const express = require('express');
const router = express.Router();
const Notification = require('../models/Notifications');
const jwt = require('jsonwebtoken');
const bcrypt = require('bcrypt');

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();
  });
}

// Fetch the 15 most recent notifications for the authenticated user
// Fetch notifications for the authenticated user, paginated
router.get('/notifications', authenticate, async (req, res) => {
  // Parse the page number from the query string (default to 1 if not provided or invalid)
  const page = parseInt(req.query.page) || 1;
  console.log(req.query)

  // Set the number of notifications per page
  const pageSize = 15;

  // Calculate the skip index (for the MongoDB query) based on the current page number and page size
  const skipIndex = (page - 1) * pageSize;

  const notifications = await Notification.find({ user: req.userId })
    .sort({ read: 1, createdAt: -1 })
    .skip(skipIndex)
    .limit(pageSize);

  res.json(notifications);
});


// Fetch a single notification by its ID (optional)
router.get('/notifications/:id', authenticate, async (req, res) => {
  const notification = await Notification.findById(req.params.id);
  if (!notification) return res.status(404).send('Notification not found');
  res.json(notification);
});

// Mark a notification as read
router.put('/notifications/:id', authenticate, async (req, res) => {
  const notification = await Notification.findById(req.params.id);
  if (!notification) return res.status(404).send('Notification not found');
  notification.read = true;
  await notification.save();
  res.json(notification);
});

module.exports = router;