export function formatDuration(ms?: number | null): string {
  if (ms == null || Number.isNaN(ms)) return '-'
  if (ms < 1000) return `${Math.round(ms)}毫秒`
  if (ms < 60000) return `${(ms / 1000).toFixed(1)}秒`
  if (ms < 3600000) return `${(ms / 60000).toFixed(1)}分钟`
  return `${(ms / 3600000).toFixed(1)}小时`
}

export function formatDateTime(value?: string | null): string {
  if (!value || value === '-') return '-'
  const d = new Date(value)
  if (Number.isNaN(d.getTime())) return value
  return d.toLocaleString()
}

/** 简单 cron 说明（6 段秒级或 5 段） */
export function getCronDescription(expr?: string | null): string {
  if (!expr?.trim()) return '未设置'
  const parts = expr.trim().split(/\s+/)
  if (parts.length < 5) return expr
  // 常见快捷
  if (expr === '0 * * * * *' || expr === '* * * * *') return '每分钟'
  if (expr === '0 0 * * * *' || expr === '0 * * * *') return '每小时'
  if (expr === '0 0 0 * * *' || expr === '0 0 * * *') return '每天 0 点'
  if (expr.startsWith('*/')) return `周期: ${expr}`
  return expr
}

export function copyToClipboard(text: string): Promise<boolean> {
  if (navigator.clipboard?.writeText) {
    return navigator.clipboard.writeText(text).then(() => true).catch(() => false)
  }
  try {
    const ta = document.createElement('textarea')
    ta.value = text
    ta.style.position = 'fixed'
    ta.style.left = '-9999px'
    document.body.appendChild(ta)
    ta.select()
    const ok = document.execCommand('copy')
    document.body.removeChild(ta)
    return Promise.resolve(ok)
  } catch {
    return Promise.resolve(false)
  }
}