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 .crud import get_user_by_id
from .db.session import get_db
from .models import User

oauth2_scheme = OAuth2PasswordBearer(tokenUrl='/auth/login')


def get_current_user(token: str = Depends(oauth2_scheme), db: Session = Depends(get_db)) -> User:
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail='Token inválido o expirado',
        headers={'WWW-Authenticate': 'Bearer'},
    )
    try:
        payload = jwt.decode(token, settings.secret_key, algorithms=[settings.algorithm])
        user_id = payload.get('sub')
        if user_id is None:
            raise credentials_exception
    except JWTError as exc:
        raise credentials_exception from exc

    user = get_user_by_id(db, int(user_id))
    if user is None:
        raise credentials_exception
    return user