Erweiterungen

src/main/java/de/assecutor/votianlt/controller/MessageController.java

@@ -9,6 +9,7 @@ import de.assecutor.votianlt.model.CargoItem;
 import de.assecutor.votianlt.model.Job;
 import de.assecutor.votianlt.model.task.BaseTask;
 import de.assecutor.votianlt.pages.service.AppUserService;
+import de.assecutor.votianlt.pages.service.UserService;
 import de.assecutor.votianlt.repository.AppUserRepository;
 import de.assecutor.votianlt.repository.CargoItemRepository;
 import de.assecutor.votianlt.repository.JobRepository;
@@ -49,6 +50,9 @@ public class MessageController {
     // Map to store userId -> clientId mapping for active sessions
     private final Map<String, String> userClientIdMapping = new ConcurrentHashMap<>();
 
+    // Map to store clientId -> userId mapping for active sessions (reverse lookup)
+    private final Map<String, String> clientIdUserMapping = new ConcurrentHashMap<>();
+
     private final MqttPublisher mqttPublisher;
 
     private final AppUserRepository appUserRepository;
@@ -67,12 +71,13 @@ public class MessageController {
     private final JobHistoryService jobHistoryService;
     private final EmailService emailService;
     private final MessageService messageService;
+    private final UserService userService;
 
     public MessageController(MqttPublisher mqttPublisher, AppUserRepository appUserRepository,
             AppUserService appUserService, JobRepository jobRepository, CargoItemRepository cargoItemRepository,
             TaskRepository taskRepository, PhotoRepository photoRepository, BarcodeRepository barcodeRepository,
-            SignatureRepository signatureRepository, CommentRepository commentRepository, JobHistoryService jobHistoryService, 
+            SignatureRepository signatureRepository, CommentRepository commentRepository, JobHistoryService jobHistoryService,
-            EmailService emailService, MessageService messageService) {
+            EmailService emailService, MessageService messageService, UserService userService) {
         this.mqttPublisher = mqttPublisher;
         this.appUserRepository = appUserRepository;
         this.appUserService = appUserService;
@@ -86,6 +91,7 @@ public class MessageController {
         this.jobHistoryService = jobHistoryService;
         this.emailService = emailService;
         this.messageService = messageService;
+        this.userService = userService;
     }
 
     /**
@@ -585,7 +591,8 @@ public class MessageController {
      */
     private void storeClientIdMapping(String userId, String clientId) {
         userClientIdMapping.put(userId, clientId);
-        log.debug("Stored clientId mapping: userId={} -> clientId={}", userId, clientId);
+        clientIdUserMapping.put(clientId, userId);
+        log.debug("Stored clientId mapping: userId={} <-> clientId={}", userId, clientId);
     }
 
     /**
@@ -595,6 +602,13 @@ public class MessageController {
         return userClientIdMapping.get(userId);
     }
 
+    /**
+     * Get the userId (AppUser ID) for a given clientId
+     */
+    private String getUserIdForClientId(String clientId) {
+        return clientIdUserMapping.get(clientId);
+    }
+
     /**
      * Handle incoming message from a client via MQTT.
      * Client sends to /server/{clientId}/message with payload:
@@ -604,21 +618,83 @@ public class MessageController {
      *   "content": "message payload",
      *   "contentType": "TEXT|IMAGE",
      *   "jobId": "optional job id",
-     *   "jobNumber": "optional job number"
+     *   "jobNumber": "optional job number",
+     *   "clientId": "extracted from topic"
      * }
+     *
+     * Logic:
+     * 1. Extract clientId from topic (this is the AppUser ID)
+     * 2. Find AppUser by ID in database
+     * 3. Get owner (User) from AppUser.owner field
+     * 4. Set receiver = User ID, sender = AppUser ID
      */
     public void handleIncomingMessage(Map<String, Object> payload) {
         log.info("MQTT Endpoint '/server/{clientId}/message' called with data: {}", payload);
 
