Fix view sync correctness, cascade delete, N+1 queries, and revert path for VSUM views

app/src/main/java/tools/vitruv/methodologist/user/service/UserService.java

@@ -247,7 +247,7 @@ public User create(UserPostRequest userPostRequest) {
    * @param ttlMinutes time-to-live for the OTP (in minutes) shown in the email
    */
   public void sendOtp(String to, String toName, String otp, int ttlMinutes) {
-    //    mailService.sendOtpMail(to, toName, otp, ttlMinutes);
+    mailService.sendOtpMail(to, toName, otp, ttlMinutes);
   }
 
   /**

app/src/main/java/tools/vitruv/methodologist/vsum/mapper/VsumHistoryMapper.java

@@ -87,6 +87,7 @@ default Set<VsumRepresentation.View> toView(Set<VsumView> views) {
                             .map(
                                 vsumViewMetaModel ->
                                     vsumViewMetaModel.getMetaModel().getSource().getId())
+                            .sorted()
                             .toList())
                     .fileStorageId(view.getFileStorage().getId())
                     .build())

app/src/main/java/tools/vitruv/methodologist/vsum/model/repository/VsumViewMetaModelRepository.java

@@ -1,7 +1,11 @@
 package tools.vitruv.methodologist.vsum.model.repository;
 
+import java.util.Collection;
 import java.util.List;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 import tools.vitruv.methodologist.vsum.model.VsumView;
 import tools.vitruv.methodologist.vsum.model.VsumViewMetaModel;
@@ -21,10 +25,29 @@ public interface VsumViewMetaModelRepository extends CrudRepository<VsumViewMeta
    */
   List<VsumViewMetaModel> findAllByVsumView(VsumView vsumView);
 
+  /**
+   * Retrieves all view-meta-model associations for the given collection of VSUM views in a single
+   * query, avoiding N+1 patterns when processing multiple views.
+   *
+   * @param views the VSUM views whose associated view-meta-model entries are requested
+   * @return a list of {@link VsumViewMetaModel} entities linked to any of the provided VSUM views
+   */
+  List<VsumViewMetaModel> findAllByVsumViewIn(Collection<VsumView> views);
+
   /**
    * Deletes all view-meta-model associations for the given VSUM view.
    *
    * @param vsumView the VSUM view whose associated view-meta-model entries should be removed
    */
   void deleteAllByVsumView(VsumView vsumView);
+
+  /**
+   * Deletes all view-meta-model associations for the given collection of VSUM views in a single
+   * bulk query.
+   *
+   * @param views the VSUM views whose associated view-meta-model entries should be removed
+   */
+  @Modifying
+  @Query("DELETE FROM VsumViewMetaModel vm WHERE vm.vsumView IN :views")
+  void deleteAllByVsumViewIn(@Param("views") Collection<VsumView> views);
 }

app/src/main/java/tools/vitruv/methodologist/vsum/service/VsumHistoryService.java

@@ -16,6 +16,7 @@
 import tools.vitruv.methodologist.user.model.repository.UserRepository;
 import tools.vitruv.methodologist.vsum.VsumRepresentation;
 import tools.vitruv.methodologist.vsum.controller.dto.request.MetaModelRelationRequest;
+import tools.vitruv.methodologist.vsum.controller.dto.request.ViewRequest;
 import tools.vitruv.methodologist.vsum.controller.dto.request.VsumSyncChangesPutRequest;
 import tools.vitruv.methodologist.vsum.controller.dto.response.VsumHistoryResponse;
 import tools.vitruv.methodologist.vsum.mapper.VsumHistoryMapper;
@@ -202,6 +203,25 @@ private VsumSyncChangesPutRequest toSyncRequest(VsumRepresentation representatio
       vsumSyncChangesPutRequest.setMetaModelRelationRequests(metaModelRelationRequests);
     }
 
+    if (representation.getViews() == null) {
+      vsumSyncChangesPutRequest.setViewRequests(List.of());
+    } else {
+      List<ViewRequest> viewRequests =
+          representation.getViews().stream()
+              .filter(Objects::nonNull)
+              .map(
+                  view ->
+                      ViewRequest.builder()
+                          .fileStorageId(view.getFileStorageId())
+                          .metaModelIds(
+                              view.getMetaModelIds() == null
+                                  ? List.of()
+                                  : List.copyOf(view.getMetaModelIds()))
+                          .build())
+              .toList();
+      vsumSyncChangesPutRequest.setViewRequests(viewRequests);
+    }
+
     return vsumSyncChangesPutRequest;
   }
 }

app/src/main/java/tools/vitruv/methodologist/vsum/service/VsumService.java

@@ -832,9 +832,7 @@ private String toViewKey(ViewRequest request) {
     return request.getFileStorageId() + "|" + metaModelPart;
   }
 
