// 一次性数据迁移: 现网 MariaDB 只读快照 -> 0.2.1 PostgreSQL
// 运行 (在 app 容器内, 具备 mariadb 驱动与 PG 客户端):
//   SRC_DATABASE_URL=mysql://... node scripts/etl-mariadb-to-pg.mjs
// 约束: 源库仅 SELECT; 目标库须为空 (Project 计数为 0), 除非 ETL_FORCE=1
// 迁移内容见 docs/V0.2/离线编辑模块/0.2.1实施方案.md §6:
//   - 任务域 6 表回填 uuid; Project 回填短编号 code; Task 按项目内 (createdAt,id) 顺序回填 number
//   - 时序大表 (ServerNodeHistory/MihomeEnv*) 仅取最近 N 条
//   - 显式 id 插入后逐表 setval 校准序列
import 'dotenv/config'
import crypto from 'node:crypto'
import mariadb from 'mariadb'
import { PrismaPg } from '@prisma/adapter-pg'
import { PrismaClient } from '../generated/prisma/client.ts'

// 顺序: 先父后子
const TABLES = [
  ['User', 'user'],
  ['Project', 'project'],
  ['ProjectMember', 'projectMember'],
  ['BoardColumn', 'boardColumn'],
  ['Habit', 'habit'],
  ['CheckList', 'checkList'],
  ['CheckListTemplate', 'checkListTemplate'],
  ['CheckListItem', 'checkListItem'],
  ['CheckIn', 'checkIn'],
  ['Task', 'task'],
  ['TaskMember', 'taskMember'],
  ['TaskTag', 'taskTag'],
  ['Article', 'article'],
  ['Strategy', 'strategy'],
  ['Indicator', 'indicator'],
  ['IndicatorPoint', 'indicatorPoint'],
  ['News', 'news'],
  ['Alert', 'alert'],
  ['ServerNode', 'serverNode'],
  ['ServerNodeHistory', 'serverNodeHistory'],
  ['ServiceCheck', 'serviceCheck'],
  ['Econ_SowInventory', 'econ_SowInventory'],
  ['ScraperCache', 'scraperCache'],
  ['OilPriceHistory', 'oilPriceHistory'],
  ['MihomeAccount', 'mihomeAccount'],
  ['MihomeHome', 'mihomeHome'],
  ['MihomeDevice', 'mihomeDevice'],
  ['MihomeEnvSample', 'mihomeEnvSample'],
  ['MihomeEnvHour', 'mihomeEnvHour'],
]

const ROW_CAP = { ServerNodeHistory: 20000, MihomeEnvSample: 20000, MihomeEnvHour: 20000 }

const JSON_COLUMNS = {
  Strategy: ['data'],
  ScraperCache: ['metadata'],
  MihomeEnvSample: ['raw'],
  MihomeEnvHour: ['raw'],
  Project: ['notes', 'taskKinds'],
  Task: ['extras'],
  CheckListTemplate: ['items'],
}

const BIGINT_COLUMNS = {
  ServerNode: ['memTotal', 'diskTotal', 'ramUsed', 'swapUsed', 'diskUsed', 'netIn', 'netOut', 'uptime'],
  ServerNodeHistory: ['ram', 'disk', 'netIn', 'netOut'],
}

const UUID_TABLES = new Set(['Project', 'ProjectMember', 'BoardColumn', 'Task', 'TaskMember', 'TaskTag'])

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(/^\//, ''),
  }
}

function parseJson(v) {
  if (v === null || v === undefined || typeof v !== 'string') return v
  try { return JSON.parse(v) } catch { return v }
}

function toBigInt(v) {
  if (v === null || v === undefined || typeof v === 'bigint') return v
  return BigInt(v)
}

function randCode(len) {
  return crypto.randomBytes(len * 2).toString('hex').toUpperCase().replace(/[^A-Z0-9]/g, '').padEnd(len, 'X').slice(0, len)
}

async function main() {
  const src = process.env.SRC_DATABASE_URL
  if (!src) throw new Error('SRC_DATABASE_URL 未配置')
  const cfg = parseUrl(src)

