import type { VueNode } from '../../../_util/type'
import { useInjectPanel } from '../../PanelContext'
import type { GenerateConfig } from '../../generate'
import useMergeProps from '../../hooks/useMergeProps'
import type { Locale } from '../../interface'
import { formatValue } from '../../utils/dateUtil'
import Header from '../Header'

export interface DateHeaderProps<DateType> {
  prefixCls: string
  viewDate: DateType
  value?: DateType | null
  locale: Locale
  generateConfig: GenerateConfig<DateType>

  onPrevYear: () => void
  onNextYear: () => void
  onPrevMonth: () => void
  onNextMonth: () => void
  onYearClick: () => void
  onMonthClick: () => void
}

function DateHeader<DateType>(_props: DateHeaderProps<DateType>) {
  const props = useMergeProps(_props)
  const {
    prefixCls,
    generateConfig,
    locale,
    viewDate,
    onNextMonth,
    onPrevMonth,
    onNextYear,
    onPrevYear,
    onYearClick,
    onMonthClick,
  } = props

  const { hideHeader } = useInjectPanel()
  if (hideHeader.value) {
    return null
  }

  const headerPrefixCls = `${prefixCls}-header`

  const monthsLocale: string[] =
    locale.shortMonths ||
    (generateConfig.locale.getShortMonths
      ? generateConfig.locale.getShortMonths(locale.locale)
      : [])

  const month = generateConfig.getMonth(viewDate)

  // =================== Month & Year ===================
  const yearNode: VueNode = (
    <button
      type="button"
      key="year"
      onClick={onYearClick}
      tabindex={-1}
      class={`${prefixCls}-year-btn`}
    >
      {formatValue(viewDate, {
        locale,
        format: locale.yearFormat,
        generateConfig,
      })}
    </button>
  )
  const monthNode: VueNode = (
    <button
      type="button"
      key="month"
      onClick={onMonthClick}
      tabindex={-1}
      class={`${prefixCls}-month-btn`}
    >
      {locale.monthFormat
        ? formatValue(viewDate, {
            locale,
            format: locale.monthFormat,
            generateConfig,
          })
        : monthsLocale[month]}
    </button>
  )

  const monthYearNodes = locale.monthBeforeYear ? [monthNode, yearNode] : [yearNode, monthNode]

  return (
    <Header
      {...props}
      prefixCls={headerPrefixCls}
      onSuperPrev={onPrevYear}
      onPrev={onPrevMonth}
      onNext={onNextMonth}
      onSuperNext={onNextYear}
    >
      {monthYearNodes}
    </Header>
  )
}

DateHeader.displayName = 'DateHeader'
DateHeader.inheritAttrs = false
export default DateHeader
