# ======================================
# main.py – FastAPI pour chatbot douanier 🇹🇳
# ======================================

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel
from typing import Optional, List, Dict
import uuid
import uvicorn

# Import des modules internes
from core.retrieval import find_relevant_articles
from core.llm import generate_synthesized_llm_response_with_sources
from core.memory import (
    start_new_session,
    add_message_to_session,
    rename_session,
    update_session_title,
    get_messages_for_session,
    load_all_sessions
)

# ======================================================
# CONFIGURATION DE L'APPLICATION
# ======================================================

app = FastAPI(title="Chatbot Douane API 🇹🇳")

# CORS (pour permettre les requêtes depuis un frontend)
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"]
)

# ----------------------------
# Pydantic models
# ----------------------------

class MessageData(BaseModel):
    type: Optional[str] = "human"
    content: str

class AddMessageRequest(BaseModel):
    session_id: str
    message: MessageData

class RenameSessionRequest(BaseModel):
    session_id: str
    new_title: str

class NewSessionResponse(BaseModel):
    session_id: str

class ChatRequest(BaseModel):
    question: str
    session_id: Optional[str] = None
    web_results: Optional[Dict] = None

class ChatResponse(BaseModel):
    session_id: str
    answer: str
    articles_found: List[Dict]

# ----------------------------
# Session endpoints
# ----------------------------

@app.get("/sessions")
def get_all_sessions():
    """Return all sessions with their titles and creation date."""
    sessions = load_all_sessions()
    return sessions

@app.post("/sessions/new", response_model=NewSessionResponse)
def create_session():
    """Create a new session and return its ID."""
    session_state = {"sessions": {}}
    session_id = start_new_session(session_state)
    return {"session_id": session_id}

@app.post("/sessions/add_message")
def add_message(req: AddMessageRequest):
    """Add a message to a session."""
    try:
        add_message_to_session(req.session_id, req.message.dict())
        return {"status": "success"}
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))

@app.post("/sessions/rename")
def rename(req: RenameSessionRequest):
    """Rename a session manually."""
    try:
        rename_session(req.session_id, req.new_title)
        return {"status": "success"}
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))

@app.post("/sessions/update_title/{session_id}")
def update_title(session_id: str):
    """Update session title automatically based on first message."""
    try:
        update_session_title(session_id)
        return {"status": "success"}
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))

@app.get("/sessions/{session_id}/messages")
def get_messages(session_id: str):
    """Get all messages for a given session."""
    try:
        messages = get_messages_for_session(session_id)
        return messages
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))

# ----------------------------
# Chatbot endpoint
# ----------------------------

@app.post("/chat", response_model=ChatResponse)
def chat_with_bot(request: ChatRequest):
    """
    Envoie une question au chatbot douanier.
    - Recherche les articles pertinents
    - Génère la réponse à l’aide du LLM
    - Sauvegarde l’historique dans MongoDB
    """
    try:
        # Si pas de session fourni, créer un nouvel ID
        session_id = request.session_id or f"session_{uuid.uuid4()}"

        # Récupérer les articles pertinents
        top_articles = find_relevant_articles(request.question)

        # Générer la réponse via LLM
        answer, _ = generate_synthesized_llm_response_with_sources(
            question=request.question,
            top_articles=top_articles,
            web_results=request.web_results or {},
            session_id=session_id
        )

        # Format des articles
        articles = [
            {
                "article_num": doc.get("article_num"),
                "similarity": round(sim, 3)
            }
            for doc, sim in top_articles
        ]

        # Retour API
        return ChatResponse(
            session_id=session_id,
            answer=answer,
            articles_found=articles
        )

    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

# ======================================================
# LANCEMENT LOCAL
# ======================================================