day.date.getTime()}
                  style={[
                    { width: cell, height: cell },
                    !day.hidden &&
                      shaded && { backgroundColor: colors.surfaceSecondary },
                    (modifiers.rangeStart ||
                      (modifiers.rangeMiddle && dayIndex === 0)) && {
                      borderTopLeftRadius: rounded,
                      borderBottomLeftRadius: rounded,
                    },
                    (modifiers.rangeEnd ||
                      (modifiers.rangeMiddle && dayIndex === 6)) && {
                      borderTopRightRadius: rounded,
                      borderBottomRightRadius: rounded,
                    },
                  ]}
                >
                  {day.hidden ? null : <CalendarDayButton day={day} />}
                </View>
              )
            })}
          </View>
        ))}
      </View>
    </View>
  )
}

function CalendarMonths({
  buttonVariant,
  captionLayout,
  showWeekNumber,
}: {
  buttonVariant: ButtonProps["variant"]
  captionLayout: CaptionLayout
  showWeekNumber: boolean
}) {
  const calendar = CalendarPrimitive.useRootContext()
  return (
    <View style={styles.months}>
      {calendar.months.map((month, index) => (
        <CalendarMonth
          key={month.getTime()}
          month={month}
          index={index}
          buttonVariant={buttonVariant}
          captionLayout={captionLayout}
          showWeekNumber={showWeekNumber}
        />
      ))}
    </View>
  )
}

function Calendar({
  style,
  size = "default",
  buttonVariant = "plain",
  captionLayout = "label",
  showWeekNumber = false,
  startMonth,
  endMonth,
  ...props
}: React.ComponentProps<typeof CalendarPrimitive.Root> & {
  buttonVariant?: ButtonProps["variant"]
  size?: CalendarSize
  captionLayout?: CaptionLayout
  showWeekNumber?: boolean
}) {
  const { colors } = useTheme()
  const yearDropdown =
    captionLayout === "dropdown" || captionLayout === "dropdown-years"
  const thisYear = new Date().getFullYear()
  const context = React.useMemo(() => ({ size }), [size])
  return (
    <CalendarContext.Provider value={context}>
      <CalendarPrimitive.Root
        startMonth={
          startMonth ?? (yearDropdown ? new Date(thisYear - 100, 0) : undefined)
        }
        endMonth={
          endMonth ?? (yearDropdown ? new Date(thisYear, 11) : undefined)
        }
        style={(state) => [
          styles.root,
          { backgroundColor: colors.surface, padding: PADDING[size] },
          resolveStyle(style, state) as StyleProp<ViewStyle>,
        ]}
        {...props}
      >
        <CalendarMonths
          buttonVariant={buttonVariant}
          captionLayout={captionLayout}
          showWeekNumber={showWeekNumber}
        />
      </CalendarPrimitive.Root>
    </CalendarContext.Provider>
  )
}

export { Calendar, CalendarDayButton }
```

4. Update the import paths to match your project.

**SwiftUI**

1. Target iOS 17 or later.

2. Add the Swift package to your app:

```swift title="Package.swift"
.package(url: "https://github.com/phosphor-icons/swift", from: "2.1.0")
```

3. Copy the theme files every view uses:

```swift title="swift/Theme/Theme.swift"
import SwiftUI
import UIKit

struct RGBA: Sendable {
  let red: CGFloat
  let green: CGFloat
  let blue: CGFloat
  let alpha: CGFloat

  init(_ hex: UInt32, _ alpha: CGFloat = 1) {
    red = CGFloat((hex >> 16) & 0xFF) / 255
    green = CGFloat((hex >> 8) & 0xFF) / 255
    blue = CGFloat(hex & 0xFF) / 255
    self.alpha = alpha
  }

  var uiColor: UIColor {
    UIColor(red: red, green: green, blue: blue, alpha: alpha)
  }
}

extension Color {
  static func adaptive(light: RGBA, dark: RGBA) -> Color {
    let lightColor = light.uiColor
    let darkColor = dark.uiColor
    return Color(uiColor: UIColor { traits in
      traits.userInterfaceStyle == .dark ? darkColor : lightColor
    })
  }
}

public struct TextStyle: Sendable, Hashable {
  public let size: CGFloat
  public let lineHeight: CGFloat
  public let letterSpacing: CGFloat

  public init(size: CGFloat, lineHeight: CGFloat, letterSpacing: CGFloat) {
    self.size = size
    self.lineHeight = lineHeight
    self.letterSpacing = letterSpacing
  }

  public func font(weight: Font.Weight = .regular) -> Font {
    .system(size: size, weight: weight)
  }

  public var lineSpacing: CGFloat {
    max(0, lineHeight - UIFont.systemFont(ofSize: size).lineHeight)
  }
}

extension Hashable where Self == Font {
  public static func textStyle(_ style: TextStyle, weight: Font.Weight = .regular) -> Font {
    style.font(weight: weight)
  }
}

private struct TextStyleModifier: ViewModifier {
  let style: TextStyle
  let weight: Font.Weight

  func body(content: Content) -> some View {
    content
      .font(style.font(weight: weight))
      .tracking(style.letterSpacing)
      .lineSpacing(style.lineSpacing)
      .padding(.vertical, style.lineSpacing / 2)
  }
}

extension View {
  public func textStyle(_ style: TextStyle, weight: Font.Weight = .regular) -> some View {
    modifier(TextStyleModifier(style: style, weight: weight))
  }
}

public struct Shadow: Sendable, Hashable {
  public let color: Color
  public let radius: CGFloat
  public let x: CGFloat
  public let y: CGFloat

  public init(color: Color, radius: CGFloat, x: CGFloat = 0, y: CGFloat = 0) {
    self.color = color
    self.radius = radius
    self.x = x
    self.y = y
  }
}

extension View {
  public func shadow(_ shadow: Shadow) -> some View {
    self.shadow(color: shadow.color, radius: shadow.radius, x: shadow.x, y: shadow.y)
  }
}
```

```swift title="swift/Theme/Tokens.swift"
import SwiftUI

extension Color {
  public static let surface = Color.adaptive(light: .init(0xFFFFFF), dark: .init(0x000000))
  public static let surfaceSecondary = Color.adaptive(light: .init(0xF5F5F7), dark: .init(0x161617))
  public static let surfaceTertiary = Color.adaptive(light: .init(0xE8E8ED), dark: .init(0x2C2C2E))
  public static let surfaceRaised = Color.adaptive(light: .init(0xFFFFFF), dark: .init(0x1D1D1F))
  public static let label = Color.adaptive(light: .init(0x1D1D1F), dark: .init(0xF5F5F7))
  public static let labelSecondary = Color.adaptive(light: .init(0x6E6E73), dark: .init(0xA1A1A6))
  public static let labelTertiary = Color.adaptive(light: .init(0x86868B), dark: .init(0x86868B))
  public static let labelQuaternary = Color.adaptive(light: .init(0xD2D2D7), dark: .init(0x424245))
  public static let control = Color.adaptive(light: .init(0x000000, 0.04), dark: .init(0xFFFFFF, 0.1))
  public static let controlPressed = Color.adaptive(light: .init(0x000000, 0.12), dark: .init(0xFFFFFF, 0.22))
  public static let controlSelected = Color.adaptive(light: .init(0x1D1D1F), dark: .init(0xF5F5F7))
  public static let controlDisabled = Color.adaptive(light: .init(0x000000, 0.03), dark: .init(0xFFFFFF, 0.05))
  public static let onControlSelected = Color.adaptive(light: .init(0xFFFFFF), dark: .init(0x000000))
  public static let itemPressed = Color.adaptive(light: .init(0x000000, 0.08), dark: .init(0xFFFFFF, 0.12))
  public static let itemSelected = Color.adaptive(light: .init(0x000000, 0.06), dark: .init(0xFFFFFF, 0.1))
  public static let separator = Color.adaptive(light: .init(0xD2D2D7), dark: .init(0x424245))
  public static let separatorStrong = Color.adaptive(light: .init(0x86868B), dark: .init(0x6E6E73))
  public static let accent = Color.adaptive(light: .init(0x0071E3), dark: .init(0x0071E3))
  public static let accentPressed = Color.adaptive(light: .init(0x005BB8), dark: .init(0x004D9E))
  public static let accentSelected = Color.adaptive(light: .init(0x0071E3), dark: .init(0x0071E3))
  public static let accentDisabled = Color.adaptive(light: .init(0x0071E3, 0.4), dark: .init(0x0071E3, 0.4))
  public static let onAccent = Color.adaptive(light: .init(0xFFFFFF), dark: .init(0xFFFFFF))
  public static let accentSurface = Color.adaptive(light: .init(0x0071E3, 0.09), dark: .init(0x0071E3, 0.18))
  public static let accentSurfacePressed = Color.adaptive(light: .init(0x0071E3, 0.18), dark: .init(0x0071E3, 0.3))
  public static let link = Color.adaptive(light: .init(0x0066CC), dark: .init(0x2997FF))
  public static let focus = Color.adaptive(light: .init(0x0071E3), dark: .init(0x0071E3))
  public static let scrim = Color.adaptive(light: .init(0x000000, 0.48), dark: .init(0x000000, 0.48))
  public static let media = Color.adaptive(light: .init(0x000000), dark: .init(0x000000))
  public static let onMedia = Color.adaptive(light: .init(0xFFFFFF), dark: .init(0xFFFFFF))
  public static let danger = Color.adaptive(light: .init(0xD0000A), dark: .init(0xFF5447))
  public static let dangerSurface = Color.adaptive(light: .init(0xD70015, 0.08), dark: .init(0xFF453A, 0.2))
  public static let dangerSurfacePressed = Color.adaptive(light: .init(0xD70015, 0.16), dark: .init(0xFF453A, 0.36))
  public static let success = Color.adaptive(light: .init(0x008009), dark: .init(0x30D158))
  public static let successSurface = Color.adaptive(light: .init(0xEFFAF1), dark: .init(0x30D158, 0.16))
  public static let warning = Color.adaptive(light: .init(0xB64400), dark: .init(0xFF9F0A))
  public static let warningSurface = Color.adaptive(light: .init(0xFFF5EA), dark: .init(0xFF9F0A, 0.16))
}

public enum Radius {
  public static let xs: CGFloat = 3
  public static let sm: CGFloat = 5
  public static let md: CGFloat = 8
  public static let lg: CGFloat = 10
  public static let xl: CGFloat = 12
  public static let xl2: CGFloat = 18
  public static let xl3: CGFloat = 28
  public static let full: CGFloat = 9999
}

extension TextStyle {
  public static let xs3 = TextStyle(size: 11, lineHeight: 13, letterSpacing: 0.066)
  public static let xs2 = TextStyle(size: 12, lineHeight: 16, letterSpacing: 0)
  public static let xs = TextStyle(size: 13, lineHeight: 18, letterSpacing: -0.078)
  public static let sm = TextStyle(size: 15, lineHeight: 20, letterSpacing: -0.24)
  public static let md = TextStyle(size: 16, lineHeight: 21, letterSpacing: -0.32)
  public static let base = TextStyle(size: 17, lineHeight: 22, letterSpacing: -0.442)
  public static let lg = TextStyle(size: 20, lineHeight: 25, letterSpacing: -0.46)
  public static let xl = TextStyle(size: 22, lineHeight: 28, letterSpacing: -0.264)
  public static let xl2 = TextStyle(size: 28, lineHeight: 34, letterSpacing: 0.392)
  public static let xl3 = TextStyle(size: 34, lineHeight: 41, letterSpacing: 0.408)

  public static let allCases: [TextStyle] = [.xs3, .xs2, .xs, .sm, .md, .base, .lg, .xl, .xl2, .xl3]
}

extension Shadow {
  public static let md = Shadow(color: .black.opacity(0.08), radius: 6, x: 2, y: 4)
  public static let lg = Shadow(color: .black.opacity(0.12), radius: 12, y: 4)
}
```

4. Copy the source and every file it uses:

```swift title="swift/Components/Calendar.swift"
import PhosphorSwift
import SwiftUI

public struct DateRange: Hashable, Sendable {
  public var from: Date
  public var to: Date?

  public init(from: Date, to: Date? = nil) {
    self.from = from
    self.to = to
  }

  public static func adding(_ day: Date, to range: DateRange?, calendar: Foundation.Calendar) -> DateRange? {
    guard let range else { return DateRange(from: day) }
    let from = range.from
    guard let to = range.to else {
      if calendar.isDate(day, inSameDayAs: from) { return DateRange(from: from, to: day) }
      return day < from ? DateRange(from: day, to: from) : DateRange(from: from, to: day)
    }
    let sameFrom = calendar.isDate(day, inSameDayAs: from)
    let sameTo = calendar.isDate(day, inSameDayAs: to)
    if sameFrom && sameTo { return nil }
    if sameFrom { return DateRange(from: to) }
    if sameTo { return DateRange(from: from) }
    if day < from { return DateRange(from: day, to: to) }
    return DateRange(from: from, to: day)
  }
}

public struct CalendarDayModifiers: Hashable, Sendable {
  public var today = false
  public var selected = false
  public var rangeStart = false
  public var rangeMiddle = false
  public var rangeEnd = false
  public var outside = false
  public var disabled = false

  public init(
    today: Bool = false,
    selected: Bool = false,
    rangeStart: Bool = false,
    rangeMiddle: Bool = false,
    rangeEnd: Bool = false,
    outside: Bool = false,
    disabled: Bool = false
  ) {
    self.today = today
    self.selected = selected
    self.rangeStart = rangeStart
    self.rangeMiddle = rangeMiddle
    self.rangeEnd = rangeEnd
    self.outside = outside
    self.disabled = disabled
  }

  var selectedSingle: Bool { selected && !rangeStart && !rangeEnd && !rangeMiddle }
}

enum CalendarMonthGrid {
  static func startOfMonth(_ date: Date, calendar: Foundation.Calendar) -> Date {
    calendar.date(from: calendar.dateComponents([.year, .month], from: date)) ?? date
  }

  static func weeks(for month: Date, calendar: Foundation.Calendar) -> [[Date]] {
    let first = startOfMonth(month, calendar: calendar)
    let days = calendar.range(of: .day, in: .month, for: first)?.count ?? 30
    let lead = (calendar.component(.weekday, from: first) - calendar.firstWeekday + 7) % 7
    let count = Int((Double(lead + days) / 7).rounded(.up))
    guard let start = calendar.date(byAdding: .day, value: -lead, to: first) else { return [] }
    return (0..<count).map { week in
      (0..<7).compactMap { day in
        calendar.date(byAdding: .day, value: week * 7 + day, to: start)
      }
    }
  }

  static func weekdaySymbols(calendar: Foundation.Calendar, locale: Locale, format: String) -> [String] {
    let formatter = DateFormatter()
    formatter.locale = locale
    formatter.calendar = calendar
    formatter.dateFormat = format
    let reference = weeks(for: Date(timeIntervalSince1970: 0), calendar: calendar).first ?? []
    return reference.map { formatter.string(from: $0) }
  }
}

enum CalendarSelection {
  case single(Binding<Date?>)
  case range(Binding<DateRange?>)
  case multiple(Binding<Set<Date>>)
}

extension EnvironmentValues {
  @Entry var calendarTransparent = false
}

public struct DateCalendar: View {
  public enum Size: CaseIterable, Sendable {
    case sm, `default`, lg

    var cell: CGFloat {
      switch self {
      case .sm: 24
      case .default: 32
      case .lg: 40
      }
    }

    var padding: CGFloat {
      switch self {
      case .sm: 8
      case .default: 12
      case .lg: 16
      }
    }

    var caption: TextStyle {
      switch self {
      case .sm: .xs
      case .default: .sm
      case .lg: .base
      }
    }

    var day: TextStyle {
      switch self {
      case .sm: .xs3
      case .default: .sm
      case .lg: .lg
      }
    }

    var weekday: TextStyle {
      self == .lg ? .xs : .xs3
    }
  }

  public enum CaptionLayout: CaseIterable, Sendable {
    case label, dropdown, dropdownMonths, dropdownYears
  }

  let selection: CalendarSelection
  let externalMonth: Binding<Date>?
  let size: Size
  let buttonVariant: VariantButtonStyle.Variant
  let captionLayout: CaptionLayout
  let numberOfMonths: Int
  let showOutsideDays: Bool
  let showWeekNumber: Bool
  let startMonth: Date?
  let endMonth: Date?
  let isDisabled: (Date) -> Bool

  @State private var internalMonth: Date
  @Environment(\.calendar) private var environmentCalendar
  @Environment(\.locale) private var locale
  @Environment(\.calendarTransparent) private var transparent
  @Environment(\.accessibilityReduceMotion) private var reduceMotion

  init(
    selection: CalendarSelection,
    initial: Date?,
    month: Binding<Date>?,
    size: Size,
    buttonVariant: VariantButtonStyle.Variant,
    captionLayout: CaptionLayout,
    numberOfMonths: Int,
    showOutsideDays: Bool,
    showWeekNumber: Bool,
    startMonth: Date?,
    endMonth: Date?,
    isDisabled: @escaping (Date) -> Bool
  ) {
    self.selection = selection
    externalMonth = month
    self.size = size
    self.buttonVariant = buttonVariant
    self.captionLayout = captionLayout
    self.numberOfMonths = max(1, numberOfMonths)
    self.showOutsideDays = showOutsideDays
    self.showWeekNumber = showWeekNumber
    self.startMonth = startMonth
    self.endMonth = endMonth
    self.isDisabled = isDisabled
    _internalMonth = State(initialValue: initial ?? Date())
  }

  public init(
    selection: Binding<Date?>,
    month: Binding<Date>? = nil,
    size: Size = .default,
    buttonVariant: VariantButtonStyle.Variant = .plain,
    captionLayout: CaptionLayout = .label,
    numberOfMonths: Int = 1,
    showOutsideDays: Bool = false,
    showWeekNumber: Bool = false,
    startMonth: Date? = nil,
    endMonth: Date? = nil,
    isDisabled: @escaping (Date) -> Bool = { _ in false }
  ) {
    self.init(
      selection: .single(selection),
      initial: selection.wrappedValue,
      month: month,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      numberOfMonths: numberOfMonths,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      startMonth: startMonth,
      endMonth: endMonth,
      isDisabled: isDisabled
    )
  }

  public init(
    selection: Binding<DateRange?>,
    month: Binding<Date>? = nil,
    size: Size = .default,
    buttonVariant: VariantButtonStyle.Variant = .plain,
    captionLayout: CaptionLayout = .label,
    numberOfMonths: Int = 1,
    showOutsideDays: Bool = false,
    showWeekNumber: Bool = false,
    startMonth: Date? = nil,
    endMonth: Date? = nil,
    isDisabled: @escaping (Date) -> Bool = { _ in false }
  ) {
    self.init(
      selection: .range(selection),
      initial: selection.wrappedValue?.from,
      month: month,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      numberOfMonths: numberOfMonths,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      startMonth: startMonth,
      endMonth: endMonth,
      isDisabled: isDisabled
    )
  }

  public init(
    selection: Binding<Set<Date>>,
    month: Binding<Date>? = nil,
    size: Size = .default,
    buttonVariant: VariantButtonStyle.Variant = .plain,
    captionLayout: CaptionLayout = .label,
    numberOfMonths: Int = 1,
    showOutsideDays: Bool = false,
    showWeekNumber: Bool = false,
    startMonth: Date? = nil,
    endMonth: Date? = nil,
    isDisabled: @escaping (Date) -> Bool = { _ in false }
  ) {
    self.init(
      selection: .multiple(selection),
      initial: selection.wrappedValue.min(),
      month: month,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      numberOfMonths: numberOfMonths,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      startMonth: startMonth,
      endMonth: endMonth,
      isDisabled: isDisabled
    )
  }

  private var calendar: Foundation.Calendar {
    var resolved = Foundation.Calendar(identifier: environmentCalendar.identifier)
    resolved.locale = locale
    resolved.timeZone = environmentCalendar.timeZone
    return resolved
  }

  private var displayed: Date {
    CalendarMonthGrid.startOfMonth(externalMonth?.wrappedValue ?? internalMonth, calendar: calendar)
  }

  private func setDisplayed(_ month: Date) {
    let start = CalendarMonthGrid.startOfMonth(month, calendar: calendar)
    if let externalMonth {
      externalMonth.wrappedValue = start
    } else {
      internalMonth = start
    }
  }

  private func shift(_ months: Int) -> Date {
    calendar.date(byAdding: .month, value: months, to: displayed) ?? displayed
  }

  private var canGoBack: Bool {
    guard let startMonth else { return true }
    return displayed > CalendarMonthGrid.startOfMonth(startMonth, calendar: calendar)
  }

  private var canGoForward: Bool {
    guard let endMonth else { return true }
    return shift(numberOfMonths - 1) < CalendarMonthGrid.startOfMonth(endMonth, calendar: calendar)
  }

  private func navigate(_ step: Int) {
    guard step < 0 ? canGoBack : canGoForward else { return }
    if reduceMotion {
      setDisplayed(shift(step))
    } else {
      withAnimation(.timingCurve(0.32, 0.72, 0, 1, duration: 0.3)) { setDisplayed(shift(step)) }
    }
  }

  public var body: some View {
    VStack(alignment: .leading, spacing: 16) {
      ForEach(0..<numberOfMonths, id: \.self) { index in
        month(shift(index), index: index)
      }
    }
    .padding(size.padding)
    .fixedSize()
    .background(transparent ? Color.clear : Color.surface)
    .contentShape(Rectangle())
    .gesture(
      DragGesture(minimumDistance: 24)
        .onEnded { value in
          let dx = value.translation.width
          guard abs(dx) > 48, abs(dx) > abs(value.translation.height) else { return }
          navigate(dx < 0 ? 1 : -1)
        }
    )
  }

  private func month(_ month: Date, index: Int) -> some View {
    let weeks = CalendarMonthGrid.weeks(for: month, calendar: calendar)
    return VStack(alignment: .leading, spacing: 16) {
      HStack(spacing: 2) {
        caption(month)
          .padding(.leading, 6)
          .frame(maxWidth: .infinity, alignment: .leading)
        if index == 0 {
          navButton(icon: Ph.caretLeft.regular, enabled: canGoBack, label: Text("Previous month")) { navigate(-1) }
          navButton(icon: Ph.caretRight.regular, enabled: canGoForward, label: Text("Next month")) { navigate(1) }
        }
      }
      .frame(height: size.cell)
      VStack(spacing: 8) {
        weekdayRow
        ForEach(weeks, id: \.self) { week in
          weekRow(week, month: month)
        }
      }
      .accessibilityElement(children: .contain)
      .accessibilityLabel(Text(verbatim: captionText(month)))
    }
    .frame(width: size.cell * CGFloat(showWeekNumber ? 8 : 7))
  }

  private func captionText(_ month: Date) -> String {
    let formatter = DateFormatter()
    formatter.locale = locale
    formatter.calendar = calendar
    formatter.setLocalizedDateFormatFromTemplate("LLLLy")
    return formatter.string(from: month)
  }

  @ViewBuilder private func caption(_ month: Date) -> some View {
    switch captionLayout {
    case .label:
      Text(verbatim: captionText(month))
        .font(size.caption.font(weight: .semibold))
        .tracking(size.caption.letterSpacing)
        .foregroundStyle(Color.label)
        .lineLimit(1)
    case .dropdown:
      HStack(spacing: 6) {
        monthMenu(month)
        yearMenu(month)
      }
    case .dropdownMonths:
      HStack(spacing: 6) {
        monthMenu(month)
        Text(verbatim: String(calendar.component(.year, from: month)))
          .font(size.caption.font(weight: .semibold))
          .foregroundStyle(Color.label)
      }
    case .dropdownYears:
      HStack(spacing: 6) {
        Text(verbatim: monthSymbol(month, short: false))
          .font(size.caption.font(weight: .semibold))
          .foregroundStyle(Color.label)
        yearMenu(month)
      }
    }
  }

  private func monthSymbol(_ month: Date, short: Bool) -> String {
    let symbols = short ? calendar.shortStandaloneMonthSymbols : calendar.standaloneMonthSymbols
    return symbols[calendar.component(.month, from: month) - 1]
  }

  private var yearBounds: ClosedRange<Int> {
    let current = calendar.component(.year, from: Date())
    let lower = startMonth.map { calendar.component(.year, from: $0) } ?? current - 100
    let upper = endMonth.map { calendar.component(.year, from: $0) } ?? current + 10
    return lower...max(lower, upper)
  }

  private func monthMenu(_ month: Date) -> some View {
    let selected = Binding<Int>(
      get: { calendar.component(.month, from: displayed) },
      set: { value in
        var components = calendar.dateComponents([.year], from: displayed)
        components.month = value
        if let date = calendar.date(from: components) { setDisplayed(date) }
      }
    )
    return Menu {
      Picker(selection: selected) {
        ForEach(1...12, id: \.self) { value in
          Text(verbatim: calendar.standaloneMonthSymbols[value - 1]).tag(value)
        }
      } label: {
        EmptyView()
      }
      .pickerStyle(.inline)
    } label: {
      dropdownLabel(monthSymbol(month, short: true))
    }
  }

  private func yearMenu(_ month: Date) -> some View {
    let selected = Binding<Int>(
      get: { calendar.component(.year, from: displayed) },
      set: { value in
        var components = calendar.dateComponents([.month], from: displayed)
        components.year = value
        if let date = calendar.date(from: components) { setDisplayed(date) }
      }
    )
    return Menu {
      Picker(selection: selected) {
        ForEach(Array(yearBounds), id: \.self) { value in
          Text(verbatim: String(value)).tag(value)
        }
      } label: {
        EmptyView()
      }
      .pickerStyle(.inline)
    } label: {
      dropdownLabel(String(calendar.component(.year, from: month)))
    }
  }

  private func dropdownLabel(_ text: String) -> some View {
    HStack(spacing: 4) {
      Text(verbatim: text)
        .font(size.caption.font(weight: .semibold))
        .tracking(size.caption.letterSpacing)
        .foregroundStyle(Color.label)
      Ph.caretDown.regular
        .frame(width: 14, height: 14)
        .foregroundStyle(Color.labelSecondary)
    }
  }

  private func navButton(icon: some View, enabled: Bool, label: Text, action: @escaping () -> Void) -> some View {
    Button(action: action) {
      icon.frame(width: 16, height: 16)
    }
    .buttonStyle(CalendarNavButtonStyle(variant: buttonVariant, size: size.cell))
    .disabled(!enabled)
    .accessibilityLabel(label)
  }

  private var weekdayRow: some View {
    let symbols = CalendarMonthGrid.weekdaySymbols(calendar: calendar, locale: locale, format: "cccccc")
    return HStack(spacing: 0) {
      if showWeekNumber {
        Color.clear.frame(width: size.cell, height: 1)
      }
      ForEach(Array(symbols.enumerated()), id: \.offset) { _, symbol in
        Text(verbatim: size == .sm ? symbol : symbol.uppercased(with: locale))
          .font(size.weekday.font(weight: .semibold))
          .tracking(size.weekday.letterSpacing)
          .foregroundStyle(Color.labelSecondary)
          .lineLimit(1)
          .frame(maxWidth: .infinity)
      }
    }
    .accessibilityHidden(true)
  }

  private func weekRow(_ week: [Date], month: Date) -> some View {
    HStack(spacing: 0) {
      if showWeekNumber, let first = week.first {
        Text(verbatim: String(calendar.component(.weekOfYear, from: first)))
          .font(TextStyle.xs.font())
          .tracking(TextStyle.xs.letterSpacing)
          .foregroundStyle(Color.labelSecondary)
          .frame(width: size.cell, height: size.cell)
      }
      ForEach(Array(week.enumerated()), id: \.offset) { position, day in
        let modifiers = modifiers(for: day, month: month)
        let hidden = modifiers.outside && !showOutsideDays
        ZStack {
          if !hidden {
            band(modifiers, first: position == 0, last: position == week.count - 1)
            CalendarDayButton(date: day, modifiers: modifiers, size: size) {
              select(day)
            }
          }
        }
        .frame(width: size.cell, height: size.cell)
      }
    }
  }