         try {
             ChatMessageInboundPayload inboundPayload = ChatMessageInboundPayload.fromPayload(payload);
-            messageService.receiveMessageFromClient(inboundPayload);
+
-            log.info("Successfully saved incoming message from {} to {}", inboundPayload.sender(),
+            // Extract clientId from payload (added by MqttV5ClientManager from topic)
-                    inboundPayload.receiver());
+            // The clientId IS the AppUser ID
+            String clientId = payload.get("clientId") != null ? payload.get("clientId").toString() : null;
+
+            if (clientId == null || clientId.isBlank()) {
+                log.warn("No clientId found in message payload, cannot process message");
+                return;
+            }
+
+            // Convert clientId (AppUser ID) to ObjectId
+            ObjectId appUserObjectId;
+            try {
+                appUserObjectId = new ObjectId(clientId);
+            } catch (IllegalArgumentException e) {
+                log.warn("Invalid clientId/AppUser ID '{}': {}", clientId, e.getMessage());
+                return;
+            }
+
+            // Find AppUser by ID
+            AppUser appUser = appUserService.findById(appUserObjectId);
+            if (appUser == null) {
+                log.warn("AppUser not found for clientId '{}'", clientId);
+                return;
+            }
+
+            // Get owner (User) of AppUser from the owner field
+            ObjectId ownerId = appUser.getOwner();
+            if (ownerId == null) {
+                log.warn("AppUser '{}' has no owner, cannot determine receiver", clientId);
+                return;
+            }
+
+            // Verify that owner exists
+            de.assecutor.votianlt.model.User owner = userService.findById(ownerId);
+            if (owner == null) {
+                log.warn("Owner User not found for AppUser '{}'", clientId);
+                return;
+            }
+
+            // Convert owner ID to string for receiver field
+            String ownerIdString = ownerId.toHexString();
+
+            // Create payload with:
+            // - sender = AppUser ID (clientId)
+            // - receiver = User ID (owner's ID as string)
+            ChatMessageInboundPayload resolvedPayload = new ChatMessageInboundPayload(
+                clientId,       // sender = AppUser ID
+                ownerIdString,  // receiver = User ID
+                inboundPayload.content(),
+                inboundPayload.contentType(),
+                inboundPayload.jobId(),
+                inboundPayload.jobNumber()
+            );
+
+            messageService.receiveMessageFromClient(resolvedPayload);
+            log.info("Successfully saved incoming message from AppUser '{}' to User '{}'", clientId, ownerIdString);
         } catch (IllegalArgumentException validationError) {
             log.warn("Incoming chat message rejected: {}", validationError.getMessage());
         } catch (Exception e) {
             log.error("Error handling incoming message: {}", e.getMessage(), e);
         }
     }
+
 }

src/main/java/de/assecutor/votianlt/event/MessageReadStatusChangedEvent.java

@@ -0,0 +1,15 @@
+package de.assecutor.votianlt.event;
+
+import org.springframework.context.ApplicationEvent;
+
+/**
+ * Event published when message read status changes (e.g., messages marked as read)
+ * This allows UI components like the sidebar badge to update accordingly
+ */
+public class MessageReadStatusChangedEvent extends ApplicationEvent {
+    
+    public MessageReadStatusChangedEvent(Object source) {
+        super(source);
+    }
+}
+

src/main/java/de/assecutor/votianlt/mqtt/MqttV5ClientManager.java

@@ -165,7 +165,14 @@ public class MqttV5ClientManager implements SmartLifecycle {
                 messageController.handleAppLogin(req);
             } else if (topic.matches("/server/.+/message")) {
                 try {
-                    // Handle incoming message from client
+                    // Extract clientId from topic: /server/{clientId}/message
+                    String[] parts = topic.split("/");
+                    String clientId = parts.length > 2 ? parts[2] : null;
+                    if (clientId != null && !clientId.isBlank()) {
+                        payload.put("clientId", clientId);
+                    } else {
+                        log.warn("Couldn't extract clientId from topic {} for message", topic);
+                    }
                     messageController.handleIncomingMessage(payload);
                 } catch (Exception e) {
                     log.error("Error handling incoming message on {}: {}", topic, e.getMessage(), e);

src/main/java/de/assecutor/votianlt/pages/base/ui/view/MainLayout.java

@@ -1,6 +1,8 @@
 package de.assecutor.votianlt.pages.base.ui.view;
 
