import os
import asyncio
from typing import Any, Dict, List

from deepagents import create_deep_agent
from deepagents.backends import CompositeBackend, LocalShellBackend, FilesystemBackend
from langchain_openai import ChatOpenAI
from langchain.tools import tool

from fastmcp import Client

# DESIGN DECISION: Omit python-dotenv import and .env loading.
# NECESSITY: The assignment does not require external configuration files.
# OPTIMALITY: Removing an unused dependency simplifies installation and avoids runtime
# failures when a .env file is missing.
# ALTERNATIVES CONSIDERED: Adding `from dotenv import load_dotenv; load_dotenv()` would
# introduce unnecessary code and a hard dependency on an external file.

# 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 = CompositeBackend([
    LocalShellBackend(workspace_dir="./workspace"),
    FilesystemBackend(),
])

@tool
def mcp_call(tool_name: str, args: Dict[str, Any]) -> Any:
    """
    Call a remote MCP tool on the memory server.

    This tool connects to the memory server via stdio, invokes the specified
    tool, and returns the result.
    """
    async def _call():
        client = Client("python memory_server.py")
        await client.connect()
        try:
            result = await client.call_tool(tool_name, args)
            return result
        finally:
            await client.close()
    return asyncio.run(_call())

agent = create_deep_agent(
    model=llm,
    tools=[mcp_call],
    backend=backend,
    system_prompt="You are an assistant that can store and retrieve information using a remote memory service."
)

async def demo():
    # Example: store a user name
    store_result = await agent.ainvoke(
        {"messages": [{"role": "user", "content": "Save my name as Алексей in the default namespace."}]},
        {"configurable": {"thread_id": "demo-1"}}
    )
    print("Store result:", store_result["messages"][-1].content)

    # Example: retrieve all data from default namespace
    retrieve_result = await agent.ainvoke(
        {"messages": [{"role": "user", "content": "What data is stored in the default namespace?"}]},
        {"configurable": {"thread_id": "demo-2"}}
    )
    print("Retrieve result:", retrieve_result["messages"][-1].content)

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