  @ViewBuilder private func band(_ modifiers: CalendarDayModifiers, first: Bool, last: Bool) -> some View {
    let inBand = modifiers.rangeMiddle || ((modifiers.rangeStart || modifiers.rangeEnd) && !(modifiers.rangeStart && modifiers.rangeEnd))
    if inBand {
      let radius = size.cell / 2
      let leading = modifiers.rangeStart || first ? radius : 0
      let trailing = modifiers.rangeEnd || last ? radius : 0
      UnevenRoundedRectangle(
        topLeadingRadius: leading,
        bottomLeadingRadius: leading,
        bottomTrailingRadius: trailing,
        topTrailingRadius: trailing,
        style: .continuous
      )
      .fill(Color.surfaceSecondary)
    }
  }

  private func modifiers(for day: Date, month: Date) -> CalendarDayModifiers {
    var result = CalendarDayModifiers()
    result.today = calendar.isDateInToday(day)
    result.outside = !calendar.isDate(day, equalTo: month, toGranularity: .month)
    result.disabled = isDisabled(day)
    switch selection {
    case .single(let binding):
      result.selected = binding.wrappedValue.map { calendar.isDate($0, inSameDayAs: day) } ?? false
    case .multiple(let binding):
      result.selected = binding.wrappedValue.contains { calendar.isDate($0, inSameDayAs: day) }
    case .range(let binding):
      guard let range = binding.wrappedValue else { break }
      let start = calendar.isDate(range.from, inSameDayAs: day)
      let end = range.to.map { calendar.isDate($0, inSameDayAs: day) } ?? false
      let middle = range.to.map { day > range.from && day < $0 && !end } ?? false
      result.rangeStart = start
      result.rangeEnd = end || (start && range.to == nil)
      result.rangeMiddle = middle && !start
      result.selected = start || end || result.rangeMiddle
    }
    if result.outside && !showOutsideDays { result.selected = false }
    return result
  }

  private func select(_ day: Date) {
    let normalized = calendar.startOfDay(for: day)
    switch selection {
    case .single(let binding):
      if let current = binding.wrappedValue, calendar.isDate(current, inSameDayAs: normalized) {
        binding.wrappedValue = nil
      } else {
        binding.wrappedValue = normalized
      }
    case .multiple(let binding):
      if let existing = binding.wrappedValue.first(where: { calendar.isDate($0, inSameDayAs: normalized) }) {
        binding.wrappedValue.remove(existing)
      } else {
        binding.wrappedValue.insert(normalized)
      }
    case .range(let binding):
      binding.wrappedValue = DateRange.adding(normalized, to: binding.wrappedValue, calendar: calendar)
    }
    if !calendar.isDate(normalized, equalTo: displayed, toGranularity: .month), numberOfMonths == 1 {
      setDisplayed(normalized)
    }
  }
}

struct CalendarNavButtonStyle: ButtonStyle {
  let variant: VariantButtonStyle.Variant
  let size: CGFloat

  @Environment(\.isEnabled) private var isEnabled

  func makeBody(configuration: Configuration) -> some View {
    let pressed = configuration.isPressed && isEnabled
    configuration.label
      .foregroundStyle(foreground)
      .frame(width: size, height: size)
      .background(background(pressed: pressed), in: Circle())
      .contentShape(Circle())
  }

  private var foreground: Color {
    guard isEnabled else { return .labelQuaternary }
    switch variant {
    case .plain, .tinted, .link: return .link
    case .default: return .onAccent
    case .destructive: return .danger
    case .outline, .secondary, .ghost: return .label
    }
  }

  private func background(pressed: Bool) -> Color {
    switch variant {
    case .default: return pressed ? .accentPressed : .accent
    case .secondary: return pressed ? .controlPressed : .control
    case .tinted: return pressed ? .accentSurfacePressed : .accentSurface
    case .destructive: return pressed ? .dangerSurfacePressed : .dangerSurface
    case .outline, .ghost, .plain: return pressed ? .itemPressed : .clear
    case .link: return .clear
    }
  }
}

public struct CalendarDayButton: View {
  let date: Date
  let modifiers: CalendarDayModifiers
  let size: DateCalendar.Size
  let action: () -> Void

  @Environment(\.locale) private var locale
  @Environment(\.calendar) private var calendar

  public init(date: Date, modifiers: CalendarDayModifiers, size: DateCalendar.Size = .default, action: @escaping () -> Void) {
    self.date = date
    self.modifiers = modifiers
    self.size = size
    self.action = action
  }

  public var body: some View {
    Button(action: action) {
      Text(verbatim: String(calendar.component(.day, from: date)))
    }
    .buttonStyle(PressReader { pressed in
      label(pressed: pressed)
    })
    .disabled(modifiers.disabled)
    .accessibilityLabel(Text(verbatim: accessibilityText))
    .accessibilityAddTraits(modifiers.selected ? .isSelected : [])
  }

  private var accessibilityText: String {
    let formatter = DateFormatter()
    formatter.locale = locale
    formatter.dateStyle = .full
    let full = formatter.string(from: date)
    guard modifiers.today else { return full }
    let relative = RelativeDateTimeFormatter()
    relative.locale = locale
    relative.dateTimeStyle = .named
    let today = relative.localizedString(from: DateComponents(day: 0))
    return "\(today.prefix(1).uppercased())\(today.dropFirst()), \(full)"
  }

  private var accent: Bool {
    modifiers.rangeStart || modifiers.rangeEnd || (modifiers.today && modifiers.selectedSingle)
  }

  private func label(pressed: Bool) -> some View {
    let bold = modifiers.today || modifiers.selectedSingle
    let style = size.day
    let cell = size.cell
    return Text(verbatim: String(calendar.component(.day, from: date)))
      .font(style.font(weight: bold ? .semibold : .regular))
      .tracking(style.letterSpacing)
      .monospacedDigit()
      .foregroundStyle(foreground)
      .frame(width: cell, height: cell)
      .background(background(pressed: pressed && !modifiers.disabled), in: Circle())
      .contentShape(Circle())
  }

  private var foreground: Color {
    if accent { return .onAccent }
    if modifiers.disabled { return .labelQuaternary }
    if modifiers.rangeMiddle { return .label }
    if modifiers.selectedSingle || modifiers.today { return .link }
    if modifiers.outside { return .labelSecondary }
    return .label
  }

  private func background(pressed: Bool) -> Color {
    if accent { return pressed ? .accentPressed : .accent }
    if modifiers.rangeMiddle { return pressed ? .itemPressed : .clear }
    if modifiers.selectedSingle { return pressed ? .accentSurfacePressed : .accentSurface }
    return pressed ? .itemPressed : .clear
  }
}
```

```swift title="swift/Components/Button.swift"
import SwiftUI

public struct VariantButtonStyle: ButtonStyle {
  public enum Variant: CaseIterable, Sendable {
    case `default`, outline, secondary, tinted, ghost, plain, destructive, link
  }

  public enum Size: CaseIterable, Sendable {
    case `default`, xs, sm, lg, xl, icon, iconXs, iconSm, iconLg, iconXl

    var height: CGFloat {
      switch self {
      case .xs, .iconXs: 24
      case .sm, .iconSm: 32
      case .default, .icon: 36
      case .lg, .iconLg: 44
      case .xl, .iconXl: 56
      }
    }

    var horizontalPadding: CGFloat {
      switch self {
      case .xs: 11
      case .sm: 12
      case .default: 16
      case .lg: 22
      case .xl: 31
      case .icon, .iconXs, .iconSm, .iconLg, .iconXl: 0
      }
    }

    var spacing: CGFloat {
      switch self {
      case .xs, .sm, .iconXs, .iconSm: 4
      case .xl, .iconXl: 8
      default: 6
      }
    }

    var textStyle: TextStyle {
      switch self {
      case .xs, .iconXs: .xs2
      case .lg, .xl: .base
      default: .sm
      }
    }

    public var iconSize: CGFloat {
      switch self {
      case .xs, .iconXs: 12
      default: 16
      }
    }

    var blockRadius: CGFloat {
      switch self {
      case .xs, .iconXs: Radius.sm
      case .lg, .iconLg: Radius.lg
      case .xl, .iconXl: Radius.xl
      default: Radius.md
      }
    }

    var isIcon: Bool {
      switch self {
      case .icon, .iconXs, .iconSm, .iconLg, .iconXl: true
      default: false
      }
    }
  }

  let variant: Variant
  let size: Size
  let block: Bool
  var metrics: ButtonMetrics?

  public init(_ variant: Variant = .default, size: Size = .default, block: Bool = false) {
    self.variant = variant
    self.size = size
    self.block = block
  }

  init(_ variant: Variant, size: Size, metrics: ButtonMetrics) {
    self.variant = variant
    self.size = size
    self.block = false
    self.metrics = metrics
  }

  public func makeBody(configuration: Configuration) -> some View {
    StyledButton(configuration: configuration, variant: variant, size: size, block: block, metrics: metrics)
  }
}

struct ButtonMetrics: Sendable {
  var horizontalPadding: CGFloat
  var spacing: CGFloat
  var iconSize: CGFloat
  var textStyle: TextStyle
}

private struct StyledButton: View {
  let configuration: ButtonStyleConfiguration
  let variant: VariantButtonStyle.Variant
  let size: VariantButtonStyle.Size
  let block: Bool
  let metrics: ButtonMetrics?

  @Environment(\.colorScheme) private var colorScheme
  @Environment(\.isEnabled) private var isEnabled
  @Environment(\.buttonGroup) private var group

  var body: some View {
    let joined = group != nil && variant != .ghost && variant != .plain
    let rounded = RoundedRectangle(
      cornerRadius: block ? size.blockRadius : Radius.full,
      style: .continuous
    )
    let shape = joined ? AnyShape(Rectangle()) : AnyShape(rounded)
    configuration.label
      .labelStyle(ButtonLabelStyle(spacing: metrics?.spacing ?? size.spacing, iconSize: metrics?.iconSize ?? size.iconSize))
    .font((metrics?.textStyle ?? size.textStyle).font())
    .tracking((metrics?.textStyle ?? size.textStyle).letterSpacing)
    .underline(variant == .link && pressed && isEnabled)
    .lineLimit(1)
    .foregroundStyle(foreground)
    .padding(.horizontal, metrics?.horizontalPadding ?? size.horizontalPadding)
    .frame(width: size.isIcon && !block ? size.height : nil, height: size.height)
    .frame(maxWidth: block || group == .vertical ? .infinity : nil)
    .background(background, in: shape)
    .overlay {
      if variant == .outline && !joined {
        rounded.strokeBorder(Color.separator)
      }
    }
    .contentShape(shape)
    .anchorPreference(key: ButtonGroupFramesKey.self, value: .bounds) { anchor in
      joined ? [ButtonGroupFrame(bounds: anchor, outlined: variant == .outline)] : []
    }
  }

  private var isDark: Bool { colorScheme == .dark }
  private var pressed: Bool { configuration.isPressed }

  private var foreground: Color {
    switch variant {
    case .default:
      .onAccent
    case .outline, .secondary, .ghost:
      isEnabled ? .label : .labelQuaternary
    case .tinted, .plain:
      isEnabled ? .link : .link.opacity(0.4)
    case .destructive:
      isEnabled ? .danger : .danger.opacity(0.4)
    case .link:
      isEnabled ? .link : .labelQuaternary
    }
  }

  private var background: Color {
    switch variant {
    case .default:
      !isEnabled ? .accentDisabled : pressed ? .accentPressed : .accent
    case .outline:
      isEnabled && pressed ? .itemPressed : isDark ? .clear : .surface
    case .secondary:
      !isEnabled ? .controlDisabled : pressed ? .controlPressed : .control
    case .tinted:
      isEnabled && pressed ? .accentSurfacePressed : .accentSurface
    case .ghost:
      isEnabled && pressed ? .itemPressed : .clear
    case .plain:
      isEnabled && pressed ? .itemPressed : .clear
    case .destructive:
      isEnabled && pressed ? .dangerSurfacePressed : .dangerSurface
    case .link:
      .clear
    }
  }
}

struct ButtonLabelStyle: LabelStyle {
  let spacing: CGFloat
  let iconSize: CGFloat

  func makeBody(configuration: Configuration) -> some View {
    HStack(spacing: spacing) {
      configuration.icon
        .frame(width: iconSize, height: iconSize)
      configuration.title
    }
  }
}

extension ButtonStyle where Self == VariantButtonStyle {
  public static func variant(
    _ variant: VariantButtonStyle.Variant = .default,
    size: VariantButtonStyle.Size = .default,
    block: Bool = false
  ) -> VariantButtonStyle {
    VariantButtonStyle(variant, size: size, block: block)
  }
}
```

```swift title="swift/Components/ButtonGroup.swift"
import SwiftUI

extension EnvironmentValues {
  @Entry var buttonGroup: Axis? = nil
  @Entry var buttonGroupSize: CGSize = .zero
}

enum ButtonGroupSpace: Hashable {
  case group
}

struct ButtonGroupFrame {
  let bounds: Anchor<CGRect>
  let outlined: Bool
}

struct ButtonGroupFramesKey: PreferenceKey {
  static var defaultValue: [ButtonGroupFrame] { [] }

  static func reduce(value: inout [ButtonGroupFrame], nextValue: () -> [ButtonGroupFrame]) {
    value.append(contentsOf: nextValue())
  }
}

struct ButtonGroupNestedKey: PreferenceKey {
  static var defaultValue: Bool { false }

  static func reduce(value: inout Bool, nextValue: () -> Bool) {
    value = value || nextValue()
  }
}

public struct ButtonGroup<Content: View>: View {
  let orientation: Axis
  let content: Content

  @State private var nested = false
  @State private var size: CGSize = .zero

  public init(orientation: Axis = .horizontal, @ViewBuilder content: () -> Content) {
    self.orientation = orientation
    self.content = content()
  }

  public var body: some View {
    let shape = orientation == .horizontal
      ? AnyShape(Capsule())
      : AnyShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
    stack
      .coordinateSpace(.named(ButtonGroupSpace.group))
      .onGeometryChange(for: CGSize.self) { $0.size } action: { size = $0 }
      .environment(\.buttonGroup, nested ? nil : orientation)
      .environment(\.buttonGroupSize, size)
      .onPreferenceChange(ButtonGroupNestedKey.self) { nested = $0 }
      .modifier(ButtonGroupClip(shape: nested ? nil : shape))
      .overlayPreferenceValue(ButtonGroupFramesKey.self) { frames in
        if !nested {
          GeometryReader { proxy in
            outline(frames.map { (proxy[$0.bounds], $0.outlined) }, shape: shape)
          }
        }
      }
      .transformPreference(ButtonGroupFramesKey.self) { $0 = [] }
      .transformPreference(ButtonGroupNestedKey.self) { $0 = true }
      .fixedSize(horizontal: orientation == .vertical, vertical: orientation == .horizontal)
      .accessibilityElement(children: .contain)
  }

  @ViewBuilder private var stack: some View {
    switch orientation {
    case .horizontal:
      HStack(spacing: nested ? 8 : 0) { content }
    case .vertical:
      VStack(spacing: nested ? 8 : 0) { content }
    }
  }

  @ViewBuilder private func outline(_ frames: [(CGRect, Bool)], shape: AnyShape) -> some View {
    if frames.contains(where: \.1) {
      ZStack(alignment: .topLeading) {
        shape
          .stroke(Color.separator, lineWidth: 1)
          .padding(0.5)
          .mask {
            Path { path in
              for (rect, outlined) in frames where outlined {
                path.addRect(rect)
              }
            }
          }
        ForEach(Array(frames.dropLast().enumerated()), id: \.offset) { _, frame in
          if frame.1 {
            divider(frame.0)
          }
        }
      }
      .clipShape(shape)
      .allowsHitTesting(false)
    }
  }

  private func divider(_ rect: CGRect) -> some View {
    let horizontal = orientation == .horizontal
    return Rectangle()
      .fill(Color.separator)
      .frame(width: horizontal ? 1 : rect.width, height: horizontal ? rect.height : 1)
      .position(
        x: horizontal ? rect.maxX - 0.5 : rect.midX,
        y: horizontal ? rect.midY : rect.maxY - 0.5
      )
  }
}

struct ButtonGroupItem<Content: View>: View {
  let radius: CGFloat
  let content: (UnevenRoundedRectangle) -> Content

  @State private var frame: CGRect = .zero
  @Environment(\.buttonGroup) private var group
  @Environment(\.buttonGroupSize) private var groupSize

  init(radius: CGFloat, @ViewBuilder content: @escaping (UnevenRoundedRectangle) -> Content) {
    self.radius = radius
    self.content = content
  }

  var body: some View {
    if let group {
      content(shape(group))
        .onGeometryChange(for: CGRect.self) { $0.frame(in: .named(ButtonGroupSpace.group)) } action: { frame = $0 }
    } else {
      content(UnevenRoundedRectangle(cornerRadii: RectangleCornerRadii(
        topLeading: radius,
        bottomLeading: radius,
        bottomTrailing: radius,
        topTrailing: radius
      ), style: .continuous))
    }
  }

  private func shape(_ group: Axis) -> UnevenRoundedRectangle {
    let horizontal = group == .horizontal
    let first = horizontal ? frame.minX <= 0.5 : frame.minY <= 0.5
    let last = horizontal
      ? frame.maxX >= groupSize.width - 0.5
      : frame.maxY >= groupSize.height - 0.5
    let round = horizontal ? frame.height / 2 : Radius.xl2
    let start: CGFloat = first ? round : 0
    let end: CGFloat = last ? round : 0
    let radii = horizontal
      ? RectangleCornerRadii(topLeading: start, bottomLeading: start, bottomTrailing: end, topTrailing: end)
      : RectangleCornerRadii(topLeading: start, bottomLeading: end, bottomTrailing: end, topTrailing: start)
    return UnevenRoundedRectangle(cornerRadii: radii, style: .continuous)
  }
}

private struct ButtonGroupClip: ViewModifier {
  let shape: AnyShape?

  func body(content: Content) -> some View {
    if let shape {
      content.clipShape(shape)
    } else {
      content
    }
  }
}

public struct ButtonGroupText<Content: View>: View {
  let content: Content

  @Environment(\.buttonGroup) private var group

  public init(@ViewBuilder content: () -> Content) {
    self.content = content()
  }

  public var body: some View {
    let shape = group == nil ? AnyShape(Capsule()) : AnyShape(Rectangle())
    HStack(spacing: 8) {
      content
    }
    .labelStyle(ButtonLabelStyle(spacing: 8, iconSize: 16))
    .scaledFont(.sm)
    .lineLimit(1)
    .foregroundStyle(Color.label)
    .padding(.horizontal, 10)
    .frame(minHeight: 36)
    .frame(maxWidth: group == .vertical ? .infinity : nil, maxHeight: group == .horizontal ? .infinity : nil)
    .background(Color.control, in: shape)
    .anchorPreference(key: ButtonGroupFramesKey.self, value: .bounds) { anchor in
      group == nil ? [] : [ButtonGroupFrame(bounds: anchor, outlined: false)]
    }
  }
}

extension ButtonGroupText where Content == Text {
  public init(_ title: LocalizedStringKey) {
    self.init { Text(title) }
  }

  public init(verbatim title: String) {
    self.init { Text(verbatim: title) }
  }
}

public struct ButtonGroupSeparator: View {
  let orientation: Axis

  public init(_ orientation: Axis = .vertical) {
    self.orientation = orientation
  }

  public var body: some View {
    let vertical = orientation == .vertical
    Rectangle()
      .fill(Color.label.opacity(0.2))
      .frame(width: vertical ? 1 : nil, height: vertical ? nil : 1)
      .padding(vertical ? .vertical : .horizontal, 9)
      .frame(maxWidth: vertical ? nil : .infinity, maxHeight: vertical ? .infinity : nil)
      .padding(vertical ? .trailing : .bottom, -1)
      .zIndex(1)
      .accessibilityHidden(true)
  }
}
```

```swift title="swift/Components/Checkbox.swift"
import PhosphorSwift
import SwiftUI

extension Shadow {
  static let control = Shadow(color: .black.opacity(0.08), radius: 0.5, y: 0.5)
  static let thumb = Shadow(color: .black.opacity(0.12), radius: 1.5, y: 1)
}

struct SelectionIndicator<Mark: View>: View {
  let checked: Bool
  let pressed: Bool
  let cornerRadius: CGFloat
  let mark: Mark

  @Environment(\.isEnabled) private var isEnabled
  @Environment(\.isInvalid) private var invalid
  @Environment(\.colorScheme) private var colorScheme

  init(checked: Bool, pressed: Bool, cornerRadius: CGFloat, @ViewBuilder mark: () -> Mark) {
    self.checked = checked
    self.pressed = pressed
    self.cornerRadius = cornerRadius
    self.mark = mark()
  }

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: cornerRadius, style: .continuous)
    ZStack {
      shape.fill(fill)
      shape.strokeBorder(border, lineWidth: 1)
      if checked {
        mark
      }
    }
    .frame(width: 16, height: 16)
    .shadow(raised ? .control : Shadow(color: .clear, radius: 0))
  }

  private var isDark: Bool { colorScheme == .dark }

  private var raised: Bool { !checked && isEnabled && !isDark }

  private var fill: Color {
    if checked {
      return !isEnabled ? .accentDisabled : pressed ? .accentPressed : .accent
    }
    if !isEnabled { return .controlDisabled }
    if isDark { return pressed ? .labelTertiary.opacity(0.6) : .labelQuaternary }
    return pressed ? .control : .surface
  }

  private var border: Color {
    if checked {
      return !isEnabled ? .clear : pressed ? .accentPressed : .accent
    }
    if !isEnabled { return isDark ? .clear : .label.opacity(0.1) }
    if invalid { return .danger }
    return isDark ? .clear : .label.opacity(0.25)
  }
}

struct PressReader<Content: View>: ButtonStyle {
  let content: (Bool) -> Content

  init(@ViewBuilder content: @escaping (Bool) -> Content) {
    self.content = content
  }

  func makeBody(configuration: Configuration) -> some View {
    content(configuration.isPressed)
  }
}

public struct CheckboxStyle: ToggleStyle {
  public init() {}

  public func makeBody(configuration: Configuration) -> some View {
    HapticButton(style: PressReader { pressed in
      HStack(spacing: 12) {
        SelectionIndicator(
          checked: configuration.isOn || configuration.isMixed,
          pressed: pressed,
          cornerRadius: 4
        ) {
          (configuration.isMixed ? Ph.minus.regular : Ph.check.regular)
            .frame(width: 14, height: 14)
            .foregroundStyle(Color.onAccent)
        }
        configuration.label
      }
      .contentShape(Rectangle().inset(by: -8))
    }) {
      configuration.isOn.toggle()
      return true
    }
    .accessibilityElement(children: .combine)
    .accessibilityRemoveTraits(.isButton)
    .accessibilityAddTraits(.isToggle)
    .accessibilityValue(
      configuration.isMixed
        ? Text("Mixed")
        : configuration.isOn ? Text("Checked") : Text("Unchecked")
    )
  }
}

extension ToggleStyle where Self == CheckboxStyle {
  public static var checkbox: CheckboxStyle { CheckboxStyle() }
}
```

```swift title="swift/Components/Field.swift"
import SwiftUI

extension EnvironmentValues {
  @Entry public var isInvalid = false
  @Entry var fieldInset = false
  @Entry var fieldGroupInset = false
  @Entry var fieldSetInset = false
}

extension View {
  public func invalid(_ isInvalid: Bool = true) -> some View {
    environment(\.isInvalid, isInvalid)
  }
}

public enum FieldOrientation: CaseIterable, Sendable {
  case vertical, horizontal
}

public struct Field<Content: View>: View {
  let orientation: FieldOrientation
  let invalid: Bool?
  let content: Content

  @Environment(\.fieldGroupInset) private var inset
  @Environment(\.isInvalid) private var inheritedInvalid

  public init(
    orientation: FieldOrientation = .vertical,
    invalid: Bool? = nil,
    @ViewBuilder content: () -> Content
  ) {
    self.orientation = orientation
    self.invalid = invalid
    self.content = content()
  }

  public var body: some View {
    Group {
      switch orientation {
      case .vertical:
        VStack(alignment: .leading, spacing: 12) { content }
      case .horizontal:
        HStack(alignment: .center, spacing: 12) { content }
      }
    }
    .frame(maxWidth: .infinity, alignment: .leading)
    .padding(.horizontal, inset ? 16 : 0)
    .padding(.vertical, inset ? 6 : 0)
    .frame(minHeight: inset ? 44 : nil)
    .overlay(alignment: .top) {
      if inset {
        Color.separator
          .frame(height: 1)
          .padding(.leading, 16)
          .offset(y: -1)
      }
    }
    .environment(\.fieldInset, inset)
    .environment(\.fieldGroupInset, false)
    .environment(\.isInvalid, invalid ?? inheritedInvalid)
  }
}

public struct FieldContent<Content: View>: View {
  let content: Content

  public init(@ViewBuilder content: () -> Content) {
    self.content = content()
  }

  public var body: some View {
    VStack(alignment: .leading, spacing: 4) {
      content
    }
    .frame(maxWidth: .infinity, alignment: .leading)
  }
}

public struct FieldTitle: View {
  let text: Text

  @Environment(\.isEnabled) private var isEnabled

  public init(_ title: LocalizedStringKey) {
    text = Text(title)
  }

  public init<S: StringProtocol>(_ title: S) {
    text = Text(title)
  }

  public var body: some View {
    text
      .scaledTextStyle(.base, weight: .semibold)
      .foregroundStyle(isEnabled ? Color.label : .labelQuaternary)
  }
}

public struct FieldDescription: View {
  let text: Text

  @Environment(\.fieldSetInset) private var inset

  public init(_ description: LocalizedStringKey) {
    text = Text(description)
  }

  public init<S: StringProtocol>(_ description: S) {
    text = Text(description)
  }

  public var body: some View {
    text
      .scaledTextStyle(inset ? .xs : .sm)
      .foregroundStyle(Color.labelSecondary)
      .multilineTextAlignment(.leading)
      .fixedSize(horizontal: false, vertical: true)
      .padding(.leading, inset ? 16 : 0)
  }
}

public struct FieldError: View {
  let messages: [String]
  let text: Text?

