"""Point d'entrée principal — CLI interactif et visualisation du graphe.

Ce fichier est FOURNI COMPLET — ce n'est pas un exercice.
Il fonctionnera dès que react_agent.py sera implémenté.

Usage :
    uv run python main.py                          # mode interactif
    uv run python main.py --verbose                # avec traces des outils
    uv run python main.py --ask "Prix d'un laptop ?"
    uv run python main.py --visualize              # diagramme Mermaid
"""

import argparse
import asyncio
import os
import sys
import uuid
from pathlib import Path

from dotenv import load_dotenv
from langchain_core.messages import HumanMessage

load_dotenv()


async def chat(question: str, thread_id: str, verbose: bool = False) -> str:
    """Envoie une question à l'agent et retourne la réponse finale."""
    # Import ici pour éviter l'import au démarrage si --visualize
    from src.agents.react_agent import agent

    config = {"configurable": {"thread_id": thread_id}}
    initial_state = {"messages": [HumanMessage(content=question)], "iterations": 0}

    if verbose:
        step_num = 0
        async for event in agent.astream_events(initial_state, config=config, version="v2"):
            kind = event.get("event", "")
            if kind == "on_tool_start":
                step_num += 1
                print(f"\n  🔧 [{step_num}] {event.get('name', '?')} "
                      f"← {event.get('data', {}).get('input', {})}")
            elif kind == "on_tool_end":
                out = str(event.get("data", {}).get("output", ""))
                print(f"       → {out[:100]}{'...' if len(out) > 100 else ''}")

        final = await agent.aget_state(config)
        msgs = final.values.get("messages", [])
        return str(msgs[-1].content) if msgs else "(aucune réponse)"
    else:
        result = await agent.ainvoke(initial_state, config=config)
        msgs = result.get("messages", [])
        return str(msgs[-1].content) if msgs else "(aucune réponse)"


async def interactive_loop(verbose: bool = False) -> None:
    """Boucle interactive. Commandes : exit | reset | verbose"""
    thread_id = f"session-{uuid.uuid4().hex[:8]}"
    show_verbose = verbose

    print(f"\n{'═'*55}")
    print("  Agent Catalogue — Formation Agents IA S1")
    print(f"{'═'*55}")
    print(f"  Modèle  : {os.getenv('MODEL_NAME', 'llama3.1:8b')}")
    print(f"  Session : {thread_id}")
    print(f"  Aide    : exit | reset | verbose")
    print(f"{'═'*55}\n")

    while True:
        try:
            question = input("Vous : ").strip()
        except (KeyboardInterrupt, EOFError):
            print("\nAu revoir !")
            break

        if not question:
            continue
        if question.lower() in ("exit", "quit", "q"):
            print("Au revoir !")
            break
        if question.lower() == "reset":
            thread_id = f"session-{uuid.uuid4().hex[:8]}"
            print(f"Nouvelle session : {thread_id}\n")
            continue
        if question.lower() == "verbose":
            show_verbose = not show_verbose
            print(f"Verbose {'activé' if show_verbose else 'désactivé'}\n")
            continue

        print("\nAgent : ", end="", flush=True)
        try:
            response = await chat(question, thread_id, verbose=show_verbose)
            print(response)
        except NotImplementedError as e:
            print(f"\n[TODO] {e}")
            print("→ Implémentez les fonctions marquées TODO dans src/")
        except Exception as e:
            print(f"\n[Erreur] {e}")
            print("→ Vérifiez qu'Ollama tourne : ollama serve")
        print()


async def ask_once(question: str, verbose: bool = False) -> None:
    """Pose une question unique."""
    thread_id = f"cli-{uuid.uuid4().hex[:8]}"
    print(f"\nQuestion : {question}\n{'─'*50}")
    try:
        response = await chat(question, thread_id, verbose=verbose)
        print(f"\n{response}\n")
    except NotImplementedError as e:
        print(f"\n[TODO] {e}")
        sys.exit(1)
    except Exception as e:
        print(f"\n[Erreur] {e}")
        sys.exit(1)


def visualize_graph() -> None:
    """Génère le diagramme Mermaid et le sauvegarde dans docs/graphs/."""
    from src.agents.react_agent import agent

    mermaid = agent.get_graph().draw_mermaid()
    print(f"\n{'═'*50}\n  Graphe LangGraph — Mermaid\n{'═'*50}")
    print(mermaid)

    path = Path("docs/graphs/agent_react.md")
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(f"# Graphe Agent ReAct\n\n```mermaid\n{mermaid}```\n", encoding="utf-8")
    print(f"\n✅ Sauvegardé dans {path}")
    print("   → Visualiser sur https://mermaid.live\n")


def main() -> None:
    parser = argparse.ArgumentParser(description="Agent Catalogue — S1")
    parser.add_argument("--visualize", action="store_true")
    parser.add_argument("--ask", type=str, metavar="QUESTION")
    parser.add_argument("--verbose", action="store_true")
    args = parser.parse_args()

    if args.visualize:
        visualize_graph()
    elif args.ask:
        asyncio.run(ask_once(args.ask, verbose=args.verbose))
    else:
        asyncio.run(interactive_loop(verbose=args.verbose))


if __name__ == "__main__":
    main()