change collection parent

app/views/book/collection.py

@@ -221,16 +221,52 @@ def collection_delete(book_id: int, collection_id: int):
 def change_collection_position(book_id: int, collection_id: int):
     collection: m.Collection = db.session.get(m.Collection, collection_id)
     new_position = request.json.get("position")
+    collection_id = request.json.get("collection_id")
 
-    collections_to_edit = m.Collection.query.filter(
+    new_parent: m.Collection = collection.parent
-        m.Collection.parent_id == collection.parent.id,
+    if collection_id is not None:
-        m.Collection.position >= new_position,
+        new_parent: m.Collection = db.session.get(m.Collection, collection_id)
-    ).all()
+        if not new_parent:
-    for child in collections_to_edit:
+            log(log.INFO, "Collection with id [%s] not found", collection_id)
-        child: m.Collection
+            return {"message": "new parent collection not found"}, 404
-        if child.position >= new_position:
+
-            child.position += 1
+        log(
-            child.save(False)
+            log.INFO,
-    collection.position = new_position
+            "Change collection [%s] parent_id to [%s]",
+            collection,
+            collection_id,
+        )
+        collection.parent_id = collection_id
+
+    if new_parent.active_children:
+        collections_to_edit = m.Collection.query.filter(
+            m.Collection.parent_id == new_parent.id,
+            m.Collection.position >= new_position,
+        ).all()
+        if collections_to_edit:
+            log(log.INFO, "Calculate new positions of collections in [%s]", collection)
+            for child in collections_to_edit:
+                child: m.Collection
+                if child.position >= new_position:
+                    child.position += 1
+                    child.save(False)
+
+        log(
+            log.INFO,
+            "Set new position [%s] of collection [%s]",
+            new_position,
+            collection,
+        )
+        collection.position = new_position
+    else:
+        log(
+            log.INFO,
+            "Collection [%s] does not have active collection. Set collection [%s] position to 1",
+            collection,
+            new_parent,
+        )
+        collection.position = 1
+
+    log(log.INFO, "Apply position changes on [%s]", collection)
     collection.save()
-    return {}
+    return {"message": "success"}

app/views/book/section.py

@@ -176,4 +176,4 @@ def change_section_position(book_id: int, section_id: int):
 
     log(log.INFO, "Apply position changes on [%s]", section)
     section.save()
-    return {}
+    return {"message": "success"}

tests/test_ordering.py

@@ -58,6 +58,30 @@ def test_change_collection_ordering(client):
         elif collection.position > new_position:
             assert current_ordering[collection.id] + 1 == collection.position
 
+    collection: m.Collection = db.session.get(m.Collection, 3)
+    collection_1, _ = create_sub_collection(client, book.id, root_collection.id)
+    assert collection.parent_id != collection_1.id
+
+    response: Response = client.post(
+        f"/book/{book.id}/{collection.id}/collection/change_position",
+        headers={"Content-Type": "application/json"},
+        json=dict(position=999, collection_id=collection_1.id),
+        follow_redirects=True,
+    )
+
+    collection: m.Collection = db.session.get(m.Collection, 3)
+    assert collection.parent_id == collection_1.id
+    assert collection.position == 1
+
+    response: Response = client.post(
+        f"/book/{book.id}/{collection.id}/collection/change_position",
+        headers={"Content-Type": "application/json"},
+        json=dict(position=999, collection_id=999),
+        follow_redirects=True,
+    )
+    assert response.status_code == 404
+    assert response.json["message"] == "new parent collection not found"
+
 
 def test_ordering_on_section_create(client):
     login(client)