Session Management in Node.js

				
					const express = require('express');
const mongoose = require('mongoose');
const session = require('express-session');
const MongoStore = require('connect-mongo')(session);
const User = require('./models/User');

// Connect to MongoDB
mongoose.connect('mongodb://localhost:27017/authSessionDB', {
    useNewUrlParser: true,
    useUnifiedTopology: true
});

const app = express();
const PORT = 3000;

app.use(express.urlencoded({ extended: true }));

// Set up session middleware with MongoDB storage
app.use(session({
    secret: 'mysecret',
    resave: false,
    saveUninitialized: false,
    store: new MongoStore({ mongooseConnection: mongoose.connection }),
    cookie: { secure: false } // Set to true in production with HTTPS
}));

// Middleware to check if user is authenticated
function isAuthenticated(req, res, next) {
    if (req.session.user) {
        return next();
    }
    res.redirect('/login');
}

// Route to serve the homepage
app.get('/', isAuthenticated, (req, res) => {
    res.send(`Hello, ${req.session.user.username}! <a href="/logout">Logout</a>`);
});

// Route to handle user registration
app.post('/register', async (req, res) => {
    const { username, password } = req.body;
    try {
        const newUser = new User({ username, password });
        await newUser.save();
        req.session.user = newUser;
        res.redirect('/');
    } catch (err) {
        res.send('Registration failed. Username might already be taken.');
    }
});

// Route to serve the registration page
app.get('/register', (req, res) => {
    res.send(`<form method="post" action="/register">
                Username: <input type="text" name="username" required><br>
                Password: <input type="password" name="password" required><br>
                <button type="submit">Register</button>
              </form>`);
});

// Route to handle user login
app.post('/login', async (req, res) => {
    const { username, password } = req.body;
    const user = await User.findOne({ username });
    if (user && await user.comparePassword(password)) {
        req.session.user = user;
        res.redirect('/');
    } else {
        res.send('Invalid username or password.');
    }
});

// Route to serve the login page
app.get('/login', (req, res) => {
    res.send(`<form method="post" action="/login">
                Username: <input type="text" name="username" required><br>
                Password: <input type="password" name="password" required><br>
                <button type="submit">Login</button>
              </form>`);
});

// Route to handle user logout
app.get('/logout', (req, res) => {
    req.session.destroy((err) => {
        if (err) {
            return res.status(500).send('Failed to logout.');
        }
        res.redirect('/login');
    });
});

app.listen(PORT, () => {
    console.log(`Server running on port ${PORT}`);
});