Merge pull request #633 from sujitha-kotyada/fix/chat-history-shared-message-fk-629

Fix/chat history shared message

Author: param20h

backend/app/routes/chat.py

@@ -946,10 +946,22 @@ def clear_chat_history(
     db: Session = Depends(get_db),
 ):
     """Delete all chat messages associated with a specific document."""
+    # Find the query/subquery of chat messages to delete
+    message_ids_query = db.query(ChatMessage.id).filter(
+        ChatMessage.user_id == user.id,
+        ChatMessage.document_id == document_id,
+    )
+
+    # Delete any associated SharedMessage records first
+    db.query(SharedMessage).filter(
+        SharedMessage.message_id.in_(message_ids_query)
+    ).delete(synchronize_session=False)
+
+    # Delete the ChatMessage records
     db.query(ChatMessage).filter(
         ChatMessage.user_id == user.id,
         ChatMessage.document_id == document_id,
-    ).delete()
+    ).delete(synchronize_session=False)
     db.commit()
 
     return {"message": "Chat history cleared"}

backend/tests/test_chat.py

@@ -127,3 +127,83 @@ class MockResponse:
     generate_answer(question="hello?", user_id="some-user", hf_token=None)
     from app.config import get_settings
     assert called_with_token == get_settings().HF_TOKEN
+
+
+def test_clear_chat_history_with_shared_messages(client, auth_headers, ready_document, db_session, user):
+    from app.models import ChatMessage, SharedMessage
+    
+    # Create a user ChatMessage and an assistant ChatMessage associated with ready_document
+    user_msg = ChatMessage(
+        user_id=user.id,
+        document_id=ready_document.id,
+        role="user",
+        content="Hello, is anyone there?",
+    )
+    assistant_msg = ChatMessage(
+        user_id=user.id,
+        document_id=ready_document.id,
+        role="assistant",
+        content="Yes, I am here.",
+    )
+    db_session.add_all([user_msg, assistant_msg])
+    db_session.commit()
+    db_session.refresh(assistant_msg)
+    
+    # Make assistant message shared by creating a SharedMessage link
+    shared = SharedMessage(message_id=assistant_msg.id)
+    db_session.add(shared)
+    db_session.commit()
+
+    assistant_msg_id = assistant_msg.id
+    
+    # Expunge objects so session doesn't try to auto-refresh deleted rows
+    db_session.expunge(user_msg)
+    db_session.expunge(assistant_msg)
+    db_session.expunge(shared)
+    
+    # Call DELETE /api/v1/chat/history/{document_id}
+    response = client.delete(
+        f"/api/v1/chat/history/{ready_document.id}",
+        headers=auth_headers,
+    )
+    
+    # Check results
+    assert response.status_code == 200
+    assert response.json() == {"message": "Chat history cleared"}
+    
+    # Check that ChatMessage records are deleted
+    remaining_messages = db_session.query(ChatMessage).filter(
+        ChatMessage.document_id == ready_document.id
+    ).all()
+    assert len(remaining_messages) == 0
+    
+    # Check that SharedMessage records are deleted
+    remaining_shared = db_session.query(SharedMessage).filter(
+        SharedMessage.message_id == assistant_msg_id
+    ).all()
+    assert len(remaining_shared) == 0
+
+
+def test_clear_chat_history_repeated_or_empty(client, auth_headers, ready_document, db_session):
+    from app.models import ChatMessage
+    # Check history is empty initially
+    remaining_messages = db_session.query(ChatMessage).filter(
+        ChatMessage.document_id == ready_document.id
+    ).all()
+    assert len(remaining_messages) == 0
+
+    # First delete on empty history
+    response = client.delete(
+        f"/api/v1/chat/history/{ready_document.id}",
+        headers=auth_headers,
+    )
+    assert response.status_code == 200
+    assert response.json() == {"message": "Chat history cleared"}
+
+    # Second delete (repeated request)
+    response = client.delete(
+        f"/api/v1/chat/history/{ready_document.id}",
+        headers=auth_headers,
+    )
+    assert response.status_code == 200
+    assert response.json() == {"message": "Chat history cleared"}