// 金额 / 时间格式化工具

function pad(n: number): string {
  return n < 10 ? `0${n}` : `${n}`
}

// 金额（分）转「¥xx.xx」字符串
export function fenToYuan(fen: number | null | undefined): string {
  if (fen === null || fen === undefined || isNaN(fen)) return '¥0.00'
  return `¥${(fen / 100).toFixed(2)}`
}

// 秒级时间戳转 YYYY-MM-DD
export function formatDate(seconds: number | null | undefined): string {
  if (!seconds) return ''
  const d = new Date(seconds * 1000)
  return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())}`
}

// 秒级时间戳转 YYYY-MM-DD HH:mm
export function formatDateTime(seconds: number | null | undefined): string {
  if (!seconds) return ''
  const d = new Date(seconds * 1000)
  return `${formatDate(seconds)} ${pad(d.getHours())}:${pad(d.getMinutes())}`
}

// 相对时间：刚刚 / x分钟前 / x小时前 / 今天 / YYYY-MM-DD
export function formatRelativeTime(seconds: number | null | undefined): string {
  if (!seconds) return ''
  const now = Math.floor(Date.now() / 1000)
  const diff = now - seconds
  if (diff < 0) return formatDate(seconds)
  if (diff < 60) return '刚刚'
  if (diff < 3600) return `${Math.floor(diff / 60)} 分钟前`

  const d = new Date(seconds * 1000)
  const today = new Date()
  const isToday =
    d.getFullYear() === today.getFullYear() &&
    d.getMonth() === today.getMonth() &&
    d.getDate() === today.getDate()

  if (diff < 86400) {
    return isToday ? '今天' : `${Math.floor(diff / 3600)} 小时前`
  }
  return formatDate(seconds)
}

// 支付倒计时（秒）转 mm:ss
export function formatCountdown(totalSeconds: number): string {
  if (totalSeconds <= 0) return '00:00'
  const m = Math.floor(totalSeconds / 60)
  const s = Math.floor(totalSeconds % 60)
  return `${pad(m)}:${pad(s)}`
}