+import com.vaadin.flow.component.AttachEvent;
 import com.vaadin.flow.component.Component;
+import com.vaadin.flow.component.DetachEvent;
 import com.vaadin.flow.component.UI;
 import com.vaadin.flow.component.applayout.AppLayout;
 import com.vaadin.flow.component.avatar.Avatar;
@@ -20,12 +22,15 @@ import com.vaadin.flow.router.Layout;
 import com.vaadin.flow.server.auth.AnonymousAllowed;
 import com.vaadin.flow.server.menu.MenuConfiguration;
 import com.vaadin.flow.server.menu.MenuEntry;
+import com.vaadin.flow.shared.Registration;
 import de.assecutor.votianlt.model.User;
 import de.assecutor.votianlt.model.UserInvoiceData;
 import de.assecutor.votianlt.pages.service.UserInvoiceDataService;
 import de.assecutor.votianlt.pages.view.EditProfileView;
 import de.assecutor.votianlt.security.SecurityService;
+import de.assecutor.votianlt.service.MessageBadgeUpdateService;
 import de.assecutor.votianlt.service.MessageService;
+import lombok.extern.slf4j.Slf4j;
 
 import static com.vaadin.flow.theme.lumo.LumoUtility.*;
 
@@ -34,21 +39,27 @@ import java.util.Optional;
 import java.util.Set;
 
 @AnonymousAllowed
-
+@Slf4j
 @Layout("main")
 public final class MainLayout extends AppLayout {
 
     private final SecurityService securityService;
     private final UserInvoiceDataService userInvoiceDataService;
     private final MessageService messageService;
+    private final MessageBadgeUpdateService messageBadgeUpdateService;
     private Div headerRef;
     private Scroller navRef;
     private Component userMenuRef;
+    private Span messagesBadge; // Reference to the messages badge for dynamic updates
+    private SideNavItem messagesNavItem; // Reference to the messages nav item
+    private Registration badgeUpdateRegistration; // Track badge update listener registration
 
-    public MainLayout(SecurityService securityService, UserInvoiceDataService userInvoiceDataService, MessageService messageService) {
+    public MainLayout(SecurityService securityService, UserInvoiceDataService userInvoiceDataService,
+            MessageService messageService, MessageBadgeUpdateService messageBadgeUpdateService) {
         this.securityService = securityService;
         this.userInvoiceDataService = userInvoiceDataService;
         this.messageService = messageService;
+        this.messageBadgeUpdateService = messageBadgeUpdateService;
         setPrimarySection(Section.DRAWER);
 
         // Always build the drawer; keep references and toggle visibility on attach and
@@ -162,24 +173,44 @@ public final class MainLayout extends AppLayout {
             item = new SideNavItem(menuEntry.title(), menuEntry.path());
         }
         if ("Nachrichten".equals(menuEntry.title())) {
-            long unreadCount = resolveUnreadMessageCount();
+            messagesNavItem = item;
-            if (unreadCount > 0) {
+        }
-                Span badge = new Span(String.valueOf(unreadCount));
+        return item;
-                badge.getElement().getThemeList().add("badge");
+    }
-                badge.getStyle().set("background-color", "var(--lumo-primary-color)");
-                badge.getStyle().set("color", "#ffffff");
-                badge.getStyle().set("border-radius", "12px");
-                badge.getStyle().set("padding", "2px 8px");
-                badge.getStyle().set("font-size", "12px");
-                badge.getStyle().set("font-weight", "bold");
-                badge.getStyle().set("min-width", "20px");
-                badge.getStyle().set("text-align", "center");
 
