"""
Main entry point for the assignment.

This script demonstrates a deep agent that:
1. Uses `create_deep_agent` from the `deepagents` package.
2. Stores conversation history with `MemorySaver`.
3. Pauses before each tool call and asks the user for confirmation.
4. Can defend its decisions when a user contradicts the original task.

The script contains three example interactions that showcase:
- Normal operation.
- Tool usage with confirmation.
- Defending the agent's choice.
"""

import os
from typing import Dict, Any

# LLM configuration – BroJS only
from langchain_openai import ChatOpenAI
from deepagents import create_deep_agent
from deepagents.backends import CompositeBackend, FilesystemBackend
from langgraph.checkpoint.memory import MemorySaver
from rich.console import Console
from rich.markdown import Markdown

# ---------------------------------------------------------------------------
# Configuration
# ---------------------------------------------------------------------------
LLM = ChatOpenAI(
    model="openai/gpt-oss-20b:free",
    base_url="https://platform.brojs.ru/jrnl-bh/api/inference/v1",
    api_key=os.getenv("JOURNAL_MCP_PAT"),
    temperature=0.0,
)

# Backend – virtual FS (real shell not needed for this demo).
backend = CompositeBackend(
    default=FilesystemBackend(root_dir="./workspace", virtual_mode=True, inherit_env=True),
    routes={},
)

# ---------------------------------------------------------------------------
# Helper tools
# ---------------------------------------------------------------------------
from langchain.tools import tool

@tool
def echo(text: str) -> str:
    """Return the same text – useful for demonstration."""
    return f"Echo: {text}"

@tool
def add(a: int, b: int) -> int:
    """Add two integers."""
    return a + b

# ---------------------------------------------------------------------------
# Agent creation
# ---------------------------------------------------------------------------
memory = MemorySaver()
agent = create_deep_agent(
    llm=LLM,
    tools=[echo, add],
    backend=backend,
    system_prompt="You are an assistant that must follow the user’s instructions and can use tools. You should ask for confirmation before calling a tool.",
    checkpointer=memory,
    interrupt_before=["tools"],  # pause before each tool call
)

console = Console()

# ---------------------------------------------------------------------------
# Interaction helpers
# ---------------------------------------------------------------------------
async def run_interaction(messages: list[Dict[str, str]], thread_id: str) -> None:
    """Run a single interaction with the agent."""
    config = {"configurable": {"thread_id": thread_id}}
    async for chunk in agent.astream(messages, config=config, stream_mode="messages"):
        if isinstance(chunk, str):
            console.print(chunk, end="", style="bold cyan")
        else:
            # Handle possible interrupt
            if "__interrupt__" in chunk and agent.get_state(config).next == ("tools",):
                console.print("\n[bold yellow]Agent wants to use a tool:[/]", style="yellow")
                console.print(Markdown(str(chunk)))
                confirm = input("Allow? (y/n) ").strip().lower()
                if confirm == "y":
                    await agent.ainvoke(Command(resume=None), config)
                else:
                    console.print("[red]Tool call rejected by user.[/]\n", style="red")
                    break
            else:
                console.print(chunk, style="green")
    console.print("\n--- End of interaction ---\n", style="bold magenta")

# ---------------------------------------------------------------------------
# Main demo loop – three examples
# ---------------------------------------------------------------------------
if __name__ == "__main__":
    import asyncio

    async def main():
        # Example 1: Simple echo
        await run_interaction(
            [{"role": "human", "content": "Say hello."}],
            thread_id="demo-echo",
        )

        # Example 2: Tool usage with confirmation
        await run_interaction(
            [{"role": "human", "content": "Add 7 and 5."}],
            thread_id="demo-add",
        )

        # Example 3: Defending the agent when user contradicts task
        await run_interaction(
            [
                {"role": "human", "content": "I think you should not use tools at all."},
                {"role": "assistant", "content": "But I need to add numbers. Let me call the tool."},
            ],
            thread_id="demo-contradiction",
        )

    asyncio.run(main())