feat: Add role middleware and update permissions documentation

backend/middleware/role.middleware.js

@@ -1,42 +1,23 @@
 /**
- * Middleware zur Überprüfung der Benutzerrolle
- * @param {string[]} requiredRoles - Die erforderlichen Rollen
- * @returns {function} Express Middleware Funktion
+ * Middleware to check if the user has the required role(s)
+ * @param {string[]} requiredRoles - Array of required roles
+ * @returns {function} Express middleware function
  */
-exports.requireRole = (requiredRoles) => {
+export const requireRole = (requiredRoles) => {
   return (req, res, next) => {
-    // Wenn kein Benutzer authentifiziert ist
-    if (!req.user) {
-      return res.status(401).json({ error: 'Authentication required' });
+    // Get the user's role from the JWT token (assuming it's in req.user.role)
+    const userRole = req.user?.role;
+
+    // If no user role is found, deny access
+    if (!userRole) {
+      return res.status(401).json({ error: 'Unauthorized' });
     }
 
-    // Überprüfe, ob der Benutzer eine der erforderlichen Rollen hat
-    const hasRequiredRole = requiredRoles.some(role => req.user.role.includes(role));
-    
-    if (!hasRequiredRole) {
-      return res.status(403).json({ error: 'Insufficient permissions' });
+    // Check if the user has at least one of the required roles
+    if (requiredRoles.includes(userRole)) {
+      next(); // User has the required role, proceed to the next middleware/route
+    } else {
+      return res.status(403).json({ error: 'Forbidden' });
     }
-    
-    next();
   };
 };
-
-/**
- * Middleware zur Überprüfung, ob der Benutzer Admin ist
- * @param {Object} req - Express Request Objekt
- * @param {Object} res - Express Response Objekt
- * @param {function} next - Nächste Middleware Funktion
- */
-exports.requireAdmin = (req, res, next) => {
-  exports.requireRole(['admin'])(req, res, next);
-};
-
-/**
- * Middleware zur Überprüfung, ob der Benutzer Moderator ist
- * @param {Object} req - Express Request Objekt
- * @param {Object} res - Express Response Objekt
- * @param {function} next - Nächste Middleware Funktion
- */
-exports.requireModerator = (req, res, next) => {
-  exports.requireRole(['moderator', 'admin'])(req, res, next);
-};