-                item.setSuffixComponent(badge);
+    /**
+     * Updates the messages badge with the current unread count
+     */
+    private void updateMessagesBadge() {
+        if (messagesNavItem == null) {
+            return;
+        }
+
+        long unreadCount = resolveUnreadMessageCount();
+
+        if (unreadCount > 0) {
+            if (messagesBadge == null) {
+                messagesBadge = new Span(String.valueOf(unreadCount));
+                messagesBadge.getElement().getThemeList().add("badge");
+                messagesBadge.getStyle().set("background-color", "var(--lumo-primary-color)");
+                messagesBadge.getStyle().set("color", "#ffffff");
+                messagesBadge.getStyle().set("border-radius", "12px");
+                messagesBadge.getStyle().set("padding", "2px 8px");
+                messagesBadge.getStyle().set("font-size", "12px");
+                messagesBadge.getStyle().set("font-weight", "bold");
+                messagesBadge.getStyle().set("min-width", "20px");
+                messagesBadge.getStyle().set("text-align", "center");
+                messagesNavItem.setSuffixComponent(messagesBadge);
+            } else {
+                messagesBadge.setText(String.valueOf(unreadCount));
+                messagesBadge.setVisible(true);
+            }
+        } else {
+            if (messagesBadge != null) {
+                messagesNavItem.setSuffixComponent(null);
+                messagesBadge = null;
             }
         }
-        
-        return item;
     }
 
     private long resolveUnreadMessageCount() {
@@ -191,6 +222,7 @@ public final class MainLayout extends AppLayout {
 
         try {
             User currentUser = securityService.getCurrentDatabaseUser();
+
             if (currentUser != null) {
                 String email = Optional.ofNullable(currentUser.getEmail()).map(String::trim).orElse("");
                 if (!email.isBlank()) {
@@ -217,6 +249,7 @@ public final class MainLayout extends AppLayout {
         for (String receiver : candidateReceivers) {
             unread += messageService.getUnreadMessageCount(receiver);
         }
+
         return unread;
     }
 
@@ -269,4 +302,28 @@ public final class MainLayout extends AppLayout {
         return false;
     }
 
-}
+    @Override
+    protected void onAttach(AttachEvent attachEvent) {
+        super.onAttach(attachEvent);
+        UI ui = attachEvent.getUI();
+
+        // Update badge immediately when layout is attached
+        updateMessagesBadge();
+
+        // Register listener for badge updates
+        badgeUpdateRegistration = messageBadgeUpdateService.register(() -> {
+            ui.access(() -> {
+                updateMessagesBadge();
+            });
+        });
+    }
+
+    @Override
+    protected void onDetach(DetachEvent detachEvent) {
+        if (badgeUpdateRegistration != null) {
+            badgeUpdateRegistration.remove();
+            badgeUpdateRegistration = null;
+        }
+        super.onDetach(detachEvent);
+    }
+}

src/main/java/de/assecutor/votianlt/pages/service/AppUserService.java

@@ -59,6 +59,14 @@ public class AppUserService {
         return appUserRepository.findById(id).orElse(null);
     }
 
+    public AppUser findByEmail(String email) {
+        return appUserRepository.findByEmail(email);
+    }
+
+    public AppUser findByBezeichnung(String bezeichnung) {
+        return appUserRepository.findByBezeichnung(bezeichnung);
+    }
+
     public AppUser updateAppUser(AppUser appUser) {
         // Hash the password if it's being updated and not empty
         if (appUser.getPassword() != null && !appUser.getPassword().isEmpty()) {

src/main/java/de/assecutor/votianlt/pages/service/UserService.java

@@ -2,6 +2,7 @@ package de.assecutor.votianlt.pages.service;
 
 import de.assecutor.votianlt.model.User;
 import de.assecutor.votianlt.repository.UserRepository;
+import org.bson.types.ObjectId;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.stereotype.Service;
 
@@ -22,6 +23,10 @@ public class UserService {
         return userRepository.findByEmail(email).orElse(null);
     }
 
+    public User findById(ObjectId id) {
+        return userRepository.findById(id).orElse(null);
+    }
+
     public User save(User user) {
         if (user.getPassword() != null && !user.getPassword().startsWith("$2a$")) {
             // Passwort verschlüsseln, falls noch nicht verschlüsselt

src/main/java/de/assecutor/votianlt/pages/view/MessageDetailsView.java

@@ -38,6 +38,8 @@ import de.assecutor.votianlt.pages.service.AppUserService;
 import de.assecutor.votianlt.service.MessageBroadcaster;
 import de.assecutor.votianlt.service.MessageService;
 import de.assecutor.votianlt.security.SecurityService;
+import de.assecutor.votianlt.event.MessageReadStatusChangedEvent;
+import org.springframework.context.ApplicationEventPublisher;
 import jakarta.annotation.security.RolesAllowed;
 import lombok.extern.slf4j.Slf4j;
 import org.bson.types.ObjectId;
@@ -75,6 +77,7 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
     private final MessageService messageService;
     private final SecurityService securityService;
     private final MessageBroadcaster messageBroadcaster;
+    private final ApplicationEventPublisher eventPublisher;
 
