const mysql = require('mysql2/promise')
const fs = require('fs')
const path = require('path')

const DB_CFG = {
  host: 'cq-cdb-8fjmemkb.sql.tencentcdb.com',
  port: 27220,
  user: 'root',
  password: 'Ylrz_1q2w3e4r5t6y',
  multipleStatements: true
}

const MIGRATION_SQL = fs.readFileSync(
  path.join(__dirname, '../../java/fs-agent/src/main/resources/db/migration/tenant/V20260623_01__lobster_execution_config_drop_task_policy.sql'),
  'utf8'
)

function dbNameFromUrl(url) {
  if (!url) return null
  const m = String(url).match(/\/([^/?]+)(?:\?|$)/)
  return m ? m[1] : null
}

async function applyMigration(database) {
  const conn = await mysql.createConnection({ ...DB_CFG, database })
  await conn.query(MIGRATION_SQL)
  const [cols] = await conn.query(
    "SHOW COLUMNS FROM lobster_execution_config LIKE 'enable_%'"
  )
  await conn.end()
  return { database, legacyCols: cols.length }
}

async function main() {
  const masterConn = await mysql.createConnection({ ...DB_CFG, database: 'ylrz_saas' })
  const dbs = new Set()
  try {
    const [tenants] = await masterConn.query(
      'SELECT id, tenant_code, db_url FROM tenant_info WHERE db_url IS NOT NULL AND db_url != \'\''
    )
    for (const t of tenants) {
      const name = dbNameFromUrl(t.db_url)
      if (name) dbs.add(name)
    }
  } catch (e) {
    console.warn('tenant_info query skipped:', e.message)
  }
  await masterConn.end()

  for (const db of dbs) {
    try {
      const r = await applyMigration(db)
      console.log(`${db}: legacy_task_policy_cols=${r.legacyCols} (0=OK)`)
    } catch (e) {
      console.error(`${db}: ERROR ${e.message}`)
    }
  }
}

main().catch(e => {
  console.error(e)
  process.exit(1)
})