feat(annotations): add updateAnnotation service method with partial-update DTO

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/main/java/org/raddatz/familienarchiv/dto/UpdateAnnotationDTO.java

@@ -0,0 +1,29 @@
+package org.raddatz.familienarchiv.dto;
+
+import jakarta.validation.constraints.DecimalMax;
+import jakarta.validation.constraints.DecimalMin;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.AllArgsConstructor;
+
+/**
+ * Partial update payload for annotation position and size.
+ * All fields are optional — only non-null values are applied.
+ */
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class UpdateAnnotationDTO {
+
+    @DecimalMin("0.0") @DecimalMax("1.0")
+    private Double x;
+
+    @DecimalMin("0.0") @DecimalMax("1.0")
+    private Double y;
+
+    @DecimalMin("0.01") @DecimalMax("1.0")
+    private Double width;
+
+    @DecimalMin("0.01") @DecimalMax("1.0")
+    private Double height;
+}

backend/src/main/java/org/raddatz/familienarchiv/service/AnnotationService.java

@@ -2,6 +2,7 @@ package org.raddatz.familienarchiv.service;
 
 import lombok.RequiredArgsConstructor;
 import org.raddatz.familienarchiv.dto.CreateAnnotationDTO;
+import org.raddatz.familienarchiv.dto.UpdateAnnotationDTO;
 import org.raddatz.familienarchiv.exception.DomainException;
 import org.raddatz.familienarchiv.exception.ErrorCode;
 import org.raddatz.familienarchiv.model.DocumentAnnotation;
@@ -61,6 +62,21 @@ public class AnnotationService {
         return annotationRepository.save(annotation);
     }
 
+    @Transactional
+    public DocumentAnnotation updateAnnotation(UUID documentId, UUID annotationId, UpdateAnnotationDTO dto) {
+        DocumentAnnotation annotation = annotationRepository
+                .findByIdAndDocumentId(annotationId, documentId)
+                .orElseThrow(() -> DomainException.notFound(
+                        ErrorCode.ANNOTATION_NOT_FOUND, "Annotation not found: " + annotationId));
+
+        if (dto.getX() != null) annotation.setX(dto.getX());
+        if (dto.getY() != null) annotation.setY(dto.getY());
+        if (dto.getWidth() != null) annotation.setWidth(dto.getWidth());
+        if (dto.getHeight() != null) annotation.setHeight(dto.getHeight());
+
+        return annotationRepository.save(annotation);
+    }
+
     @Transactional
     public void deleteAnnotation(UUID documentId, UUID annotationId, UUID userId) {
         DocumentAnnotation annotation = annotationRepository

backend/src/test/java/org/raddatz/familienarchiv/service/AnnotationServiceTest.java

@@ -6,6 +6,7 @@ import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 import org.raddatz.familienarchiv.dto.CreateAnnotationDTO;
+import org.raddatz.familienarchiv.dto.UpdateAnnotationDTO;
 import org.raddatz.familienarchiv.exception.DomainException;
 import org.raddatz.familienarchiv.model.DocumentAnnotation;
 import org.raddatz.familienarchiv.repository.AnnotationRepository;
@@ -203,6 +204,42 @@ class AnnotationServiceTest {
                 .satisfies(e -> assertThat(((DomainException) e).getStatus()).isEqualTo(FORBIDDEN));
     }
 
+    // ─── updateAnnotation ─────────────────────────────────────────────────────
+
+    @Test
+    void updateAnnotation_throwsNotFound_whenAnnotationNotInDocument() {
+        UUID docId = UUID.randomUUID();
+        UUID annotId = UUID.randomUUID();
+        when(annotationRepository.findByIdAndDocumentId(annotId, docId)).thenReturn(Optional.empty());
+
+        assertThatThrownBy(() -> annotationService.updateAnnotation(docId, annotId, new UpdateAnnotationDTO()))
+                .isInstanceOf(DomainException.class)
+                .satisfies(e -> assertThat(((DomainException) e).getStatus()).isEqualTo(NOT_FOUND));
+    }
+
+    @Test
+    void updateAnnotation_updatesOnlyPresentFields() {
+        UUID docId = UUID.randomUUID();
+        UUID annotId = UUID.randomUUID();
+        DocumentAnnotation annotation = DocumentAnnotation.builder()
+                .id(annotId).documentId(docId)
+                .x(0.1).y(0.2).width(0.3).height(0.4).build();
+        when(annotationRepository.findByIdAndDocumentId(annotId, docId))
+                .thenReturn(Optional.of(annotation));
+        when(annotationRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        UpdateAnnotationDTO dto = new UpdateAnnotationDTO();
+        dto.setX(0.5);
+        dto.setY(0.6);
+
+        DocumentAnnotation result = annotationService.updateAnnotation(docId, annotId, dto);
+
+        assertThat(result.getX()).isEqualTo(0.5);
+        assertThat(result.getY()).isEqualTo(0.6);
+        assertThat(result.getWidth()).isEqualTo(0.3);  // unchanged
+        assertThat(result.getHeight()).isEqualTo(0.4); // unchanged
+    }
+
     // ─── listAnnotations ──────────────────────────────────────────────────────
 
     @Test