     private String participantKey;
     private String conversationId;
@@ -95,15 +98,17 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
     private static final float JPEG_COMPRESSION_QUALITY = 0.8f;
 
     public MessageDetailsView(AppUserService appUserService, MessageService messageService,
-            SecurityService securityService, MessageBroadcaster messageBroadcaster) {
+            SecurityService securityService, MessageBroadcaster messageBroadcaster,
+            ApplicationEventPublisher eventPublisher) {
         this.appUserService = appUserService;
         this.messageService = messageService;
         this.securityService = securityService;
         this.messageBroadcaster = messageBroadcaster;
-        
+        this.eventPublisher = eventPublisher;
+
         // Set height to 100% to prevent page from growing beyond viewport
         setHeightFull();
-        
+
         // Create main layout with fixed positioning
         contentLayout = new VerticalLayout();
         contentLayout.setPadding(true);
@@ -119,7 +124,7 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
     public void beforeEnter(BeforeEnterEvent event) {
         // Extract route parameters from URL
         RouteParameters parameters = event.getRouteParameters();
-        
+
         this.participantKey = parameters.get("clientId").orElse(null);
         this.conversationId = parameters.get("conversationId").orElse(null);
 
@@ -164,10 +169,10 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
 
         // Store current messages for rendering and future updates
         this.currentMessages = filteredMessages;
-        
+
         // Reset scroll anchor for new container
         scrollAnchor = null;
-        
+
         // Create messages container
         messagesContainer = new VerticalLayout();
         messagesContainer.setPadding(false);
@@ -190,10 +195,10 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
 
         HorizontalLayout inputLayout = createMessageInputArea();
         contentLayout.add(inputLayout);
-        
+
         // Render messages using Vaadin components
         renderMessages();
-        
+
         // Ensure scroll anchor exists and scroll to bottom
         ensureScrollAnchor();
         scrollToBottom();
@@ -210,22 +215,54 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
         // Reset anchor so a fresh one can be attached after re-rendering
         scrollAnchor = null;
         messagesContainer.removeAll();
-        
+
         LocalDate currentDate = null;
-        
+
         for (Message message : currentMessages) {
             LocalDateTime timestamp = resolveTimestamp(message);
             LocalDate messageDate = timestamp.toLocalDate();
-            
+
             // Add date separator if date changed
             if (currentDate == null || !currentDate.equals(messageDate)) {
                 messagesContainer.add(createDateSeparator(messageDate));
                 currentDate = messageDate;
             }
-            
+
             // Add message bubble
             messagesContainer.add(createMessageBubble(message, timestamp));
         }
+
+        // After rendering, mark any unread messages directed to the current user as read
+        markVisibleMessagesAsRead();
+    }
+
+    /**
+     * Marks all currently visible messages that are addressed to the logged-in user as read.
+     * This is triggered after (re)rendering the conversation and will also update the in-memory
+     * message objects to keep UI state consistent.
+     */
+    private void markVisibleMessagesAsRead() {
+        try {
+            if (currentMessages == null || currentMessages.isEmpty()) {
+                return;
+            }
+            boolean anyMarked = false;
+            for (Message msg : currentMessages) {
+                if (!msg.isRead() && msg.getId() != null) {
+                    // Update persistence
+                    messageService.markAsRead(msg.getId());
+                    // Update in-memory object so UI reflects read state immediately
+                    msg.markAsRead();
+                    anyMarked = true;
+                }
+            }
+            // Publish event to update badge in sidebar
+            if (anyMarked) {
+                eventPublisher.publishEvent(new MessageReadStatusChangedEvent(this));
+            }
+        } catch (Exception e) {
+            log.warn("Failed to mark messages as read: {}", e.getMessage());
+        }
     }
 
