/**
 * 将用户粘贴的中文日期时间（如「2026年6月22日12时18分」）解析为系统标准格式。
 */
export type ChineseDatetimeFormat = 'date' | 'datetime' | 'datetime-minute'

/** 将日期时间规范为 `YYYY-MM-DD HH:mm`（去掉秒，兼容历史带秒数据） */
export function formatDatetimeToMinute(val: string): string {
  const s = String(val || '').trim()
  if (!s) return ''
  const parsed = parseChineseDatetimeText(s, 'datetime-minute')
  return parsed || s
}

export function parseChineseDatetimeText(
  text: string,
  format: ChineseDatetimeFormat
): string | null {
  const raw = text.trim()
  if (!raw) return null

  if (/^\d{4}-\d{2}-\d{2}$/.test(raw)) {
    return raw
  }

  if (/^\d{4}-\d{2}-\d{2}[ T]\d{2}:\d{2}(:\d{2})?$/.test(raw)) {
    const normalized = raw.replace('T', ' ')
    if (format === 'date') return normalized.slice(0, 10)
    const parts = normalized.split(' ')
    const time = parts[1] || '00:00:00'
    const timeParts = time.split(':')
    const hh = timeParts[0]?.padStart(2, '0') ?? '00'
    const mm = timeParts[1]?.padStart(2, '0') ?? '00'
    if (format === 'datetime-minute') {
      return `${parts[0]} ${hh}:${mm}`
    }
    const ss = timeParts[2]?.padStart(2, '0') ?? '00'
    return `${parts[0]} ${hh}:${mm}:${ss}`
  }

  const cnMatch = raw.match(
    /^(\d{4})年(\d{1,2})月(\d{1,2})日(?:\s*(\d{1,2})[时点:：](\d{1,2})(?:[分:：](\d{1,2})[秒]?)?)?/
  )
  if (!cnMatch) return null

  const y = cnMatch[1]
  const mo = String(Number(cnMatch[2])).padStart(2, '0')
  const d = String(Number(cnMatch[3])).padStart(2, '0')
  const dateStr = `${y}-${mo}-${d}`

  if (format === 'date') return dateStr

  const h = String(Number(cnMatch[4] || 0)).padStart(2, '0')
  const mi = String(Number(cnMatch[5] || 0)).padStart(2, '0')
  if (format === 'datetime-minute') {
    return `${dateStr} ${h}:${mi}`
  }
  const s = String(Number(cnMatch[6] || 0)).padStart(2, '0')
  return `${dateStr} ${h}:${mi}:${s}`
}

export function handleChineseDatetimePaste(
  e: ClipboardEvent,
  format: ChineseDatetimeFormat,
  setter: (val: string) => void
) {
  const text = e.clipboardData?.getData('text')?.trim()
  if (!text) return
  const parsed = parseChineseDatetimeText(text, format)
  if (!parsed) return
  e.preventDefault()
  e.stopPropagation()
  setter(parsed)
}