Create server.js

server.js

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+// server.js (Node.js backend)
+
+const express = require('express');
+const multer = require('multer');
+const cors = require('cors');
+const fs = require('fs');
+const path = require('path');
+const bcrypt = require('bcrypt');
+const jwt = require('jsonwebtoken');
+
+const app = express();
+const port = process.env.PORT || 3000;
+const secretKey = 'your-secret-key'; // Replace with a strong, randomly generated secret key
+const usersFilePath = 'users.json'; // File to store user data
+
+// --- Middleware ---
+app.use(cors({
+    origin: 'http://localhost:8080' // Replace with your frontend's origin (e.g., your domain)
+})); // Enable CORS for your frontend origin
+app.use(express.json());
+app.use(express.static('public'));
+
+// --- File Upload Configuration ---
+const storage = multer.diskStorage({
+    destination: (req, file, cb) => {
+        const uploadPath = 'uploads/';
+        fs.mkdirSync(uploadPath, { recursive: true });
+        cb(null, uploadPath);
+    },
+    filename: (req, file, cb) => {
+        const uniqueSuffix = Date.now() + '-' + Math.round(Math.random() * 1E9);
+        const ext = path.extname(file.originalname);
+        cb(null, file.fieldname + '-' + uniqueSuffix + ext);
+    }
+});
+
+const upload = multer({ storage: storage });
+
+// --- Load Users from File (Database Simulation) ---
+let users = [];
+function loadUsers() {
+    try {
+        const data = fs.readFileSync(usersFilePath, 'utf8');
+        users = JSON.parse(data);
+    } catch (error) {
+        console.log('No existing users file found or error loading users. Starting with an empty user list.');
+        users = []; // Start with an empty array if the file doesn't exist or has an error
+    }
+}
+
+function saveUsers() {
+    try {
+        fs.writeFileSync(usersFilePath, JSON.stringify(users, null, 2), 'utf8'); // Pretty print the JSON
+        console.log('Users saved to file.');
+    } catch (error) {
+        console.error('Error saving users to file:', error);
+    }
+}
+
+loadUsers(); // Load users when the server starts
+
+// --- Helper Functions ---
+
+function generateToken(user) {
+    const payload = {
+        userId: user.id,
+        email: user.email,
+        name: user.name
+    };
+    const options = {
+        expiresIn: '1h'
+    };
+    return jwt.sign(payload, secretKey, options);
+}
+
+// --- API Endpoints ---
+
+// 1. Registration
+app.post('/register', async (req, res) => {
+    try {
+        const { name, email, password, age, medicalHistory } = req.body;
+
+        // Input validation (enhanced)
+        if (!name || name.length < 2) {
+            return res.status(400).json({ message: 'Name must be at least 2 characters long.' });
+        }
+        if (!email || !email.includes('@')) {
+            return res.status(400).json({ message: 'Invalid email format.' });
+        }
+        if (!password || password.length < 6) {
+            return res.status(400).json({ message: 'Password must be at least 6 characters long.' });
+        }
+
+        // Check if the email is already registered
+        if (users.find(user => user.email === email)) {
+            return res.status(400).json({ message: 'Email already exists.' });
+        }
+
+        // Hash the password
+        const hashedPassword = await bcrypt.hash(password, 10);
+
+        // Create a new user object
+        const newUser = {
+            id: users.length > 0 ? users[users.length - 1].id + 1 : 1, // Simple ID generation
+            name,
+            email,
+            password: hashedPassword,
+            age,
+            medicalHistory,
+            analysisHistory: [] // Initialize analysis history
+        };
+
+        // Add the new user to the users array
+        users.push(newUser);
+        saveUsers(); // Save the updated user list to the file
+
+        res.status(201).json({ message: 'User registered successfully.' });
+
+    } catch (error) {
+        console.error('Registration error:', error);
+        res.status(500).json({ message: 'Registration failed. Please try again later.' });
+    }
+});
+
+// 2. Login
+app.post('/login', async (req, res) => {
+    try {
+        const { email, password } = req.body;
+
+        // Find the user by email
+        const user = users.find(user => user.email === email);
+
+        // Check if the user exists
+        if (!user) {
+            return res.status(401).json({ message: 'Invalid credentials.' });
+        }