-  private String toViewKey(VsumView vsumView) {
-    List<VsumViewMetaModel> relations = vsumViewMetaModelRepository.findAllByVsumView(vsumView);
-
+  private String toViewKey(VsumView vsumView, List<VsumViewMetaModel> relations) {
     String metaModelPart =
         relations.stream()
             .map(VsumViewMetaModel::getMetaModel)
@@ -855,9 +853,22 @@ private String toViewKey(VsumView vsumView) {
   private ViewSyncPlan buildViewSyncPlan(Vsum vsum, List<ViewRequest> desiredViewRequests) {
     List<VsumView> existingViews = vsumViewRepository.findAllByVsum(vsum);
 
+    Map<Long, List<VsumViewMetaModel>> relationsByViewId = new HashMap<>();
+    if (!existingViews.isEmpty()) {
+      List<VsumViewMetaModel> allRelations =
+          vsumViewMetaModelRepository.findAllByVsumViewIn(existingViews);
+      for (VsumViewMetaModel relation : allRelations) {
+        relationsByViewId
+            .computeIfAbsent(relation.getVsumView().getId(), k -> new ArrayList<>())
+            .add(relation);
+      }
+    }
+
     Map<String, VsumView> existingByKey = new HashMap<>();
     for (VsumView existingView : existingViews) {
-      existingByKey.put(toViewKey(existingView), existingView);
+      List<VsumViewMetaModel> viewRelations =
+          relationsByViewId.getOrDefault(existingView.getId(), List.of());
+      existingByKey.put(toViewKey(existingView, viewRelations), existingView);
     }
 
     Set<String> existingKeys = new HashSet<>(existingByKey.keySet());

app/src/main/java/tools/vitruv/methodologist/vsum/service/VsumViewMetaModelService.java

@@ -3,6 +3,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
+import java.util.stream.StreamSupport;
 import lombok.AccessLevel;
 import lombok.AllArgsConstructor;
 import lombok.experimental.FieldDefaults;
@@ -34,14 +35,19 @@ public class VsumViewMetaModelService {
   /**
    * Creates associations between a view and the provided metamodel ids.
    *
-   * <p>Only source metamodels are considered valid for association.
+   * <p>Only source metamodels are considered valid for association. A {@code null} or empty {@code
+   * metaModelIds} set results in an empty list being returned without querying the database.
    *
    * @param vsumView target view
-   * @param metaModelIds metamodel ids to associate
+   * @param metaModelIds metamodel ids to associate; may be {@code null} (treated as empty)
    * @return persisted join entities
    */
   @Transactional
   public List<VsumViewMetaModel> create(VsumView vsumView, Set<Long> metaModelIds) {
+    if (metaModelIds == null || metaModelIds.isEmpty()) {
+      return List.of();
+    }
+
     List<VsumMetaModel> vsumMetaModels =
         vsumMetaModelRepository.findAllByVsumAndMetaModel_source_idIn(
             vsumView.getVsum(), metaModelIds);
@@ -55,7 +61,9 @@ public List<VsumViewMetaModel> create(VsumView vsumView, Set<Long> metaModelIds)
               .build());
     }
 
-    return (List<VsumViewMetaModel>) vsumViewMetaModelRepository.saveAll(entities);
+    return StreamSupport.stream(
+            vsumViewMetaModelRepository.saveAll(entities).spliterator(), false)
+        .toList();
   }
 
   /**

app/src/main/java/tools/vitruv/methodologist/vsum/service/VsumViewService.java

@@ -2,6 +2,7 @@
 
 import static tools.vitruv.methodologist.messages.Error.VIEW_FILE_ID_NOT_FOUND_ERROR;
 
+import java.util.List;
 import lombok.AccessLevel;
 import lombok.AllArgsConstructor;
 import lombok.experimental.FieldDefaults;
@@ -14,6 +15,7 @@
 import tools.vitruv.methodologist.general.model.repository.FileStorageRepository;
 import tools.vitruv.methodologist.vsum.model.Vsum;
 import tools.vitruv.methodologist.vsum.model.VsumView;
+import tools.vitruv.methodologist.vsum.model.repository.VsumViewMetaModelRepository;
 import tools.vitruv.methodologist.vsum.model.repository.VsumViewRepository;
 
