const bcrypt = require('bcrypt');
const jwt = require('jsonwebtoken');
const { Pool } = require('pg');
const pool = new Pool({
  connectionString: process.env.DATABASE_URL, 
});


async function registerUser(req, res) {
  const { email, display_name, password } = req.body;
  const hashedPassword = await bcrypt.hash(password, 10);

  try {
    const client = await pool.connect();
    try {
      const result = await client.query(
        `INSERT INTO users (email, display_name, password_hash) VALUES ($1, $2, $3) RETURNING uid;`,
        [email, display_name, hashedPassword]
      );
      const uid = result.rows[0].uid;
      res.status(201).json({ uid });
    } finally {
      client.release();
    }
  } catch (error) {
    console.error('Error registering user:', error);
    res.status(500).json({ error: 'Server error' });
  }
}

async function authenticateUser(req, res) {
  const { email, password } = req.body;

  try {
    const client = await pool.connect();
    try {
      const result = await client.query('SELECT uid, password_hash FROM users WHERE email = $1;', [email]);
      const user = result.rows[0];

      if (user && bcrypt.compareSync(password, user.password_hash)) {
        const token = jwt.sign(
          { uid: user.uid, email: email },
          process.env.JWT_SECRET,  
          { expiresIn: '5d' } 
        );
        res.status(200).json({ token });
      } else {
        res.status(401).json({ error: 'Invalid credentials' });
      }
    } finally {
      client.release();
    }
  } catch (error) {
    console.error('Error authenticating user:', error);
    res.status(500).json({ error: 'Server error' });
  }
}

async function resetPassword(req, res) {
  const { uid, email, new_password } = req.body;
  const hashedPassword = await bcrypt.hash(new_password, 10);

  try {
    const client = await pool.connect();
    try {
      const result = await client.query(
        'UPDATE users SET password_hash = $1 WHERE uid = $2 AND email = $3;',
        [hashedPassword, uid, email]
      );
      if (result.rowCount === 0) {
        return res.status(400).json({ error: 'User not found' });
      }
      res.status(200).json({ message: 'Password reset successfully' });
    } finally {
      client.release();
    }
  } catch (error) {
    console.error('Error resetting password:', error);
    res.status(500).json({ error: 'Server error' });
  }
}

async function getLeaderboard(req, res) {
    try {
      const client = await pool.connect();
      try {
        const result = await client.query(
          'SELECT display_name, openskill_mu, current_elo, uid FROM users WHERE current_elo IS NOT NULL ORDER BY current_elo DESC;'
        );
        const players = result.rows;
  
        const playerEloList = players.map(player => ({
          player_name: player.display_name,
          osk_mu: player.openskill_mu,
          elo_rating: player.current_elo,
          friend_code: player.uid
        }));
  
        res.status(200).json(playerEloList); 
      } finally {
        client.release();
      }
    } catch (error) {
      console.error('Error fetching leaderboard:', error);
      res.status(500).json({ error: 'Server error' });
    }
  }

module.exports = {
  registerUser,
  authenticateUser,
  resetPassword,
  getLeaderboard,
};