import { Pool } from 'pg';

const pool = new Pool({
  host: process.env.DB_HOST || 'localhost',
  port: Number(process.env.DB_PORT) || 5432,
  database: process.env.DB_NAME || 'demo_app',
  user: process.env.DB_USER || 'postgres',
  password: process.env.DB_PASSWORD
});

export async function query(sql: string, params: any[] = []) {
  const client = await pool.connect();
  try {
    return await client.query(sql, params);
  } finally {
    client.release();
  }
}

export async function queryOne(sql: string, params: any[] = []) {
  const result = await query(sql, params);
  if (result.rows.length === 0) {
    return null;
  }
  return result.rows[0];
}

export async function transaction<T>(
  callback: (client: any) => Promise<T>
): Promise<T> {
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    const result = await callback(client);
    await client.query('COMMIT');
    return result;
  } catch (error) {
    await client.query('ROLLBACK');
    throw error;
  } finally {
    client.release();
  }
}

// Made with Bob