  public init(_ message: LocalizedStringKey) {
    messages = []
    text = Text(message)
  }

  public init(errors: [String?]) {
    var seen = Set<String>()
    messages = errors.compactMap { $0 }.filter { !$0.isEmpty && seen.insert($0).inserted }
    text = nil
  }

  public var body: some View {
    if let content {
      content
        .scaledTextStyle(.sm)
        .foregroundStyle(Color.danger)
        .multilineTextAlignment(.leading)
        .fixedSize(horizontal: false, vertical: true)
    }
  }

  private var content: Text? {
    if let text { return text }
    switch messages.count {
    case 0: return nil
    case 1: return Text(verbatim: messages[0])
    default: return Text(verbatim: messages.map { "\u{2022} \($0)" }.joined(separator: "\n"))
    }
  }
}

public enum FieldGroupVariant: CaseIterable, Sendable {
  case `default`, inset
}

public struct FieldGroup<Content: View>: View {
  let variant: FieldGroupVariant
  let content: Content

  public init(_ variant: FieldGroupVariant = .default, @ViewBuilder content: () -> Content) {
    self.variant = variant
    self.content = content()
  }

  public var body: some View {
    styled
      .environment(\.fieldGroupInset, variant == .inset)
      .environment(\.fieldSetInset, false)
      .transformPreference(FieldSetInsetKey.self) { $0 = variant == .inset }
  }

  @ViewBuilder private var styled: some View {
    let stack = VStack(alignment: .leading, spacing: variant == .inset ? 0 : 28) {
      content
    }
    .frame(maxWidth: .infinity, alignment: .leading)
    if variant == .inset {
      let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
      stack
        .background(Color.surfaceSecondary, in: shape)
        .clipShape(shape)
    } else {
      stack
    }
  }
}

struct FieldSetInsetKey: PreferenceKey {
  static let defaultValue = false

  static func reduce(value: inout Bool, nextValue: () -> Bool) {
    value = value || nextValue()
  }
}

public struct FieldSet<Content: View>: View {
  let content: Content

  @State private var inset = false

  public init(@ViewBuilder content: () -> Content) {
    self.content = content()
  }

  public var body: some View {
    VStack(alignment: .leading, spacing: inset ? 8 : 24) {
      content
    }
    .frame(maxWidth: .infinity, alignment: .leading)
    .environment(\.fieldSetInset, inset)
    .onPreferenceChange(FieldSetInsetKey.self) { inset = $0 }
    .transformPreference(FieldSetInsetKey.self) { $0 = false }
    .accessibilityElement(children: .contain)
  }
}

public struct FieldLegend: View {
  public enum Variant: CaseIterable, Sendable {
    case legend, label
  }

  let text: Text
  let variant: Variant

  @Environment(\.fieldSetInset) private var inset
  @Environment(\.isEnabled) private var isEnabled

  public init(_ title: LocalizedStringKey, variant: Variant = .legend) {
    text = Text(title)
    self.variant = variant
  }

  public init<S: StringProtocol>(_ title: S, variant: Variant = .legend) {
    text = Text(title)
    self.variant = variant
  }

  public var body: some View {
    Group {
      if inset {
        text
          .textCase(.uppercase)
          .scaledTextStyle(.xs)
          .foregroundStyle(isEnabled ? Color.labelSecondary : .labelQuaternary)
          .padding(.leading, 16)
      } else {
        text
          .scaledTextStyle(.base, weight: .semibold)
          .foregroundStyle(isEnabled ? Color.label : .labelQuaternary)
          .padding(.bottom, 12)
      }
    }
    .accessibilityAddTraits(variant == .legend ? .isHeader : [])
  }
}

public struct FieldSeparator<Content: View>: View {
  let content: Content

  public init(@ViewBuilder content: () -> Content) {
    self.content = content()
  }

  public var body: some View {
    ZStack {
      Separator()
      content
        .scaledTextStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .padding(.horizontal, 8)
        .background(Color.surface)
    }
    .frame(minHeight: 20)
    .padding(.vertical, -8)
  }
}

extension FieldSeparator where Content == EmptyView {
  public init() {
    self.init { EmptyView() }
  }
}

extension FieldSeparator where Content == Text {
  public init(_ title: LocalizedStringKey) {
    self.init { Text(title) }
  }
}
```

```swift title="swift/Components/Haptics.swift"
import SwiftUI

extension EnvironmentValues {
  @Entry public var hapticsEnabled = true
}

extension View {
  public func haptics(_ enabled: Bool) -> some View {
    environment(\.hapticsEnabled, enabled)
  }

  func hapticFeedback<Trigger: Equatable>(_ feedback: SensoryFeedback, trigger: Trigger) -> some View {
    modifier(HapticFeedbackModifier(feedback: feedback, trigger: trigger) { _, _ in true })
  }

  func hapticFeedback<Trigger: Equatable>(
    _ feedback: SensoryFeedback,
    trigger: Trigger,
    condition: @escaping (Trigger, Trigger) -> Bool
  ) -> some View {
    modifier(HapticFeedbackModifier(feedback: feedback, trigger: trigger, condition: condition))
  }
}

private struct HapticFeedbackModifier<Trigger: Equatable>: ViewModifier {
  let feedback: SensoryFeedback
  let trigger: Trigger
  let condition: (Trigger, Trigger) -> Bool

  @Environment(\.hapticsEnabled) private var enabled

  func body(content: Content) -> some View {
    let enabled = enabled
    let condition = condition
    content.sensoryFeedback(feedback, trigger: trigger) { old, new in
      enabled && condition(old, new)
    }
  }
}

enum HapticMoments {
  static func step(_ value: Double, bounds: ClosedRange<Double>, step: Double?) -> Int? {
    guard let step, step > 0 else { return nil }
    return Int(((value - bounds.lowerBound) / step).rounded())
  }

  static func lifted<Value: Equatable>(_ old: Value?, _ new: Value?) -> Bool {
    new != nil && old != new
  }

  static func crossed<Value: Equatable>(_ old: Value?, _ new: Value?) -> Bool {
    old == nil && new != nil
  }

  static func moved(_ old: Int?, _ new: Int?) -> Bool {
    guard let old, let new else { return false }
    return old != new
  }
}

struct HapticButton<Style: ButtonStyle>: View {
  let feedback: SensoryFeedback
  let action: () -> Bool
  let style: Style

  @State private var count = 0

  init(_ feedback: SensoryFeedback = .selection, style: Style, action: @escaping () -> Bool) {
    self.feedback = feedback
    self.style = style
    self.action = action
  }

  var body: some View {
    Button {
      if action() { count += 1 }
    } label: {
      EmptyView()
    }
    .buttonStyle(style)
    .hapticFeedback(feedback, trigger: count)
  }
}
```

```swift title="swift/Components/Separator.swift"
import SwiftUI

public struct Separator: View {
  let orientation: Axis

  public init(_ orientation: Axis = .horizontal) {
    self.orientation = orientation
  }

  public var body: some View {
    Rectangle()
      .fill(Color.separator)
      .frame(width: orientation == .vertical ? 1 : nil, height: orientation == .horizontal ? 1 : nil)
      .frame(maxWidth: orientation == .horizontal ? .infinity : nil, maxHeight: orientation == .vertical ? .infinity : nil)
      .accessibilityHidden(true)
  }
}
```

```swift title="swift/Components/TextVariant.swift"
import SwiftUI

public enum TextVariant: CaseIterable, Sendable {
  case `default`, h1, h2, h3, h4, p, blockquote, code, lead, large, small, muted

  var style: TextStyle {
    switch self {
    case .h1: .xl3
    case .h2: .xl2
    case .h3: .xl
    case .h4, .lead, .large: .lg
    case .code, .small, .muted: .sm
    default: .base
    }
  }

  var weight: Font.Weight {
    switch self {
    case .h1, .h2: .bold
    case .h3, .h4, .large, .code: .semibold
    case .small: .medium
    default: .regular
    }
  }

  var color: Color {
    switch self {
    case .lead, .muted: .labelSecondary
    default: .label
    }
  }

  var isHeading: Bool {
    switch self {
    case .h1, .h2, .h3, .h4: true
    default: false
    }
  }
}

private struct TextVariantModifier: ViewModifier {
  let variant: TextVariant

  func body(content: Content) -> some View {
    switch variant {
    case .blockquote:
      styled(content)
        .italic()
        .padding(.leading, 12)
        .overlay(alignment: .leading) {
          Rectangle().fill(Color.separator).frame(width: 2)
        }
        .padding(.top, 16)
    case .code:
      styled(content)
        .monospaced()
        .padding(.horizontal, 4)
        .padding(.vertical, 2)
        .background(Color.surfaceSecondary, in: RoundedRectangle(cornerRadius: Radius.sm, style: .continuous))
    case .p:
      styled(content).padding(.top, 12)
    default:
      styled(content)
    }
  }

  private func styled(_ content: Content) -> some View {
    content
      .scaledTextStyle(variant.style, weight: variant.weight)
      .foregroundStyle(variant.color)
      .accessibilityAddTraits(variant.isHeading ? .isHeader : [])
  }
}

extension View {
  public func textVariant(_ variant: TextVariant) -> some View {
    modifier(TextVariantModifier(variant: variant))
  }
}

private struct ScaledTextStyleModifier: ViewModifier {
  let style: TextStyle
  let weight: Font.Weight

  @ScaledMetric(relativeTo: .body) private var scale: CGFloat = 1

  func body(content: Content) -> some View {
    let size = style.size * scale
    let lineSpacing = max(0, style.lineHeight * scale - UIFont.systemFont(ofSize: size).lineHeight)
    content
      .font(.system(size: size, weight: weight))
      .tracking(style.letterSpacing)
      .lineSpacing(lineSpacing)
      .padding(.vertical, lineSpacing / 2)
  }
}

extension View {
  func scaledTextStyle(_ style: TextStyle, weight: Font.Weight = .regular) -> some View {
    modifier(ScaledTextStyleModifier(style: style, weight: weight))
  }

  func scaledFont(_ style: TextStyle, weight: Font.Weight = .regular) -> some View {
    modifier(ScaledFontModifier(style: style, weight: weight))
  }
}

private struct ScaledFontModifier: ViewModifier {
  let style: TextStyle
  let weight: Font.Weight

  @ScaledMetric(relativeTo: .body) private var scale: CGFloat = 1

  func body(content: Content) -> some View {
    content
      .font(.system(size: style.size * scale, weight: weight))
      .tracking(style.letterSpacing)
  }
}
```

5. Add the files to your app target.

**Jetpack Compose**

1. Set `minSdk` to 24 or higher and add the dependencies:

```kotlin title="build.gradle.kts"
implementation(platform("androidx.compose:compose-bom:2026.09.00"))
implementation("androidx.compose.foundation:foundation")
implementation("androidx.compose.ui:ui")
implementation("com.adamglin:phosphor-icon-android:1.0.0")
```

2. Copy the theme files every view uses:

```kt title="kotlin/theme/Theme.kt"
package com.esuiss.ui.theme

import androidx.compose.foundation.isSystemInDarkTheme
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.dropShadow
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.Shape
import androidx.compose.ui.graphics.shadow.Shadow as DropShadow
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.style.LineHeightStyle
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.DpOffset
import androidx.compose.ui.unit.em
import androidx.compose.ui.unit.sp

internal fun textStyle(size: Double, lineHeight: Double, letterSpacing: Double) = TextStyle(
    fontSize = size.sp,
    lineHeight = lineHeight.sp,
    letterSpacing = letterSpacing.em,
    lineHeightStyle = LineHeightStyle(
        alignment = LineHeightStyle.Alignment.Center,
        trim = LineHeightStyle.Trim.None,
    ),
)

@Immutable
data class Shadow(
    val offsetX: Dp,
    val offsetY: Dp,
    val blur: Dp,
    val color: Color,
)

fun Modifier.shadow(shadow: Shadow, shape: Shape): Modifier = dropShadow(
    shape,
    DropShadow(
        radius = shadow.blur,
        color = shadow.color,
        offset = DpOffset(shadow.offsetX, shadow.offsetY),
    ),
)

val LocalColors = staticCompositionLocalOf { LightColors }

object EsuissTheme {
    val colors: Colors
        @Composable get() = LocalColors.current

    val typography: Typography
        get() = Typography

    val radius: Radius
        get() = Radius

    val shadows: Shadows
        get() = Shadows
}

@Composable
fun EsuissTheme(
    darkTheme: Boolean = isSystemInDarkTheme(),
    content: @Composable () -> Unit,
) {
    CompositionLocalProvider(
        LocalColors provides if (darkTheme) DarkColors else LightColors,
        content = content,
    )
}
```

```kt title="kotlin/theme/Tokens.kt"
package com.esuiss.ui.theme

import androidx.compose.runtime.Immutable
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp

@Immutable
data class Colors(
    val surface: Color,
    val surfaceSecondary: Color,
    val surfaceTertiary: Color,
    val surfaceRaised: Color,
    val label: Color,
    val labelSecondary: Color,
    val labelTertiary: Color,
    val labelQuaternary: Color,
    val control: Color,
    val controlPressed: Color,
    val controlSelected: Color,
    val controlDisabled: Color,
    val onControlSelected: Color,
    val itemPressed: Color,
    val itemSelected: Color,
    val separator: Color,
    val separatorStrong: Color,
    val accent: Color,
    val accentPressed: Color,
    val accentSelected: Color,
    val accentDisabled: Color,
    val onAccent: Color,
    val accentSurface: Color,
    val accentSurfacePressed: Color,
    val link: Color,
    val focus: Color,
    val scrim: Color,
    val media: Color,
    val onMedia: Color,
    val danger: Color,
    val dangerSurface: Color,
    val dangerSurfacePressed: Color,
    val success: Color,
    val successSurface: Color,
    val warning: Color,
    val warningSurface: Color,
    val blue: Color,
    val green: Color,
    val orange: Color,
    val red: Color,
    val yellow: Color,
    val purple: Color,
    val pink: Color,
    val indigo: Color,
    val teal: Color,
    val mint: Color,
    val cyan: Color,
    val brown: Color,
    val gray: Color,
    val isDark: Boolean,
)

val LightColors = Colors(
    surface = Color(0xFFFFFFFF),
    surfaceSecondary = Color(0xFFF5F5F7),
    surfaceTertiary = Color(0xFFE8E8ED),
    surfaceRaised = Color(0xFFFFFFFF),
    label = Color(0xFF1D1D1F),
    labelSecondary = Color(0xFF6E6E73),
    labelTertiary = Color(0xFF86868B),
    labelQuaternary = Color(0xFFD2D2D7),
    control = Color(0xFF000000).copy(alpha = 0.04f),
    controlPressed = Color(0xFF000000).copy(alpha = 0.12f),
    controlSelected = Color(0xFF1D1D1F),
    controlDisabled = Color(0xFF000000).copy(alpha = 0.03f),
    onControlSelected = Color(0xFFFFFFFF),
    itemPressed = Color(0xFF000000).copy(alpha = 0.08f),
    itemSelected = Color(0xFF000000).copy(alpha = 0.06f),
    separator = Color(0xFFD2D2D7),
    separatorStrong = Color(0xFF86868B),
    accent = Color(0xFF0071E3),
    accentPressed = Color(0xFF005BB8),
    accentSelected = Color(0xFF0071E3),
    accentDisabled = Color(0xFF0071E3).copy(alpha = 0.4f),
    onAccent = Color(0xFFFFFFFF),
    accentSurface = Color(0xFF0071E3).copy(alpha = 0.09f),
    accentSurfacePressed = Color(0xFF0071E3).copy(alpha = 0.18f),
    link = Color(0xFF0066CC),
    focus = Color(0xFF0071E3),
    scrim = Color(0xFF000000).copy(alpha = 0.48f),
    media = Color(0xFF000000),
    onMedia = Color(0xFFFFFFFF),
    danger = Color(0xFFD0000A),
    dangerSurface = Color(0xFFD70015).copy(alpha = 0.08f),
    dangerSurfacePressed = Color(0xFFD70015).copy(alpha = 0.16f),
    success = Color(0xFF008009),
    successSurface = Color(0xFFEFFAF1),
    warning = Color(0xFFB64400),
    warningSurface = Color(0xFFFFF5EA),
    blue = Color(0xFF007AFF),
    green = Color(0xFF34C759),
    orange = Color(0xFFFF9500),
    red = Color(0xFFFF3B30),
    yellow = Color(0xFFFFCC00),
    purple = Color(0xFFAF52DE),
    pink = Color(0xFFFF2D55),
    indigo = Color(0xFF5856D6),
    teal = Color(0xFF30B0C7),
    mint = Color(0xFF00C7BE),
    cyan = Color(0xFF32ADE6),
    brown = Color(0xFFA2845E),
    gray = Color(0xFF8E8E93),
    isDark = false,
)

val DarkColors = Colors(
    surface = Color(0xFF000000),
    surfaceSecondary = Color(0xFF161617),
    surfaceTertiary = Color(0xFF2C2C2E),
    surfaceRaised = Color(0xFF1D1D1F),
    label = Color(0xFFF5F5F7),
    labelSecondary = Color(0xFFA1A1A6),
    labelTertiary = Color(0xFF86868B),
    labelQuaternary = Color(0xFF424245),
    control = Color(0xFFFFFFFF).copy(alpha = 0.1f),
    controlPressed = Color(0xFFFFFFFF).copy(alpha = 0.22f),
    controlSelected = Color(0xFFF5F5F7),
    controlDisabled = Color(0xFFFFFFFF).copy(alpha = 0.05f),
    onControlSelected = Color(0xFF000000),
    itemPressed = Color(0xFFFFFFFF).copy(alpha = 0.12f),
    itemSelected = Color(0xFFFFFFFF).copy(alpha = 0.1f),
    separator = Color(0xFF424245),
    separatorStrong = Color(0xFF6E6E73),
    accent = Color(0xFF0071E3),
    accentPressed = Color(0xFF004D9E),
    accentSelected = Color(0xFF0071E3),
    accentDisabled = Color(0xFF0071E3).copy(alpha = 0.4f),
    onAccent = Color(0xFFFFFFFF),
    accentSurface = Color(0xFF0071E3).copy(alpha = 0.18f),
    accentSurfacePressed = Color(0xFF0071E3).copy(alpha = 0.3f),
    link = Color(0xFF2997FF),
    focus = Color(0xFF0071E3),
    scrim = Color(0xFF000000).copy(alpha = 0.48f),
    media = Color(0xFF000000),
    onMedia = Color(0xFFFFFFFF),
    danger = Color(0xFFFF5447),
    dangerSurface = Color(0xFFFF453A).copy(alpha = 0.2f),
    dangerSurfacePressed = Color(0xFFFF453A).copy(alpha = 0.36f),
    success = Color(0xFF30D158),
    successSurface = Color(0xFF30D158).copy(alpha = 0.16f),
    warning = Color(0xFFFF9F0A),
    warningSurface = Color(0xFFFF9F0A).copy(alpha = 0.16f),
    blue = Color(0xFF0A84FF),
    green = Color(0xFF30D158),
    orange = Color(0xFFFF9F0A),
    red = Color(0xFFFF453A),
    yellow = Color(0xFFFFD60A),
    purple = Color(0xFFBF5AF2),
    pink = Color(0xFFFF375F),
    indigo = Color(0xFF5E5CE6),
    teal = Color(0xFF40C8E0),
    mint = Color(0xFF66D4CF),
    cyan = Color(0xFF64D2FF),
    brown = Color(0xFFAC8E68),
    gray = Color(0xFF8E8E93),
    isDark = true,
)

object Radius {
    val xs = 3.dp
    val sm = 5.dp
    val md = 8.dp
    val lg = 10.dp
    val xl = 12.dp
    val xl2 = 18.dp
    val xl3 = 28.dp
    val full = 9999.dp
}

object Typography {
    val xs3 = textStyle(11.0, 13.0, 0.006)
    val xs2 = textStyle(12.0, 16.0, 0.0)
    val xs = textStyle(13.0, 18.0, -0.006)
    val sm = textStyle(15.0, 20.0, -0.016)
    val md = textStyle(16.0, 21.0, -0.02)
    val base = textStyle(17.0, 22.0, -0.026)
    val lg = textStyle(20.0, 25.0, -0.023)
    val xl = textStyle(22.0, 28.0, -0.012)
    val xl2 = textStyle(28.0, 34.0, 0.014)
    val xl3 = textStyle(34.0, 41.0, 0.012)

    val all = listOf(xs3, xs2, xs, sm, md, base, lg, xl, xl2, xl3)
}

object Shadows {
    val md = Shadow(2.dp, 4.dp, 12.dp, Color.Black.copy(alpha = 0.08f))
    val lg = Shadow(0.dp, 4.dp, 24.dp, Color.Black.copy(alpha = 0.12f))
}
```

3. Copy the source and every file it uses:

```kt title="kotlin/components/Calendar.kt"
package com.esuiss.ui.components

import androidx.compose.animation.AnimatedContent
import androidx.compose.animation.core.tween
import androidx.compose.animation.fadeIn
import androidx.compose.animation.fadeOut
import androidx.compose.animation.slideInHorizontally
import androidx.compose.animation.slideOutHorizontally
import androidx.compose.animation.togetherWith
import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.gestures.detectHorizontalDragGestures
import androidx.compose.foundation.interaction.MutableInteractionSource
import androidx.compose.foundation.interaction.collectIsPressedAsState
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.IntrinsicSize
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.aspectRatio
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.layout.widthIn
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableIntStateOf
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberUpdatedState
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.graphicsLayer
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.input.pointer.pointerInput
import androidx.compose.ui.platform.LocalLayoutDirection
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.Role
import androidx.compose.ui.semantics.clearAndSetSemantics
import androidx.compose.ui.semantics.contentDescription
import androidx.compose.ui.semantics.heading
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.selected
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.LayoutDirection
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.CaretDown
import com.adamglin.phosphoricons.regular.CaretLeft
import com.adamglin.phosphoricons.regular.CaretRight
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography
import java.util.Calendar as JavaCalendar
import java.util.Date
import java.util.Locale

enum class CalendarSize(internal val cell: Dp, internal val padding: Dp) {
    Sm(24.dp, 8.dp),
    Default(32.dp, 12.dp),
    Lg(40.dp, 16.dp),
}

enum class CalendarCaptionLayout { Label, Dropdown, DropdownMonths, DropdownYears }

@Immutable
data class DateRange(val from: Date?, val to: Date? = null)

@Immutable
data class CalendarDayState(
    val selected: Boolean = false,
    val today: Boolean = false,
    val rangeStart: Boolean = false,
    val rangeMiddle: Boolean = false,
    val rangeEnd: Boolean = false,
    val outside: Boolean = false,
    val disabled: Boolean = false,
)

typealias CalendarDayButtonSlot = @Composable (date: Date, state: CalendarDayState, onClick: () -> Unit) -> Unit

@Composable
fun Calendar(
    selected: Date?,
    onSelect: (Date?) -> Unit,
    modifier: Modifier = Modifier,
    defaultMonth: Date? = null,
    numberOfMonths: Int = 1,
    startMonth: Date? = null,
    endMonth: Date? = null,
    showOutsideDays: Boolean = false,
    showWeekNumber: Boolean = false,
    weekStartsOn: Int? = null,
    disabled: (Date) -> Boolean = { false },
    today: Date = remember { Date() },
    locale: Locale = Locale.getDefault(),
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    dayButton: CalendarDayButtonSlot? = null,
) {
    val selectedKey = selected?.let(::dayKey)
    CalendarGrid(
        modifier = modifier,
        initialMonth = defaultMonth ?: selected ?: today,
        numberOfMonths = numberOfMonths,
        startMonth = startMonth,
        endMonth = endMonth,
        showOutsideDays = showOutsideDays,
        showWeekNumber = showWeekNumber,
        weekStartsOn = weekStartsOn,
        disabled = disabled,
        today = today,
        locale = locale,
        buttonVariant = buttonVariant,
        size = size,
        captionLayout = captionLayout,
        dayButton = dayButton,
        selection = { key -> if (key == selectedKey) DaySelection.Single else DaySelection.None },
        onDayClick = { date -> onSelect(if (dayKey(date) == selectedKey) null else date) },
    )
}

@Composable
fun Calendar(
    selected: DateRange?,
    onSelect: (DateRange?) -> Unit,
    modifier: Modifier = Modifier,
    defaultMonth: Date? = null,
    numberOfMonths: Int = 1,
    startMonth: Date? = null,
    endMonth: Date? = null,
    showOutsideDays: Boolean = false,
    showWeekNumber: Boolean = false,
    weekStartsOn: Int? = null,
    disabled: (Date) -> Boolean = { false },
    today: Date = remember { Date() },
    locale: Locale = Locale.getDefault(),
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    dayButton: CalendarDayButtonSlot? = null,
) {
    val from = selected?.from?.let(::dayKey)
    val to = selected?.to?.let(::dayKey)
    CalendarGrid(
        modifier = modifier,
        initialMonth = defaultMonth ?: selected?.from ?: today,
        numberOfMonths = numberOfMonths,
        startMonth = startMonth,
        endMonth = endMonth,
        showOutsideDays = showOutsideDays,
        showWeekNumber = showWeekNumber,
        weekStartsOn = weekStartsOn,
        disabled = disabled,
        today = today,
        locale = locale,
        buttonVariant = buttonVariant,
        size = size,
        captionLayout = captionLayout,
        dayButton = dayButton,
        selection = { key ->
            when {
                from == null -> DaySelection.None
                to == null -> if (key == from) DaySelection.RangeBoth else DaySelection.None
                key == from && key == to -> DaySelection.RangeBoth
                key == from -> DaySelection.RangeStart
                key == to -> DaySelection.RangeEnd
                key in from..to -> DaySelection.RangeMiddle
                else -> DaySelection.None
            }
        },
        onDayClick = { date -> onSelect(addToRange(date, selected)) },
    )
}

