# agent.py

from llama_index.llms.openai import OpenAI
from llama_index.core.agent.workflow import AgentWorkflow
from llama_index.core.tools import FunctionTool

# LangChain-based tools
from langchain_community.tools import DuckDuckGoSearchRun, WikipediaQueryRun
from langchain_experimental.tools.python.tool import PythonREPLTool
from langchain_community.document_loaders import YoutubeLoader

# Tool wrappers
def search_duckduckgo(query: str) -> str:
    return DuckDuckGoSearchRun().run(query)

def search_wikipedia(query: str) -> str:
    return WikipediaQueryRun(api_wrapper=None).run(query)

def run_python(code: str) -> str:
    return PythonREPLTool().run(code)

def get_youtube_transcript(url: str) -> str:
    loader = YoutubeLoader.from_youtube_url(url, add_video_info=False)
    docs = loader.load()
    return " ".join(d.page_content for d in docs)

TOOLS = [
    FunctionTool.from_defaults(search_duckduckgo),
    FunctionTool.from_defaults(search_wikipedia),
    FunctionTool.from_defaults(run_python),
    FunctionTool.from_defaults(get_youtube_transcript),
]

llm = OpenAI(model="gpt-4")
agent = AgentWorkflow.from_tools_or_functions(
    TOOLS,
    llm=llm,
    system_prompt="You are a helpful AI agent using external tools."
)

import asyncio
async def answer_question(question: str) -> str:
    return await agent.arun(question)