/**
 * 一次性数据迁移: 把 Indicator.data (JSON) 拆分到 IndicatorPoint 明细表
 * 用法: 在迁移 A (建表+加列) 之后、迁移 B (删 data 列) 之前运行
 * 幂等: 同 (indicatorId, period) 重复插入会更新 value, 可安全重跑
 */
require('dotenv').config()
const mysql = require('mysql2/promise')

function parseUrl(url) {
  const u = new URL(url)
  return {
    host: u.hostname,
    port: Number(u.port) || 3306,
    user: decodeURIComponent(u.username),
    password: decodeURIComponent(u.password),
    database: u.pathname.replace(/^\//, ''),
  }
}

// 根据 row 的时间字段推断频率: year | quarter | month | day
function inferFrequency(row) {
  if (row && row.month !== undefined) return 'month'
  if (row && row.year !== undefined) return 'year'
  const p = String((row && row.period) || '')
  if (/^\d{4}$/.test(p)) return 'year'
  if (/^\d{4}-Q[1-4]$/.test(p)) return 'quarter'
  if (/^\d{4}-\d{2}$/.test(p)) return 'month'
  if (/^\d{4}-\d{2}-\d{2}$/.test(p)) return 'day'
  return 'month'
}

// 统一 row 的时间字段为 period
function periodOf(row) {
  if (!row) return ''
  return String(row.period !== undefined ? row.period : (row.month !== undefined ? row.month : row.year))
}

async function main() {
  const conn = await mysql.createConnection(parseUrl(process.env.DATABASE_URL))
  try {
    const [rows] = await conn.execute('SELECT id, name, groupName, data FROM Indicator')
    console.log('[Migrate] 读取', rows.length, '个 Indicator')

    let points = 0, updated = 0
    for (const ind of rows) {
      // mysql2 对 JSON 列已自动解析为对象, 兼容字符串兜底
      let data = ind.data
      if (typeof data === 'string') {
        try { data = JSON.parse(data) } catch { data = null }
      }
      const title = (data && data.title) || ind.name
      const unit = (data && data.unit) || ''
      const source = (data && data.source) || ''
      const rowsArr = (data && Array.isArray(data.rows)) ? data.rows : []
      const freq = rowsArr.length ? inferFrequency(rowsArr[0]) : 'month'

      // 更新 Indicator 元数据列
      await conn.execute(
        'UPDATE Indicator SET title=?, unit=?, source=?, frequency=?, updatedAt=NOW(3) WHERE id=?',
        [title, unit, source, freq, ind.id],
      )
      updated++

      // 写入明细
      for (const r of rowsArr) {
        const period = periodOf(r)
        const value = Number(r.value)
        if (!period || Number.isNaN(value)) continue
        const [res] = await conn.execute(
          'INSERT INTO IndicatorPoint (indicatorId, period, value, createdAt, updatedAt) VALUES (?, ?, ?, NOW(3), NOW(3)) ' +
          'ON DUPLICATE KEY UPDATE value=VALUES(value), updatedAt=NOW(3)',
          [ind.id, period, value],
        )
        points += (res.affectedRows > 0 ? 1 : 0)
      }
      console.log('[Migrate]', ind.name, '->', rowsArr.length, '个点, 频率', freq)
    }
    console.log('[Migrate] 完成: 更新', updated, '个 Indicator, 写入/更新', points, '个明细点')
  } finally {
    await conn.end()
  }
}

main().catch((e) => { console.error('[Migrate] 失败:', e); process.exit(1) })