@Composable
fun Calendar(
    selected: List<Date>,
    onSelect: (List<Date>) -> Unit,
    modifier: Modifier = Modifier,
    defaultMonth: Date? = null,
    numberOfMonths: Int = 1,
    startMonth: Date? = null,
    endMonth: Date? = null,
    showOutsideDays: Boolean = false,
    showWeekNumber: Boolean = false,
    weekStartsOn: Int? = null,
    disabled: (Date) -> Boolean = { false },
    today: Date = remember { Date() },
    locale: Locale = Locale.getDefault(),
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    dayButton: CalendarDayButtonSlot? = null,
) {
    val keys = selected.map(::dayKey).toSet()
    CalendarGrid(
        modifier = modifier,
        initialMonth = defaultMonth ?: selected.firstOrNull() ?: today,
        numberOfMonths = numberOfMonths,
        startMonth = startMonth,
        endMonth = endMonth,
        showOutsideDays = showOutsideDays,
        showWeekNumber = showWeekNumber,
        weekStartsOn = weekStartsOn,
        disabled = disabled,
        today = today,
        locale = locale,
        buttonVariant = buttonVariant,
        size = size,
        captionLayout = captionLayout,
        dayButton = dayButton,
        selection = { key -> if (key in keys) DaySelection.Single else DaySelection.None },
        onDayClick = { date ->
            val key = dayKey(date)
            onSelect(if (key in keys) selected.filter { dayKey(it) != key } else selected + date)
        },
    )
}

@Composable
fun CalendarDayButton(
    date: Date,
    state: CalendarDayState,
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    size: CalendarSize = CalendarSize.Default,
    locale: Locale = Locale.getDefault(),
) {
    val colors = EsuissTheme.colors
    val interaction = remember { MutableInteractionSource() }
    val pressed by interaction.collectIsPressedAsState()
    val range = state.rangeStart || state.rangeEnd
    val single = state.selected && !range && !state.rangeMiddle
    val background = when {
        range -> if (pressed) colors.accentPressed else colors.accent
        single && state.today -> if (pressed) colors.accentPressed else colors.accent
        single -> if (pressed) colors.accentSurfacePressed else colors.accentSurface
        pressed && !state.disabled -> colors.itemPressed
        else -> Color.Transparent
    }
    val foreground = when {
        range -> colors.onAccent
        single && state.today -> colors.onAccent
        state.disabled -> colors.labelQuaternary
        state.rangeMiddle -> colors.label
        single -> colors.link
        state.outside -> colors.labelSecondary
        state.today -> colors.link
        else -> colors.label
    }
    val bold = state.today || single
    val style = dayTextStyle(size).copy(
        color = foreground,
        fontWeight = if (bold) FontWeight.SemiBold else FontWeight.Normal,
        fontFeatureSettings = "tnum",
    )
    val description = remember(date, locale, state.today) {
        val full = android.icu.text.DateFormat.getDateInstance(android.icu.text.DateFormat.FULL, locale).format(date)
        if (state.today) "${todayLabel(locale)}, $full" else full
    }
    val number = remember(date) { JavaCalendar.getInstance().apply { time = date }.get(JavaCalendar.DAY_OF_MONTH) }
    Box(
        modifier = modifier
            .fillMaxSize()
            .clip(CircleShape)
            .background(background, CircleShape)
            .clickable(
                interactionSource = interaction,
                indication = null,
                enabled = !state.disabled,
                role = Role.Button,
                onClick = onClick,
            )
            .semantics {
                contentDescription = description
                selected = state.selected || state.rangeStart || state.rangeEnd || state.rangeMiddle
            },
        contentAlignment = Alignment.Center,
    ) {
        BasicText(number.toString(), style = style, maxLines = 1)
    }
}

private enum class DaySelection { None, Single, RangeStart, RangeMiddle, RangeEnd, RangeBoth }

private fun dayTextStyle(size: CalendarSize): TextStyle = when (size) {
    CalendarSize.Sm -> Typography.xs3
    CalendarSize.Default -> Typography.sm
    CalendarSize.Lg -> Typography.lg
}

private fun captionStyle(size: CalendarSize): TextStyle = when (size) {
    CalendarSize.Sm -> Typography.xs
    CalendarSize.Default -> Typography.sm
    CalendarSize.Lg -> Typography.base
}

private fun todayLabel(locale: Locale): String =
    android.icu.text.RelativeDateTimeFormatter.getInstance(locale).format(
        android.icu.text.RelativeDateTimeFormatter.Direction.THIS,
        android.icu.text.RelativeDateTimeFormatter.AbsoluteUnit.DAY,
    ).replaceFirstChar { it.titlecase(locale) }

private fun dayKey(date: Date): Int {
    val calendar = JavaCalendar.getInstance().apply { time = date }
    return calendar.get(JavaCalendar.YEAR) * 10000 + calendar.get(JavaCalendar.MONTH) * 100 + calendar.get(JavaCalendar.DAY_OF_MONTH)
}

private fun monthIndex(date: Date): Int {
    val calendar = JavaCalendar.getInstance().apply { time = date }
    return calendar.get(JavaCalendar.YEAR) * 12 + calendar.get(JavaCalendar.MONTH)
}

private fun dateOf(year: Int, month: Int, day: Int): Date =
    JavaCalendar.getInstance().apply {
        clear()
        set(year, month, day)
    }.time

private fun addToRange(date: Date, range: DateRange?): DateRange? {
    val key = dayKey(date)
    val from = range?.from
    val to = range?.to
    return when {
        from == null -> DateRange(date, null)
        to == null -> when {
            key == dayKey(from) -> DateRange(from, from)
            key < dayKey(from) -> DateRange(date, from)
            else -> DateRange(from, date)
        }
        key == dayKey(from) && key == dayKey(to) -> null
        key == dayKey(from) || key == dayKey(to) -> DateRange(date, null)
        key < dayKey(from) -> DateRange(date, to)
        else -> DateRange(from, date)
    }
}

@Composable
private fun CalendarGrid(
    modifier: Modifier,
    initialMonth: Date,
    numberOfMonths: Int,
    startMonth: Date?,
    endMonth: Date?,
    showOutsideDays: Boolean,
    showWeekNumber: Boolean,
    weekStartsOn: Int?,
    disabled: (Date) -> Boolean,
    today: Date,
    locale: Locale,
    buttonVariant: ButtonVariant,
    size: CalendarSize,
    captionLayout: CalendarCaptionLayout,
    dayButton: CalendarDayButtonSlot?,
    selection: (Int) -> DaySelection,
    onDayClick: (Date) -> Unit,
) {
    val colors = EsuissTheme.colors
    val first = startMonth?.let(::monthIndex)
    val last = endMonth?.let(::monthIndex)?.minus(numberOfMonths - 1)
    var month by remember { mutableIntStateOf(monthIndex(initialMonth)) }
    val canPrevious = first == null || month > first
    val canNext = last == null || month < last
    val currentMonth by rememberUpdatedState(month)
    val currentCanPrevious by rememberUpdatedState(canPrevious)
    val currentCanNext by rememberUpdatedState(canNext)
    val rtl = LocalLayoutDirection.current == LayoutDirection.Rtl
    val weekStart = weekStartsOn ?: (JavaCalendar.getInstance(locale).firstDayOfWeek - 1)
    val todayKey = dayKey(today)
    var direction by remember { mutableIntStateOf(1) }
    val go: (Int) -> Unit = { step ->
        direction = step
        month = currentMonth + step
    }

    Column(
        modifier = modifier
            .width(IntrinsicSize.Max)
            .background(colors.surface)
            .padding(size.padding)
            .pointerInput(rtl) {
                var total = 0f
                detectHorizontalDragGestures(
                    onDragStart = { total = 0f },
                    onDragEnd = {
                        val threshold = 48.dp.toPx()
                        val forward = if (rtl) total > threshold else total < -threshold
                        val back = if (rtl) total < -threshold else total > threshold
                        if (forward && currentCanNext) go(1)
                        if (back && currentCanPrevious) go(-1)
                    },
                ) { change, amount ->
                    change.consume()
                    total += amount
                }
            },
    ) {
        AnimatedContent(
            targetState = month,
            transitionSpec = {
                val sign = if (direction >= 0) 1 else -1
                (slideInHorizontally(tween(250)) { it / 3 * sign } + fadeIn(tween(250))) togetherWith
                    (slideOutHorizontally(tween(250)) { -it / 3 * sign } + fadeOut(tween(150)))
            },
            label = "calendar-month",
        ) { shown ->
            Column(verticalArrangement = Arrangement.spacedBy(16.dp)) {
                repeat(numberOfMonths) { offset ->
                    CalendarMonth(
                        monthIndex = shown + offset,
                        showNav = offset == 0,
                        canPrevious = canPrevious,
                        canNext = canNext,
                        onPrevious = { go(-1) },
                        onNext = { go(1) },
                        onMonthSelect = { target -> go(target - offset - currentMonth) },
                        captionLayout = captionLayout,
                        firstMonth = first,
                        lastMonth = endMonth?.let(::monthIndex),
                        showOutsideDays = showOutsideDays,
                        showWeekNumber = showWeekNumber,
                        weekStart = weekStart,
                        disabled = disabled,
                        todayKey = todayKey,
                        locale = locale,
                        buttonVariant = buttonVariant,
                        size = size,
                        dayButton = dayButton,
                        selection = selection,
                        onDayClick = onDayClick,
                    )
                }
            }
        }
    }
}

@Composable
private fun CalendarMonth(
    monthIndex: Int,
    showNav: Boolean,
    canPrevious: Boolean,
    canNext: Boolean,
    onPrevious: () -> Unit,
    onNext: () -> Unit,
    onMonthSelect: (Int) -> Unit,
    captionLayout: CalendarCaptionLayout,
    firstMonth: Int?,
    lastMonth: Int?,
    showOutsideDays: Boolean,
    showWeekNumber: Boolean,
    weekStart: Int,
    disabled: (Date) -> Boolean,
    todayKey: Int,
    locale: Locale,
    buttonVariant: ButtonVariant,
    size: CalendarSize,
    dayButton: CalendarDayButtonSlot?,
    selection: (Int) -> DaySelection,
    onDayClick: (Date) -> Unit,
) {
    val colors = EsuissTheme.colors
    val year = Math.floorDiv(monthIndex, 12)
    val month = Math.floorMod(monthIndex, 12)
    val firstDay = dateOf(year, month, 1)
    val caption = remember(monthIndex, locale) {
        android.icu.text.DateFormat.getInstanceForSkeleton("yMMMM", locale).format(firstDay)
    }
    val calendar = JavaCalendar.getInstance().apply { time = firstDay }
    val daysInMonth = calendar.getActualMaximum(JavaCalendar.DAY_OF_MONTH)
    val leading = Math.floorMod(calendar.get(JavaCalendar.DAY_OF_WEEK) - 1 - weekStart, 7)
    val rows = (leading + daysInMonth + 6) / 7
    val weekdayFormat = remember(locale) { android.icu.text.SimpleDateFormat("EEEEEE", locale) }
    val weekdayFull = remember(locale) { android.icu.text.SimpleDateFormat("EEEE", locale) }
    val weekdayStyle = when (size) {
        CalendarSize.Lg -> Typography.xs
        else -> Typography.xs3
    }.copy(color = colors.labelSecondary, fontWeight = FontWeight.SemiBold)
    val cell = size.cell

    Column(verticalArrangement = Arrangement.spacedBy(16.dp)) {
        Box(modifier = Modifier.fillMaxWidth().height(cell)) {
            CalendarCaption(
                caption = caption,
                monthIndex = monthIndex,
                captionLayout = captionLayout,
                firstMonth = firstMonth,
                lastMonth = lastMonth,
                locale = locale,
                size = size,
                onMonthSelect = onMonthSelect,
                modifier = Modifier
                    .align(Alignment.CenterStart)
                    .padding(start = if (captionLayout == CalendarCaptionLayout.Label) 6.dp else 0.dp, end = cell * 2),
            )
            if (showNav) {
                Row(
                    modifier = Modifier.align(Alignment.CenterEnd),
                    horizontalArrangement = Arrangement.spacedBy(2.dp),
                ) {
                    CalendarNavButton(PhosphorIcons.Regular.CaretLeft, "Go to the Previous Month", canPrevious, buttonVariant, cell, onPrevious)
                    CalendarNavButton(PhosphorIcons.Regular.CaretRight, "Go to the Next Month", canNext, buttonVariant, cell, onNext)
                }
            }
        }
        Column {
            Row(modifier = Modifier.fillMaxWidth()) {
                if (showWeekNumber) Box(Modifier.width(cell))
                repeat(7) { column ->
                    val weekday = dateOf(2000, 0, 2 + Math.floorMod(weekStart + column, 7))
                    val short = weekdayFormat.format(weekday)
                    BasicText(
                        if (size == CalendarSize.Sm) short else short.uppercase(locale),
                        modifier = Modifier
                            .weight(1f)
                            .widthIn(min = cell)
                            .clearAndSetSemantics { contentDescription = weekdayFull.format(weekday) },
                        style = weekdayStyle.copy(textAlign = TextAlign.Center),
                        maxLines = 1,
                    )
                }
            }
            repeat(rows) { row ->
                Row(modifier = Modifier.fillMaxWidth().padding(top = 8.dp)) {
                    if (showWeekNumber) {
                        val rowStart = dateOf(year, month, 1 - leading + row * 7)
                        val week = JavaCalendar.getInstance(locale).apply {
                            firstDayOfWeek = weekStart + 1
                            time = rowStart
                        }.get(JavaCalendar.WEEK_OF_YEAR)
                        Box(Modifier.size(cell), contentAlignment = Alignment.Center) {
                            BasicText(week.toString(), style = Typography.xs.copy(color = colors.labelSecondary))
                        }
                    }
                    repeat(7) { column ->
                        val dayNumber = row * 7 + column - leading + 1
                        val date = dateOf(year, month, dayNumber)
                        val outside = dayNumber < 1 || dayNumber > daysInMonth
                        DayCell(
                            date = date,
                            column = column,
                            visible = !outside || showOutsideDays,
                            outside = outside,
                            disabled = disabled(date),
                            todayKey = todayKey,
                            cell = cell,
                            size = size,
                            locale = locale,
                            dayButton = dayButton,
                            selection = if (outside) DaySelection.None else selection(dayKey(date)),
                            onClick = { onDayClick(date) },
                        )
                    }
                }
            }
        }
    }
}

@Composable
private fun CalendarCaption(
    caption: String,
    monthIndex: Int,
    captionLayout: CalendarCaptionLayout,
    firstMonth: Int?,
    lastMonth: Int?,
    locale: Locale,
    size: CalendarSize,
    onMonthSelect: (Int) -> Unit,
    modifier: Modifier,
) {
    val colors = EsuissTheme.colors
    val style = captionStyle(size).copy(color = colors.label, fontWeight = FontWeight.SemiBold)
    val semantics = Modifier.semantics {
        heading()
        liveRegion = LiveRegionMode.Polite
    }
    if (captionLayout == CalendarCaptionLayout.Label) {
        BasicText(caption, modifier = modifier.then(semantics), style = style, maxLines = 1, softWrap = false)
        return
    }
    val year = Math.floorDiv(monthIndex, 12)
    val month = Math.floorMod(monthIndex, 12)
    val firstYear = firstMonth?.let { Math.floorDiv(it, 12) } ?: year
    val lastYear = lastMonth?.let { Math.floorDiv(it, 12) } ?: year
    val shortMonth = remember(locale) { android.icu.text.SimpleDateFormat("LLL", locale) }
    val longMonth = remember(locale) { android.icu.text.SimpleDateFormat("LLLL", locale) }
    val outOfRange = { target: Int -> (firstMonth != null && target < firstMonth) || (lastMonth != null && target > lastMonth) }
    Row(
        modifier = modifier.then(semantics),
        horizontalArrangement = Arrangement.spacedBy(6.dp),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        if (captionLayout == CalendarCaptionLayout.DropdownYears) {
            BasicText(longMonth.format(dateOf(year, month, 1)), style = style, maxLines = 1, softWrap = false)
        } else {
            CalendarDropdown(
                label = "Choose the Month",
                text = shortMonth.format(dateOf(year, month, 1)),
                value = month.toString(),
                options = List(12) { index ->
                    Triple(index.toString(), shortMonth.format(dateOf(year, index, 1)), !outOfRange(year * 12 + index))
                },
                style = style,
                onChange = { onMonthSelect(year * 12 + it.toInt()) },
            )
        }
        if (captionLayout == CalendarCaptionLayout.DropdownMonths) {
            BasicText(year.toString(), style = style, maxLines = 1, softWrap = false)
        } else {
            CalendarDropdown(
                label = "Choose the Year",
                text = year.toString(),
                value = year.toString(),
                options = (firstYear..maxOf(firstYear, lastYear)).map { Triple(it.toString(), it.toString(), true) },
                style = style,
                onChange = { onMonthSelect(it.toInt() * 12 + month) },
            )
        }
    }
}

@Composable
private fun CalendarDropdown(
    label: String,
    text: String,
    value: String,
    options: List<Triple<String, String, Boolean>>,
    style: TextStyle,
    onChange: (String) -> Unit,
) {
    val colors = EsuissTheme.colors
    var expanded by remember { mutableStateOf(false) }
    val interaction = remember { MutableInteractionSource() }
    val pressed by interaction.collectIsPressedAsState()
    DropdownMenu(
        expanded = expanded,
        onExpandedChange = { expanded = it },
        trigger = {
            Row(
                modifier = Modifier
                    .clip(CircleShape)
                    .background(if (pressed) colors.itemPressed else Color.Transparent, CircleShape)
                    .clickable(
                        interactionSource = interaction,
                        indication = null,
                        role = Role.DropdownList,
                        onClick = { expanded = !expanded },
                    )
                    .semantics { contentDescription = label }
                    .padding(horizontal = 6.dp, vertical = 2.dp),
                horizontalArrangement = Arrangement.spacedBy(4.dp),
                verticalAlignment = Alignment.CenterVertically,
            ) {
                BasicText(text, style = style, maxLines = 1, softWrap = false)
                Icon(PhosphorIcons.Regular.CaretDown, contentDescription = null, size = 14.dp, tint = colors.labelSecondary)
            }
        },
    ) {
        DropdownMenuRadioGroup(
            value = value,
            onValueChange = {
                expanded = false
                if (it != value) onChange(it)
            },
        ) {
            options.forEach { (option, optionLabel, enabled) ->
                DropdownMenuRadioItem(option, optionLabel, enabled = enabled)
            }
        }
    }
}

@Composable
private fun RowScope.DayCell(
    date: Date,
    column: Int,
    visible: Boolean,
    outside: Boolean,
    disabled: Boolean,
    todayKey: Int,
    cell: Dp,
    size: CalendarSize,
    locale: Locale,
    dayButton: CalendarDayButtonSlot?,
    selection: DaySelection,
    onClick: () -> Unit,
) {
    val colors = EsuissTheme.colors
    Box(
        modifier = Modifier
            .weight(1f)
            .widthIn(min = cell)
            .aspectRatio(1f),
    ) {
        if (!visible) return@Box
        val inRange = selection == DaySelection.RangeStart || selection == DaySelection.RangeMiddle || selection == DaySelection.RangeEnd
        if (inRange) {
            val roundStart = selection == DaySelection.RangeStart || column == 0
            val roundEnd = selection == DaySelection.RangeEnd || column == 6
            val radius = cell
            Box(
                modifier = Modifier
                    .fillMaxSize()
                    .background(
                        colors.surfaceSecondary,
                        RoundedCornerShape(
                            topStart = if (roundStart) radius else 0.dp,
                            bottomStart = if (roundStart) radius else 0.dp,
                            topEnd = if (roundEnd) radius else 0.dp,
                            bottomEnd = if (roundEnd) radius else 0.dp,
                        ),
                    ),
            )
        }
        val state = CalendarDayState(
            selected = selection != DaySelection.None,
            today = dayKey(date) == todayKey,
            rangeStart = selection == DaySelection.RangeStart || selection == DaySelection.RangeBoth,
            rangeMiddle = selection == DaySelection.RangeMiddle,
            rangeEnd = selection == DaySelection.RangeEnd || selection == DaySelection.RangeBoth,
            outside = outside,
            disabled = disabled,
        )
        if (dayButton != null) {
            dayButton(date, state, onClick)
        } else {
            CalendarDayButton(date, state, onClick, size = size, locale = locale)
        }
    }
}

@Composable
private fun CalendarNavButton(
    icon: ImageVector,
    label: String,
    enabled: Boolean,
    variant: ButtonVariant,
    cell: Dp,
    onClick: () -> Unit,
) {
    val colors = EsuissTheme.colors
    val interaction = remember { MutableInteractionSource() }
    val pressed by interaction.collectIsPressedAsState()
    val background = when (variant) {
        ButtonVariant.Secondary -> if (pressed && enabled) colors.controlPressed else colors.control
        ButtonVariant.Tinted -> if (pressed && enabled) colors.accentSurfacePressed else colors.accentSurface
        ButtonVariant.Default -> if (pressed && enabled) colors.accentPressed else colors.accent
        else -> if (pressed && enabled) colors.itemPressed else Color.Transparent
    }
    val foreground = when {
        !enabled -> colors.labelQuaternary
        variant == ButtonVariant.Default -> colors.onAccent
        variant == ButtonVariant.Ghost || variant == ButtonVariant.Secondary || variant == ButtonVariant.Outline -> colors.label
        else -> colors.link
    }
    val rtl = LocalLayoutDirection.current == LayoutDirection.Rtl
    Box(
        modifier = Modifier
            .size(cell)
            .clip(CircleShape)
            .background(background, CircleShape)
            .clickable(
                interactionSource = interaction,
                indication = null,
                enabled = enabled,
                role = Role.Button,
                onClick = onClick,
            )
            .semantics { contentDescription = label },
        contentAlignment = Alignment.Center,
    ) {
        Icon(
            icon,
            contentDescription = null,
            size = 16.dp,
            tint = foreground,
            modifier = if (rtl) Modifier.graphicsLayer { scaleX = -1f } else Modifier,
        )
    }
}
```

```kt title="kotlin/components/Button.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.clickable
import androidx.compose.foundation.interaction.MutableInteractionSource
import androidx.compose.foundation.interaction.collectIsPressedAsState
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.getValue
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.semantics.Role
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.style.TextDecoration
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.Colors
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

enum class ButtonVariant { Default, Outline, Secondary, Tinted, Ghost, Plain, Destructive, Link }

enum class ButtonSize(
    val height: Dp,
    val horizontalPadding: Dp,
    val spacing: Dp,
    val iconSize: Dp,
    val blockRadius: Dp,
    val isIcon: Boolean,
) {
    Default(36.dp, 16.dp, 6.dp, 16.dp, Radius.md, false),
    Xs(24.dp, 11.dp, 4.dp, 12.dp, Radius.sm, false),
    Sm(32.dp, 12.dp, 4.dp, 16.dp, Radius.md, false),
    Lg(44.dp, 22.dp, 6.dp, 16.dp, Radius.lg, false),
    Xl(56.dp, 31.dp, 8.dp, 16.dp, Radius.xl, false),
    Icon(36.dp, 0.dp, 6.dp, 16.dp, Radius.md, true),
    IconXs(24.dp, 0.dp, 4.dp, 12.dp, Radius.sm, true),
    IconSm(32.dp, 0.dp, 4.dp, 16.dp, Radius.md, true),
    IconLg(44.dp, 0.dp, 6.dp, 16.dp, Radius.lg, true),
    IconXl(56.dp, 0.dp, 8.dp, 16.dp, Radius.xl, true),
    ;

    val textStyle: TextStyle
        get() = when (this) {
            Xs, IconXs -> Typography.xs2
            Lg, Xl -> Typography.base
            else -> Typography.sm
        }
}

@Composable
fun Button(
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    variant: ButtonVariant = ButtonVariant.Default,
    size: ButtonSize = ButtonSize.Default,
    block: Boolean = false,
    enabled: Boolean = true,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val interaction = remember { MutableInteractionSource() }
    val pressed by interaction.collectIsPressedAsState()
    val foreground = buttonForeground(variant, colors, enabled)
    val group = LocalButtonGroup.current?.takeIf { variant != ButtonVariant.Ghost && variant != ButtonVariant.Plain }
    RegisterButtonGroupOutline(group, variant == ButtonVariant.Outline)
    val shape = group.itemShape(if (block) RoundedCornerShape(size.blockRadius) else CircleShape)
    val sizing = when {
        block -> Modifier.fillMaxWidth().height(size.height)
        size.isIcon -> Modifier.size(size.height)
        else -> Modifier.height(size.height)
    }

    Row(
        modifier = modifier
            .then(sizing)
            .clip(shape)
            .background(buttonBackground(variant, colors, pressed && enabled, enabled), shape)
            .then(
                when {
                    variant != ButtonVariant.Outline -> Modifier
                    group != null -> Modifier.buttonGroupEdge(group, colors.separator)
                    else -> Modifier.border(1.dp, colors.separator, shape)
                },
            )
            .clickable(
                interactionSource = interaction,
                indication = null,
                enabled = enabled,
                role = Role.Button,
                onClick = onClick,
            )
            .padding(horizontal = size.horizontalPadding),
        horizontalArrangement = Arrangement.spacedBy(size.spacing, Alignment.CenterHorizontally),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        CompositionLocalProvider(
            LocalButtonGroup provides null,
            LocalContentStyle provides size.textStyle.copy(
                color = foreground,
                textDecoration = if (variant == ButtonVariant.Link && pressed && enabled) {
                    TextDecoration.Underline
                } else {
                    null
                },
            ),
            LocalContentColor provides foreground,
            LocalIconSize provides size.iconSize,
        ) {
            content()
        }
    }
}