     private void openImageUploadDialog() {
@@ -372,7 +409,7 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
             .set("text-align", "center")
             .set("margin", "20px 0");
         separator.setWidthFull();
-        
+
         Span dateLabel = new Span(date.format(DATE_FORMATTER));
         dateLabel.getStyle()
             .set("background-color", "#d0d0d0")
@@ -382,7 +419,7 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
             .set("font-weight", "500")
             .set("color", "#333333")
             .set("display", "inline-block");
-        
+
         separator.add(dateLabel);
         return separator;
     }
@@ -394,7 +431,7 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
         // Determine alignment based on message origin
         // CLIENT origin = client messages (left), SERVER origin = server messages (right)
         boolean isServerMessage = message.getOrigin() == MessageOrigin.SERVER;
-        
+
         // Container for the message (aligns left or right)
         Div messageWrapper = new Div();
         String alignment = isServerMessage ? "right" : "left";
@@ -404,7 +441,7 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
             .set("justify-content", isServerMessage ? "flex-end" : "flex-start")
             .set("margin", "5px 0")
             .set("width", "100%");
-        
+
         // Message bubble
         Div bubble = new Div();
         bubble.getStyle()
@@ -416,10 +453,10 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
             .set("word-wrap", "break-word")
             .set("white-space", "pre-wrap")
             .set("text-align", alignment);
-        
+
         // Message content component (text or media)
         Component contentComponent = createContentComponent(message, alignment);
-        
+
         // Timestamp
         Span timeSpan = new Span(timestamp.format(TIME_FORMATTER));
         timeSpan.getStyle()
@@ -427,10 +464,10 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
             .set("color", isServerMessage ? "#666666" : "#999999")
             .set("display", "block")
             .set("text-align", alignment);
-        
+
         bubble.add(contentComponent, timeSpan);
         messageWrapper.add(bubble);
-        
+
         return messageWrapper;
     }
 
@@ -692,25 +729,25 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
     private HorizontalLayout createHeaderLayout(String clientName, String conversationTitle) {
         Button backButton = new Button("Zurück", VaadinIcon.ARROW_LEFT.create());
         backButton.addClickListener(e -> UI.getCurrent().navigate("user-messages/" + participantKey));
-        
+
         VerticalLayout titleLayout = new VerticalLayout();
         titleLayout.setPadding(false);
         titleLayout.setSpacing(false);
-        
+
         H2 title = new H2(clientName);
         title.getStyle().set("margin", "0");
-        
+
         Span subtitle = new Span(conversationTitle);
         subtitle.getStyle().set("color", "#666666");
         subtitle.getStyle().set("font-size", "14px");
-        
+
         titleLayout.add(title, subtitle);
-        
+
         HorizontalLayout layout = new HorizontalLayout(backButton, titleLayout);
         layout.setWidthFull();
         layout.setAlignItems(com.vaadin.flow.component.orderedlayout.FlexComponent.Alignment.CENTER);
         layout.setSpacing(true);
-        
+
         return layout;
     }
 
@@ -778,6 +815,16 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
                         contentType);
             }
 
+            // Mark own outgoing message as read immediately
+            if (saved != null && saved.getId() != null) {
+                try {
+                    messageService.markAsRead(saved.getId());
+                    saved.markAsRead(); // keep UI state consistent
+                } catch (Exception ignore) {
+                    // non-fatal
+                }
+            }
+
             Notification.show("Nachricht gesendet", 2000, Notification.Position.BOTTOM_END)
                     .addThemeVariants(NotificationVariant.LUMO_SUCCESS);
 
@@ -939,12 +986,12 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
     protected void onAttach(AttachEvent attachEvent) {
         super.onAttach(attachEvent);
         UI ui = attachEvent.getUI();
-        
+
         // Register listener for incoming messages
         broadcasterRegistration = messageBroadcaster.register(message -> {
             handleIncomingMessage(ui, message);
         });
-        
+
         log.info("MessageDetailsView attached and listener registered for conversation: {}", conversationId);
     }
 
@@ -972,9 +1019,9 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
         }
 
