chore: remove langchain in tools (#3247)

api/core/tools/provider/builtin/brave/tools/brave_search.py

@@ -1,11 +1,95 @@
-from typing import Any
+import json
+from typing import Any, Optional
 
-from langchain.tools import BraveSearch
+import requests
+from pydantic import BaseModel, Field
 
 from core.tools.entities.tool_entities import ToolInvokeMessage
 from core.tools.tool.builtin_tool import BuiltinTool
 
 
+class BraveSearchWrapper(BaseModel):
+    """Wrapper around the Brave search engine."""
+
+    api_key: str
+    """The API key to use for the Brave search engine."""
+    search_kwargs: dict = Field(default_factory=dict)
+    """Additional keyword arguments to pass to the search request."""
+    base_url = "https://api.search.brave.com/res/v1/web/search"
+    """The base URL for the Brave search engine."""
+
+    def run(self, query: str) -> str:
+        """Query the Brave search engine and return the results as a JSON string.
+
+        Args:
+            query: The query to search for.
+
+        Returns: The results as a JSON string.
+
+        """
+        web_search_results = self._search_request(query=query)
+        final_results = [
+            {
+                "title": item.get("title"),
+                "link": item.get("url"),
+                "snippet": item.get("description"),
+            }
+            for item in web_search_results
+        ]
+        return json.dumps(final_results)
+    
+    def _search_request(self, query: str) -> list[dict]:
+        headers = {
+            "X-Subscription-Token": self.api_key,
+            "Accept": "application/json",
+        }
+        req = requests.PreparedRequest()
+        params = {**self.search_kwargs, **{"q": query}}
+        req.prepare_url(self.base_url, params)
+        if req.url is None:
+            raise ValueError("prepared url is None, this should not happen")
+
+        response = requests.get(req.url, headers=headers)
+        if not response.ok:
+            raise Exception(f"HTTP error {response.status_code}")
+
+        return response.json().get("web", {}).get("results", [])
+
+class BraveSearch(BaseModel):
+    """Tool that queries the BraveSearch."""
+
+    name = "brave_search"
+    description = (
+        "a search engine. "
+        "useful for when you need to answer questions about current events."
+        " input should be a search query."
+    )
+    search_wrapper: BraveSearchWrapper
+
+    @classmethod
+    def from_api_key(
+        cls, api_key: str, search_kwargs: Optional[dict] = None, **kwargs: Any
+    ) -> "BraveSearch":
+        """Create a tool from an api key.
+
+        Args:
+            api_key: The api key to use.
+            search_kwargs: Any additional kwargs to pass to the search wrapper.
+            **kwargs: Any additional kwargs to pass to the tool.
+
+        Returns:
+            A tool.
+        """
+        wrapper = BraveSearchWrapper(api_key=api_key, search_kwargs=search_kwargs or {})
+        return cls(search_wrapper=wrapper, **kwargs)
+
+    def _run(
+        self,
+        query: str,
+    ) -> str:
+        """Use the tool."""
+        return self.search_wrapper.run(query)
+
 class BraveSearchTool(BuiltinTool):
     """
     Tool for performing a search using Brave search engine.
@@ -31,7 +115,7 @@ class BraveSearchTool(BuiltinTool):
 
         tool = BraveSearch.from_api_key(api_key=api_key, search_kwargs={"count": count})
 
-        results = tool.run(query)
+        results = tool._run(query)
 
         if not results:
             return self.create_text_message(f"No results found for '{query}' in Tavily")