import os
import asyncio
from langchain_openai import ChatOpenAI
from langchain_core.messages import HumanMessage
from langchain.tools import tool
from deepagents import create_deep_agent
from deepagents.backends import FilesystemBackend, LocalShellBackend, CompositeBackend
import requests
from bs4 import BeautifulSoup

# LLM configuration – OpenRouter
llm = ChatOpenAI(
    model="openai/gpt-oss-20b:free",
    base_url="https://openrouter.ai/api/v1",
    api_key=os.getenv("OPENAI_API_KEY"),
    temperature=0.0,
)

# Backend: virtual workspace + ability to export to real FS
backend = CompositeBackend([
    LocalShellBackend(workspace_dir="./workspace"),
    FilesystemBackend(),
])

# ---------- Tools ----------
@tool
def search_web(query: str) -> str:
    """Search the web using DuckDuckGo and return the first paragraph of the first result."""
    try:
        resp = requests.get(
            "https://duckduckgo.com/html/",
            params={"q": query},
            timeout=10,
        )
        resp.raise_for_status()
        soup = BeautifulSoup(resp.text, "html.parser")
        results = soup.select("a.result__a")
        if not results:
            return "No results found."
        first_link = results[0].get("href")
        # fetch the linked page
        page_resp = requests.get(first_link, timeout=10)
        page_resp.raise_for_status()
        page_soup = BeautifulSoup(page_resp.text, "html.parser")
        # grab first paragraph
        para = page_soup.find("p")
        return para.get_text(strip=True) if para else "No paragraph found."
    except Exception as e:
        return f"Error during search: {e}"

@tool
def write_file(filename: str, content: str) -> str:
    """Write content to a virtual file in the workspace."""
    try:
        backend.write_file(filename, content)
        return f"File '{filename}' written successfully."
    except Exception as e:
        return f"Failed to write file: {e}"

# ---------- Agent ----------
agent = create_deep_agent(
    model=llm,
    tools=[search_web, write_file],
    backend=backend,
    system_prompt="You are a research assistant. Search the web, create virtual files, and finally export them to the real filesystem.",
)

async def main():
    # Example task: gather information about "Python asyncio" and store in a file
    user_prompt = "Collect a concise summary about Python asyncio and save it to summary.txt"
    result = await agent.ainvoke(
        {"messages": [HumanMessage(content=user_prompt)]},
        {"configurable": {"thread_id": "session-1"}},
    )
    print("Agent finished.")
    # Export virtual workspace to real filesystem
    backend.export("./exported_workspace")
    print("Exported virtual files to ./exported_workspace")

if __name__ == "__main__":
    asyncio.run(main())