Fix error when faking chat

backend/app/api/routes/chat.py

 import json
+import uuid
 from collections.abc import AsyncGenerator, Sequence
 from enum import Enum
 from random import randrange
@@ -45,7 +46,7 @@ ChatEventType = Enum(
 
 
 async def transform_sofia_chat_response(
-    sofia_chat_response: AsyncGenerator[str], doc_to_map: Sequence[Document]
+    sofia_chat_response: AsyncGenerator[str], doc_to_map: Sequence[uuid.UUID]
 ) -> AsyncGenerator[str]:
     """
     Transform sofia_chat response in a format compatible with caradoc based chat
@@ -85,9 +86,7 @@ async def transform_sofia_chat_response(
             document_list = res[ChatEventType.DOCS.value]
             viewer_sources = [
                 {
-                    "id": doc["document_id"]
-                    if len(doc_to_map) == 0
-                    else str(doc_to_map[randrange(len(doc_to_map))].id),
+                    "id": doc["document_id"] if len(doc_to_map) == 0 else str(doc_to_map[randrange(len(doc_to_map))]),
                     "content": doc["extrait"],
                     "score": doc["score"],
                     # Title and filename are not available for now, they'll be retrieve by the front from the DB
@@ -142,9 +141,9 @@ async def process_message(session: SessionDep, current_user: CurrentUser, chat_m
 
     with user_permissions(current_user):
         # Retieve collection documents and map them to the response
-        documents_to_map: Sequence[Document] = []
+        documents_to_map: Sequence[uuid.UUID] = []
         if settings.CHAT.fake:
-            sql_req = select(Document).where(Document.collection_id == chat_message.collection_ids[0])
+            sql_req = select(Document.id).where(Document.collection_id == chat_message.collection_ids[0])
             documents_to_map = session.exec(sql_req).all()
         statement = select(Collection).where(col(Collection.id).in_(chat_message.collection_ids))
         collections = session.exec(statement).all()