import type { Locale } from 'date-fns'
import {
  formatDateAsNumeral,
  formatDateAsText,
  isDisabledDate,
  isInvalidDate,
  isSelectingDayInCalendar,
  parseDateFromNumeralFormatValue,
  parseDateFromTextFormatValue,
  type DisabledDays,
} from '~components/Calendar'
import { type DateInputProps } from '~components/DateInput'

type UseDateInputHandlersArgs = {
  locale: Locale
  disabledDays?: DisabledDays
  setInputValue: (value: string) => void
  onDateChange: (date: Date | undefined) => void
  onDateSubmit?: (date: Date) => void
  onChange?: DateInputProps['onChange']
  onFocus?: DateInputProps['onFocus']
  onBlur?: DateInputProps['onBlur']
  onKeyDown?: DateInputProps['onKeyDown']
}

type UseDateInputHandlersValue = {
  onChange: DateInputProps['onChange']
  onFocus: DateInputProps['onFocus']
  onBlur: DateInputProps['onBlur']
  onKeyDown: DateInputProps['onKeyDown']
}

export const useDateInputHandlers = ({
  locale,
  disabledDays,
  setInputValue,
  onDateChange,
  onDateSubmit,
  onChange,
  onFocus,
  onBlur,
  onKeyDown,
}: UseDateInputHandlersArgs): UseDateInputHandlersValue => {
  const isValidDate = (date: Date): boolean =>
    !isInvalidDate(date) && !isDisabledDate(date, disabledDays)

  const handleChange: DateInputProps['onChange'] = (e) => {
    setInputValue(e.currentTarget.value)
    onChange?.(e)
  }

  const handleFocus: DateInputProps['onFocus'] = (e) => {
    const date = parseDateFromTextFormatValue(e.currentTarget.value, locale)
    if (!isInvalidDate(date)) {
      const newInputValue = formatDateAsNumeral(date, locale)
      setInputValue(newInputValue)
    }
    onFocus?.(e)
  }

  const handleBlur: DateInputProps['onBlur'] = (e) => {
    if (isSelectingDayInCalendar(e.relatedTarget)) return

    if (e.currentTarget.value === '') {
      onDateChange(undefined)
      onBlur?.(e)
      return
    }

    const date = parseDateFromNumeralFormatValue(e.currentTarget.value, locale)

    if (isValidDate(date)) {
      const newInputValue = formatDateAsText(date, disabledDays, locale)
      setInputValue(newInputValue)
    }

    onDateChange(date)
    onBlur?.(e)
  }

  const handleKeyDown: DateInputProps['onKeyDown'] = (e) => {
    if (e.key === 'Enter') {
      e.preventDefault()
      const date = parseDateFromNumeralFormatValue(e.currentTarget.value, locale)
      onDateChange(date)
      onDateSubmit?.(date)
    }
    onKeyDown?.(e)
  }

  return {
    onChange: handleChange,
    onFocus: handleFocus,
    onBlur: handleBlur,
    onKeyDown: handleKeyDown,
  }
}