const SHANGHAI_TIME_ZONE = 'Asia/Shanghai'

type ShanghaiDateTimeParts = {
  year: string
  month: string
  day: string
  hour: string
  minute: string
  second: string
}

const getShanghaiDateTimeParts = (date: Date): ShanghaiDateTimeParts => {
  if (Number.isNaN(date.getTime())) {
    throw new Error('导出时间无效')
  }

  const parts = new Intl.DateTimeFormat('en-CA', {
    timeZone: SHANGHAI_TIME_ZONE,
    year: 'numeric',
    month: '2-digit',
    day: '2-digit',
    hour: '2-digit',
    minute: '2-digit',
    second: '2-digit',
    hourCycle: 'h23'
  }).formatToParts(date)
  const partMap = new Map(parts.map((part) => [part.type, part.value]))

  return {
    year: partMap.get('year') || '',
    month: partMap.get('month') || '',
    day: partMap.get('day') || '',
    hour: partMap.get('hour') || '',
    minute: partMap.get('minute') || '',
    second: partMap.get('second') || ''
  }
}

export const formatShanghaiExportDateTime = (date: Date) => {
  const parts = getShanghaiDateTimeParts(date)
  return `${parts.year}-${parts.month}-${parts.day} ${parts.hour}:${parts.minute}:${parts.second}`
}

export const formatShanghaiExportFilenameTimestamp = (date: Date) => {
  const parts = getShanghaiDateTimeParts(date)
  return `${parts.year}${parts.month}${parts.day}_${parts.hour}${parts.minute}${parts.second}`
}

export const buildEquipmentExportDescriptionRows = (exportedAt: Date) => [
  { item: '文件性质', description: '导出时点快照' },
  {
    item: '导出时间',
    description: `${formatShanghaiExportDateTime(exportedAt)}（Asia/Shanghai）`
  },
  {
    item: '关系口径',
    description:
      '按导出时同一次只读事务快照中的当前 parent_id / children 父子关系生成，不包含历史挂载记录。'
  },
  {
    item: '时效提醒',
    description: '父子关系会随挂载、卸载而变化，请以系统最新导出为准。'
  },
  {
    item: '台账阅读',
    description:
      '“行政资产台账”每个根资产只占一行；当前子资产按 CPU、主板、内存、固态硬盘、机械硬盘、显卡六类拆列，无法识别的类型完整保留在“其他子资产”。同一分类有多项时按资产编码稳定排序并换行显示。'
  },
  {
    item: '关系核对',
    description:
      '“关系核对”只提示非电脑类根资产包含硬件子资产、存在未识别子资产或存在多个当前借用记录，不会自动改写当前资产关系；完整父子关系请查看“资产关系明细”。'
  },
  {
    item: '金额口径',
    description:
      '“当前价值（元）”沿用现有金额口径：根资产组合金额在导出快照内汇总组内全部本体价值，每个根资产只占一行，可安全求和；子资产自身价值请查看“资产关系明细”。'
  }
]