+
+        // Compare the provided password with the hashed password
+        const passwordMatch = await bcrypt.compare(password, user.password);
+
+        // Check if the passwords match
+        if (!passwordMatch) {
+            return res.status(401).json({ message: 'Invalid credentials.' });
+        }
+
+        // Generate a JWT
+        const token = generateToken(user);
+
+        // Respond with the token
+        res.status(200).json({ token: token, message: 'Login successful' });
+
+    } catch (error) {
+        console.error('Login error:', error);
+        res.status(500).json({ message: 'Login failed.' });
+    }
+});
+
+// 3. Authentication Middleware
+function authenticateToken(req, res, next) {
+    const authHeader = req.headers['authorization'];
+    const token = authHeader && authHeader.split(' ')[1];
+
+    if (!token) {
+        return res.status(401).json({ message: 'Unauthorized: No token provided.' });
+    }
+
+    jwt.verify(token, secretKey, (err, user) => {
+        if (err) {
+            console.error('Token verification error:', err);
+            return res.status(403).json({ message: 'Forbidden: Invalid token.' });
+        }
+        req.user = user;
+        next();
+    });
+}
+
+// 4. Get User Data (Protected Route)
+app.get('/user', authenticateToken, (req, res) => {
+    try {
+        const userId = req.user.userId;
+        const user = users.find(user => user.id === userId);
+
+        if (!user) {
+            return res.status(404).json({ message: 'User not found.' });
+        }
+
+        // Return user data (excluding the password)
+        const userData = {
+            name: user.name,
+            email: user.email,
+            age: user.age,
+            medicalHistory: user.medicalHistory,
+            analysisHistory: user.analysisHistory || [] // Get analysis history
+        };
+
+        res.status(200).json(userData);
+
+    } catch (error) {
+        console.error('Error fetching user data:', error);
+        res.status(500).json({ message: 'Failed to fetch user data.' });
+    }
+});
+
+// 5. Image Analysis
+app.post('/analyze', authenticateToken, upload.single('image'), async (req, res) => {
+    try {
+        if (!req.file) {
+            return res.status(400).json({ message: 'No image uploaded.' });
+        }
+
+        const imagePath = req.file.path;
+        const userId = req.user.userId;
+
+        // --- Placeholder for Model Prediction ---
+        const glaucomaProbability = Math.random();
+        const otherDiseases = {
+            'Diabetic Retinopathy': Math.random(),
+            'Macular Degeneration': Math.random()
+        };
+
+        const analysisDescription = glaucomaProbability > 0.7 ? 'Possible signs of glaucoma detected. Consult an ophthalmologist.' : 'No significant signs of glaucoma detected.';
+
+        // --- Store Analysis History ---
+        const userIndex = users.findIndex(user => user.id === userId);
+        if (userIndex !== -1) {
+            users[userIndex].analysisHistory.push({
+                date: new Date(),
+                imagePath: imagePath,
+                glaucoma_probability: glaucomaProbability,
+                analysis_description: analysisDescription,
+                other_diseases: otherDiseases
+            });
+            saveUsers(); // Save the updated user list to the file
+        } else {
+            console.warn(`User with ID ${userId} not found for analysis history update.`);
+        }
+
+        // --- Respond with the analysis results ---
+        res.status(200).json({
+            glaucoma_probability: glaucomaProbability,
+            analysis_description: analysisDescription,
+            other_diseases: otherDiseases,
+            image_path: imagePath // Send the image path back to the client
+        });
+
+    } catch (error) {
+        console.error('Analysis error:', error);
+        res.status(500).json({ message: 'Image analysis failed. Please try again later.' });
+    }
+});
+
+// 6. Contact Form (Placeholder)
+app.post('/contact', (req, res) => {
+    const { name, email, message } = req.body;
+
+    if (!name || !email || !message) {
+        return res.status(400).json({ message: 'All fields are required.' });
+    }
+
+    console.log('Contact form submission:', { name, email, message });
+    res.status(200).json({ message: 'Your message has been sent (simulated).' });
+});
+
+// --- Start the Server ---
+app.listen(port, () => {
+    console.log(`Server listening on port ${port}`);
+});