feat: implement core backend API structure and frontend service layer for case management and authentication

backend/middleware.py

@@ -0,0 +1,32 @@
+import os
+import jwt
+from functools import wraps
+from flask import request, jsonify
+
+# Should ideally be set in .env
+SECRET_KEY = os.getenv('JWT_SECRET', 'super-secret-jwt-key-automarket')
+
+def token_required(f):
+    @wraps(f)
+    def decorated(*args, **kwargs):
+        token = None
+        auth_header = request.headers.get('Authorization')
+        
+        if auth_header and auth_header.startswith('Bearer '):
+            token = auth_header.split(" ")[1]
+        
+        # Fallback to query param for file downloads
+        if not token:
+            token = request.args.get('token')
+            
+        if not token:
+            return jsonify({'message': 'Token is missing!'}), 401
+
+        try:
+            data = jwt.decode(token, SECRET_KEY, algorithms=["HS256"])
+            current_user_id = data['user_id']
+        except Exception as e:
+            return jsonify({'message': 'Token is invalid or expired!'}), 401
+
+        return f(current_user_id, *args, **kwargs)
+    return decorated