Fix flashcard order race condition

back/bots/models/chat.py

@@ -135,15 +135,15 @@ def create_flashcard(deck_name: str, front: str, back: str) -> str:
             logger.info(f"🃏 CREATE_FLASHCARD_TOOL_INVOKED: deck_name='{deck_name}'")
             try:
                 with transaction.atomic():
-                    deck = Deck.objects.filter(profile=self.profile, name=deck_name).first()
+                    deck = Deck.objects.select_for_update().filter(profile=self.profile, name=deck_name).first()
                     if not deck:
                         deck = Deck.objects.create(
                             profile=self.profile,
                             chat=self,
                             name=deck_name,
                             description=""
                         )
-                    deck = Deck.objects.select_for_update().get(pk=deck.pk)
+                        deck = Deck.objects.select_for_update().get(pk=deck.pk)
                     max_order = Flashcard.objects.filter(deck=deck).aggregate(models.Max('order'))['order__max'] or -1
                     Flashcard.objects.create(
                         deck=deck,

back/bots/tests/test_chat.py

@@ -6,6 +6,9 @@
 from bots.models.chat import Chat
 from bots.models.bot import Bot
 from bots.models.ai_model import AiModel
+from bots.models.deck import Deck
+from bots.models.profile import Profile
+from bots.models.flashcard import Flashcard
 from langchain_core.messages import AIMessage
 import uuid
 
@@ -181,3 +184,20 @@ def it_should_not_use_web_search_when_disabled(load_fixture, chat, ai, ai_output
                 result = chat.get_response(ai=ai)
 
                 assert result == "Hello! How can I assist you today?"
+
+
+@pytest.mark.django_db
+def test_flashcard_order_increments():
+    chat = Chat.objects.create()
+    profile = Profile.objects.create(user=chat.user)
+    deck = Deck.objects.create(chat=chat, name="Test Deck", profile=profile)
+
+    Flashcard.objects.create(deck=deck, front="front0", back="back0", order=0)
+    Flashcard.objects.create(deck=deck, front="front1", back="back1", order=1)
+    Flashcard.objects.create(deck=deck, front="front2", back="back2", order=2)
+
+    card_count = Flashcard.objects.filter(deck=deck).count()
+    assert card_count == 3, f"Expected 3 cards, got {card_count}"
+
+    orders = list(Flashcard.objects.filter(deck=deck).order_by('order').values_list('order', flat=True))
+    assert orders == [0, 1, 2], f"Expected orders [0, 1, 2], got {orders}"