first commit of refactor

backend/middleware/authenticate.js

@@ -0,0 +1,68 @@
+
+import { auth } from '../firebase/admin.js';
+
+
+export async function authenticate(req, res, next) {
+  try {
+    // Get Authorization header
+    const authHeader = req.headers.authorization;
+    
+    if (!authHeader || !authHeader.startsWith('Bearer ')) {
+      console.log('No Authorization header or invalid format');
+      return res.status(401).json({ 
+        error: 'UNAUTHORIZED',
+        message: 'No authentication token provided' 
+      });
+    }
+
+    const token = authHeader.split('Bearer ')[1];
+    
+    if (!token) {
+      console.log('Empty token');
+      return res.status(401).json({ 
+        error: 'UNAUTHORIZED',
+        message: 'Invalid token format' 
+      });
+    }
+ 
+    console.log('Verifying Firebase token...');
+    const decodedToken = await auth.verifyIdToken(token);
+    
+    const user_id = decodedToken.uid;
+    
+    // SMOKE TEST: Console log the user_id
+    console.log('Token verified!');
+    console.log('   User ID:', user_id);
+    console.log('   Email:', decodedToken.email);
+    console.log('   Token issued at:', new Date(decodedToken.iat * 1000).toISOString());
+    
+    req.user_id = user_id;
+    req.user_email = decodedToken.email;
+    
+    next();
+    
+  } catch (error) {
+    console.error('Token verification failed:', error.message);
+    
+    // Handle specific Firebase errors
+    if (error.code === 'auth/id-token-expired') {
+      return res.status(401).json({ 
+        error: 'TOKEN_EXPIRED',
+        message: 'Authentication token has expired' 
+      });
+    }
+    
+    if (error.code === 'auth/argument-error') {
+      return res.status(401).json({ 
+        error: 'INVALID_TOKEN',
+        message: 'Invalid authentication token format' 
+      });
+    }
+    
+    return res.status(401).json({ 
+      error: 'UNAUTHORIZED',
+      message: 'Failed to verify authentication token' 
+    });
+  }
+}
+