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

async function addFriend(req, res) {
    const { friend_uid } = req.body;
    const token = req.headers['authorization'] && req.headers['authorization'].split(' ')[1];
  
    if (!token) {
      return res.status(403).json({ error: 'Access denied. No token provided.' });
    }
  
    try {
      const decoded = jwt.verify(token, process.env.JWT_SECRET);
      const userUid = decoded.uid; 
  
      const client = await pool.connect();
      try {
        const result = await client.query(
          'SELECT friend_list FROM users WHERE uid = $1;',
          [userUid]
        );
        let friends = result.rows[0]?.friend_list || {};
  
        if (Object.values(friends).includes(friend_uid)) {
          return res.status(400).json({ error: 'Friend already in the list.' });
        }
  
        const friendKey = `friend${Object.keys(friends).length}`;
        friends[friendKey] = friend_uid;
        const friendsJson = JSON.stringify(friends);
  
        await client.query(
          'UPDATE users SET friend_list = $1 WHERE uid = $2;',
          [friendsJson, userUid]
        );
  
        res.status(200).json({ message: 'Friend added successfully!' });
      } finally {
        client.release();
      }
    } catch (error) {
      console.error('Error adding friend:', error);
      res.status(500).json({ error: 'Server error' });
    }
  }

  async function getFriendDetails(friendUid) {
    const client = await pool.connect();
    try {
      const result = await client.query('SELECT display_name, uid FROM users WHERE uid = $1', [friendUid]);
      if (result.rows.length > 0) {
        return result.rows[0];
      }
      return null; 
    } finally {
      client.release();
    }
  }
  
  async function getFriendsList(req, res) {
    const userId = req.user.id;
  
    try {
      const client = await pool.connect();
      try {
        const result = await client.query(
          'SELECT friend_list FROM users WHERE uid = $1;',
          [userId]
        );
  
        const user = result.rows[0];
        if (!user || !user.friend_list) {
          return res.status(404).json({ error: 'No friends found.' });
        }
  
        const friends = JSON.parse(user.friend_list);
        const friendsDetails = [];
  
        for (const key in friends) {
          const friendUid = friends[key];
          const friendDetails = await getFriendDetails(friendUid);
          if (friendDetails) {
            friendsDetails.push(friendDetails);
          }
        }
  
        return res.status(200).json({ friends: friendsDetails });
      } finally {
        client.release();
      }
    } catch (error) {
      console.error('Error fetching friends:', error);
      res.status(400).json({ error: error.message });
    }
  }


  module.exports = {
    addFriend
  };