import { readdirSync, readFileSync } from 'node:fs';
import { resolve } from 'node:path';
import { fileURLToPath } from 'node:url';
import { Pool } from 'pg';

const databaseUrl = process.env.DATABASE_URL;

if (!databaseUrl) {
  // eslint-disable-next-line no-console
  console.error('DATABASE_URL is required');
  process.exit(1);
}

const scriptDir = resolve(fileURLToPath(new URL('.', import.meta.url)));
const migrationsDir = resolve(scriptDir, '../sql/v2');

const migrationFiles = readdirSync(migrationsDir)
  .filter((file) => file.endsWith('.sql'))
  .sort();

const pool = new Pool({
  connectionString: databaseUrl,
  max: Number.parseInt(process.env.DB_POOL_MAX || '5', 10),
});

async function ensureMigrationTable(client) {
  await client.query(`
    CREATE TABLE IF NOT EXISTS schema_migrations (
      version TEXT PRIMARY KEY,
      applied_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );
  `);
}

try {
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    await ensureMigrationTable(client);

    for (const file of migrationFiles) {
      const alreadyApplied = await client.query(
        'SELECT 1 FROM schema_migrations WHERE version = $1',
        [file]
      );
      if (alreadyApplied.rowCount > 0) {
        continue;
      }

      const sql = readFileSync(resolve(migrationsDir, file), 'utf8');
      await client.query(sql);
      await client.query(
        'INSERT INTO schema_migrations (version) VALUES ($1)',
        [file]
      );
      // eslint-disable-next-line no-console
      console.log(`Applied migration ${file}`);
    }

    await client.query('COMMIT');
  } catch (error) {
    await client.query('ROLLBACK');
    throw error;
  } finally {
    client.release();
  }
} finally {
  await pool.end();
}