 /**
@@ -30,6 +32,7 @@ public class VsumViewService {
 
   VsumViewRepository vsumViewRepository;
   FileStorageRepository fileStorageRepository;
+  VsumViewMetaModelRepository vsumViewMetaModelRepository;
 
   /**
    * Creates and persists a new {@link VsumView} for the given VSUM and NeoJoin file.
@@ -60,11 +63,15 @@ public VsumView create(Vsum vsum, Long fileStorageId) {
   /**
    * Deletes the specified view and removes it from the in-memory VSUM collection if present.
    *
+   * <p>Metamodel associations ({@code VsumViewMetaModel}) for the view are deleted before the view
+   * itself to satisfy foreign key constraints.
+   *
    * @param vsum target VSUM
    * @param vsumView view to delete
    */
   @Transactional
   public void delete(Vsum vsum, VsumView vsumView) {
+    vsumViewMetaModelRepository.deleteAllByVsumView(vsumView);
     vsumViewRepository.delete(vsumView);
 
     if (vsum.getViews() != null) {
@@ -75,10 +82,17 @@ public void delete(Vsum vsum, VsumView vsumView) {
   /**
    * Deletes all views associated with the given VSUM.
    *
+   * <p>Metamodel associations ({@code VsumViewMetaModel}) for all views are deleted before the
+   * views themselves to satisfy foreign key constraints.
+   *
    * @param vsum target VSUM
    */
   @Transactional
   public void deleteByVsum(Vsum vsum) {
+    List<VsumView> views = vsumViewRepository.findAllByVsum(vsum);
+    if (!views.isEmpty()) {
+      vsumViewMetaModelRepository.deleteAllByVsumViewIn(views);
+    }
     vsumViewRepository.deleteAllByVsum(vsum);
 
     if (vsum.getViews() != null) {

app/src/main/resources/db/migration/V9__VIEW_TYPE_CONSTRAINTS.sql

@@ -0,0 +1,6 @@
+ALTER TABLE vsum_view_meta_model
+    ADD CONSTRAINT uk_vsum_view_meta_model UNIQUE (vsum_view_id, meta_model_id);
+
+CREATE INDEX idx_vsum_view_meta_model_vsum_view_id ON vsum_view_meta_model (vsum_view_id);
+
+CREATE INDEX idx_vsum_view_meta_model_meta_model_id ON vsum_view_meta_model (meta_model_id);

app/src/test/java/tools/vitruv/methodologist/vsum/service/VsumHistoryServiceTest.java

