const express = require('express');
const router = express.Router();
const DirectMessage = require('../models/DirectMessage');
const jwt = require('jsonwebtoken');
const User = require('../models/User');

function authenticate(req, res, next) {
  const token = req.header('Authorization');
  if (!token) return res.sendStatus(401);
  jwt.verify(token, 'SECRET_KEY', (err, decoded) => {
    if (err) return res.sendStatus(401);
    req.userId = decoded.userId;
    next();
  });
}

router.get('/', authenticate, async (req, res) => {
    try {
        const dms = await DirectMessage.find({
            $or: [
                { sender: req.userId },
                { recipient: req.userId },
            ],
        }).populate('sender recipient', 'username');

        // Group the messages by conversation
        let conversations = {};
        dms.forEach(dm => {
            const otherUserId = dm.sender._id.toString() === req.userId ? dm.recipient._id.toString() : dm.sender._id.toString();
            if (!conversations[otherUserId]) {
                conversations[otherUserId] = {
                    userId: otherUserId,
                    username: dm.sender._id.toString() === req.userId ? dm.recipient.username : dm.sender.username,
                    messages: [],
                };
            }
            conversations[otherUserId].messages.push(dm);
        });

        // Convert the conversations object to an array
        const conversationsArray = Object.values(conversations);

        res.json(conversationsArray);
    } catch (error) {
        console.error(error);
        res.status(500).json({ error: "Could not get Direct Messages." });
    }
});


router.get('/:otherUserId', authenticate, async (req, res) => {
    const { otherUserId } = req.params;

    try {
        const dms = await DirectMessage.find({
            $or: [
                { sender: req.userId, recipient: otherUserId },
                { sender: otherUserId, recipient: req.userId },
            ],
        }).populate('sender recipient', 'username');

        res.json(dms);
    } catch (error) {
        console.error(error);
        res.status(500).json({ error: "Could not get Direct Messages." });
    }
});

router.delete('/:dmId', authenticate, async (req, res) => {
    const { dmId } = req.params;

    try {
        const dm = await DirectMessage.findById(dmId);

        if (!dm) {
            return res.status(404).json({ error: "Direct Message not found." });
        }

        // Check if the authenticated user is the sender of the DM
        if (dm.sender.toString() !== req.userId) {
            return res.status(403).json({ error: "You can only delete your own Direct Messages." });
        }

        await dm.remove();

        res.json({ message: "Direct Message deleted." });
    } catch (error) {
        console.error(error);
        res.status(500).json({ error: "Could not delete Direct Message." });
    }
});

router.post('/send', authenticate, async (req, res) => {
    const { recipientId, text, senderId } = req.body;
    console.log(req.user)
  
    if (!recipientId || !text) {
      return res.status(400).json({ error: "Recipient ID and text are required." });
    }
  
    try {
      // Check if the recipient exists
      const recipient = await User.findById(recipientId);
      if (!recipient) {
        return res.status(404).json({ error: "Recipient not found." });
      }
// Create the Direct Message
const dm = new DirectMessage({
    sender: senderId,
    recipient: recipientId,
    content: text,
  });
  
  // Save the Direct Message
  const savedDm = await dm.save();
  
  // Populate the sender and recipient fields with full user objects
  await savedDm.populate('sender recipient', 'username').exec;
  
  // Now emit the `new_dm` event with the populated Direct Message
  const io = req.app.io;
  const senderSocketId = req.app.onlineUsers[senderId];
  const recipientSocketId = req.app.onlineUsers[recipientId];
  if (senderSocketId) {
    io.to(senderSocketId).emit('new_dm', savedDm);
  }
  if (recipientSocketId) {
    io.to(recipientSocketId).emit('new_dm', savedDm);
  }
  


      res.json(savedDm);
    } catch (error) {
      console.error(error);
      res.status(500).json({ error: "Could not send Direct Message." });
    }
  });

module.exports = router;