import pg from 'pg'

const { Pool } = pg

let pool: pg.Pool | null = null

export function getPool(): pg.Pool {
  if (!pool) {
    const config = useRuntimeConfig()
    pool = new Pool({
      connectionString: config.databaseUrl,
      max: 20,
      idleTimeoutMillis: 30000,
      connectionTimeoutMillis: 2000
    })

    pool.on('error', (err) => {
      console.error('Unexpected error on idle client', err)
    })
  }

  return pool
}

export async function query<T = any>(
  text: string,
  params?: any[]
): Promise<pg.QueryResult<T>> {
  const client = await getPool().connect()
  try {
    return await client.query<T>(text, params)
  } finally {
    client.release()
  }
}

export async function transaction<T>(
  callback: (client: pg.PoolClient) => Promise<T>
): Promise<T> {
  const client = await getPool().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()
  }
}