feat: show unread message count

src/main/java/com/openisle/controller/NotificationController.java

@@ -29,6 +29,14 @@ public class NotificationController {
                 .collect(Collectors.toList());
     }
 
+    @GetMapping("/unread-count")
+    public UnreadCount unreadCount(Authentication auth) {
+        long count = notificationService.countUnread(auth.getName());
+        UnreadCount uc = new UnreadCount();
+        uc.setCount(count);
+        return uc;
+    }
+
     @PostMapping("/read")
     public void markRead(@RequestBody MarkReadRequest req, Authentication auth) {
         notificationService.markRead(auth.getName(), req.getIds());
@@ -115,4 +123,9 @@ public class NotificationController {
         private String username;
         private String avatar;
     }
+
+    @Data
+    private static class UnreadCount {
+        private long count;
+    }
 }

src/main/java/com/openisle/repository/NotificationRepository.java

@@ -10,4 +10,5 @@ import java.util.List;
 public interface NotificationRepository extends JpaRepository<Notification, Long> {
     List<Notification> findByUserOrderByCreatedAtDesc(User user);
     List<Notification> findByUserAndReadOrderByCreatedAtDesc(User user, boolean read);
+    long countByUserAndRead(User user, boolean read);
 }

src/main/java/com/openisle/service/NotificationService.java

@@ -45,4 +45,10 @@ public class NotificationService {
         }
         notificationRepository.saveAll(notifs);
     }
+
+    public long countUnread(String username) {
+        User user = userRepository.findByUsername(username)
+                .orElseThrow(() -> new IllegalArgumentException("User not found"));
+        return notificationRepository.countByUserAndRead(user, false);
+    }
 }