fix: Address review comments

Signed-off-by: Marcel Klehr <mklehr@gmx.net>

context_chat_backend/controller.py

@@ -12,7 +12,7 @@
 from .config_parser import get_config
 from .download import background_init, ensure_models
 from .dyn_loader import EmbeddingModelLoader, LLMModelLoader, LoaderException, VectorDBLoader
-from .models.nc_texttotext import LlmException
+from .models import LlmException
 from .ocs_utils import AppAPIAuthMiddleware
 from .setup_functions import ensure_config_file, repair_run, setup_env_vars
 from .utils import JSONResponse, enabled_guard, update_progress, value_of

context_chat_backend/models/__init__.py

@@ -12,7 +12,7 @@
 	'llm': _llm_models,
 }
 
-__all__ = ['init_model', 'load_model', 'models']
+__all__ = ['init_model', 'load_model', 'models', 'LlmException']
 
 
 def load_model(model_type: str, model_info: tuple[str, dict]) -> Embeddings | LLM | None:
@@ -54,3 +54,6 @@ def init_model(model_type: str, model_info: tuple[str, dict]):
 		raise AssertionError(f'Error: {model} does not implement "llm" type or has returned an invalid object')
 
 	return model
+
+class LlmException(Exception):
+	...

context_chat_backend/models/nc_texttotext.py

@@ -1,12 +1,15 @@
 import json
 import time
 from typing import Any, Dict, List, Optional
-from pydantic import BaseModel
+from pydantic import BaseModel, ValidationError
 
 from nc_py_api import Nextcloud
 from langchain_core.callbacks.manager import CallbackManagerForLLMRun
 from langchain_core.language_models.llms import LLM
 
+from context_chat_backend.models import LlmException
+
+
 def get_model_for(model_type: str, model_config: dict):
 	if model_config is None:
 		return None
@@ -62,13 +65,16 @@ def _call(
 			}
 		})
 
-		task = Task.model_validate(response["task"])
-
-		while task.status != 'STATUS_SUCCESSFUL' and task.status != 'STATUS_FAILED':
-			time.sleep(5)
-			response = nc.ocs("GET", f"/ocs/v1.php/taskprocessing/task/{task.id}")
+		try:
 			task = Task.model_validate(response["task"])
 
+			while task.status != 'STATUS_SUCCESSFUL' and task.status != 'STATUS_FAILED':
+				time.sleep(5)
+				response = nc.ocs("GET", f"/ocs/v1.php/taskprocessing/task/{task.id}")
+				task = Task.model_validate(response["task"])
+		except ValidationError as e:
+			raise LlmException('Failed to parse Nextcloud TaskProcessing task result')
+
 		if task.status == 'STATUS_FAILED':
 			raise LlmException('Nextcloud TaskProcessing Task failed')
 
@@ -89,6 +95,3 @@ def _identifying_params(self) -> Dict[str, Any]:
 	def _llm_type(self) -> str:
 		"""Get the type of language model used by this chat model. Used for logging purposes only."""
 		return "nc_texttotetx"
-
-class LlmException(Exception):
-	...