@Composable
fun Button(
    text: String,
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    variant: ButtonVariant = ButtonVariant.Default,
    size: ButtonSize = ButtonSize.Default,
    block: Boolean = false,
    enabled: Boolean = true,
) {
    Button(onClick, modifier, variant, size, block, enabled) {
        BasicText(text, style = LocalContentStyle.current, maxLines = 1)
    }
}

private fun buttonForeground(variant: ButtonVariant, colors: Colors, enabled: Boolean): Color =
    when (variant) {
        ButtonVariant.Default -> colors.onAccent
        ButtonVariant.Outline, ButtonVariant.Secondary, ButtonVariant.Ghost ->
            if (enabled) colors.label else colors.labelQuaternary
        ButtonVariant.Tinted, ButtonVariant.Plain ->
            if (enabled) colors.link else colors.link.copy(alpha = 0.4f)
        ButtonVariant.Destructive ->
            if (enabled) colors.danger else colors.danger.copy(alpha = 0.4f)
        ButtonVariant.Link -> if (enabled) colors.link else colors.labelQuaternary
    }

private fun buttonBackground(variant: ButtonVariant, colors: Colors, pressed: Boolean, enabled: Boolean): Color =
    when (variant) {
        ButtonVariant.Default -> when {
            !enabled -> colors.accentDisabled
            pressed -> colors.accentPressed
            else -> colors.accent
        }
        ButtonVariant.Outline -> when {
            pressed -> colors.itemPressed
            colors.isDark -> Color.Transparent
            else -> colors.surface
        }
        ButtonVariant.Secondary -> when {
            !enabled -> colors.controlDisabled
            pressed -> colors.controlPressed
            else -> colors.control
        }
        ButtonVariant.Tinted -> if (pressed) colors.accentSurfacePressed else colors.accentSurface
        ButtonVariant.Ghost -> if (pressed) colors.itemPressed else Color.Transparent
        ButtonVariant.Plain -> if (pressed) colors.itemPressed else Color.Transparent
        ButtonVariant.Destructive -> if (pressed) colors.dangerSurfacePressed else colors.dangerSurface
        ButtonVariant.Link -> Color.Transparent
    }
```

```kt title="kotlin/components/ButtonGroup.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.background
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.CornerSize
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.DisposableEffect
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.Stable
import androidx.compose.runtime.compositionLocalOf
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableIntStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.draw.drawBehind
import androidx.compose.ui.draw.drawWithContent
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.RectangleShape
import androidx.compose.ui.graphics.Shape
import androidx.compose.ui.graphics.drawOutline
import androidx.compose.ui.graphics.drawscope.Stroke
import androidx.compose.ui.graphics.drawscope.translate
import androidx.compose.ui.graphics.takeOrElse
import androidx.compose.ui.layout.Layout
import androidx.compose.ui.layout.Placeable
import androidx.compose.ui.layout.layout
import androidx.compose.ui.layout.layoutId
import androidx.compose.ui.layout.onPlaced
import androidx.compose.ui.platform.LocalLayoutDirection
import androidx.compose.ui.semantics.isTraversalGroup
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.Constraints
import androidx.compose.ui.unit.LayoutDirection
import androidx.compose.ui.unit.constrainHeight
import androidx.compose.ui.unit.constrainWidth
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

enum class ButtonGroupOrientation { Horizontal, Vertical }

@Stable
internal class ButtonGroupState(val orientation: ButtonGroupOrientation) {
    var nested by mutableIntStateOf(0)
    var outlined by mutableIntStateOf(0)
}

internal val LocalButtonGroup = compositionLocalOf<ButtonGroupState?> { null }

internal object ButtonGroupFill

private object ButtonGroupDivider

internal fun ButtonGroupState?.itemShape(default: Shape): Shape = if (this == null) default else RectangleShape

@Immutable
internal class ButtonGroupItem(val shape: Shape, val modifier: Modifier)

@Composable
internal fun rememberButtonGroupItem(group: ButtonGroupState?, default: Shape): ButtonGroupItem {
    var edges by remember { mutableIntStateOf(0) }
    val horizontal = group?.orientation != ButtonGroupOrientation.Vertical
    val rtl = LocalLayoutDirection.current == LayoutDirection.Rtl
    val shape = remember(edges, horizontal) {
        val round = if (horizontal) CornerSize(50) else CornerSize(Radius.xl2)
        val square = CornerSize(0)
        val start = if (edges and 1 != 0) round else square
        val end = if (edges and 2 != 0) round else square
        if (horizontal) {
            RoundedCornerShape(topStart = start, topEnd = end, bottomEnd = end, bottomStart = start)
        } else {
            RoundedCornerShape(topStart = start, topEnd = start, bottomEnd = end, bottomStart = end)
        }
    }
    if (group == null || group.nested > 0) return ButtonGroupItem(default, Modifier)
    return ButtonGroupItem(
        shape = shape,
        modifier = Modifier.onPlaced { coordinates ->
            val parent = coordinates.parentLayoutCoordinates ?: return@onPlaced
            val bounds = parent.localBoundingBoxOf(coordinates, clipBounds = false)
            val first: Boolean
            val last: Boolean
            if (horizontal) {
                val left = bounds.left <= 0.5f
                val right = bounds.right >= parent.size.width - 0.5f
                first = if (rtl) right else left
                last = if (rtl) left else right
            } else {
                first = bounds.top <= 0.5f
                last = bounds.bottom >= parent.size.height - 0.5f
            }
            edges = (if (first) 1 else 0) or (if (last) 2 else 0)
        },
    )
}

internal fun Modifier.buttonGroupEdge(group: ButtonGroupState?, color: Color): Modifier {
    if (group == null) return this
    return drawBehind {
        val stroke = 1.dp.toPx()
        if (group.orientation == ButtonGroupOrientation.Horizontal) {
            val x = if (layoutDirection == LayoutDirection.Rtl) 0f else size.width - stroke
            drawRect(color, Offset(x, 0f), Size(stroke, size.height))
        } else {
            drawRect(color, Offset(0f, size.height - stroke), Size(size.width, stroke))
        }
    }
}

@Composable
internal fun RegisterButtonGroupOutline(group: ButtonGroupState?, outlined: Boolean) {
    DisposableEffect(group, outlined) {
        if (group != null && outlined) group.outlined += 1
        onDispose {
            if (group != null && outlined) group.outlined -= 1
        }
    }
}

@Composable
fun ButtonGroup(
    modifier: Modifier = Modifier,
    orientation: ButtonGroupOrientation = ButtonGroupOrientation.Horizontal,
    content: @Composable () -> Unit,
) {
    val parent = LocalButtonGroup.current
    DisposableEffect(parent) {
        parent?.let { it.nested += 1 }
        onDispose { parent?.let { it.nested -= 1 } }
    }
    val state = remember(orientation) { ButtonGroupState(orientation) }
    val colors = EsuissTheme.colors
    val joined = state.nested == 0
    val horizontal = orientation == ButtonGroupOrientation.Horizontal
    val shape = if (horizontal) CircleShape else RoundedCornerShape(Radius.xl2)
    val outline = colors.separator
    Layout(
        content = {
            CompositionLocalProvider(LocalButtonGroup provides state, content = content)
        },
        modifier = modifier
            .semantics { isTraversalGroup = true }
            .then(
                if (joined) {
                    Modifier
                        .clip(shape)
                        .drawWithContent {
                            drawContent()
                            if (state.outlined > 0) {
                                val stroke = 1.dp.toPx()
                                val inset = stroke / 2
                                val path = shape.createOutline(
                                    Size(size.width - stroke, size.height - stroke),
                                    layoutDirection,
                                    this,
                                )
                                translate(inset, inset) {
                                    drawOutline(path, outline, style = Stroke(stroke))
                                }
                            }
                        }
                } else {
                    Modifier
                },
            ),
    ) { measurables, constraints ->
        val gap = if (joined) 0 else 8.dp.roundToPx()
        val items = measurables.filter { it.layoutId != ButtonGroupDivider }
        if (horizontal) {
            val height = if (constraints.hasFixedHeight) {
                constraints.maxHeight
            } else {
                constraints.constrainHeight(items.maxOfOrNull { it.maxIntrinsicHeight(Constraints.Infinity) } ?: 0)
            }
            val fills = measurables.count { it.layoutId == ButtonGroupFill }
            val placeables = arrayOfNulls<Placeable>(measurables.size)
            var used = 0
            measurables.forEachIndexed { index, measurable ->
                if (measurable.layoutId != ButtonGroupFill) {
                    val placeable = measurable.measure(Constraints(minHeight = height, maxHeight = height))
                    placeables[index] = placeable
                    used += placeable.width
                }
            }
            val gaps = gap * (items.size - 1).coerceAtLeast(0)
            val remaining = if (constraints.hasBoundedWidth) {
                (constraints.maxWidth - used - gaps).coerceAtLeast(0)
            } else {
                0
            }
            measurables.forEachIndexed { index, measurable ->
                if (measurable.layoutId == ButtonGroupFill) {
                    val placeable = if (constraints.hasBoundedWidth) {
                        val width = remaining / fills
                        measurable.measure(Constraints(width, width, height, height))
                    } else {
                        measurable.measure(Constraints(minHeight = height, maxHeight = height))
                    }
                    placeables[index] = placeable
                    used += placeable.width
                }
            }
            val width = constraints.constrainWidth(used + gaps)
            layout(width, height) {
                var x = 0
                measurables.forEachIndexed { index, measurable ->
                    val placeable = placeables[index] ?: return@forEachIndexed
                    val divider = measurable.layoutId == ButtonGroupDivider
                    placeable.placeRelative(x, 0, zIndex = if (divider) 1f else 0f)
                    if (!divider) x += placeable.width + gap
                }
            }
        } else {
            val width = if (constraints.hasFixedWidth) {
                constraints.maxWidth
            } else {
                constraints.constrainWidth(items.maxOfOrNull { it.maxIntrinsicWidth(Constraints.Infinity) } ?: 0)
            }
            val placeables = measurables.map { it.measure(Constraints(minWidth = width, maxWidth = width)) }
            val gaps = gap * (items.size - 1).coerceAtLeast(0)
            val height = constraints.constrainHeight(
                placeables.filterIndexed { index, _ -> measurables[index].layoutId != ButtonGroupDivider }.sumOf { it.height } + gaps,
            )
            layout(width, height) {
                var y = 0
                measurables.forEachIndexed { index, measurable ->
                    val divider = measurable.layoutId == ButtonGroupDivider
                    placeables[index].placeRelative(0, y, zIndex = if (divider) 1f else 0f)
                    if (!divider) y += placeables[index].height + gap
                }
            }
        }
    }
}

@Composable
fun ButtonGroupText(
    modifier: Modifier = Modifier,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val shape = LocalButtonGroup.current.itemShape(CircleShape)
    Row(
        modifier = modifier
            .clip(shape)
            .background(colors.control, shape)
            .padding(horizontal = 10.dp),
        horizontalArrangement = Arrangement.spacedBy(8.dp),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        CompositionLocalProvider(
            LocalButtonGroup provides null,
            LocalContentStyle provides Typography.sm.copy(color = colors.label),
            LocalContentColor provides colors.label,
            LocalIconSize provides 16.dp,
        ) {
            content()
        }
    }
}

@Composable
fun ButtonGroupSeparator(
    modifier: Modifier = Modifier,
    orientation: Orientation = Orientation.Vertical,
    color: Color = Color.Unspecified,
) {
    val line = color.takeOrElse { EsuissTheme.colors.label.copy(alpha = 0.2f) }
    Box(
        modifier = modifier
            .layoutId(ButtonGroupDivider)
            .then(
                if (orientation == Orientation.Vertical) {
                    Modifier.layout { measurable, constraints ->
                        val placeable = measurable.measure(constraints.copy(minWidth = 0, maxWidth = 0))
                        layout(0, placeable.height) { placeable.place(0, 0) }
                    }
                } else {
                    Modifier.layout { measurable, constraints ->
                        val placeable = measurable.measure(constraints.copy(minHeight = 0, maxHeight = 0))
                        layout(placeable.width, 0) { placeable.place(0, 0) }
                    }
                },
            )
            .drawBehind {
                val stroke = 1.dp.toPx()
                val inset = 9.dp.toPx()
                if (orientation == Orientation.Vertical) {
                    val x = if (layoutDirection == LayoutDirection.Rtl) -stroke else 0f
                    drawRect(line, Offset(x, inset), Size(stroke, (size.height - inset * 2).coerceAtLeast(0f)))
                } else {
                    drawRect(line, Offset(inset, 0f), Size((size.width - inset * 2).coerceAtLeast(0f), stroke))
                }
            },
    )
}
```

```kt title="kotlin/components/Checkbox.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.interaction.MutableInteractionSource
import androidx.compose.foundation.interaction.collectIsPressedAsState
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.selection.triStateToggleable
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.semantics.Role
import androidx.compose.ui.semantics.error
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.state.ToggleableState
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.Check
import com.adamglin.phosphoricons.regular.Minus
import com.esuiss.ui.theme.Colors
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.shadow

@Composable
fun Checkbox(
    checked: Boolean,
    onCheckedChange: ((Boolean) -> Unit)?,
    modifier: Modifier = Modifier,
    enabled: Boolean = LocalFieldState.current.enabled,
    invalid: Boolean = LocalFieldState.current.invalid,
    interactionSource: MutableInteractionSource? = null,
) {
    TriStateCheckbox(
        state = ToggleableState(checked),
        onClick = onCheckedChange?.let { { it(!checked) } },
        modifier = modifier,
        enabled = enabled,
        invalid = invalid,
        interactionSource = interactionSource,
    )
}

@Composable
fun TriStateCheckbox(
    state: ToggleableState,
    onClick: (() -> Unit)?,
    modifier: Modifier = Modifier,
    enabled: Boolean = LocalFieldState.current.enabled,
    invalid: Boolean = LocalFieldState.current.invalid,
    interactionSource: MutableInteractionSource? = null,
) {
    val colors = EsuissTheme.colors
    val haptics = rememberHaptics()
    val source = interactionSource ?: remember { MutableInteractionSource() }
    val pressed by source.collectIsPressedAsState()
    val on = state != ToggleableState.Off
    val shape = RoundedCornerShape(4.dp)
    val look = selectionControlLook(colors, on, enabled, invalid, pressed)
    val toggle = if (onClick != null) {
        Modifier
            .triStateToggleable(
                state = state,
                interactionSource = source,
                indication = null,
                enabled = enabled,
                role = Role.Checkbox,
                onClick = {
                    haptics.toggle(state != ToggleableState.On)
                    onClick()
                },
            )
            .formTouchTarget()
    } else {
        Modifier
    }
    Box(
        modifier = modifier
            .then(toggle)
            .then(if (invalid) Modifier.semantics { error("Invalid") } else Modifier)
            .size(16.dp)
            .then(if (look.shadow) Modifier.shadow(FormShadowXs, shape) else Modifier)
            .background(look.background, shape)
            .border(1.dp, look.border, shape),
        contentAlignment = Alignment.Center,
    ) {
        if (on) {
            Icon(
                if (state == ToggleableState.Indeterminate) PhosphorIcons.Regular.Minus else PhosphorIcons.Regular.Check,
                contentDescription = null,
                size = 14.dp,
                tint = colors.onAccent,
            )
        }
    }
}

internal class SelectionControlLook(val background: Color, val border: Color, val shadow: Boolean)

internal fun selectionControlLook(
    colors: Colors,
    on: Boolean,
    enabled: Boolean,
    invalid: Boolean,
    pressed: Boolean,
): SelectionControlLook = when {
    on && !enabled -> SelectionControlLook(colors.accentDisabled, Color.Transparent, false)
    on -> {
        val color = if (pressed) colors.accentPressed else colors.accent
        SelectionControlLook(color, color, false)
    }
    !enabled -> SelectionControlLook(
        colors.controlDisabled,
        if (colors.isDark) Color.Transparent else colors.label.copy(alpha = 0.1f),
        false,
    )
    colors.isDark -> SelectionControlLook(
        colors.labelQuaternary,
        if (invalid) colors.danger else Color.Transparent,
        false,
    )
    else -> SelectionControlLook(
        if (pressed) colors.control else colors.surface,
        if (invalid) colors.danger else colors.label.copy(alpha = 0.25f),
        true,
    )
}
```

```kt title="kotlin/components/Content.kt"
package com.esuiss.ui.components

import androidx.compose.runtime.compositionLocalOf
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.dp

val LocalContentStyle = compositionLocalOf { TextStyle.Default }

val LocalContentColor = compositionLocalOf { Color.Unspecified }

val LocalIconSize = compositionLocalOf { 20.dp }
```

```kt title="kotlin/components/DropdownMenu.kt"
package com.esuiss.ui.components

import androidx.compose.animation.core.animateFloatAsState
import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.interaction.MutableInteractionSource
import androidx.compose.foundation.interaction.collectIsPressedAsState
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.ColumnScope
import androidx.compose.foundation.layout.IntrinsicSize
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.heightIn
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.layout.widthIn
import androidx.compose.foundation.rememberScrollState
import androidx.compose.foundation.selection.selectable
import androidx.compose.foundation.selection.selectableGroup
import androidx.compose.foundation.selection.toggleable
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.BasicText
import androidx.compose.foundation.verticalScroll
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.draw.rotate
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.layout.layout
import androidx.compose.ui.semantics.Role
import androidx.compose.ui.semantics.heading
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.semantics.stateDescription
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.IntOffset
import androidx.compose.ui.unit.constrainWidth
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.CaretRight
import com.adamglin.phosphoricons.regular.Check
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

enum class MenuItemVariant { Default, Destructive }

@Immutable
internal data class MenuContext(val dismiss: () -> Unit)

internal val LocalMenu = staticCompositionLocalOf { MenuContext {} }

@Immutable
private data class MenuRadioContext(val value: String?, val onValueChange: (String) -> Unit)

private val LocalMenuRadio = staticCompositionLocalOf { MenuRadioContext(null) {} }

@Composable
fun DropdownMenu(
    expanded: Boolean,
    onExpandedChange: (Boolean) -> Unit,
    trigger: @Composable () -> Unit,
    modifier: Modifier = Modifier,
    side: PopupSide = PopupSide.Bottom,
    align: PopupAlign = PopupAlign.Start,
    sideOffset: Dp = 4.dp,
    alignOffset: Dp = 0.dp,
    content: @Composable ColumnScope.() -> Unit,
) {
    Box {
        trigger()
        MenuPopup(
            expanded = expanded,
            onDismissRequest = { onExpandedChange(false) },
            modifier = modifier,
            side = side,
            align = align,
            sideOffset = sideOffset,
            alignOffset = alignOffset,
            minWidth = 192.dp,
            content = content,
        )
    }
}

@Composable
internal fun MenuPopup(
    expanded: Boolean,
    onDismissRequest: () -> Unit,
    modifier: Modifier,
    side: PopupSide,
    align: PopupAlign,
    sideOffset: Dp,
    alignOffset: Dp,
    minWidth: Dp,
    point: IntOffset? = null,
    content: @Composable ColumnScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    AnchoredPopup(
        expanded = expanded,
        onDismissRequest = onDismissRequest,
        side = side,
        align = align,
        sideOffset = sideOffset,
        alignOffset = alignOffset,
        point = point,
    ) {
        CompositionLocalProvider(
            LocalMenu provides MenuContext(onDismissRequest),
            LocalContentStyle provides Typography.base.copy(color = colors.label),
            LocalContentColor provides colors.label,
            LocalIconSize provides 16.dp,
        ) {
            Column(
                modifier = modifier
                    .widthIn(min = minWidth)
                    .width(IntrinsicSize.Max)
                    .raisedSurface(colors, RoundedCornerShape(Radius.xl))
                    .verticalScroll(rememberScrollState())
                    .padding(6.dp),
                content = content,
            )
        }
    }
}

@Composable
private fun MenuRow(
    modifier: Modifier,
    enabled: Boolean,
    foreground: Color,
    pressedBackground: Color,
    restingBackground: Color,
    interaction: MutableInteractionSource,
    startPadding: Dp,
    endPadding: Dp,
    indicator: (@Composable () -> Unit)?,
    content: @Composable RowScope.() -> Unit,
) {
    val pressed by interaction.collectIsPressedAsState()
    val shape = RoundedCornerShape(Radius.md)
    Box(
        modifier = Modifier
            .fillMaxWidth()
            .heightIn(min = 44.dp)
            .clip(shape)
            .background(if (pressed && enabled) pressedBackground else restingBackground, shape)
            .then(modifier),
        contentAlignment = Alignment.CenterEnd,
    ) {
        CompositionLocalProvider(
            LocalContentStyle provides Typography.base.copy(color = foreground),
            LocalContentColor provides foreground,
            LocalIconSize provides 16.dp,
        ) {
            Row(
                modifier = Modifier
                    .fillMaxWidth()
                    .heightIn(min = 44.dp)
                    .padding(start = startPadding, end = endPadding, top = 8.dp, bottom = 8.dp),
                horizontalArrangement = Arrangement.spacedBy(10.dp),
                verticalAlignment = Alignment.CenterVertically,
                content = content,
            )
            if (indicator != null) {
                Box(
                    modifier = Modifier.padding(start = 12.dp, end = 8.dp),
                    contentAlignment = Alignment.Center,
                ) {
                    indicator()
                }
            }
        }
    }
}

@Composable
private fun menuForeground(enabled: Boolean, destructive: Boolean = false): Color {
    val colors = EsuissTheme.colors
    return when {
        !enabled -> colors.labelQuaternary
        destructive -> colors.danger
        else -> colors.label
    }
}

@Composable
fun DropdownMenuItem(
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    variant: MenuItemVariant = MenuItemVariant.Default,
    enabled: Boolean = true,
    inset: Boolean = false,
    closeOnClick: Boolean = true,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val menu = LocalMenu.current
    val interaction = remember { MutableInteractionSource() }
    val destructive = variant == MenuItemVariant.Destructive
    MenuRow(
        modifier = modifier.clickable(
            interactionSource = interaction,
            indication = null,
            enabled = enabled,
            role = Role.Button,
            onClick = {
                onClick()
                if (closeOnClick) menu.dismiss()
            },
        ),
        enabled = enabled,
        foreground = menuForeground(enabled, destructive),
        pressedBackground = if (destructive) colors.dangerSurfacePressed else colors.itemPressed,
        restingBackground = Color.Transparent,
        interaction = interaction,
        startPadding = if (inset) 38.dp else 12.dp,
        endPadding = 12.dp,
        indicator = null,
        content = content,
    )
}

@Composable
fun DropdownMenuItem(
    text: String,
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    icon: ImageVector? = null,
    variant: MenuItemVariant = MenuItemVariant.Default,
    enabled: Boolean = true,
    inset: Boolean = false,
    closeOnClick: Boolean = true,
) {
    DropdownMenuItem(onClick, modifier, variant, enabled, inset, closeOnClick) {
        if (icon != null) Icon(icon, contentDescription = null)
        BasicText(text, style = LocalContentStyle.current, maxLines = 1)
    }
}

@Composable
private fun CheckIndicator(visible: Boolean) {
    Box(modifier = Modifier.width(16.dp)) {
        if (visible) Icon(PhosphorIcons.Regular.Check, contentDescription = null, size = 16.dp)
    }
}

@Composable
fun DropdownMenuCheckboxItem(
    checked: Boolean,
    onCheckedChange: (Boolean) -> Unit,
    modifier: Modifier = Modifier,
    enabled: Boolean = true,
    inset: Boolean = false,
    closeOnClick: Boolean = false,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val menu = LocalMenu.current
    val interaction = remember { MutableInteractionSource() }
    MenuRow(
        modifier = modifier.toggleable(
            value = checked,
            interactionSource = interaction,
            indication = null,
            enabled = enabled,
            role = Role.Checkbox,
            onValueChange = {
                onCheckedChange(it)
                if (closeOnClick) menu.dismiss()
            },
        ),
        enabled = enabled,
        foreground = menuForeground(enabled),
        pressedBackground = colors.itemPressed,
        restingBackground = Color.Transparent,
        interaction = interaction,
        startPadding = if (inset) 38.dp else 12.dp,
        endPadding = 32.dp,
        indicator = { CheckIndicator(checked) },
        content = content,
    )
}

@Composable
fun DropdownMenuCheckboxItem(
    text: String,
    checked: Boolean,
    onCheckedChange: (Boolean) -> Unit,
    modifier: Modifier = Modifier,
    enabled: Boolean = true,
    inset: Boolean = false,
) {
    DropdownMenuCheckboxItem(checked, onCheckedChange, modifier, enabled, inset) {
        BasicText(text, style = LocalContentStyle.current, maxLines = 1)
    }
}

@Composable
fun DropdownMenuRadioGroup(
    value: String?,
    onValueChange: (String) -> Unit,
    modifier: Modifier = Modifier,
    content: @Composable ColumnScope.() -> Unit,
) {
    CompositionLocalProvider(LocalMenuRadio provides MenuRadioContext(value, onValueChange)) {
        Column(modifier = modifier.fillMaxWidth().selectableGroup(), content = content)
    }
}

@Composable
fun DropdownMenuRadioItem(
    value: String,
    modifier: Modifier = Modifier,
    enabled: Boolean = true,
    inset: Boolean = false,
    closeOnClick: Boolean = false,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val menu = LocalMenu.current
    val group = LocalMenuRadio.current
    val selected = group.value == value
    val interaction = remember { MutableInteractionSource() }
    MenuRow(
        modifier = modifier.selectable(
            selected = selected,
            interactionSource = interaction,
            indication = null,
            enabled = enabled,
            role = Role.RadioButton,
            onClick = {
                group.onValueChange(value)
                if (closeOnClick) menu.dismiss()
            },
        ),
        enabled = enabled,
        foreground = menuForeground(enabled),
        pressedBackground = colors.itemPressed,
        restingBackground = Color.Transparent,
        interaction = interaction,
        startPadding = if (inset) 38.dp else 12.dp,
        endPadding = 32.dp,
        indicator = { CheckIndicator(selected) },
        content = content,
    )
}

@Composable
fun DropdownMenuRadioItem(
    value: String,
    text: String,
    modifier: Modifier = Modifier,
    enabled: Boolean = true,
    inset: Boolean = false,
) {
    DropdownMenuRadioItem(value, modifier, enabled, inset) {
        BasicText(text, style = LocalContentStyle.current, maxLines = 1)
    }
}

@Composable
fun DropdownMenuLabel(
    text: String,
    modifier: Modifier = Modifier,
    inset: Boolean = false,
) {
    BasicText(
        text,
        modifier = modifier
            .fillMaxWidth()
            .semantics { heading() }
            .padding(start = if (inset) 38.dp else 12.dp, end = 12.dp, top = 10.dp, bottom = 10.dp),
        style = Typography.xs.copy(color = EsuissTheme.colors.labelSecondary, fontWeight = FontWeight.SemiBold),
    )
}

