import { readdir, readFile } from 'node:fs/promises'
import { fileURLToPath } from 'node:url'
import { createHash } from 'node:crypto'
import { createDatabase } from '@trumpsignal/database'
const url = process.env.DATABASE_URL
if (!url) throw new Error('DATABASE_URL required')
const { pool, lockPool } = createDatabase(url),
  client = await pool.connect()
try {
  await client.query('SELECT pg_advisory_lock(hashtextextended($1,0))', ['trumpsignal-migration'])
  await client.query(
    'CREATE TABLE IF NOT EXISTS typescript_migrations (name TEXT PRIMARY KEY, sha256 TEXT NOT NULL, applied_at TIMESTAMPTZ NOT NULL DEFAULT now())',
  )
  const folder = fileURLToPath(new URL('../packages/database/migrations/', import.meta.url)),
    files = (await readdir(folder)).filter((n) => n.endsWith('.sql')).sort()
  for (const name of files) {
    const source = await readFile(folder + name, 'utf8'),
      hash = createHash('sha256').update(source).digest('hex'),
      old = await client.query<{ sha256: string }>(
        'SELECT sha256 FROM typescript_migrations WHERE name=$1',
        [name],
      )
    if (old.rows[0]) {
      if (old.rows[0].sha256 !== hash)
        throw new Error('Previously applied migration changed: ' + name)
      continue
    }
    if (name.startsWith('0001')) {
      const legacy = await client.query<{ exists: boolean }>(
        "SELECT to_regclass('public.alembic_version') IS NOT NULL AS exists",
      )
      if (legacy.rows[0].exists) {
        const head = await client.query<{ version_num: string }>(
          'SELECT version_num FROM alembic_version',
        )
        if (!head.rows.some((r) => r.version_num.startsWith('027')))
          throw new Error('Existing legacy database must reach Alembic head 027 first')
      }
    }
    await client.query('BEGIN')
    try {
      await client.query(source)
      await client.query('INSERT INTO typescript_migrations(name,sha256) VALUES ($1,$2)', [
        name,
        hash,
      ])
      await client.query('COMMIT')
      process.stdout.write('Applied ' + name + '\n')
    } catch (e) {
      await client.query('ROLLBACK')
      throw e
    }
  }
} finally {
  await client.query('SELECT pg_advisory_unlock(hashtextextended($1,0))', ['trumpsignal-migration'])
  client.release()
  await pool.end()
  await lockPool.end()
}