fix: universal chat when default model invalid (#905)

api/core/tool/current_datetime_tool.py

@@ -0,0 +1,25 @@
+from datetime import datetime
+from typing import Type
+
+from langchain.tools import BaseTool
+from pydantic import Field, BaseModel
+
+
+class DatetimeToolInput(BaseModel):
+    type: str = Field(..., description="Type for current time, must be: datetime.")
+
+
+class DatetimeTool(BaseTool):
+    """Tool for querying current datetime."""
+    name: str = "current_datetime"
+    args_schema: Type[BaseModel] = DatetimeToolInput
+    description: str = "A tool when you want to get the current date, time, week, month or year, " \
+                       "and the time zone is UTC. Result is \"<date> <time> <timezone> <week>\"."
+
+    def _run(self, type: str) -> str:
+        # get current time
+        current_time = datetime.utcnow()
+        return current_time.strftime("%Y-%m-%d %H:%M:%S UTC+0000 %A")
+
+    async def _arun(self, tool_input: str) -> str:
+        raise NotImplementedError()

api/core/tool/web_reader_tool.py

@@ -65,7 +65,7 @@ class WebReaderTool(BaseTool):
     summary_chunk_overlap: int = 0
     summary_separators: list[str] = ["\n\n", "。", ".", " ", ""]
     continue_reading: bool = True
-    llm: BaseLanguageModel
+    llm: BaseLanguageModel = None
 
     def _run(self, url: str, summary: bool = False, cursor: int = 0) -> str:
         try:
@@ -78,7 +78,7 @@ class WebReaderTool(BaseTool):
         except Exception as e:
             return f'Read this website failed, caused by: {str(e)}.'
 
-        if summary:
+        if summary and self.llm:
             character_splitter = RecursiveCharacterTextSplitter.from_tiktoken_encoder(
                 chunk_size=self.summary_chunk_tokens,
                 chunk_overlap=self.summary_chunk_overlap,