@Composable
fun DropdownMenuSeparator(modifier: Modifier = Modifier) {
    MenuSeparatorLine(modifier, bleed = 6.dp, color = EsuissTheme.colors.separator.copy(alpha = 0.5f))
}

@Composable
internal fun MenuSeparatorLine(modifier: Modifier, bleed: Dp, color: Color) {
    Box(
        modifier = modifier
            .padding(vertical = bleed)
            .layout { measurable, constraints ->
                val extra = bleed.roundToPx()
                val width = if (constraints.hasBoundedWidth) constraints.maxWidth + extra * 2 else constraints.minWidth
                val placeable = measurable.measure(constraints.copy(minWidth = width, maxWidth = width))
                layout(constraints.constrainWidth(placeable.width - extra * 2), placeable.height) {
                    placeable.place(-extra, 0)
                }
            }
            .height(1.dp)
            .background(color),
    )
}

@Composable
fun DropdownMenuGroup(
    modifier: Modifier = Modifier,
    content: @Composable ColumnScope.() -> Unit,
) {
    Column(modifier = modifier.fillMaxWidth(), content = content)
}

@Composable
fun DropdownMenuSub(
    text: String,
    modifier: Modifier = Modifier,
    icon: ImageVector? = null,
    enabled: Boolean = true,
    inset: Boolean = false,
    content: @Composable ColumnScope.() -> Unit,
) {
    DropdownMenuSub(
        trigger = {
            if (icon != null) Icon(icon, contentDescription = null)
            BasicText(text, style = LocalContentStyle.current, maxLines = 1)
        },
        modifier = modifier,
        enabled = enabled,
        inset = inset,
        content = content,
    )
}

@Composable
fun DropdownMenuSub(
    trigger: @Composable RowScope.() -> Unit,
    modifier: Modifier = Modifier,
    enabled: Boolean = true,
    inset: Boolean = false,
    content: @Composable ColumnScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val menu = LocalMenu.current
    var open by remember { mutableStateOf(false) }
    val interaction = remember { MutableInteractionSource() }
    val rotation by animateFloatAsState(if (open) 90f else 0f, label = "caret")
    Box {
        MenuRow(
            modifier = modifier
                .semantics { stateDescription = if (open) "Expanded" else "Collapsed" }
                .clickable(
                    interactionSource = interaction,
                    indication = null,
                    enabled = enabled,
                    role = Role.Button,
                    onClick = { open = !open },
                ),
            enabled = enabled,
            foreground = menuForeground(enabled),
            pressedBackground = colors.itemPressed,
            restingBackground = if (open) colors.itemSelected else Color.Transparent,
            interaction = interaction,
            startPadding = if (inset) 38.dp else 12.dp,
            endPadding = 12.dp,
            indicator = null,
        ) {
            Row(
                modifier = Modifier.weight(1f),
                horizontalArrangement = Arrangement.spacedBy(8.dp),
                verticalAlignment = Alignment.CenterVertically,
                content = trigger,
            )
            Icon(PhosphorIcons.Regular.CaretRight, contentDescription = null, modifier = Modifier.rotate(rotation), size = 16.dp)
        }
        MenuPopup(
            expanded = open,
            onDismissRequest = { open = false },
            modifier = Modifier,
            side = PopupSide.Right,
            align = PopupAlign.Start,
            sideOffset = 0.dp,
            alignOffset = (-6).dp,
            minWidth = 144.dp,
        ) {
            CompositionLocalProvider(
                LocalMenu provides MenuContext(
                    dismiss = {
                        open = false
                        menu.dismiss()
                    },
                ),
            ) {
                content()
            }
        }
    }
}
```

```kt title="kotlin/components/Field.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.background
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.ColumnScope
import androidx.compose.foundation.layout.LayoutScopeMarker
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.heightIn
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.remember
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.layout.layout
import androidx.compose.ui.platform.LocalConfiguration
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.heading
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

enum class FieldOrientation { Vertical, Horizontal, Responsive }

enum class FieldGroupVariant { Default, Inset }

enum class FieldLegendVariant { Legend, Label }

@Immutable
internal class FieldState(val enabled: Boolean, val invalid: Boolean)

internal val LocalFieldState = staticCompositionLocalOf { FieldState(enabled = true, invalid = false) }

private val LocalFieldSetInset = staticCompositionLocalOf { false }

private val LocalFieldGroupVariant = staticCompositionLocalOf<FieldGroupVariant?> { null }

private val LocalFieldInset = staticCompositionLocalOf { false }

@LayoutScopeMarker
@Immutable
interface FieldScope {
    fun Modifier.weight(weight: Float): Modifier
}

private class RowFieldScope(private val scope: RowScope) : FieldScope {
    override fun Modifier.weight(weight: Float): Modifier = with(scope) { this@weight.weight(weight, true) }
}

private object ColumnFieldScope : FieldScope {
    override fun Modifier.weight(weight: Float): Modifier = this
}

@Composable
fun FieldSet(
    modifier: Modifier = Modifier,
    variant: FieldGroupVariant = FieldGroupVariant.Default,
    enabled: Boolean = true,
    content: @Composable ColumnScope.() -> Unit,
) {
    val inset = variant == FieldGroupVariant.Inset
    CompositionLocalProvider(
        LocalFieldSetInset provides inset,
        LocalFieldState provides FieldState(enabled, LocalFieldState.current.invalid),
    ) {
        Column(
            modifier = modifier.fillMaxWidth(),
            verticalArrangement = Arrangement.spacedBy(if (inset) 8.dp else 24.dp),
            content = content,
        )
    }
}

@Composable
fun FieldLegend(
    text: String,
    modifier: Modifier = Modifier,
    variant: FieldLegendVariant = FieldLegendVariant.Legend,
) {
    val colors = EsuissTheme.colors
    val inset = LocalFieldSetInset.current
    val enabled = LocalFieldState.current.enabled
    val style = if (inset) {
        Typography.xs.copy(color = if (enabled) colors.labelSecondary else colors.labelQuaternary)
    } else {
        Typography.base.copy(color = if (enabled) colors.label else colors.labelQuaternary, fontWeight = FontWeight.SemiBold)
    }
    BasicText(
        text = if (inset) text.uppercase() else text,
        modifier = modifier
            .then(if (variant == FieldLegendVariant.Legend) Modifier.semantics { heading() } else Modifier)
            .padding(start = if (inset) 16.dp else 0.dp, bottom = if (inset) 0.dp else 12.dp),
        style = style,
    )
}

@Composable
fun FieldGroup(
    modifier: Modifier = Modifier,
    variant: FieldGroupVariant = FieldGroupVariant.Default,
    content: @Composable () -> Unit,
) {
    val colors = EsuissTheme.colors
    CompositionLocalProvider(
        LocalFieldSetInset provides false,
        LocalFieldGroupVariant provides variant,
    ) {
        if (variant == FieldGroupVariant.Inset) {
            FormDividedStack(
                orientation = Orientation.Vertical,
                dividerColor = colors.separator,
                modifier = modifier
                    .fillMaxWidth()
                    .clip(RoundedCornerShape(Radius.xl2))
                    .background(colors.surfaceSecondary),
                dividerInsetStart = 16.dp,
                content = content,
            )
        } else {
            Column(
                modifier = modifier.fillMaxWidth(),
                verticalArrangement = Arrangement.spacedBy(28.dp),
            ) {
                content()
            }
        }
    }
}

@Composable
fun Field(
    modifier: Modifier = Modifier,
    orientation: FieldOrientation = FieldOrientation.Vertical,
    enabled: Boolean = LocalFieldState.current.enabled,
    invalid: Boolean = false,
    content: @Composable FieldScope.() -> Unit,
) {
    val inset = LocalFieldGroupVariant.current == FieldGroupVariant.Inset
    val horizontal = when (orientation) {
        FieldOrientation.Vertical -> false
        FieldOrientation.Horizontal -> true
        FieldOrientation.Responsive -> LocalConfiguration.current.screenWidthDp >= 768
    }
    val sizing = modifier
        .fillMaxWidth()
        .then(if (inset) Modifier.heightIn(min = 44.dp).padding(horizontal = 16.dp, vertical = 6.dp) else Modifier)
    CompositionLocalProvider(
        LocalFieldGroupVariant provides null,
        LocalFieldInset provides inset,
        LocalFieldState provides FieldState(enabled, invalid),
    ) {
        if (horizontal) {
            Row(
                modifier = sizing,
                horizontalArrangement = Arrangement.spacedBy(12.dp),
                verticalAlignment = Alignment.CenterVertically,
            ) {
                val scope = remember(this) { RowFieldScope(this) }
                scope.content()
            }
        } else {
            Column(
                modifier = sizing,
                verticalArrangement = Arrangement.spacedBy(12.dp, Alignment.CenterVertically),
            ) {
                ColumnFieldScope.content()
            }
        }
    }
}

@Composable
fun FieldScope.FieldContent(
    modifier: Modifier = Modifier,
    content: @Composable ColumnScope.() -> Unit,
) {
    Column(
        modifier = modifier.weight(1f),
        verticalArrangement = Arrangement.spacedBy(4.dp),
        content = content,
    )
}

@Composable
fun FieldLabel(text: String, modifier: Modifier = Modifier) {
    val colors = EsuissTheme.colors
    val enabled = LocalFieldState.current.enabled
    BasicText(
        text = text,
        modifier = modifier,
        style = Typography.base.copy(
            color = if (enabled) colors.label else colors.labelQuaternary,
            fontWeight = if (LocalFieldInset.current) FontWeight.Normal else FontWeight.SemiBold,
        ),
    )
}

@Composable
fun FieldTitle(text: String, modifier: Modifier = Modifier) {
    val colors = EsuissTheme.colors
    val enabled = LocalFieldState.current.enabled
    BasicText(
        text = text,
        modifier = modifier,
        style = Typography.base.copy(
            color = if (enabled) colors.label else colors.labelQuaternary,
            fontWeight = FontWeight.SemiBold,
        ),
    )
}

@Composable
fun FieldDescription(text: String, modifier: Modifier = Modifier) {
    val colors = EsuissTheme.colors
    val inset = LocalFieldSetInset.current
    BasicText(
        text = text,
        modifier = modifier.padding(start = if (inset) 16.dp else 0.dp),
        style = (if (inset) Typography.xs else Typography.sm).copy(color = colors.labelSecondary),
    )
}

@Composable
fun FieldSeparator(
    modifier: Modifier = Modifier,
    text: String? = null,
) {
    val colors = EsuissTheme.colors
    Box(
        modifier = modifier
            .fillMaxWidth()
            .layout { measurable, constraints ->
                val placeable = measurable.measure(constraints)
                val overlap = 8.dp.roundToPx()
                val height = (placeable.height - overlap * 2).coerceAtLeast(0)
                layout(placeable.width, height) { placeable.place(0, -overlap) }
            }
            .heightIn(min = 20.dp),
        contentAlignment = Alignment.Center,
    ) {
        Separator()
        if (text != null) {
            BasicText(
                text = text,
                modifier = Modifier.background(colors.surface).padding(horizontal = 8.dp),
                style = Typography.sm.copy(color = colors.labelSecondary),
            )
        }
    }
}

@Composable
fun FieldError(text: String?, modifier: Modifier = Modifier) {
    if (text.isNullOrEmpty()) return
    BasicText(
        text = text,
        modifier = modifier.semantics { liveRegion = LiveRegionMode.Polite },
        style = Typography.sm.copy(color = EsuissTheme.colors.danger),
    )
}

@Composable
fun FieldError(errors: List<String?>, modifier: Modifier = Modifier) {
    val messages = errors.filterNotNull().filter { it.isNotEmpty() }.distinct()
    val text = when (messages.size) {
        0 -> null
        1 -> messages[0]
        else -> messages.joinToString("\n") { "• $it" }
    }
    FieldError(text, modifier)
}
```

```kt title="kotlin/components/FormSupport.kt"
package com.esuiss.ui.components

import android.provider.Settings
import androidx.compose.animation.core.CubicBezierEasing
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.text.selection.TextSelectionColors
import androidx.compose.runtime.Composable
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.draw.drawWithContent
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.Shape
import androidx.compose.ui.layout.Layout
import androidx.compose.ui.layout.layout
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.unit.Constraints
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.LayoutDirection
import androidx.compose.ui.unit.constrainHeight
import androidx.compose.ui.unit.constrainWidth
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.Colors
import com.esuiss.ui.theme.Shadow

internal val FormShadowXs = Shadow(0.dp, 1.dp, 2.dp, Color.Black.copy(alpha = 0.05f))

internal val FormShadowSm = Shadow(0.dp, 1.dp, 3.dp, Color.Black.copy(alpha = 0.1f))

internal val FormEasing = CubicBezierEasing(0.32f, 0.72f, 0f, 1f)

internal fun Modifier.formTouchTarget(): Modifier = layout { measurable, constraints ->
    val minimum = 48.dp.roundToPx()
    val placeable = measurable.measure(constraints)
    val width = constraints.constrainWidth(maxOf(placeable.width, minimum))
    val height = constraints.constrainHeight(maxOf(placeable.height, minimum))
    layout(width, height) {
        placeable.place((width - placeable.width) / 2, (height - placeable.height) / 2)
    }
}

@Composable
internal fun formReducedMotion(): Boolean {
    val context = LocalContext.current
    return remember(context) {
        Settings.Global.getFloat(context.contentResolver, Settings.Global.ANIMATOR_DURATION_SCALE, 1f) == 0f
    }
}

internal fun formSelectionColors(colors: Colors) = TextSelectionColors(
    handleColor = colors.accent,
    backgroundColor = colors.accent.copy(alpha = 0.3f),
)

internal fun Modifier.formInputSurface(
    colors: Colors,
    shape: Shape,
    focused: Boolean,
    invalid: Boolean,
    enabled: Boolean,
): Modifier {
    val background = when {
        !enabled -> colors.controlDisabled
        invalid -> colors.danger.copy(alpha = if (colors.isDark) 0.1f else 0.05f)
        else -> colors.control
    }
    val border = when {
        invalid -> colors.danger
        focused -> colors.focus
        else -> Color.Transparent
    }
    return clip(shape).background(background, shape).border(1.dp, border, shape)
}

@Composable
internal fun FormDividedStack(
    orientation: Orientation,
    dividerColor: Color,
    modifier: Modifier = Modifier,
    dividerInsetStart: Dp = 0.dp,
    content: @Composable () -> Unit,
) {
    val boundaries = remember { mutableStateOf(IntArray(0)) }
    val vertical = orientation == Orientation.Vertical
    Layout(
        content = content,
        modifier = modifier.drawWithContent {
            drawContent()
            val stroke = 1.dp.toPx()
            val inset = dividerInsetStart.toPx()
            boundaries.value.forEach { position ->
                if (vertical) {
                    val start = if (layoutDirection == LayoutDirection.Rtl) 0f else inset
                    drawRect(dividerColor, Offset(start, position.toFloat()), Size(size.width - inset, stroke))
                } else {
                    val x = if (layoutDirection == LayoutDirection.Rtl) size.width - position - stroke else position.toFloat()
                    drawRect(dividerColor, Offset(x, 0f), Size(stroke, size.height))
                }
            }
        },
    ) { measurables, constraints ->
        if (vertical) {
            val width = if (constraints.hasFixedWidth) {
                constraints.maxWidth
            } else {
                constraints.constrainWidth(measurables.maxOfOrNull { it.maxIntrinsicWidth(Constraints.Infinity) } ?: 0)
            }
            val placeables = measurables.map {
                it.measure(Constraints(minWidth = width, maxWidth = width))
            }
            val offsets = IntArray(placeables.size)
            var y = 0
            placeables.forEachIndexed { index, placeable ->
                offsets[index] = y
                y += placeable.height
            }
            val next = offsets.drop(1).toIntArray()
            if (!next.contentEquals(boundaries.value)) boundaries.value = next
            layout(width, constraints.constrainHeight(y)) {
                placeables.forEachIndexed { index, placeable -> placeable.placeRelative(0, offsets[index]) }
            }
        } else {
            val height = if (constraints.hasFixedHeight) {
                constraints.maxHeight
            } else {
                constraints.constrainHeight(measurables.maxOfOrNull { it.maxIntrinsicHeight(Constraints.Infinity) } ?: 0)
            }
            val placeables = measurables.map {
                it.measure(Constraints(minHeight = height, maxHeight = height))
            }
            val offsets = IntArray(placeables.size)
            var x = 0
            placeables.forEachIndexed { index, placeable ->
                offsets[index] = x
                x += placeable.width
            }
            val next = offsets.drop(1).toIntArray()
            if (!next.contentEquals(boundaries.value)) boundaries.value = next
            layout(constraints.constrainWidth(x), height) {
                placeables.forEachIndexed { index, placeable -> placeable.placeRelative(offsets[index], 0) }
            }
        }
    }
}
```

```kt title="kotlin/components/Haptics.kt"
package com.esuiss.ui.components

import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.remember
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.hapticfeedback.HapticFeedback
import androidx.compose.ui.hapticfeedback.HapticFeedbackType
import androidx.compose.ui.platform.LocalHapticFeedback

val LocalHapticsEnabled = staticCompositionLocalOf { true }

@Composable
fun ProvideHaptics(enabled: Boolean, content: @Composable () -> Unit) {
    CompositionLocalProvider(LocalHapticsEnabled provides enabled, content = content)
}

internal class Haptics(private val feedback: HapticFeedback, private val enabled: Boolean) {
    fun perform(type: HapticFeedbackType) {
        if (enabled) feedback.performHapticFeedback(type)
    }

    fun toggle(on: Boolean) = perform(if (on) HapticFeedbackType.ToggleOn else HapticFeedbackType.ToggleOff)

    fun selection() = perform(HapticFeedbackType.SegmentTick)
}

@Composable
internal fun rememberHaptics(): Haptics {
    val feedback = LocalHapticFeedback.current
    val enabled = LocalHapticsEnabled.current
    return remember(feedback, enabled) { Haptics(feedback, enabled) }
}
```

```kt title="kotlin/components/Icon.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.Image
import androidx.compose.foundation.layout.size
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.ColorFilter
import androidx.compose.ui.graphics.takeOrElse
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.unit.Dp
import com.esuiss.ui.theme.EsuissTheme

@Composable
fun Icon(
    imageVector: ImageVector,
    contentDescription: String?,
    modifier: Modifier = Modifier,
    size: Dp = LocalIconSize.current,
    tint: Color = LocalContentColor.current.takeOrElse { EsuissTheme.colors.label },
) {
    Image(
        imageVector = imageVector,
        contentDescription = contentDescription,
        modifier = modifier.size(size),
        colorFilter = ColorFilter.tint(tint),
    )
}
```

```kt title="kotlin/components/Label.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

@Composable
fun Label(
    modifier: Modifier = Modifier,
    enabled: Boolean = true,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val color = if (enabled) colors.label else colors.labelQuaternary
    Row(
        modifier = modifier,
        horizontalArrangement = Arrangement.spacedBy(8.dp),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        CompositionLocalProvider(
            LocalContentStyle provides Typography.base.copy(color = color, fontWeight = FontWeight.SemiBold),
            LocalContentColor provides color,
        ) {
            content()
        }
    }
}

@Composable
fun Label(
    text: String,
    modifier: Modifier = Modifier,
    enabled: Boolean = true,
) {
    Label(modifier, enabled) {
        BasicText(text, style = LocalContentStyle.current)
    }
}
```

```kt title="kotlin/components/Overlay.kt"
package com.esuiss.ui.components

import android.os.Build
import android.view.Window
import android.view.WindowManager
import androidx.compose.animation.AnimatedVisibility
import androidx.compose.animation.AnimatedVisibilityScope
import androidx.compose.animation.EnterExitState
import androidx.compose.animation.core.MutableTransitionState
import androidx.compose.animation.core.animateFloat
import androidx.compose.animation.core.tween
import androidx.compose.animation.fadeIn
import androidx.compose.animation.fadeOut
import androidx.compose.animation.scaleIn
import androidx.compose.animation.scaleOut
import androidx.compose.animation.slideIn
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.clickable
import androidx.compose.foundation.gestures.awaitEachGesture
import androidx.compose.foundation.gestures.awaitFirstDown
import androidx.compose.foundation.gestures.detectTapGestures
import androidx.compose.foundation.interaction.MutableInteractionSource
import androidx.compose.foundation.interaction.collectIsPressedAsState
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.WindowInsets
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.ime
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.SideEffect
import androidx.compose.runtime.Stable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableIntStateOf
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberUpdatedState
import androidx.compose.runtime.setValue
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.CompositingStrategy
import androidx.compose.ui.graphics.Shape
import androidx.compose.ui.graphics.TransformOrigin
import androidx.compose.ui.graphics.graphicsLayer
import androidx.compose.ui.input.pointer.PointerEventPass
import androidx.compose.ui.input.pointer.pointerInput
import androidx.compose.ui.platform.LocalDensity
import androidx.compose.ui.platform.LocalView
import androidx.compose.ui.platform.LocalWindowInfo
import androidx.compose.ui.semantics.Role
import androidx.compose.ui.semantics.contentDescription
import androidx.compose.ui.semantics.heading
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.IntOffset
import androidx.compose.ui.unit.IntRect
import androidx.compose.ui.unit.IntSize
import androidx.compose.ui.unit.LayoutDirection
import androidx.compose.ui.unit.dp
import androidx.compose.ui.window.Dialog as WindowDialog
import androidx.compose.ui.window.DialogProperties
import androidx.compose.ui.window.DialogWindowProvider
import androidx.compose.ui.window.Popup
import androidx.compose.ui.window.PopupPositionProvider
import androidx.compose.ui.window.PopupProperties
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.X
import com.esuiss.ui.theme.Colors
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Shadow
import com.esuiss.ui.theme.Shadows
import com.esuiss.ui.theme.Typography
import com.esuiss.ui.theme.shadow
import kotlin.math.max
import kotlin.math.min

enum class PopupSide { Top, Bottom, Left, Right }

enum class PopupAlign { Start, Center, End }

internal val PopupInset = 16.dp

internal val PopupMargin = 8.dp

@Stable
internal class PopupPlacement {
    var anchorWidth by mutableIntStateOf(0)
}

internal class AnchoredPositionProvider(
    private val side: PopupSide,
    private val align: PopupAlign,
    private val sideOffset: Int,
    private val alignOffset: Int,
    private val inset: Int,
    private val margin: Int,
    private val bottomLimit: Int,
    private val point: IntOffset?,
    private val placement: PopupPlacement,
) : PopupPositionProvider {
    override fun calculatePosition(
        anchorBounds: IntRect,
        windowSize: IntSize,
        layoutDirection: LayoutDirection,
        popupContentSize: IntSize,
    ): IntOffset {
        val anchor = if (point != null) {
            val x = anchorBounds.left + point.x
            val y = anchorBounds.top + point.y
            IntRect(x, y, x, y)
        } else {
            anchorBounds
        }
        val width = (popupContentSize.width - inset * 2).coerceAtLeast(0)
        val height = (popupContentSize.height - inset * 2).coerceAtLeast(0)
        val left = margin
        val top = margin
        val right = windowSize.width - margin
        val bottom = min(windowSize.height, bottomLimit) - margin

        fun space(candidate: PopupSide): Int = when (candidate) {
            PopupSide.Bottom -> bottom - anchor.bottom - sideOffset
            PopupSide.Top -> anchor.top - sideOffset - top
            PopupSide.Right -> right - anchor.right - sideOffset
            PopupSide.Left -> anchor.left - sideOffset - left
        }

        val opposite = when (side) {
            PopupSide.Bottom -> PopupSide.Top
            PopupSide.Top -> PopupSide.Bottom
            PopupSide.Left -> PopupSide.Right
            PopupSide.Right -> PopupSide.Left
        }
        val vertical = side == PopupSide.Top || side == PopupSide.Bottom
        val needed = if (vertical) height else width
        val resolved = if (space(side) >= needed || space(side) >= space(opposite)) side else opposite
        val rtl = layoutDirection == LayoutDirection.Rtl

        var x: Int
        var y: Int
        if (vertical) {
            x = when (align) {
                PopupAlign.Start -> if (rtl) anchor.right - width else anchor.left
                PopupAlign.Center -> anchor.left + (anchor.width - width) / 2
                PopupAlign.End -> if (rtl) anchor.left else anchor.right - width
            } + if (rtl) -alignOffset else alignOffset
            y = if (resolved == PopupSide.Bottom) anchor.bottom + sideOffset else anchor.top - sideOffset - height
        } else {
            y = when (align) {
                PopupAlign.Start -> anchor.top
                PopupAlign.Center -> anchor.top + (anchor.height - height) / 2
                PopupAlign.End -> anchor.bottom - height
            } + alignOffset
            x = if (resolved == PopupSide.Right) anchor.right + sideOffset else anchor.left - sideOffset - width
        }
        x = x.coerceIn(left, max(left, right - width))
        y = y.coerceIn(top, max(top, bottom - height))
        placement.anchorWidth = anchorBounds.width
        return IntOffset(x - inset, y - inset)
    }
}

private fun transformOrigin(side: PopupSide): TransformOrigin = when (side) {
    PopupSide.Bottom -> TransformOrigin(0.5f, 0f)
    PopupSide.Top -> TransformOrigin(0.5f, 1f)
    PopupSide.Left -> TransformOrigin(1f, 0.5f)
    PopupSide.Right -> TransformOrigin(0f, 0.5f)
}

