const test = require('node:test')
const assert = require('node:assert')
const { execFileSync } = require('node:child_process')
const Database = require('better-sqlite3')
const fs = require('node:fs')
const os = require('node:os')
const path = require('node:path')

// db.js 的迁移是在 require 时执行一次的（模块单例），所以没法在同一个进程里反复触发。
// 这里用子进程来「启动一次后端的数据层」，父进程只用 better-sqlite3 直接开同一个文件做
// 前置造数和结果断言。全程使用系统临时目录，绝不碰 server/data/birthday.db。
const DB_JS = path.join(__dirname, '..', 'src', 'db.js')

function bootDb(dbPath) {
  execFileSync(process.execPath, ['-e', 'require(process.env.MIGRATION_ENTRY)'], {
    env: { ...process.env, MIGRATION_ENTRY: DB_JS, DB_PATH: dbPath },
    stdio: 'ignore'
  })
}

function tempDbPath() {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'bday-mig-'))
  return path.join(dir, 'mig.db')
}

// 造一个「老库」：表结构齐全、有纪念日数据，但 subscribe_quota 为空、user_version 还是 0。
// 这正是本次改造上线时线上生产库的样子。
function makeLegacyDb(rows) {
  const dbPath = tempDbPath()
  bootDb(dbPath) // 先借 db.js 建出完整表结构
  const raw = new Database(dbPath)
  const insert = raw.prepare(`
    INSERT INTO anniversaries (id, openid, personName, type, solarMonth, solarDay, remindEnabled, remindDays)
    VALUES (?, ?, ?, 'birthday', 1, 1, 1, 3)
  `)
  for (const [id, openid] of rows) insert.run(id, openid, '某人')
  raw.prepare('DELETE FROM subscribe_quota').run()
  raw.pragma('user_version = 0')
  raw.close()
  return dbPath
}

function readQuota(dbPath) {
  const raw = new Database(dbPath, { readonly: true })
  const list = raw.prepare('SELECT * FROM subscribe_quota ORDER BY openid').all()
  const version = raw.pragma('user_version', { simple: true })
  raw.close()
  return { list, version }
}

test('迁移 v1：按纪念日条数给存量用户补初始余额', () => {
  const dbPath = makeLegacyDb([
    ['a1', 'uOld1'], ['a2', 'uOld1'], ['a3', 'uOld1'], // 3 条
    ['b1', 'uOld2']                                     // 1 条
  ])

  bootDb(dbPath)

  const { list, version } = readQuota(dbPath)
  assert.strictEqual(version, 1, 'user_version 应被推进到 1')
  assert.deepStrictEqual(
    list.map(r => [r.openid, r.balance, r.grantedTotal, r.sentTotal]),
    [['uOld1', 3, 3, 0], ['uOld2', 1, 1, 0]],
    '每个存量用户的初始余额应等于其纪念日条数'
  )
})

test('迁移 v1：重复启动不会重复累加（幂等）', () => {
  const dbPath = makeLegacyDb([['a1', 'uIdem'], ['a2', 'uIdem']])

  bootDb(dbPath) // 第一次：补 2
  bootDb(dbPath) // 第二次：user_version 已是 1，应直接跳过
  bootDb(dbPath) // 第三次：同上

  const { list } = readQuota(dbPath)
  assert.strictEqual(list.length, 1)
  assert.strictEqual(list[0].balance, 2, '反复启动后余额仍应是 2，不能累加成 4 或 6')
  assert.strictEqual(list[0].grantedTotal, 2)
})

test('迁移 v1：已有额度记录的用户不被覆盖', () => {
  const dbPath = makeLegacyDb([['a1', 'uHas'], ['a2', 'uHas'], ['c1', 'uNone']])

  // 模拟「已经用新版小程序补过额度」的用户：subscribe_quota 里已有一行
  const raw = new Database(dbPath)
  raw.prepare(`
    INSERT INTO subscribe_quota (openid, balance, grantedTotal, sentTotal, updateTime)
    VALUES ('uHas', 7, 9, 2, 0)
  `).run()
  raw.close()

  bootDb(dbPath)

  const { list } = readQuota(dbPath)
  const has = list.find(r => r.openid === 'uHas')
  const none = list.find(r => r.openid === 'uNone')
  assert.deepStrictEqual(
    [has.balance, has.grantedTotal, has.sentTotal], [7, 9, 2],
    '已有记录必须原样保留，不能被按纪念日条数估算出来的值覆盖'
  )
  assert.strictEqual(none.balance, 1, '尚无记录的用户照常补')
})

test('迁移 v1：全新空库也能正常推进版本号', () => {
  const dbPath = tempDbPath()

  bootDb(dbPath)

  const { list, version } = readQuota(dbPath)
  assert.strictEqual(version, 1)
  assert.strictEqual(list.length, 0, '没有纪念日就没有要补的用户')
})