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

export default async function handler(req, res) {
  try {
    const pool = new Pool({
      connectionString: process.env.DATABASE_URL,
      ssl: process.env.NODE_ENV === 'production' ? { rejectUnauthorized: false } : false,
    });

    const client = await pool.connect();

    // Test basic connection
    const result = await client.query('SELECT NOW() as current_time');
    
    // Test if users table exists
    const tableCheck = await client.query(`
      SELECT table_name 
      FROM information_schema.tables 
      WHERE table_schema = 'public' 
      AND table_name IN ('users', 'roles', 'user_roles')
    `);

    // If users table exists, check for test user
    let userCheck = null;
    if (tableCheck.rows.some(row => row.table_name === 'users')) {
      try {
        userCheck = await client.query(
          'SELECT id, username, email FROM users WHERE username = $1',
          ['testuser']
        );
      } catch (err) {
        userCheck = { error: err.message };
      }
    }

    client.release();

    res.status(200).json({
      success: true,
      message: 'Database connection test',
      timestamp: result.rows[0].current_time,
      environment: {
        NODE_ENV: process.env.NODE_ENV,
        has_database_url: !!process.env.DATABASE_URL,
        has_jwt_secret: !!process.env.JWT_SECRET
      },
      tables: tableCheck.rows.map(row => row.table_name),
      testUser: userCheck ? {
        exists: userCheck.rows ? userCheck.rows.length > 0 : false,
        data: userCheck.rows ? userCheck.rows[0] : null,
        error: userCheck.error || null
      } : null
    });

  } catch (error) {
    console.error('Database test error:', error);
    res.status(500).json({
      success: false,
      error: error.message,
      stack: error.stack
    });
  }
}