const { Pool } = require('pg');

let pool;

async function connectDB() {
  pool = new Pool({
    connectionString: process.env.DATABASE_URL,
    ssl: process.env.NODE_ENV === 'production' && process.env.DATABASE_URL && !process.env.DATABASE_URL.includes('localhost') && !process.env.DATABASE_URL.includes('postgres:') 
      ? { rejectUnauthorized: false } 
      : false
  });
  
  // Test connection
  const client = await pool.connect();
  console.log('✅ PostgreSQL connected');
  
  // Run migrations
  await runMigrations(client);
  client.release();
  
  return pool;
}

async function runMigrations(client) {
  // Create migrations tracking table
  await client.query(`
    CREATE TABLE IF NOT EXISTS schema_migrations (
      id SERIAL PRIMARY KEY,
      filename VARCHAR(255) UNIQUE NOT NULL,
      applied_at TIMESTAMP DEFAULT NOW()
    )
  `);
  
  const fs = require('fs');
  const path = require('path');
  const migrationsDir = path.join(__dirname, 'migrations');
  
  if (!fs.existsSync(migrationsDir)) return;
  
  const files = fs.readdirSync(migrationsDir).sort();
  for (const file of files) {
    if (!file.endsWith('.sql')) continue;
    
    const { rows } = await client.query(
      'SELECT id FROM schema_migrations WHERE filename = $1',
      [file]
    );
    if (rows.length > 0) continue;
    
    const sql = fs.readFileSync(path.join(migrationsDir, file), 'utf8');
    await client.query(sql);
    await client.query(
      'INSERT INTO schema_migrations (filename) VALUES ($1)',
      [file]
    );
    console.log(`✅ Migration applied: ${file}`);
  }
}

function getPool() {
  return pool;
}

module.exports = { connectDB, getPool };