import asyncio
from logging import getLogger
from fastapi import WebSocket, WebSocketDisconnect, Query, status
from fastapi.routing import APIRouter
from services.data_service import UserDataService
from config.settings import SECRET_KEY
from jose import jwt, JWTError

# Importar tus configuraciones y servicios existentes
# from security import SECRET_KEY, ALGORITHM, user_data_service (Ajusta según tu estructura)
logger = getLogger(__name__)
debug_router = APIRouter()
user_data_service = UserDataService()

async def validate_ws_token(token: str):
    """Valida el token manualmente para WebSocket ya que no usan HTTPBearer standard"""
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=["HS256"])
        email = payload.get("sub")
        if email is None:
            return None
        
        # Busca el usuario usando tu servicio existente
        user = user_data_service.get_by_email(email)
        return user
    except (JWTError, Exception):
        return None

@debug_router.websocket("/logs")
async def websocket_endpoint(websocket: WebSocket, token: str = Query(...)):
    logger.info("WebSocket connection established")
    # 1. Autenticación
    user = await validate_ws_token(token)
    
    if not user:
        # Cierre con código de política violada si el token es inválido
        await websocket.close(code=status.WS_1008_POLICY_VIOLATION)
        return

    # 2. Verificación de Permisos (Permission >= 2)
    # Asumo que tu modelo User tiene el atributo 'permission'
    if getattr(user, 'permission', 0) < 2:
        await websocket.close(code=status.WS_1008_POLICY_VIOLATION, reason="Permisos insuficientes")
        return

    await websocket.accept()

    # 3. Proceso de Streaming de Logs
    try:
        # Ejecuta journalctl en modo 'follow' (-f) para el servicio específico
        # -n 50 trae las ultimas 50 lineas para contexto inicial
        process = await asyncio.create_subprocess_exec(
            "journalctl", "-u", "pedidos_express", "-f", "-n", "50", "--output", "cat",
            stdout=asyncio.subprocess.PIPE,
            stderr=asyncio.subprocess.PIPE
        )

        # Bucle de lectura asíncrona
        while True:
            line = await process.stdout.readline()
            if line:
                # Decodificar bytes a string y enviar
                await websocket.send_text(line.decode("utf-8").strip())
            else:
                # Pequeña pausa si no hay datos para no saturar el CPU
                await asyncio.sleep(0.1)

    except WebSocketDisconnect:
        # El cliente se desconectó, matar el proceso de journalctl para no dejar zombies
        if process.returncode is None:
            process.terminate()
            await process.wait()
            
    except Exception as e:
        logger.error(f"Error en websocket logs: {e}")
        if process.returncode is None:
            process.terminate()
        await websocket.close(code=status.WS_1011_INTERNAL_ERROR)