@@ -400,4 +400,104 @@ void revert_filtersNullRelationsWhileMapping() {
 
     assertThat(reqCap.getValue().getMetaModelRelationRequests()).hasSize(1);
   }
+
+  @Test
+  void revert_mapsViewsToViewRequests_whenRepresentationContainsViews() {
+    String callerEmail = "u@ex.com";
+
+    User user = new User();
+    user.setEmail(callerEmail);
+    when(userRepository.findByEmailIgnoreCaseAndRemovedAtIsNull(callerEmail))
+        .thenReturn(Optional.of(user));
+
+    Vsum vsum = new Vsum();
+    vsum.setId(104L);
+
+    VsumRepresentation.View view1 =
+        VsumRepresentation.View.builder()
+            .fileStorageId(10L)
+            .metaModelIds(List.of(1L, 2L))
+            .build();
+    VsumRepresentation.View view2 =
+        VsumRepresentation.View.builder()
+            .fileStorageId(20L)
+            .metaModelIds(List.of(3L))
+            .build();
+
+    VsumRepresentation rep =
+        VsumRepresentation.builder()
+            .metaModels(Set.of())
+            .metaModelsRealation(Set.of())
+            .views(new HashSet<>(Set.of(view1, view2)))
+            .build();
+
+    Long historyId = 16L;
+    VsumHistory history =
+        VsumHistory.builder().id(historyId).vsum(vsum).representation(rep).build();
+    when(vsumHistoryRepository.findById(historyId)).thenReturn(Optional.of(history));
+
+    when(vsumUserRepository
+            .findByVsum_IdAndUser_EmailAndUser_RemovedAtIsNullAndVsum_RemovedAtIsNull(
+                vsum.getId(), callerEmail))
+        .thenReturn(Optional.of(new VsumUser()));
+
+    service.revert(callerEmail, historyId);
+
+    ArgumentCaptor<VsumSyncChangesPutRequest> reqCap =
+        ArgumentCaptor.forClass(VsumSyncChangesPutRequest.class);
+    verify(vsumService).applySyncChanges(eq(vsum), eq(user), reqCap.capture(), eq(false));
+
+    VsumSyncChangesPutRequest applied = reqCap.getValue();
+    assertThat(applied.getViewRequests()).hasSize(2);
+    assertThat(applied.getViewRequests())
+        .anySatisfy(
+            v -> {
+              assertThat(v.getFileStorageId()).isEqualTo(10L);
+              assertThat(v.getMetaModelIds()).containsExactlyInAnyOrder(1L, 2L);
+            });
+    assertThat(applied.getViewRequests())
+        .anySatisfy(
+            v -> {
+              assertThat(v.getFileStorageId()).isEqualTo(20L);
+              assertThat(v.getMetaModelIds()).containsExactly(3L);
+            });
+  }
+
+  @Test
+  void revert_mapsNullViewsToEmptyViewRequests() {
+    String callerEmail = "u@ex.com";
+
+    User user = new User();
+    user.setEmail(callerEmail);
+    when(userRepository.findByEmailIgnoreCaseAndRemovedAtIsNull(callerEmail))
+        .thenReturn(Optional.of(user));
+
+    Vsum vsum = new Vsum();
+    vsum.setId(105L);
+
+    VsumRepresentation rep =
+        VsumRepresentation.builder()
+            .metaModels(null)
+            .metaModelsRealation(null)
+            .views(null)
+            .build();
+
+    Long historyId = 17L;
+    VsumHistory history =
+        VsumHistory.builder().id(historyId).vsum(vsum).representation(rep).build();
+    when(vsumHistoryRepository.findById(historyId)).thenReturn(Optional.of(history));
+
+    when(vsumUserRepository
+            .findByVsum_IdAndUser_EmailAndUser_RemovedAtIsNullAndVsum_RemovedAtIsNull(
+                vsum.getId(), callerEmail))
+        .thenReturn(Optional.of(new VsumUser()));
+
+    service.revert(callerEmail, historyId);
+
+    ArgumentCaptor<VsumSyncChangesPutRequest> reqCap =
+        ArgumentCaptor.forClass(VsumSyncChangesPutRequest.class);
+    verify(vsumService).applySyncChanges(eq(vsum), eq(user), reqCap.capture(), eq(false));
+
+    assertThat(reqCap.getValue().getViewRequests()).isNotNull().isEmpty();
+  }
 }

app/src/test/java/tools/vitruv/methodologist/vsum/service/VsumServiceTest.java

@@ -193,7 +193,7 @@ void setUp() {
 
     lenient().when(vsumViewRepository.findAllByVsum(any(Vsum.class))).thenReturn(List.of());
     lenient()
-        .when(vsumViewMetaModelRepository.findAllByVsumView(any(VsumView.class)))
+        .when(vsumViewMetaModelRepository.findAllByVsumViewIn(anyList()))
         .thenReturn(List.of());
   }
 
@@ -765,9 +765,12 @@ void update_deletesViews_whenExistingViewIsRemoved_andWritesHistory() {
 
     VsumViewMetaModel vm1 = new VsumViewMetaModel();
     vm1.setMetaModel(clonedMetaModel(1001L, 1L));
+    vm1.setVsumView(existingView);
     VsumViewMetaModel vm2 = new VsumViewMetaModel();
     vm2.setMetaModel(clonedMetaModel(1002L, 2L));
-    when(vsumViewMetaModelRepository.findAllByVsumView(existingView)).thenReturn(List.of(vm1, vm2));
+    vm2.setVsumView(existingView);
+    when(vsumViewMetaModelRepository.findAllByVsumViewIn(List.of(existingView)))
+        .thenReturn(List.of(vm1, vm2));
 
     VsumSyncChangesPutRequest put = new VsumSyncChangesPutRequest();
     put.setViewRequests(List.of());
@@ -806,9 +809,12 @@ void update_doesNotTouchViews_whenDesiredMatchesExistingAfterNormalization() {
 
     VsumViewMetaModel vm1 = new VsumViewMetaModel();
     vm1.setMetaModel(clonedMetaModel(2001L, 1L));
+    vm1.setVsumView(existingView);
     VsumViewMetaModel vm2 = new VsumViewMetaModel();
     vm2.setMetaModel(clonedMetaModel(2002L, 2L));
-    when(vsumViewMetaModelRepository.findAllByVsumView(existingView)).thenReturn(List.of(vm1, vm2));
+    vm2.setVsumView(existingView);
+    when(vsumViewMetaModelRepository.findAllByVsumViewIn(List.of(existingView)))
+        .thenReturn(List.of(vm1, vm2));
 
     VsumSyncChangesPutRequest put = new VsumSyncChangesPutRequest();
     put.setViewRequests(