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
from langgraph.checkpoint.memory import MemorySaver
from rich.console import Console

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

# ---------- Tool ----------
@tool
def get_price(query: str) -> str:
    """Return a mock price for a city and date."""
    return f"Price for {query} is $42"

# ---------- Memory ----------
memory = MemorySaver()

# ---------- Console ----------
console = Console()

# ---------- Agent ----------
agent = create_deep_agent(
    model=llm,
    tools=[get_price],
    backend=backend,
    system_prompt="You are a helpful agent that can fetch prices.",
    checkpointer=memory,
    interrupt_before=["tools"],
)

# ---------- Helper to display tool call ----------
async def display_tool_call(state):
    # Get the last tool call from the messages
    messages = state.values.get("messages", [])
    if not messages:
        return
    last_msg = messages[-1]
    if hasattr(last_msg, "tool_calls") and last_msg.tool_calls:
        tool_call = last_msg.tool_calls[0]
        name = tool_call.get("name")
        args = tool_call.get("args")
        console.print(f"\n[bold cyan]Agent wants to call tool:[/bold cyan] {name}({args})")

# ---------- Main loop ----------
async def ask_and_run(user_input, config):
    async for chunk in agent.stream(user_input, config=config, stream_mode=["messages", "updates"]):
        chunk_type, chunk_data = chunk
        state = agent.get_state(config)

        if chunk_type == "messages":
            # Stream token output
            console.print(chunk_data, end="")

        if chunk_type == "updates":
            # Tool execution output
            console.print(chunk_data, end="")

        # Handle interrupt before tool call
        if "__interrupt__" in chunk_data and state.next == ("tools",):
            await display_tool_call(state)
            answer = input("Разрешить? (Y/n): ")
            if answer.lower().strip() in ("", "y", "yes"):
                # Resume by calling ask_and_run with None to continue
                await ask_and_run(None, config)
            else:
                console.print("[red]Отменено[/red]")
                break

async def main():
    config = {"configurable": {"thread_id": "conversation-1"}}
    console.print("[bold green]Добро пожаловать! Введите 'exit' для выхода.[/bold green]")
    while True:
        user_input = input("\nВы: ")
        if user_input.lower() == "exit":
            break
        await ask_and_run({"messages": [{"role": "human", "content": user_input}]}, config)

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