@Composable
internal fun AnchoredPopup(
    expanded: Boolean,
    onDismissRequest: () -> Unit,
    side: PopupSide = PopupSide.Bottom,
    align: PopupAlign = PopupAlign.Center,
    sideOffset: Dp = 4.dp,
    alignOffset: Dp = 0.dp,
    focusable: Boolean = true,
    point: IntOffset? = null,
    enterMillis: Int = 150,
    exitMillis: Int = 100,
    content: @Composable (PopupPlacement) -> Unit,
) {
    val transition = remember { MutableTransitionState(false) }
    transition.targetState = expanded
    if (!transition.currentState && !transition.targetState) return

    val density = LocalDensity.current
    val imeBottom = WindowInsets.ime.getBottom(density)
    val containerHeight = LocalWindowInfo.current.containerSize.height
    val bottomLimit = if (containerHeight > 0) containerHeight - imeBottom else Int.MAX_VALUE
    val placement = remember { PopupPlacement() }
    val provider = remember(side, align, sideOffset, alignOffset, point, bottomLimit, density) {
        with(density) {
            AnchoredPositionProvider(
                side = side,
                align = align,
                sideOffset = sideOffset.roundToPx(),
                alignOffset = alignOffset.roundToPx(),
                inset = PopupInset.roundToPx(),
                margin = PopupMargin.roundToPx(),
                bottomLimit = bottomLimit,
                point = point,
                placement = placement,
            )
        }
    }
    val currentExpanded by rememberUpdatedState(expanded)
    val dismiss by rememberUpdatedState(onDismissRequest)
    val properties = PopupProperties(
        focusable = focusable,
        dismissOnBackPress = true,
        dismissOnClickOutside = true,
    )
    val slide = with(density) { 8.dp.roundToPx() }
    val origin = transformOrigin(side)
    Popup(
        popupPositionProvider = provider,
        onDismissRequest = { if (currentExpanded) dismiss() },
        properties = properties,
    ) {
        Box(
            modifier = Modifier
                .pointerInput(Unit) {
                    val insetPx = PopupInset.toPx()
                    detectTapGestures { position ->
                        val inside = position.x >= insetPx && position.y >= insetPx &&
                            position.x <= size.width - insetPx && position.y <= size.height - insetPx
                        if (!inside && currentExpanded) dismiss()
                    }
                }
                .padding(PopupInset),
        ) {
            AnimatedVisibility(
                visibleState = transition,
                enter = scaleIn(tween(enterMillis), initialScale = 0.95f, transformOrigin = origin) +
                    slideIn(tween(enterMillis)) {
                        when (side) {
                            PopupSide.Bottom -> IntOffset(0, -slide)
                            PopupSide.Top -> IntOffset(0, slide)
                            PopupSide.Left -> IntOffset(slide, 0)
                            PopupSide.Right -> IntOffset(-slide, 0)
                        }
                    },
                exit = scaleOut(tween(exitMillis), targetScale = 0.95f, transformOrigin = origin),
            ) {
                Box(fadeWithShadow(enterMillis, exitMillis)) {
                    CompositionLocalProvider(LocalButtonGroup provides null) {
                        content(placement)
                    }
                }
            }
        }
    }
}

@Composable
internal fun ModalWindow(
    visible: Boolean,
    onDismissRequest: () -> Unit,
    dismissOnBackPress: Boolean,
    paneTitle: String?,
    content: @Composable () -> Unit,
) {
    if (!visible) return
    WindowDialog(
        onDismissRequest = onDismissRequest,
        properties = DialogProperties(
            dismissOnBackPress = dismissOnBackPress,
            dismissOnClickOutside = false,
            usePlatformDefaultWidth = false,
            decorFitsSystemWindows = false,
            windowTitle = paneTitle.orEmpty(),
        ),
    ) {
        val window = (LocalView.current.parent as? DialogWindowProvider)?.window
        SideEffect {
            window?.apply {
                setDimAmount(0f)
                clearFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND)
                setLayout(WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.MATCH_PARENT)
                val params = attributes
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
                    params.fitInsetsTypes = 0
                    params.fitInsetsSides = 0
                    params.layoutInDisplayCutoutMode = WindowManager.LayoutParams.LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS
                } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
                    params.layoutInDisplayCutoutMode = WindowManager.LayoutParams.LAYOUT_IN_DISPLAY_CUTOUT_MODE_SHORT_EDGES
                }
                attributes = params
                addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS)
                clearSystemBarColors()
            }
        }
        CompositionLocalProvider(LocalButtonGroup provides null, content = content)
    }
}

@Suppress("DEPRECATION")
private fun Window.clearSystemBarColors() {
    statusBarColor = android.graphics.Color.TRANSPARENT
    navigationBarColor = android.graphics.Color.TRANSPARENT
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
        isStatusBarContrastEnforced = false
        isNavigationBarContrastEnforced = false
    }
}

@Composable
internal fun AnimatedVisibilityScope.fadeWithShadow(enterMillis: Int, exitMillis: Int): Modifier {
    val alpha by transition.animateFloat(
        transitionSpec = { tween(if (targetState == EnterExitState.Visible) enterMillis else exitMillis) },
        label = "alpha",
    ) { if (it == EnterExitState.Visible) 1f else 0f }
    return Modifier.graphicsLayer {
        this.alpha = alpha
        compositingStrategy = CompositingStrategy.ModulateAlpha
    }
}

@Composable
internal fun Scrim(
    transition: MutableTransitionState<Boolean>,
    enterMillis: Int,
    exitMillis: Int,
    onClick: (() -> Unit)?,
) {
    val color = EsuissTheme.colors.scrim
    val click by rememberUpdatedState(onClick)
    AnimatedVisibility(
        visibleState = transition,
        enter = fadeIn(tween(enterMillis)),
        exit = fadeOut(tween(exitMillis)),
    ) {
        Box(
            modifier = Modifier
                .fillMaxSize()
                .background(color)
                .pointerInput(Unit) { detectTapGestures { click?.invoke() } },
        )
    }
}

@Stable
internal class PaneTitleState {
    var value by mutableStateOf<String?>(null)
}

internal val LocalPaneTitle = staticCompositionLocalOf<PaneTitleState?> { null }

@Composable
internal fun RegisterPaneTitle(text: String) {
    val state = LocalPaneTitle.current
    SideEffect { state?.value = text }
}

internal fun Modifier.raisedSurface(colors: Colors, shape: Shape, shadow: Shadow = Shadows.lg): Modifier =
    this
        .shadow(shadow, shape)
        .clip(shape)
        .background(colors.surfaceRaised, shape)
        .border(1.dp, colors.label.copy(alpha = if (colors.isDark) 0.1f else 0.05f), shape)

internal fun titleStyle(colors: Colors, style: TextStyle = Typography.base, centered: Boolean = false): TextStyle =
    style.copy(
        color = colors.label,
        fontWeight = FontWeight.SemiBold,
        textAlign = if (centered) TextAlign.Center else TextAlign.Unspecified,
    )

internal fun descriptionStyle(colors: Colors, centered: Boolean = false): TextStyle =
    Typography.sm.copy(
        color = colors.labelSecondary,
        textAlign = if (centered) TextAlign.Center else TextAlign.Unspecified,
    )

@Composable
internal fun OverlayTitle(text: String, modifier: Modifier, style: TextStyle) {
    RegisterPaneTitle(text)
    BasicText(text, modifier = modifier.semantics { heading() }, style = style)
}

@Composable
internal fun OverlayCloseButton(
    onClick: () -> Unit,
    label: String?,
    modifier: Modifier = Modifier,
) {
    val colors = EsuissTheme.colors
    if (label != null) {
        Button(onClick = onClick, modifier = modifier, variant = ButtonVariant.Plain, size = ButtonSize.Sm) {
            BasicText(label, style = Typography.base.copy(color = LocalContentColor.current), maxLines = 1)
        }
        return
    }
    val interaction = remember { MutableInteractionSource() }
    val pressed by interaction.collectIsPressedAsState()
    Box(
        modifier = modifier
            .size(44.dp)
            .clip(CircleShape)
            .clickable(interactionSource = interaction, indication = null, role = Role.Button, onClick = onClick)
            .semantics { contentDescription = "Close" },
        contentAlignment = Alignment.Center,
    ) {
        Box(
            modifier = Modifier
                .size(32.dp)
                .background(if (pressed) colors.separator else colors.surfaceTertiary, CircleShape),
            contentAlignment = Alignment.Center,
        ) {
            Icon(PhosphorIcons.Regular.X, contentDescription = null, size = 16.dp, tint = colors.label)
        }
    }
}

@Composable
internal fun rememberLongPressModifier(enabled: Boolean, onLongPress: (Offset) -> Unit): Modifier {
    val callback by rememberUpdatedState(onLongPress)
    if (!enabled) return Modifier
    return Modifier.pointerInput(Unit) {
        awaitEachGesture {
            val down = awaitFirstDown(requireUnconsumed = false, pass = PointerEventPass.Initial)
            val released = withTimeoutOrNull(viewConfiguration.longPressTimeoutMillis) {
                while (true) {
                    val event = awaitPointerEvent(PointerEventPass.Initial)
                    val change = event.changes.firstOrNull { it.id == down.id }
                    if (change == null || !change.pressed) break
                    if ((change.position - down.position).getDistance() > viewConfiguration.touchSlop) break
                }
                true
            }
            if (released == null) {
                callback(down.position)
                while (true) {
                    val event = awaitPointerEvent(PointerEventPass.Initial)
                    event.changes.forEach { it.consume() }
                    if (event.changes.none { it.pressed }) break
                }
            }
        }
    }
}
```

```kt title="kotlin/components/Separator.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.background
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxHeight
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.width
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.EsuissTheme

@Composable
fun Separator(
    modifier: Modifier = Modifier,
    orientation: Orientation = Orientation.Horizontal,
) {
    val sizing = if (orientation == Orientation.Horizontal) {
        Modifier.fillMaxWidth().height(1.dp)
    } else {
        Modifier.fillMaxHeight().width(1.dp)
    }
    Box(modifier.then(sizing).background(EsuissTheme.colors.separator))
}
```

4. Update the `com.esuiss.ui` package names to match your project.

## Usage

```tsx
import { CalendarDayButton, Calendar } from "@/components/ui/calendar"
```

```tsx
<SingleCalendar />
```

Pass `mode`, `selected` and `onSelect` to control the selection; `selected` is a `Date`, a `Date[]` or a `{ from, to }` range depending on the mode. Use `month`, `defaultMonth` and `onMonthChange` to control the visible month, and `numberOfMonths` to show several months.

Use `disabled` with date matchers, such as `{ dayOfWeek: [0, 6] }`, to block days. Limit navigation with `startMonth` and `endMonth`; with a year dropdown they default to the last 100 years.

Set `locale` for month and weekday names, and `weekStartsOn` to change the first day of the week. `CalendarDayButton` is exported for custom day rendering.

## Examples

### Sizes

The `sm`, `default` and `lg` sizes.

![Preview](https://uim.suiss.app/previews/components-calendar--sizes.light.webp)

```tsx
import * as React from "react"
import { ScrollView } from "react-native"
import { Calendar } from "@/components/ui/calendar"

type CalendarProps = React.ComponentProps<typeof Calendar>

function SingleCalendar(
  props: Omit<CalendarProps, "mode" | "selected" | "onSelect">
) {
  const today = new Date()
  const [date, setDate] = React.useState<Date | undefined>(
    new Date(today.getFullYear(), today.getMonth(), today.getDate() + 3)
  )
  return (
    <Calendar
      {...props}
      mode="single"
      selected={date}
      onSelect={setDate}
      className="rounded-2xl border border-separator"
    />
  )
}

export function CalendarSizesExample() {
  return (
    <ScrollView contentContainerClassName="items-start gap-6">
      <SingleCalendar size="sm" />
      <SingleCalendar size="default" />
      <SingleCalendar size="lg" />
    </ScrollView>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CalendarSizesExample: View {
  var body: some View {
    VStack(alignment: .leading, spacing: 24) {
      CalendarSingleDemo(size: .sm)
      CalendarSingleDemo(size: .default)
      CalendarSingleDemo(size: .lg)
    }
  }
}

enum CalendarDates {
  static func day(_ offset: Int) -> Date {
    let calendar = Foundation.Calendar.current
    let start = calendar.startOfDay(for: Date())
    return calendar.date(byAdding: .day, value: offset, to: start) ?? start
  }

  static func dayOfMonth(_ day: Int) -> Date {
    let calendar = Foundation.Calendar.current
    var components = calendar.dateComponents([.year, .month], from: Date())
    components.day = day
    return calendar.date(from: components) ?? Date()
  }
}

struct CalendarBordered: ViewModifier {
  func body(content: Content) -> some View {
    content
      .clipShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
      .overlay {
        RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).strokeBorder(Color.separator)
      }
  }
}

struct CalendarSingleDemo: View {
  var size: DateCalendar.Size = .default
  var buttonVariant: VariantButtonStyle.Variant = .plain
  var captionLayout: DateCalendar.CaptionLayout = .label
  var showOutsideDays = false
  var showWeekNumber = false
  var weekendsDisabled = false

  @State private var date: Date? = CalendarDates.day(3)

  var body: some View {
    DateCalendar(
      selection: $date,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      isDisabled: { day in
        guard weekendsDisabled else { return false }
        let weekday = Foundation.Calendar.current.component(.weekday, from: day)
        return weekday == 1 || weekday == 7
      }
    )
    .modifier(CalendarBordered())
  }
}

func day(_ offset: Int) -> Date {
  let calendar = Foundation.Calendar.current
  let start = calendar.startOfDay(for: Date())
  return calendar.date(byAdding: .day, value: offset, to: start) ?? start
}

func dayOfMonth(_ day: Int) -> Date {
  let calendar = Foundation.Calendar.current
  var components = calendar.dateComponents([.year, .month], from: Date())
  components.day = day
  return calendar.date(from: components) ?? Date()
}
```

```kotlin
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Calendar
import com.esuiss.ui.components.CalendarCaptionLayout
import com.esuiss.ui.components.CalendarSize
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import java.util.Date
import java.util.GregorianCalendar
import java.util.Locale

fun calendarDay(offsetDays: Int = 0, dayOfMonth: Int? = null): Date {
    val now = GregorianCalendar()
    val result = GregorianCalendar(now.get(GregorianCalendar.YEAR), now.get(GregorianCalendar.MONTH), now.get(GregorianCalendar.DAY_OF_MONTH))
    if (dayOfMonth != null) result.set(GregorianCalendar.DAY_OF_MONTH, dayOfMonth)
    result.add(GregorianCalendar.DAY_OF_MONTH, offsetDays)
    return result.time
}

fun calendarIsWeekend(date: Date): Boolean {
    val day = GregorianCalendar().apply { time = date }.get(GregorianCalendar.DAY_OF_WEEK)
    return day == GregorianCalendar.SATURDAY || day == GregorianCalendar.SUNDAY
}

@Composable
fun CalendarFrame(content: @Composable () -> Unit) {
    Box(
        Modifier
            .border(1.dp, EsuissTheme.colors.separator, RoundedCornerShape(Radius.xl2))
            .padding(1.dp),
    ) {
        content()
    }
}

@Composable
fun CalendarSingle(
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    showWeekNumber: Boolean = false,
    showOutsideDays: Boolean = false,
    weekendsDisabled: Boolean = false,
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    locale: Locale = Locale.getDefault(),
    key: String = "",
) {
    var date by rememberSaveable(key) { mutableStateOf<Date?>(calendarDay(offsetDays = 3)) }
    CalendarFrame {
        Calendar(
            selected = date,
            onSelect = { date = it },
            size = size,
            captionLayout = captionLayout,
            showWeekNumber = showWeekNumber,
            showOutsideDays = showOutsideDays,
            disabled = { weekendsDisabled && calendarIsWeekend(it) },
            buttonVariant = buttonVariant,
            locale = locale,
        )
    }
}

@Composable
fun CalendarSizes() {
    Column(verticalArrangement = Arrangement.spacedBy(24.dp)) {
        CalendarSingle(size = CalendarSize.Sm, key = "sm")
        CalendarSingle(size = CalendarSize.Default, key = "default")
        CalendarSingle(size = CalendarSize.Lg, key = "lg")
    }
}
```

### Range

Range selection across two months.

![Preview](https://uim.suiss.app/previews/components-calendar--range.light.webp)

```tsx
import * as React from "react"
import { ScrollView } from "react-native"
import { DateRange } from "@/components/primitives/calendar"
import { Calendar } from "@/components/ui/calendar"

function RangeCalendar() {
  const today = new Date()
  const [range, setRange] = React.useState<DateRange | undefined>({
    from: today,
    to: new Date(today.getFullYear(), today.getMonth(), today.getDate() + 6),
  })
  return (
    <ScrollView>
      <Calendar
        mode="range"
        selected={range}
        onSelect={setRange}
        numberOfMonths={2}
        className="rounded-2xl border border-separator"
      />
    </ScrollView>
  )
}

export function CalendarRangeExample() {
  return (
    <RangeCalendar />
  )
}
```

```swift
import EsuissUI
import SwiftUI

enum CalendarDates {
  static func day(_ offset: Int) -> Date {
    let calendar = Foundation.Calendar.current
    let start = calendar.startOfDay(for: Date())
    return calendar.date(byAdding: .day, value: offset, to: start) ?? start
  }

  static func dayOfMonth(_ day: Int) -> Date {
    let calendar = Foundation.Calendar.current
    var components = calendar.dateComponents([.year, .month], from: Date())
    components.day = day
    return calendar.date(from: components) ?? Date()
  }
}

struct CalendarBordered: ViewModifier {
  func body(content: Content) -> some View {
    content
      .clipShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
      .overlay {
        RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).strokeBorder(Color.separator)
      }
  }
}

struct CalendarRangeDemo: View {
  @State private var range: DateRange? = DateRange(from: CalendarDates.day(0), to: CalendarDates.day(6))

  var body: some View {
    DateCalendar(selection: $range, numberOfMonths: 2)
      .modifier(CalendarBordered())
  }
}

func day(_ offset: Int) -> Date {
  let calendar = Foundation.Calendar.current
  let start = calendar.startOfDay(for: Date())
  return calendar.date(byAdding: .day, value: offset, to: start) ?? start
}

func dayOfMonth(_ day: Int) -> Date {
  let calendar = Foundation.Calendar.current
  var components = calendar.dateComponents([.year, .month], from: Date())
  components.day = day
  return calendar.date(from: components) ?? Date()
}
```

```kotlin
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.Calendar
import com.esuiss.ui.components.DateRange
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import java.util.Date
import java.util.GregorianCalendar

fun calendarDay(offsetDays: Int = 0, dayOfMonth: Int? = null): Date {
    val now = GregorianCalendar()
    val result = GregorianCalendar(now.get(GregorianCalendar.YEAR), now.get(GregorianCalendar.MONTH), now.get(GregorianCalendar.DAY_OF_MONTH))
    if (dayOfMonth != null) result.set(GregorianCalendar.DAY_OF_MONTH, dayOfMonth)
    result.add(GregorianCalendar.DAY_OF_MONTH, offsetDays)
    return result.time
}

@Composable
fun CalendarFrame(content: @Composable () -> Unit) {
    Box(
        Modifier
            .border(1.dp, EsuissTheme.colors.separator, RoundedCornerShape(Radius.xl2))
            .padding(1.dp),
    ) {
        content()
    }
}

@Composable
fun CalendarRange() {
    var from by rememberSaveable { mutableStateOf<Date?>(calendarDay()) }
    var to by rememberSaveable { mutableStateOf<Date?>(calendarDay(offsetDays = 6)) }
    CalendarFrame {
        Calendar(
            selected = if (from == null) null else DateRange(from, to),
            onSelect = { range: DateRange? ->
                from = range?.from
                to = range?.to
            },
            numberOfMonths = 2,
        )
    }
}
```

### Multiple

Several separate dates selected with `mode="multiple"`.

![Preview](https://uim.suiss.app/previews/components-calendar--multiple.light.webp)

```tsx
import * as React from "react"
import { Calendar } from "@/components/ui/calendar"

function MultipleCalendar() {
  const today = new Date()
  const [dates, setDates] = React.useState<Date[] | undefined>([
    new Date(today.getFullYear(), today.getMonth(), 8),
    new Date(today.getFullYear(), today.getMonth(), 15),
    new Date(today.getFullYear(), today.getMonth(), 22),
  ])
  return (
    <Calendar
      mode="multiple"
      selected={dates}
      onSelect={setDates}
      className="rounded-2xl border border-separator"
    />
  )
}

export function CalendarMultipleExample() {
  return (
    <MultipleCalendar />
  )
}
```

```swift
import EsuissUI
import SwiftUI

enum CalendarDates {
  static func day(_ offset: Int) -> Date {
    let calendar = Foundation.Calendar.current
    let start = calendar.startOfDay(for: Date())
    return calendar.date(byAdding: .day, value: offset, to: start) ?? start
  }

  static func dayOfMonth(_ day: Int) -> Date {
    let calendar = Foundation.Calendar.current
    var components = calendar.dateComponents([.year, .month], from: Date())
    components.day = day
    return calendar.date(from: components) ?? Date()
  }
}

struct CalendarBordered: ViewModifier {
  func body(content: Content) -> some View {
    content
      .clipShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
      .overlay {
        RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).strokeBorder(Color.separator)
      }
  }
}

struct CalendarMultipleDemo: View {
  @State private var dates: Set<Date> = [
    CalendarDates.dayOfMonth(8),
    CalendarDates.dayOfMonth(15),
    CalendarDates.dayOfMonth(22),
  ]

  var body: some View {
    DateCalendar(selection: $dates)
      .modifier(CalendarBordered())
  }
}

func day(_ offset: Int) -> Date {
  let calendar = Foundation.Calendar.current
  let start = calendar.startOfDay(for: Date())
  return calendar.date(byAdding: .day, value: offset, to: start) ?? start
}

func dayOfMonth(_ day: Int) -> Date {
  let calendar = Foundation.Calendar.current
  var components = calendar.dateComponents([.year, .month], from: Date())
  components.day = day
  return calendar.date(from: components) ?? Date()
}
```

```kotlin
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.Calendar
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import java.util.Date
import java.util.GregorianCalendar

fun calendarDay(offsetDays: Int = 0, dayOfMonth: Int? = null): Date {
    val now = GregorianCalendar()
    val result = GregorianCalendar(now.get(GregorianCalendar.YEAR), now.get(GregorianCalendar.MONTH), now.get(GregorianCalendar.DAY_OF_MONTH))
    if (dayOfMonth != null) result.set(GregorianCalendar.DAY_OF_MONTH, dayOfMonth)
    result.add(GregorianCalendar.DAY_OF_MONTH, offsetDays)
    return result.time
}

@Composable
fun CalendarFrame(content: @Composable () -> Unit) {
    Box(
        Modifier
            .border(1.dp, EsuissTheme.colors.separator, RoundedCornerShape(Radius.xl2))
            .padding(1.dp),
    ) {
        content()
    }
}

@Composable
fun CalendarMultiple() {
    var dates by rememberSaveable {
        mutableStateOf(listOf(calendarDay(dayOfMonth = 8), calendarDay(dayOfMonth = 15), calendarDay(dayOfMonth = 22)))
    }
    CalendarFrame {
        Calendar(selected = dates, onSelect = { value: List<Date> -> dates = value })
    }
}
```

### Dropdown caption

Month and year dropdowns in the caption.

![Preview](https://uim.suiss.app/previews/components-calendar--dropdown-caption.light.webp)

```tsx
import * as React from "react"
import { Calendar } from "@/components/ui/calendar"

type CalendarProps = React.ComponentProps<typeof Calendar>

function SingleCalendar(
  props: Omit<CalendarProps, "mode" | "selected" | "onSelect">
) {
  const today = new Date()
  const [date, setDate] = React.useState<Date | undefined>(
    new Date(today.getFullYear(), today.getMonth(), today.getDate() + 3)
  )
  return (
    <Calendar
      {...props}
      mode="single"
      selected={date}
      onSelect={setDate}
      className="rounded-2xl border border-separator"
    />
  )
}

export function CalendarDropdownCaptionExample() {
  return (
    <SingleCalendar captionLayout="dropdown" />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CalendarDropdownCaptionExample: View {
  var body: some View {
    CalendarSingleDemo(captionLayout: .dropdown)
  }
}

enum CalendarDates {
  static func day(_ offset: Int) -> Date {
    let calendar = Foundation.Calendar.current
    let start = calendar.startOfDay(for: Date())
    return calendar.date(byAdding: .day, value: offset, to: start) ?? start
  }

  static func dayOfMonth(_ day: Int) -> Date {
    let calendar = Foundation.Calendar.current
    var components = calendar.dateComponents([.year, .month], from: Date())
    components.day = day
    return calendar.date(from: components) ?? Date()
  }
}

struct CalendarBordered: ViewModifier {
  func body(content: Content) -> some View {
    content
      .clipShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
      .overlay {
        RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).strokeBorder(Color.separator)
      }
  }
}

struct CalendarSingleDemo: View {
  var size: DateCalendar.Size = .default
  var buttonVariant: VariantButtonStyle.Variant = .plain
  var captionLayout: DateCalendar.CaptionLayout = .label
  var showOutsideDays = false
  var showWeekNumber = false
  var weekendsDisabled = false

  @State private var date: Date? = CalendarDates.day(3)

  var body: some View {
    DateCalendar(
      selection: $date,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      isDisabled: { day in
        guard weekendsDisabled else { return false }
        let weekday = Foundation.Calendar.current.component(.weekday, from: day)
        return weekday == 1 || weekday == 7
      }
    )
    .modifier(CalendarBordered())
  }
}

func day(_ offset: Int) -> Date {
  let calendar = Foundation.Calendar.current
  let start = calendar.startOfDay(for: Date())
  return calendar.date(byAdding: .day, value: offset, to: start) ?? start
}

func dayOfMonth(_ day: Int) -> Date {
  let calendar = Foundation.Calendar.current
  var components = calendar.dateComponents([.year, .month], from: Date())
  components.day = day
  return calendar.date(from: components) ?? Date()
}
```

```kotlin
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Calendar
import com.esuiss.ui.components.CalendarCaptionLayout
import com.esuiss.ui.components.CalendarSize
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import java.util.Date
import java.util.GregorianCalendar
import java.util.Locale

@Composable
fun CalendarDropdownCaptionExample() {
    CalendarSingle(captionLayout = CalendarCaptionLayout.Dropdown)
}

fun calendarDay(offsetDays: Int = 0, dayOfMonth: Int? = null): Date {
    val now = GregorianCalendar()
    val result = GregorianCalendar(now.get(GregorianCalendar.YEAR), now.get(GregorianCalendar.MONTH), now.get(GregorianCalendar.DAY_OF_MONTH))
    if (dayOfMonth != null) result.set(GregorianCalendar.DAY_OF_MONTH, dayOfMonth)
    result.add(GregorianCalendar.DAY_OF_MONTH, offsetDays)
    return result.time
}

fun calendarIsWeekend(date: Date): Boolean {
    val day = GregorianCalendar().apply { time = date }.get(GregorianCalendar.DAY_OF_WEEK)
    return day == GregorianCalendar.SATURDAY || day == GregorianCalendar.SUNDAY
}

@Composable
fun CalendarFrame(content: @Composable () -> Unit) {
    Box(
        Modifier
            .border(1.dp, EsuissTheme.colors.separator, RoundedCornerShape(Radius.xl2))
            .padding(1.dp),
    ) {
        content()
    }
}

