import os, 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

# LLM configuration
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 FS + real shell
backend = CompositeBackend([
    LocalShellBackend(workspace_dir="./workspace"),
    FilesystemBackend(),
])

# Tool: web search using duckduckgo-search
@tool
def web_search(query: str) -> str:
    """Search the web for information."""
    try:
        from duckduckgo_search import DDGS
        with DDGS() as ddgs:
            results = list(ddgs.text(query, max_results=5))
        return "\n".join(f"{r['title']}: {r['body']}" for r in results)
    except Exception as e:
        return f"Search error: {e}"

# Tool: create virtual file in the virtual FS
@tool
def create_virtual_file(path: str, content: str) -> str:
    """Create a file in the virtual filesystem."""
    try:
        backend.write_file(path, content)
        return f"Virtual file {path} created."
    except Exception as e:
        return f"Error creating virtual file: {e}"

# Tool: write virtual files to real filesystem
@tool
def write_to_real_fs() -> str:
    """Copy all files from virtual FS to the real workspace."""
    try:
        # FilesystemBackend stores files in memory; we iterate over its internal dict if available
        if hasattr(backend, "_backend") and isinstance(backend._backend, FilesystemBackend):
            fs = backend._backend
            for path, content in fs._files.items():
                dst = os.path.join("./real_files", path.lstrip("/"))
                os.makedirs(os.path.dirname(dst), exist_ok=True)
                with open(dst, "w", encoding="utf-8") as f:
                    f.write(content)
        return "All virtual files written to real filesystem."
    except Exception as e:
        return f"Error writing to real FS: {e}"

# Create the deep agent
agent = create_deep_agent(
    llm=llm,
    tools=[web_search, create_virtual_file, write_to_real_fs],
    backend=backend,
    system_prompt="You are a deep agent that can search the web, create virtual files, and finally write them to the real filesystem.",
)

async def main():
    # Example interaction: search, create file, write to real FS
    result = await agent.ainvoke(
        {"messages": [HumanMessage(content="Search for Python async programming examples and store results in a file called async_examples.txt")]},
        {"configurable": {"thread_id": "session-1"}},
    )
    print(result["messages"][-1].content)

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