resolve issues with new features

frontend/src/components/shared/NotificationBell.tsx

@@ -21,9 +21,10 @@ import {
 } from '@mui/icons-material';
 import { useNavigate } from 'react-router-dom';
 import { notificationsApi } from '../../services/notifications';
+import { useNotification } from '../../contexts/NotificationContext';
 import type { Notification, NotificationSchwere } from '../../types/notification.types';
 
-const POLL_INTERVAL_MS = 60_000; // 60 seconds
+const POLL_INTERVAL_MS = 15_000; // 15 seconds
 
 /**
  * Only allow window.open for URLs whose origin matches the current app origin.
@@ -58,29 +59,50 @@ function formatRelative(iso: string): string {
 
 const NotificationBell: React.FC = () => {
   const navigate = useNavigate();
+  const { showNotificationToast } = useNotification();
   const [unreadCount, setUnreadCount] = useState(0);
   const [notifications, setNotifications] = useState<Notification[]>([]);
   const [loadingList, setLoadingList] = useState(false);
   const [anchorEl, setAnchorEl] = useState<null | HTMLElement>(null);
   const pollTimerRef = useRef<ReturnType<typeof setInterval> | null>(null);
+  // Track known notification IDs to detect new ones; null = not yet initialized
+  const knownIdsRef = useRef<Set<string> | null>(null);
 
-  const fetchUnreadCount = useCallback(async () => {
+  const fetchAndToastNew = useCallback(async () => {
     try {
-      const count = await notificationsApi.getUnreadCount();
+      const data = await notificationsApi.getNotifications();
+      const unread = data.filter((n) => !n.gelesen);
+      const count = unread.length;
       setUnreadCount(count);
+
+      if (knownIdsRef.current === null) {
+        // First load — initialize without toasting
+        knownIdsRef.current = new Set(data.map((n) => n.id));
+        return;
+      }
+
+      // Find notifications we haven't seen before
+      const newOnes = unread.filter((n) => !knownIdsRef.current!.has(n.id));
+      newOnes.forEach((n) => {
+        knownIdsRef.current!.add(n.id);
+        const severity = n.schwere === 'fehler' ? 'error' : n.schwere === 'warnung' ? 'warning' : 'info';
+        showNotificationToast(n.titel, severity);
+      });
+      // Also add all known IDs to avoid re-toasting on re-fetch
+      data.forEach((n) => knownIdsRef.current!.add(n.id));
     } catch {
       // non-critical
     }
-  }, []);
+  }, [showNotificationToast]);
 
-  // Poll unread count every 60 seconds
+  // Poll for new notifications every 15 seconds
   useEffect(() => {
-    fetchUnreadCount();
-    pollTimerRef.current = setInterval(fetchUnreadCount, POLL_INTERVAL_MS);
+    fetchAndToastNew();
+    pollTimerRef.current = setInterval(fetchAndToastNew, POLL_INTERVAL_MS);
     return () => {
       if (pollTimerRef.current) clearInterval(pollTimerRef.current);
     };
-  }, [fetchUnreadCount]);
+  }, [fetchAndToastNew]);
 
   const handleOpen = async (event: React.MouseEvent<HTMLElement>) => {
     setAnchorEl(event.currentTarget);
@@ -88,6 +110,12 @@ const NotificationBell: React.FC = () => {
     try {
       const data = await notificationsApi.getNotifications();
       setNotifications(data);
+      // Mark all as known so we don't toast them again
+      if (knownIdsRef.current === null) {
+        knownIdsRef.current = new Set(data.map((n) => n.id));
+      } else {
+        data.forEach((n) => knownIdsRef.current!.add(n.id));
+      }
       // Refresh count after loading full list
       const count = await notificationsApi.getUnreadCount();
       setUnreadCount(count);