chat : adapt to the new sofia chat format and handle empty docs

backend/app/api/routes/chat.py

@@ -80,7 +80,9 @@ async def transform_sofia_chat_response(
     async for line in sofia_chat_response:
         # Response is in json
         res = json.loads(line)
-        content_list, document_list_str, rephrased_query, year_list = res
+        content_list = res["history"]
+        document_list_str = res["docs_html"]
+        rephrased_query = res["output_query"]
         document_list = json.loads(document_list_str)
         if rephrased_query and not has_send_rephrased_query:
             has_send_rephrased_query = True
@@ -90,7 +92,11 @@ async def transform_sofia_chat_response(
                     "query": rephrased_query,
                 },
             })}$$$\n"""
-        if len(document_list) > 0 and not has_send_documents:
+        # If there is no relevant document, document_list will be : ['No document to show.']
+        if len(document_list) == 1 and type(document_list[0]) is str:
+            has_send_documents = True
+            viewer_sources = []
+        elif len(document_list) > 0 and not has_send_documents:
             viewer_sources = [
                 {
                     "id": doc["document_id"]