  const conn = await mariadb.createConnection({
    host: cfg.host, port: cfg.port, user: cfg.user, password: cfg.password, database: cfg.database, connectTimeout: 8000,
  })
  console.log('[etl] 源库已连接 (只读):', `${cfg.host}:${cfg.port}/${cfg.database}`)

  const adapter = new PrismaPg({ connectionString: process.env.DATABASE_URL })
  const prisma = new PrismaClient({ adapter })

  const existing = await prisma.project.count()
  if (existing > 0 && process.env.ETL_FORCE !== '1') {
    console.log(`[etl] 目标库已有 ${existing} 个项目, 跳过 (ETL_FORCE=1 可强制)`)
    await conn.end()
    return
  }

  // Project.code 回填: 优先按名称推导字母, 冲突加随机尾缀
  const projectRows = await conn.query('SELECT * FROM `Project`')
  const usedCodes = new Set()
  for (const p of projectRows) {
    const letters = String(p.name || '').toUpperCase().replace(/[^A-Z0-9]/g, '')
    let cand = ''
    for (let i = 0; i < 30 && !cand; i++) {
      const base = i === 0
        ? (letters.length >= 2 ? letters.slice(0, 8) : ('P' + String(p.id) + randCode(4)).slice(0, 8))
        : (letters.slice(0, 5) + randCode(3)).slice(0, 8)
      if (base.length >= 2 && !usedCodes.has(base)) cand = base
    }
    if (!cand) cand = randCode(6)
    usedCodes.add(cand)
    p.code = cand
  }

  // Task.number 回填: 项目内按 (createdAt, id) 顺序 1..n
  const taskRows = (await conn.query('SELECT * FROM `Task`')).sort((a, b) => {
    if (a.projectId !== b.projectId) return a.projectId - b.projectId
    const ta = a.createdAt ? new Date(a.createdAt).getTime() : 0
    const tb = b.createdAt ? new Date(b.createdAt).getTime() : 0
    if (ta !== tb) return ta - tb
    return a.id - b.id
  })
  const taskNumber = new Map()
  for (const r of taskRows) {
    const key = String(r.projectId)
    const next = (taskNumber.get(key) || 0) + 1
    taskNumber.set(key, next)
    r.number = next
  }

  const counts = {}
  for (const [table, model] of TABLES) {
    let rows
    if (table === 'Project') rows = projectRows
    else if (table === 'Task') rows = taskRows
    else {
      const cap = ROW_CAP[table]
      rows = await conn.query(cap ? `SELECT * FROM \`${table}\` ORDER BY id DESC LIMIT ${cap}` : `SELECT * FROM \`${table}\``)
    }
    if (rows.length) {
      const jsonCols = JSON_COLUMNS[table] || []
      const bigCols = BIGINT_COLUMNS[table] || []
      for (const r of rows) {
        for (const c of jsonCols) r[c] = parseJson(r[c])
        for (const c of bigCols) r[c] = toBigInt(r[c])
        if (UUID_TABLES.has(table)) r.uuid = crypto.randomUUID()
      }
      const chunk = 500
      for (let i = 0; i < rows.length; i += chunk) {
        await prisma[model].createMany({ data: rows.slice(i, i + chunk) })
      }
    }
    counts[table] = rows.length
    console.log(`[etl] ${table}: ${rows.length}`)
  }

  // 序列校准: 显式插入 id 后必须 setval, 否则新插入主键冲突
  for (const [table] of TABLES) {
    await prisma.$executeRawUnsafe(
      `SELECT setval(pg_get_serial_sequence('"${table}"', 'id'), COALESCE((SELECT MAX(id) FROM "${table}"), 0) + 1, false)`,
    )
  }

  await conn.end()
  const summary = {
    users: await prisma.user.count(),
    projects: await prisma.project.count(),
    tasks: await prisma.task.count(),
    checkIns: await prisma.checkIn.count(),
    news: await prisma.news.count(),
  }
  console.log('[etl] 完成:', JSON.stringify(summary))
}

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