services/mcp_service.py

"""Service pour initialiser le serveur MCP avec FastMCP"""

from mcp.server.fastmcp import FastMCP
from typing import Dict, Any, Optional
import logging

from fastapi import FastAPI

from services.stance_model_manager import stance_model_manager
from services.label_model_manager import kpa_model_manager  
from services.stt_service import speech_to_text
from services.tts_service import text_to_speech
from services.generate_model_manager import generate_model_manager
from services.topic_service import topic_service
from services.chat_service import generate_chat_response

logger = logging.getLogger(__name__)

# Créer l'instance FastMCP
mcp_server = FastMCP("NLP-Debater-MCP", json_response=True, stateless_http=False)  # Stateful pour sessions

# Tools (inchangés, OK)
@mcp_server.tool()
def detect_stance(topic: str, argument: str) -> Dict[str, Any]:
    if not stance_model_manager.model_loaded:
        raise ValueError("Modèle stance non chargé")
    result = stance_model_manager.predict(topic, argument)
    return {
        "predicted_stance": result["predicted_stance"],
        "confidence": result["confidence"],
        "probability_con": result["probability_con"],
        "probability_pro": result["probability_pro"]
    }

@mcp_server.tool()
def match_keypoint_argument(argument: str, key_point: str) -> Dict[str, Any]:
    if not kpa_model_manager.model_loaded:
        raise ValueError("Modèle KPA non chargé")
    result = kpa_model_manager.predict(argument, key_point)
    return {
        "prediction": result["prediction"],
        "label": result["label"],
        "confidence": result["confidence"],
        "probabilities": result["probabilities"]
    }

@mcp_server.tool()
def transcribe_audio(audio_path: str) -> str:
    return speech_to_text(audio_path)

@mcp_server.tool()
def generate_speech(text: str, voice: str = "en", format: str = "mp3") -> str:
    """
    Generate speech using the free gTTS backend (MP3 only).
    'voice' expects a language code (e.g., 'en', 'fr').
    """
    return text_to_speech(text, voice, format)

@mcp_server.tool()
def generate_argument(topic: str, position: str) -> Dict[str, Any]:
    """Generate an argument for a given topic and position"""
    if not generate_model_manager.model_loaded:
        raise ValueError("Modèle de génération non chargé")
    argument = generate_model_manager.generate(topic=topic, position=position)
    return {
        "topic": topic,
        "position": position,
        "argument": argument
    }

@mcp_server.tool()
def extract_topic(text: str) -> Dict[str, Any]:
    """Extract a topic from the given text/argument"""
    if not topic_service.initialized:
        topic_service.initialize()
    topic = topic_service.extract_topic(text)
    return {
        "text": text,
        "topic": topic
    }

@mcp_server.tool()
def voice_chat(user_input: str, conversation_id: Optional[str] = None) -> Dict[str, Any]:
    """Generate a chatbot response for voice chat (English only)"""
    response_text = generate_chat_response(
        user_input=user_input,
        conversation_id=conversation_id
    )
    return {
        "user_input": user_input,
        "conversation_id": conversation_id,
        "response": response_text
    }

@mcp_server.resource("debate://prompt")
def get_debate_prompt() -> str:
    return "Tu es un expert en débat. Génère 3 arguments PRO pour le topic donné. Sois concis et persuasif."

# Health tool (enregistré avant l'initialisation)
@mcp_server.tool()
def health_check() -> Dict[str, Any]:
    """Health check pour le serveur MCP"""
    try:
        # Liste hardcodée pour éviter les problèmes avec list_tools()
        tool_names = [
            "detect_stance",
            "match_keypoint_argument",
            "transcribe_audio",
            "generate_speech",
            "generate_argument",
            "extract_topic",
            "voice_chat",
            "health_check"
        ]
    except Exception:
        tool_names = []
    return {"status": "healthy", "tools": tool_names}

def init_mcp_server(app: FastAPI) -> None:
    """
    Initialise et monte le serveur MCP sur l'app FastAPI.
    """
    # CORRIGÉ : Utilise streamable_http_app() qui retourne l'ASGI app
    mcp_app = mcp_server.streamable_http_app()  # L'ASGI app pour mounting (gère /health, /tools, etc. nativement)
    
    # Monte à /api/v1/mcp - FastAPI gère le lifespan auto
    app.mount("/api/v1/mcp", mcp_app)
    
    logger.info("✓ Serveur MCP monté sur /api/v1/mcp avec tools NLP/STT/TTS")