@Composable
fun CalendarSingle(
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    showWeekNumber: Boolean = false,
    showOutsideDays: Boolean = false,
    weekendsDisabled: Boolean = false,
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    locale: Locale = Locale.getDefault(),
    key: String = "",
) {
    var date by rememberSaveable(key) { mutableStateOf<Date?>(calendarDay(offsetDays = 3)) }
    CalendarFrame {
        Calendar(
            selected = date,
            onSelect = { date = it },
            size = size,
            captionLayout = captionLayout,
            showWeekNumber = showWeekNumber,
            showOutsideDays = showOutsideDays,
            disabled = { weekendsDisabled && calendarIsWeekend(it) },
            buttonVariant = buttonVariant,
            locale = locale,
        )
    }
}
```

### Week numbers

Week numbers in a leading column.

![Preview](https://uim.suiss.app/previews/components-calendar--week-numbers.light.webp)

```tsx
import * as React from "react"
import { Calendar } from "@/components/ui/calendar"

type CalendarProps = React.ComponentProps<typeof Calendar>

function SingleCalendar(
  props: Omit<CalendarProps, "mode" | "selected" | "onSelect">
) {
  const today = new Date()
  const [date, setDate] = React.useState<Date | undefined>(
    new Date(today.getFullYear(), today.getMonth(), today.getDate() + 3)
  )
  return (
    <Calendar
      {...props}
      mode="single"
      selected={date}
      onSelect={setDate}
      className="rounded-2xl border border-separator"
    />
  )
}

export function CalendarWeekNumbersExample() {
  return (
    <SingleCalendar showWeekNumber />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CalendarWeekNumbersExample: View {
  var body: some View {
    CalendarSingleDemo(showWeekNumber: true)
  }
}

enum CalendarDates {
  static func day(_ offset: Int) -> Date {
    let calendar = Foundation.Calendar.current
    let start = calendar.startOfDay(for: Date())
    return calendar.date(byAdding: .day, value: offset, to: start) ?? start
  }

  static func dayOfMonth(_ day: Int) -> Date {
    let calendar = Foundation.Calendar.current
    var components = calendar.dateComponents([.year, .month], from: Date())
    components.day = day
    return calendar.date(from: components) ?? Date()
  }
}

struct CalendarBordered: ViewModifier {
  func body(content: Content) -> some View {
    content
      .clipShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
      .overlay {
        RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).strokeBorder(Color.separator)
      }
  }
}

struct CalendarSingleDemo: View {
  var size: DateCalendar.Size = .default
  var buttonVariant: VariantButtonStyle.Variant = .plain
  var captionLayout: DateCalendar.CaptionLayout = .label
  var showOutsideDays = false
  var showWeekNumber = false
  var weekendsDisabled = false

  @State private var date: Date? = CalendarDates.day(3)

  var body: some View {
    DateCalendar(
      selection: $date,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      isDisabled: { day in
        guard weekendsDisabled else { return false }
        let weekday = Foundation.Calendar.current.component(.weekday, from: day)
        return weekday == 1 || weekday == 7
      }
    )
    .modifier(CalendarBordered())
  }
}

func day(_ offset: Int) -> Date {
  let calendar = Foundation.Calendar.current
  let start = calendar.startOfDay(for: Date())
  return calendar.date(byAdding: .day, value: offset, to: start) ?? start
}

func dayOfMonth(_ day: Int) -> Date {
  let calendar = Foundation.Calendar.current
  var components = calendar.dateComponents([.year, .month], from: Date())
  components.day = day
  return calendar.date(from: components) ?? Date()
}
```

```kotlin
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Calendar
import com.esuiss.ui.components.CalendarCaptionLayout
import com.esuiss.ui.components.CalendarSize
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import java.util.Date
import java.util.GregorianCalendar
import java.util.Locale

@Composable
fun CalendarWeekNumbersExample() {
    CalendarSingle(showWeekNumber = true)
}

fun calendarDay(offsetDays: Int = 0, dayOfMonth: Int? = null): Date {
    val now = GregorianCalendar()
    val result = GregorianCalendar(now.get(GregorianCalendar.YEAR), now.get(GregorianCalendar.MONTH), now.get(GregorianCalendar.DAY_OF_MONTH))
    if (dayOfMonth != null) result.set(GregorianCalendar.DAY_OF_MONTH, dayOfMonth)
    result.add(GregorianCalendar.DAY_OF_MONTH, offsetDays)
    return result.time
}

fun calendarIsWeekend(date: Date): Boolean {
    val day = GregorianCalendar().apply { time = date }.get(GregorianCalendar.DAY_OF_WEEK)
    return day == GregorianCalendar.SATURDAY || day == GregorianCalendar.SUNDAY
}

@Composable
fun CalendarFrame(content: @Composable () -> Unit) {
    Box(
        Modifier
            .border(1.dp, EsuissTheme.colors.separator, RoundedCornerShape(Radius.xl2))
            .padding(1.dp),
    ) {
        content()
    }
}

@Composable
fun CalendarSingle(
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    showWeekNumber: Boolean = false,
    showOutsideDays: Boolean = false,
    weekendsDisabled: Boolean = false,
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    locale: Locale = Locale.getDefault(),
    key: String = "",
) {
    var date by rememberSaveable(key) { mutableStateOf<Date?>(calendarDay(offsetDays = 3)) }
    CalendarFrame {
        Calendar(
            selected = date,
            onSelect = { date = it },
            size = size,
            captionLayout = captionLayout,
            showWeekNumber = showWeekNumber,
            showOutsideDays = showOutsideDays,
            disabled = { weekendsDisabled && calendarIsWeekend(it) },
            buttonVariant = buttonVariant,
            locale = locale,
        )
    }
}
```

### Disabled days

Weekends disabled with a `dayOfWeek` matcher.

![Preview](https://uim.suiss.app/previews/components-calendar--disabled-days.light.webp)

```tsx
import * as React from "react"
import { Calendar } from "@/components/ui/calendar"

type CalendarProps = React.ComponentProps<typeof Calendar>

function SingleCalendar(
  props: Omit<CalendarProps, "mode" | "selected" | "onSelect">
) {
  const today = new Date()
  const [date, setDate] = React.useState<Date | undefined>(
    new Date(today.getFullYear(), today.getMonth(), today.getDate() + 3)
  )
  return (
    <Calendar
      {...props}
      mode="single"
      selected={date}
      onSelect={setDate}
      className="rounded-2xl border border-separator"
    />
  )
}

export function CalendarDisabledDaysExample() {
  return (
    <SingleCalendar disabled={{ dayOfWeek: [0, 6] }} />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CalendarDisabledDaysExample: View {
  var body: some View {
    CalendarSingleDemo(weekendsDisabled: true)
  }
}

enum CalendarDates {
  static func day(_ offset: Int) -> Date {
    let calendar = Foundation.Calendar.current
    let start = calendar.startOfDay(for: Date())
    return calendar.date(byAdding: .day, value: offset, to: start) ?? start
  }

  static func dayOfMonth(_ day: Int) -> Date {
    let calendar = Foundation.Calendar.current
    var components = calendar.dateComponents([.year, .month], from: Date())
    components.day = day
    return calendar.date(from: components) ?? Date()
  }
}

struct CalendarBordered: ViewModifier {
  func body(content: Content) -> some View {
    content
      .clipShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
      .overlay {
        RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).strokeBorder(Color.separator)
      }
  }
}

struct CalendarSingleDemo: View {
  var size: DateCalendar.Size = .default
  var buttonVariant: VariantButtonStyle.Variant = .plain
  var captionLayout: DateCalendar.CaptionLayout = .label
  var showOutsideDays = false
  var showWeekNumber = false
  var weekendsDisabled = false

  @State private var date: Date? = CalendarDates.day(3)

  var body: some View {
    DateCalendar(
      selection: $date,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      isDisabled: { day in
        guard weekendsDisabled else { return false }
        let weekday = Foundation.Calendar.current.component(.weekday, from: day)
        return weekday == 1 || weekday == 7
      }
    )
    .modifier(CalendarBordered())
  }
}

func day(_ offset: Int) -> Date {
  let calendar = Foundation.Calendar.current
  let start = calendar.startOfDay(for: Date())
  return calendar.date(byAdding: .day, value: offset, to: start) ?? start
}

func dayOfMonth(_ day: Int) -> Date {
  let calendar = Foundation.Calendar.current
  var components = calendar.dateComponents([.year, .month], from: Date())
  components.day = day
  return calendar.date(from: components) ?? Date()
}
```

```kotlin
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Calendar
import com.esuiss.ui.components.CalendarCaptionLayout
import com.esuiss.ui.components.CalendarSize
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import java.util.Date
import java.util.GregorianCalendar
import java.util.Locale

@Composable
fun CalendarDisabledDaysExample() {
    CalendarSingle(weekendsDisabled = true)
}

fun calendarDay(offsetDays: Int = 0, dayOfMonth: Int? = null): Date {
    val now = GregorianCalendar()
    val result = GregorianCalendar(now.get(GregorianCalendar.YEAR), now.get(GregorianCalendar.MONTH), now.get(GregorianCalendar.DAY_OF_MONTH))
    if (dayOfMonth != null) result.set(GregorianCalendar.DAY_OF_MONTH, dayOfMonth)
    result.add(GregorianCalendar.DAY_OF_MONTH, offsetDays)
    return result.time
}

fun calendarIsWeekend(date: Date): Boolean {
    val day = GregorianCalendar().apply { time = date }.get(GregorianCalendar.DAY_OF_WEEK)
    return day == GregorianCalendar.SATURDAY || day == GregorianCalendar.SUNDAY
}

@Composable
fun CalendarFrame(content: @Composable () -> Unit) {
    Box(
        Modifier
            .border(1.dp, EsuissTheme.colors.separator, RoundedCornerShape(Radius.xl2))
            .padding(1.dp),
    ) {
        content()
    }
}

@Composable
fun CalendarSingle(
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    showWeekNumber: Boolean = false,
    showOutsideDays: Boolean = false,
    weekendsDisabled: Boolean = false,
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    locale: Locale = Locale.getDefault(),
    key: String = "",
) {
    var date by rememberSaveable(key) { mutableStateOf<Date?>(calendarDay(offsetDays = 3)) }
    CalendarFrame {
        Calendar(
            selected = date,
            onSelect = { date = it },
            size = size,
            captionLayout = captionLayout,
            showWeekNumber = showWeekNumber,
            showOutsideDays = showOutsideDays,
            disabled = { weekendsDisabled && calendarIsWeekend(it) },
            buttonVariant = buttonVariant,
            locale = locale,
        )
    }
}
```

### Outside days

Days from adjacent months shown with `showOutsideDays`.

![Preview](https://uim.suiss.app/previews/components-calendar--outside-days.light.webp)

```tsx
import * as React from "react"
import { Calendar } from "@/components/ui/calendar"

type CalendarProps = React.ComponentProps<typeof Calendar>

function SingleCalendar(
  props: Omit<CalendarProps, "mode" | "selected" | "onSelect">
) {
  const today = new Date()
  const [date, setDate] = React.useState<Date | undefined>(
    new Date(today.getFullYear(), today.getMonth(), today.getDate() + 3)
  )
  return (
    <Calendar
      {...props}
      mode="single"
      selected={date}
      onSelect={setDate}
      className="rounded-2xl border border-separator"
    />
  )
}

export function CalendarOutsideDaysExample() {
  return (
    <SingleCalendar showOutsideDays />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CalendarOutsideDaysExample: View {
  var body: some View {
    CalendarSingleDemo(showOutsideDays: true)
  }
}

enum CalendarDates {
  static func day(_ offset: Int) -> Date {
    let calendar = Foundation.Calendar.current
    let start = calendar.startOfDay(for: Date())
    return calendar.date(byAdding: .day, value: offset, to: start) ?? start
  }

  static func dayOfMonth(_ day: Int) -> Date {
    let calendar = Foundation.Calendar.current
    var components = calendar.dateComponents([.year, .month], from: Date())
    components.day = day
    return calendar.date(from: components) ?? Date()
  }
}

struct CalendarBordered: ViewModifier {
  func body(content: Content) -> some View {
    content
      .clipShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
      .overlay {
        RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).strokeBorder(Color.separator)
      }
  }
}

struct CalendarSingleDemo: View {
  var size: DateCalendar.Size = .default
  var buttonVariant: VariantButtonStyle.Variant = .plain
  var captionLayout: DateCalendar.CaptionLayout = .label
  var showOutsideDays = false
  var showWeekNumber = false
  var weekendsDisabled = false

  @State private var date: Date? = CalendarDates.day(3)

  var body: some View {
    DateCalendar(
      selection: $date,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      isDisabled: { day in
        guard weekendsDisabled else { return false }
        let weekday = Foundation.Calendar.current.component(.weekday, from: day)
        return weekday == 1 || weekday == 7
      }
    )
    .modifier(CalendarBordered())
  }
}

func day(_ offset: Int) -> Date {
  let calendar = Foundation.Calendar.current
  let start = calendar.startOfDay(for: Date())
  return calendar.date(byAdding: .day, value: offset, to: start) ?? start
}

func dayOfMonth(_ day: Int) -> Date {
  let calendar = Foundation.Calendar.current
  var components = calendar.dateComponents([.year, .month], from: Date())
  components.day = day
  return calendar.date(from: components) ?? Date()
}
```

```kotlin
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Calendar
import com.esuiss.ui.components.CalendarCaptionLayout
import com.esuiss.ui.components.CalendarSize
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import java.util.Date
import java.util.GregorianCalendar
import java.util.Locale

@Composable
fun CalendarOutsideDaysExample() {
    CalendarSingle(showOutsideDays = true)
}

fun calendarDay(offsetDays: Int = 0, dayOfMonth: Int? = null): Date {
    val now = GregorianCalendar()
    val result = GregorianCalendar(now.get(GregorianCalendar.YEAR), now.get(GregorianCalendar.MONTH), now.get(GregorianCalendar.DAY_OF_MONTH))
    if (dayOfMonth != null) result.set(GregorianCalendar.DAY_OF_MONTH, dayOfMonth)
    result.add(GregorianCalendar.DAY_OF_MONTH, offsetDays)
    return result.time
}

fun calendarIsWeekend(date: Date): Boolean {
    val day = GregorianCalendar().apply { time = date }.get(GregorianCalendar.DAY_OF_WEEK)
    return day == GregorianCalendar.SATURDAY || day == GregorianCalendar.SUNDAY
}

@Composable
fun CalendarFrame(content: @Composable () -> Unit) {
    Box(
        Modifier
            .border(1.dp, EsuissTheme.colors.separator, RoundedCornerShape(Radius.xl2))
            .padding(1.dp),
    ) {
        content()
    }
}

@Composable
fun CalendarSingle(
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    showWeekNumber: Boolean = false,
    showOutsideDays: Boolean = false,
    weekendsDisabled: Boolean = false,
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    locale: Locale = Locale.getDefault(),
    key: String = "",
) {
    var date by rememberSaveable(key) { mutableStateOf<Date?>(calendarDay(offsetDays = 3)) }
    CalendarFrame {
        Calendar(
            selected = date,
            onSelect = { date = it },
            size = size,
            captionLayout = captionLayout,
            showWeekNumber = showWeekNumber,
            showOutsideDays = showOutsideDays,
            disabled = { weekendsDisabled && calendarIsWeekend(it) },
            buttonVariant = buttonVariant,
            locale = locale,
        )
    }
}
```

### Button variants

Navigation buttons in the `ghost`, `secondary` and `tinted` variants.

![Preview](https://uim.suiss.app/previews/components-calendar--button-variants.light.webp)

```tsx
import * as React from "react"
import { ScrollView } from "react-native"
import { Calendar } from "@/components/ui/calendar"

type CalendarProps = React.ComponentProps<typeof Calendar>

function SingleCalendar(
  props: Omit<CalendarProps, "mode" | "selected" | "onSelect">
) {
  const today = new Date()
  const [date, setDate] = React.useState<Date | undefined>(
    new Date(today.getFullYear(), today.getMonth(), today.getDate() + 3)
  )
  return (
    <Calendar
      {...props}
      mode="single"
      selected={date}
      onSelect={setDate}
      className="rounded-2xl border border-separator"
    />
  )
}

export function CalendarButtonVariantsExample() {
  return (
    <ScrollView contentContainerClassName="items-start gap-6">
      <SingleCalendar buttonVariant="ghost" />
      <SingleCalendar buttonVariant="secondary" />
      <SingleCalendar buttonVariant="tinted" />
    </ScrollView>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CalendarButtonVariantsExample: View {
  var body: some View {
    VStack(alignment: .leading, spacing: 24) {
      CalendarSingleDemo(buttonVariant: .ghost)
      CalendarSingleDemo(buttonVariant: .secondary)
      CalendarSingleDemo(buttonVariant: .tinted)
    }
  }
}

enum CalendarDates {
  static func day(_ offset: Int) -> Date {
    let calendar = Foundation.Calendar.current
    let start = calendar.startOfDay(for: Date())
    return calendar.date(byAdding: .day, value: offset, to: start) ?? start
  }

  static func dayOfMonth(_ day: Int) -> Date {
    let calendar = Foundation.Calendar.current
    var components = calendar.dateComponents([.year, .month], from: Date())
    components.day = day
    return calendar.date(from: components) ?? Date()
  }
}

struct CalendarBordered: ViewModifier {
  func body(content: Content) -> some View {
    content
      .clipShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
      .overlay {
        RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).strokeBorder(Color.separator)
      }
  }
}

struct CalendarSingleDemo: View {
  var size: DateCalendar.Size = .default
  var buttonVariant: VariantButtonStyle.Variant = .plain
  var captionLayout: DateCalendar.CaptionLayout = .label
  var showOutsideDays = false
  var showWeekNumber = false
  var weekendsDisabled = false

  @State private var date: Date? = CalendarDates.day(3)

  var body: some View {
    DateCalendar(
      selection: $date,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      isDisabled: { day in
        guard weekendsDisabled else { return false }
        let weekday = Foundation.Calendar.current.component(.weekday, from: day)
        return weekday == 1 || weekday == 7
      }
    )
    .modifier(CalendarBordered())
  }
}

func day(_ offset: Int) -> Date {
  let calendar = Foundation.Calendar.current
  let start = calendar.startOfDay(for: Date())
  return calendar.date(byAdding: .day, value: offset, to: start) ?? start
}

func dayOfMonth(_ day: Int) -> Date {
  let calendar = Foundation.Calendar.current
  var components = calendar.dateComponents([.year, .month], from: Date())
  components.day = day
  return calendar.date(from: components) ?? Date()
}
```

```kotlin
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Calendar
import com.esuiss.ui.components.CalendarCaptionLayout
import com.esuiss.ui.components.CalendarSize
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import java.util.Date
import java.util.GregorianCalendar
import java.util.Locale

fun calendarDay(offsetDays: Int = 0, dayOfMonth: Int? = null): Date {
    val now = GregorianCalendar()
    val result = GregorianCalendar(now.get(GregorianCalendar.YEAR), now.get(GregorianCalendar.MONTH), now.get(GregorianCalendar.DAY_OF_MONTH))
    if (dayOfMonth != null) result.set(GregorianCalendar.DAY_OF_MONTH, dayOfMonth)
    result.add(GregorianCalendar.DAY_OF_MONTH, offsetDays)
    return result.time
}

fun calendarIsWeekend(date: Date): Boolean {
    val day = GregorianCalendar().apply { time = date }.get(GregorianCalendar.DAY_OF_WEEK)
    return day == GregorianCalendar.SATURDAY || day == GregorianCalendar.SUNDAY
}

@Composable
fun CalendarFrame(content: @Composable () -> Unit) {
    Box(
        Modifier
            .border(1.dp, EsuissTheme.colors.separator, RoundedCornerShape(Radius.xl2))
            .padding(1.dp),
    ) {
        content()
    }
}

@Composable
fun CalendarSingle(
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    showWeekNumber: Boolean = false,
    showOutsideDays: Boolean = false,
    weekendsDisabled: Boolean = false,
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    locale: Locale = Locale.getDefault(),
    key: String = "",
) {
    var date by rememberSaveable(key) { mutableStateOf<Date?>(calendarDay(offsetDays = 3)) }
    CalendarFrame {
        Calendar(
            selected = date,
            onSelect = { date = it },
            size = size,
            captionLayout = captionLayout,
            showWeekNumber = showWeekNumber,
            showOutsideDays = showOutsideDays,
            disabled = { weekendsDisabled && calendarIsWeekend(it) },
            buttonVariant = buttonVariant,
            locale = locale,
        )
    }
}

@Composable
fun CalendarButtonVariants() {
    Column(verticalArrangement = Arrangement.spacedBy(24.dp)) {
        CalendarSingle(buttonVariant = ButtonVariant.Ghost, key = "ghost")
        CalendarSingle(buttonVariant = ButtonVariant.Secondary, key = "secondary")
        CalendarSingle(buttonVariant = ButtonVariant.Tinted, key = "tinted")
    }
}
```

### Locale

Turkish month and weekday names with `locale="tr-TR"`.

![Preview](https://uim.suiss.app/previews/components-calendar--locale.light.webp)

```tsx
import * as React from "react"
import { Calendar } from "@/components/ui/calendar"

type CalendarProps = React.ComponentProps<typeof Calendar>

function SingleCalendar(
  props: Omit<CalendarProps, "mode" | "selected" | "onSelect">
) {
  const today = new Date()
  const [date, setDate] = React.useState<Date | undefined>(
    new Date(today.getFullYear(), today.getMonth(), today.getDate() + 3)
  )
  return (
    <Calendar
      {...props}
      mode="single"
      selected={date}
      onSelect={setDate}
      className="rounded-2xl border border-separator"
    />
  )
}

export function CalendarLocaleExample() {
  return (
    <SingleCalendar locale="tr-TR" />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CalendarLocaleExample: View {
  var body: some View {
    CalendarSingleDemo()
      .environment(\.locale, Locale(identifier: "tr_TR"))
  }
}

enum CalendarDates {
  static func day(_ offset: Int) -> Date {
    let calendar = Foundation.Calendar.current
    let start = calendar.startOfDay(for: Date())
    return calendar.date(byAdding: .day, value: offset, to: start) ?? start
  }

  static func dayOfMonth(_ day: Int) -> Date {
    let calendar = Foundation.Calendar.current
    var components = calendar.dateComponents([.year, .month], from: Date())
    components.day = day
    return calendar.date(from: components) ?? Date()
  }
}

struct CalendarBordered: ViewModifier {
  func body(content: Content) -> some View {
    content
      .clipShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
      .overlay {
        RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).strokeBorder(Color.separator)
      }
  }
}

struct CalendarSingleDemo: View {
  var size: DateCalendar.Size = .default
  var buttonVariant: VariantButtonStyle.Variant = .plain
  var captionLayout: DateCalendar.CaptionLayout = .label
  var showOutsideDays = false
  var showWeekNumber = false
  var weekendsDisabled = false

  @State private var date: Date? = CalendarDates.day(3)

  var body: some View {
    DateCalendar(
      selection: $date,
      size: size,
      buttonVariant: buttonVariant,
      captionLayout: captionLayout,
      showOutsideDays: showOutsideDays,
      showWeekNumber: showWeekNumber,
      isDisabled: { day in
        guard weekendsDisabled else { return false }
        let weekday = Foundation.Calendar.current.component(.weekday, from: day)
        return weekday == 1 || weekday == 7
      }
    )
    .modifier(CalendarBordered())
  }
}

func day(_ offset: Int) -> Date {
  let calendar = Foundation.Calendar.current
  let start = calendar.startOfDay(for: Date())
  return calendar.date(byAdding: .day, value: offset, to: start) ?? start
}

func dayOfMonth(_ day: Int) -> Date {
  let calendar = Foundation.Calendar.current
  var components = calendar.dateComponents([.year, .month], from: Date())
  components.day = day
  return calendar.date(from: components) ?? Date()
}
```

```kotlin
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Calendar
import com.esuiss.ui.components.CalendarCaptionLayout
import com.esuiss.ui.components.CalendarSize
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import java.util.Date
import java.util.GregorianCalendar
import java.util.Locale

@Composable
fun CalendarLocaleExample() {
    CalendarSingle(locale = Locale.forLanguageTag("tr-TR"))
}

fun calendarDay(offsetDays: Int = 0, dayOfMonth: Int? = null): Date {
    val now = GregorianCalendar()
    val result = GregorianCalendar(now.get(GregorianCalendar.YEAR), now.get(GregorianCalendar.MONTH), now.get(GregorianCalendar.DAY_OF_MONTH))
    if (dayOfMonth != null) result.set(GregorianCalendar.DAY_OF_MONTH, dayOfMonth)
    result.add(GregorianCalendar.DAY_OF_MONTH, offsetDays)
    return result.time
}

fun calendarIsWeekend(date: Date): Boolean {
    val day = GregorianCalendar().apply { time = date }.get(GregorianCalendar.DAY_OF_WEEK)
    return day == GregorianCalendar.SATURDAY || day == GregorianCalendar.SUNDAY
}

@Composable
fun CalendarFrame(content: @Composable () -> Unit) {
    Box(
        Modifier
            .border(1.dp, EsuissTheme.colors.separator, RoundedCornerShape(Radius.xl2))
            .padding(1.dp),
    ) {
        content()
    }
}

@Composable
fun CalendarSingle(
    size: CalendarSize = CalendarSize.Default,
    captionLayout: CalendarCaptionLayout = CalendarCaptionLayout.Label,
    showWeekNumber: Boolean = false,
    showOutsideDays: Boolean = false,
    weekendsDisabled: Boolean = false,
    buttonVariant: ButtonVariant = ButtonVariant.Plain,
    locale: Locale = Locale.getDefault(),
    key: String = "",
) {
    var date by rememberSaveable(key) { mutableStateOf<Date?>(calendarDay(offsetDays = 3)) }
    CalendarFrame {
        Calendar(
            selected = date,
            onSelect = { date = it },
            size = size,
            captionLayout = captionLayout,
            showWeekNumber = showWeekNumber,
            showOutsideDays = showOutsideDays,
            disabled = { weekendsDisabled && calendarIsWeekend(it) },
            buttonVariant = buttonVariant,
            locale = locale,
        )
    }
}
```

## API Reference

### CalendarDayButton

Pressable day cell styled for each selection state.

### Calendar

Month grids with caption and navigation.

## Accessibility

- Each month is a `grid` labelled with its caption.
- Day cells have the `button` role, a full date label, and `selected` and `disabled` state.
- The previous and next buttons are labelled "Go to the Previous Month" and "Go to the Next Month".
- Caption dropdowns are labelled "Choose the Month" and "Choose the Year".

## Notes

- Navigation arrows swap in right-to-left layouts.
- Uses `bg-accent`, `bg-accent-surface`, `bg-surface-secondary` and `text-link` tokens; light and dark follow the system appearance.