Auto-handle parent tags in tag update

src/documents/tests/test_tag_hierarchy.py

@@ -90,3 +90,17 @@ class TestTagHierarchy(APITestCase):
         run_workflows(trigger.type, self.document)
         self.document.refresh_from_db()
         assert self.document.tags.count() == 0
+
+    def test_tag_view_parent_update_adds_parent_to_docs(self):
+        orphan = Tag.objects.create(name="Orphan")
+        self.document.tags.add(orphan)
+
+        self.client.patch(
+            f"/api/tags/{orphan.pk}/",
+            {"parent": self.parent.pk},
+            format="json",
+        )
+
+        self.document.refresh_from_db()
+        tags = set(self.document.tags.values_list("pk", flat=True))
+        assert tags == {self.parent.pk, orphan.pk}

src/documents/views.py

@@ -341,6 +341,39 @@ class TagViewSet(ModelViewSet, PermissionsAwareDocumentCountMixin):
     filterset_class = TagFilterSet
     ordering_fields = ("color", "name", "matching_algorithm", "match", "document_count")
 
+    def perform_update(self, serializer):
+        old_parent = self.get_object().parent
+        tag = serializer.save()
+        new_parent = tag.parent
+        if old_parent != new_parent:
+            self._update_document_parent_tags(tag, old_parent, new_parent)
+
+    def _update_document_parent_tags(self, tag, old_parent, new_parent):
+        DocumentTagRelationship = Document.tags.through
+        doc_ids = list(Document.objects.filter(tags=tag).values_list("pk", flat=True))
+        affected = set()
+
+        if new_parent:
+            parents_to_add = [new_parent, *new_parent.get_all_ancestors()]
+            to_create = []
+            for parent in parents_to_add:
+                missing = Document.objects.filter(id__in=doc_ids).exclude(tags=parent)
+                to_create.extend(
+                    DocumentTagRelationship(document_id=doc_id, tag_id=parent.id)
+                    for doc_id in missing.values_list("pk", flat=True)
+                )
+                affected.update(missing.values_list("pk", flat=True))
+            if to_create:
+                DocumentTagRelationship.objects.bulk_create(
+                    to_create,
+                    ignore_conflicts=True,
+                )
+
+        if affected:
+            from documents.tasks import bulk_update_documents
+
+            bulk_update_documents.delay(document_ids=list(affected))
+
 
 @extend_schema_view(**generate_object_with_permissions_schema(DocumentTypeSerializer))
 class DocumentTypeViewSet(ModelViewSet, PermissionsAwareDocumentCountMixin):