fix : 삭제한 문제에 대한 알림 삭제 (#381)

Author: sh0723

src/main/java/com/gamzabat/algohub/feature/notification/repository/NotificationRepository.java

@@ -8,6 +8,7 @@
 
 import com.gamzabat.algohub.feature.group.studygroup.domain.StudyGroup;
 import com.gamzabat.algohub.feature.notification.domain.Notification;
+import com.gamzabat.algohub.feature.problem.domain.Problem;
 import com.gamzabat.algohub.feature.user.domain.User;
 
 public interface NotificationRepository extends JpaRepository<Notification, Long> {
@@ -19,6 +20,10 @@ public interface NotificationRepository extends JpaRepository<Notification, Long
 	@Query("delete from Notification n where n.studyGroup = :studyGroup")
 	void deleteAllByStudyGroup(StudyGroup studyGroup);
 
+    @Modifying
+    @Query("DELETE FROM Notification n WHERE n.problem = :problem")
+    void deleteAllByProblem(Problem problem);
+
 	@Modifying
 	@Query("DELETE FROM Notification n WHERE n.user = :user AND n.studyGroup = :studyGroup")
 	void deleteAllByUserAndStudyGroup(User user, StudyGroup studyGroup);

src/main/java/com/gamzabat/algohub/feature/problem/service/ProblemService.java

@@ -29,6 +29,7 @@
 import com.gamzabat.algohub.feature.group.studygroup.repository.GroupMemberRepository;
 import com.gamzabat.algohub.feature.group.studygroup.repository.StudyGroupRepository;
 import com.gamzabat.algohub.feature.notification.enums.NotificationCategory;
+import com.gamzabat.algohub.feature.notification.repository.NotificationRepository;
 import com.gamzabat.algohub.feature.notification.service.NotificationService;
 import com.gamzabat.algohub.feature.problem.domain.Problem;
 import com.gamzabat.algohub.feature.problem.dto.CreateProblemRequest;
@@ -53,6 +54,7 @@ public class ProblemService {
 	private final GroupMemberRepository groupMemberRepository;
 	private final NotificationService notificationService;
 	private final RestTemplate restTemplate;
+	private final NotificationRepository notificationRepository;
 
 	@Transactional
 	public void createProblem(User user, Long groupId, CreateProblemRequest request) {
@@ -212,6 +214,7 @@ public void deleteProblem(User user, Long problemId) {
 
 		solutionRepository.deleteAllByProblem(problem);
 		problemRepository.delete(problem);
+		notificationRepository.deleteAllByProblem(problem);
 		log.info("success to delete problem user_id={} , problem_id = {}", user.getId(), problemId);
 	}