         // Check if message involves the current participant
-        boolean involvesParticipant = participantKey.equals(message.getSender()) 
+        boolean involvesParticipant = participantKey.equals(message.getSender())
                                     || participantKey.equals(message.getReceiver());
-        
+
         if (!involvesParticipant) {
             log.debug("Message does not involve current participant, ignoring");
             return;
@@ -982,7 +1029,7 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
 
         // Check if message belongs to the current conversation
         boolean belongsToConversation = false;
-        
+
         if ("general".equalsIgnoreCase(conversationId)) {
             // General conversation: messages without job context
             belongsToConversation = message.getJobId() == null && message.getJobNumber() == null;
@@ -998,7 +1045,7 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
         }
 
         log.info("New message belongs to current conversation {}, updating UI", conversationId);
-        
+
         // Update UI in a thread-safe manner using UI.access()
         ui.access(() -> {
             try {
@@ -1010,11 +1057,11 @@ public class MessageDetailsView extends Main implements BeforeEnterObserver {
 
                     // Re-render all messages with the new message included
                     renderMessages();
-                    
+
                     // Ensure scroll anchor exists and scroll to show new message
                     ensureScrollAnchor();
                     scrollToBottom();
-                    
+
                     log.info("Messages re-rendered with new message");
                 }
             } catch (Exception e) {

src/main/java/de/assecutor/votianlt/repository/AppUserRepository.java

@@ -21,6 +21,6 @@ public interface AppUserRepository extends MongoRepository<AppUser, ObjectId> {
     // Find AppUser by appCode for task completion notifications
     java.util.Optional<AppUser> findByAppCode(String appCode);
 
-    // Custom query methods can be added here if needed
+    // Find AppUser by bezeichnung
-    // List<AppUser> findByBezeichnung(String bezeichnung);
+    AppUser findByBezeichnung(String bezeichnung);
 }

src/main/java/de/assecutor/votianlt/service/MessageBadgeUpdateService.java

@@ -0,0 +1,77 @@
+package de.assecutor.votianlt.service;
+
+import com.vaadin.flow.shared.Registration;
+import de.assecutor.votianlt.event.MessageReadStatusChangedEvent;
+import de.assecutor.votianlt.event.MessageReceivedEvent;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Service;
+
+import java.util.LinkedHashSet;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+
+/**
+ * Service that listens for message-related events and notifies registered UI components
+ * to update their message badges (e.g., in the sidebar navigation)
+ */
+@Service
+@Slf4j
+public class MessageBadgeUpdateService {
+    
+    private final Executor executor = Executors.newSingleThreadExecutor();
+    private final LinkedHashSet<Runnable> listeners = new LinkedHashSet<>();
+    
+    /**
+     * Register a listener that will be called when message badge should be updated
+     * 
+     * @param listener Runnable that will be called when badge update is needed
+     * @return Registration object that can be used to unregister the listener
+     */
+    public synchronized Registration register(Runnable listener) {
+        listeners.add(listener);
+        log.debug("Registered badge update listener. Total listeners: {}", listeners.size());
+        
+        return () -> {
+            synchronized (MessageBadgeUpdateService.this) {
+                listeners.remove(listener);
+                log.debug("Unregistered badge update listener. Total listeners: {}", listeners.size());
+            }
+        };
+    }
+    
+    /**
+     * Notify all registered listeners that badge should be updated
+     */
+    private synchronized void notifyListeners() {
+        log.debug("Notifying {} badge update listeners", listeners.size());
+        for (Runnable listener : listeners) {
+            executor.execute(() -> {
+                try {
+                    listener.run();
+                } catch (Exception e) {
+                    log.error("Error notifying badge update listener", e);
+                }
+            });
+        }
+    }
+    
+    /**
+     * Spring event listener for message read status changes
+     */
+    @EventListener
+    public void onMessageReadStatusChanged(MessageReadStatusChangedEvent event) {
+        log.debug("MessageBadgeUpdateService received MessageReadStatusChangedEvent");
+        notifyListeners();
+    }
+    
+    /**
+     * Spring event listener for new messages received
+     */
+    @EventListener
+    public void onMessageReceived(MessageReceivedEvent event) {
+        log.debug("MessageBadgeUpdateService received MessageReceivedEvent");
+        notifyListeners();
+    }
+}
+