from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import JWTError, jwt
from sqlalchemy.orm import Session

from core.config import settings
from core.database import get_db
from crud import user as crud_user
from schemas import user as schemas_user # Pour la validation du modèle de l'utilisateur

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="auth/login") # URL où le client peut obtenir un token

async def get_current_user(
    token: str = Depends(oauth2_scheme), 
    db: Session = Depends(get_db)
):
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Impossible de valider les identifiants",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
    except JWTError:
        raise credentials_exception
    
    user = crud_user.get_user_by_email(db, email=username)
    if user is None:
        raise credentials_exception
    
    # Retourne l'utilisateur sous forme de Pydantic model pour la réponse
    return schemas_user.UserResponse.model_validate(user)