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

# ---------- LLM ----------
# Use OpenRouter – cloud API, no local GPU required
llm = ChatOpenAI(
    model="openai/gpt-oss-20b:free",
    base_url="https://openrouter.ai/api/v1",
    api_key=os.getenv("OPENAI_API_KEY"),
    temperature=0.7,
)

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

# ---------- Tool with sub‑agent ----------
@tool
def get_price(product: str, city: str) -> str:
    """Return a realistic price table for a product in a city.
    The tool internally creates a sub‑agent that generates the table.
    """
    # Sub‑agent that simply produces a price table
    sub_agent = create_agent(
        model=llm,
        tools=[],
        system_prompt=f"You are a price estimator for {city}. Provide a realistic price for {product} in a table format.",
    )
    prompt = (
        f"Generate a table with columns Продукт, Цена (руб.), Магазин for product '{product}' in city '{city}'."
    )
    result = sub_agent.invoke({"messages": [HumanMessage(content=prompt)]})
    # The last message contains the table
    return result["messages"][-1].content

# ---------- Main agent ----------
agent = create_deep_agent(
    model=llm,
    tools=[get_price],
    backend=backend,
    system_prompt="Ты помощник по планированию покупок.",
)

# ---------- Helper to pretty‑print messages ----------

def format_message(msg):
    if hasattr(msg, "content") and msg.content:
        return msg.content
    if hasattr(msg, "tool_calls") and msg.tool_calls:
        call = msg.tool_calls[0]
        return f"{call['name']}({call['args']})"
    return ""

# ---------- Main execution ----------
async def main():
    user_query = "Помоги составить список покупок: молоко, хлеб, яблоки. Я нахожусь в Казани."
    result = await agent.ainvoke(
        {"messages": [HumanMessage(content=user_query)]},
        {"configurable": {"thread_id": "session-1"}},
    )
    # Print all messages in order
    for msg in result["messages"]:
        print(format_message(msg))
        print("---")

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