Want To Add Backend Of Login/Signup Page #191 (#220)

* added backend of login/signup

* updated

* removed node_modules

backend/index.js

@@ -0,0 +1,100 @@
+const express = require('express');
+const mongoose = require('mongoose');
+const bcrypt = require('bcryptjs');
+const jwt = require('jsonwebtoken');
+const bodyParser = require('body-parser');
+const cors = require('cors');
+
+const app = express();
+const PORT = process.env.PORT || 5000;
+const JWT_SECRET = 'your_jwt_secret'; // Replace with your own secret
+
+// Middleware
+app.use(bodyParser.json());
+app.use(cors());
+
+// MongoDB connection
+mongoose.connect('ADD_MONGO_DB_URI', {
+    useNewUrlParser: true,
+    useUnifiedTopology: true
+})
+.then(() => console.log('MongoDB connected'))
+.catch(err => console.error('MongoDB connection error:', err));
+
+// User schema and model
+const userSchema = new mongoose.Schema({
+    username: { type: String, required: true, unique: true },
+    email: { type: String, required: true, unique: true },
+    password: { type: String, required: true }
+});
+
+const User = mongoose.model('User', userSchema);
+
+// Signup route
+app.post('/api/signup', async (req, res) => {
+    const { username, email, password } = req.body;
+
+    try {
+        // Check if user already exists
+        const existingUser = await User.findOne({ email });
+        const existingUsername = await User.findOne({ username });
+        if (existingUser) {
+            return res.status(400).json({ message: 'User already exists' });
+        }
+      if (existingUsername) {
+            return res.status(400).json({ message: 'Username already exists' });
+        }
+        // Hash the password
+        const hashedPassword = await bcrypt.hash(password, 10);
+
+        // Create new user
+        const newUser = new User({
+            username,
+            email,
+            password: hashedPassword
+        });
+
+        await newUser.save();
+
+        // Generate JWT token
+        const token = jwt.sign({ userId: newUser._id }, JWT_SECRET, { expiresIn: '1h' });
+
+        // Respond with token
+        res.status(201).json({ token });
+    } catch (error) {
+        console.error('Signup error:', error);
+        res.status(500).json({ message: 'Server error' });
+    }
+});
+
+// Login route
+app.post('/api/login', async (req, res) => {
+    const { email, password } = req.body;
+
+    try {
+        // Check if user exists
+        const user = await User.findOne({ email });
+        if (!user) {
+            return res.status(400).json({ message: 'Invalid email or password' });
+        }
+
+        // Check password
+        const isMatch = await bcrypt.compare(password, user.password);
+        if (!isMatch) {
+            return res.status(400).json({ message: 'Invalid email or password' });
+        }
+
+        // Generate JWT token
+        const token = jwt.sign({ userId: user._id }, JWT_SECRET, { expiresIn: '1h' });
+
+        // Respond with token
+        res.status(200).json({ token });
+    } catch (error) {
+        console.error('Login error:', error);
+        res.status(500).json({ message: 'Server error' });
+    }
+});
+
+app.listen(PORT, () => {
+    console.log(`Server running on port ${PORT}`);
+});