import { Pool, PoolConfig, PoolClient } from 'pg';

// Re-export PoolClient for use in services
export type { PoolClient };
import { config } from './index.js';

// Simple logger for now (can be replaced with winston later)
const logger = {
  debug: (msg: string, meta?: object) => console.debug(`[DEBUG] ${msg}`, meta || ''),
  info: (msg: string, meta?: object) => console.info(`[INFO] ${msg}`, meta || ''),
  warn: (msg: string, meta?: object) => console.warn(`[WARN] ${msg}`, meta || ''),
  error: (msg: string, meta?: object) => console.error(`[ERROR] ${msg}`, meta || ''),
};

const poolConfig: PoolConfig = {
  host: config.database.host,
  port: config.database.port,
  database: config.database.name,
  user: config.database.user,
  password: config.database.password,
  max: 20,
  idleTimeoutMillis: 30000,
  connectionTimeoutMillis: 2000,
};

export const pool = new Pool(poolConfig);

pool.on('connect', () => {
  logger.debug('New database connection established');
});

pool.on('error', (err) => {
  logger.error('Unexpected database error', { error: err.message });
});

export async function testConnection(): Promise<boolean> {
  try {
    const client = await pool.connect();
    const result = await client.query('SELECT NOW()');
    client.release();
    logger.info('Database connection successful', { timestamp: result.rows[0].now });
    return true;
  } catch (error) {
    logger.error('Database connection failed', { error: (error as Error).message });
    return false;
  }
}

export async function query<T = any>(text: string, params?: any[]): Promise<T[]> {
  const start = Date.now();
  const result = await pool.query(text, params);
  const duration = Date.now() - start;

  logger.debug('Query executed', {
    text: text.substring(0, 100),
    duration: `${duration}ms`,
    rows: result.rowCount
  });

  return result.rows as T[];
}

export async function queryOne<T = any>(text: string, params?: any[]): Promise<T | null> {
  const rows = await query<T>(text, params);
  return rows[0] || null;
}

export async function getClient() {
  const client = await pool.connect();
  return client;
}

export async function closePool(): Promise<void> {
  await pool.end();
  logger.info('Database pool closed');
}