SEBSERV-255 added automated deletion of client notification on exam

deletion

src/main/java/ch/ethz/seb/sebserver/gbl/model/session/ClientNotification.java

@@ -16,6 +16,7 @@ import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import ch.ethz.seb.sebserver.gbl.Constants;
+import ch.ethz.seb.sebserver.gbl.api.EntityType;
 import ch.ethz.seb.sebserver.gbl.model.Domain;
 import ch.ethz.seb.sebserver.gbl.util.Pair;
 
@@ -95,6 +96,11 @@ public class ClientNotification extends ClientEvent {
         return this.notificationType;
     }
 
+    @Override
+    public EntityType entityType() {
+        return EntityType.CLIENT_NOTIFICATION;
+    }
+
     @Override
     public String toString() {
         final StringBuilder builder = new StringBuilder();

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/ClientEventDAO.java

@@ -13,6 +13,7 @@ import java.util.List;
 import java.util.Set;
 import java.util.function.Predicate;
 
+import ch.ethz.seb.sebserver.gbl.model.EntityKey;
 import ch.ethz.seb.sebserver.gbl.model.session.ClientEvent;
 import ch.ethz.seb.sebserver.gbl.model.session.ClientNotification;
 import ch.ethz.seb.sebserver.gbl.model.session.ExtendedClientEvent;
@@ -67,4 +68,12 @@ public interface ClientEventDAO extends EntityDAO<ClientEvent, ClientEvent> {
      * @return Result refer to the confirmed notification or to en error when happened */
     Result<ClientNotification> confirmPendingNotification(Long notificationId);
 
+    /** Used to get all client notification identifiers/PKs that are mapped to a specified exam.
+     *
+     * @param examId The identifier/PK of the exam
+     * @return Result refer to a set of client notification identifiers or to an error when happened */
+    Result<Set<EntityKey>> getNotificationIdsForExam(Long examId);
+
+    Result<Collection<EntityKey>> deleteClientNotification(Set<EntityKey> keys);
+
 }

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/impl/ClientEventDAOImpl.java

@@ -204,6 +204,26 @@ public class ClientEventDAOImpl implements ClientEventDAO {
                 .flatMap(ClientEventDAOImpl::toDomainModel);
     }
 
+    @Override
+    @Transactional(readOnly = true)
+    public Result<Set<EntityKey>> getNotificationIdsForExam(final Long examId) {
+        return Result.tryCatch(() -> this.clientNotificationRecordMapper
+                .selectByExample()
+                .leftJoin(ClientConnectionRecordDynamicSqlSupport.clientConnectionRecord)
+                .on(
+                        ClientConnectionRecordDynamicSqlSupport.id,
+                        equalTo(ClientNotificationRecordDynamicSqlSupport.clientConnectionId))
+                .where(
+                        ClientConnectionRecordDynamicSqlSupport.examId,
+                        isEqualToWhenPresent(examId))
+                .build()
+                .execute()
+                .stream()
+                .map(ClientNotificationRecord::getClientConnectionId)
+                .map(id -> new EntityKey(id, EntityType.CLIENT_NOTIFICATION))
+                .collect(Collectors.toSet()));
+    }
+
     @Override
     @Transactional(readOnly = true)
     public Result<ClientNotification> getPendingNotificationByValue(
@@ -377,6 +397,30 @@ public class ClientEventDAOImpl implements ClientEventDAO {
         });
     }
 
+    @Override
+    @Transactional
+    public Result<Collection<EntityKey>> deleteClientNotification(final Set<EntityKey> keys) {
+        return Result.tryCatch(() -> {
+
+            final List<Long> pks = keys
+                    .stream()
+                    .map(EntityKey::getModelId)
+                    .map(Long::parseLong)
+                    .collect(Collectors.toList());
+
+            this.clientNotificationRecordMapper
+                    .deleteByExample()
+                    .where(ClientNotificationRecordDynamicSqlSupport.id, isIn(pks))
+                    .build()
+                    .execute();
+
+            return pks
+                    .stream()
+                    .map(pk -> new EntityKey(String.valueOf(pk), EntityType.CLIENT_NOTIFICATION))
+                    .collect(Collectors.toList());
+        });
+    }
+
     private Result<ClientEventRecord> recordById(final Long id) {
         return Result.tryCatch(() -> {
 

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/impl/ExamDAOImpl.java

@@ -451,7 +451,7 @@ public class ExamDAOImpl implements ExamDAO {
 
             final List<Long> ids = extractListOfPKs(all);
 
-            // notify exam deletition listener about following deletion, to cleanup stuff before deletion
+            // notify exam deletion listener about following deletion, to cleanup stuff before deletion
             this.applicationEventPublisher.publishEvent(new ExamDeletionEvent(ids));
 
             this.examRecordMapper.deleteByExample()

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/SEBClientNotificationServiceImpl.java

@@ -18,6 +18,7 @@ import java.util.Set;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.context.annotation.Lazy;
+import org.springframework.context.event.EventListener;
 import org.springframework.stereotype.Service;
 
 import ch.ethz.seb.sebserver.gbl.Constants;
@@ -32,6 +33,7 @@ import ch.ethz.seb.sebserver.gbl.util.Result;
 import ch.ethz.seb.sebserver.webservice.WebserviceInfo;
 import ch.ethz.seb.sebserver.webservice.servicelayer.dao.ClientConnectionDAO;
 import ch.ethz.seb.sebserver.webservice.servicelayer.dao.ClientEventDAO;
+import ch.ethz.seb.sebserver.webservice.servicelayer.dao.impl.ExamDeletionEvent;
 import ch.ethz.seb.sebserver.webservice.servicelayer.session.SEBClientInstructionService;
 import ch.ethz.seb.sebserver.webservice.servicelayer.session.SEBClientNotificationService;
 
@@ -122,6 +124,18 @@ public class SEBClientNotificationServiceImpl implements SEBClientNotificationSe
                 .onError(error -> log.error("Failed to store new client notification: {}", notification, error));
     }
 
+    @EventListener(ExamDeletionEvent.class)
+    public void notifyExamDeletionEvent(final ExamDeletionEvent event) {
+        // delete all notifications for given exams
+        event.ids.forEach(id -> this.clientEventDAO.getNotificationIdsForExam(id)
+                .flatMap(this.clientEventDAO::deleteClientNotification)
+                .map(deleted -> {
+                    log.debug("Deleted client notifications during exam deletion: {}", deleted);
+                    return deleted;
+                })
+                .onError(error -> log.error("Failed to delete client notifications for exam: {}", id, error)));
+    }
+
     private ClientNotification notifyNewNotifiaction(final ClientNotification notification) {
         if (notification.eventType == EventType.NOTIFICATION) {
             this.pendingNotifications.add(notification.id);