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

import os
SECRET_KEY = os.getenv("JWT_SECRET", "your-secret-key")
ALGORITHM = "HS256"

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

def get_current_user(token: str = Depends(oauth2_scheme), db: Session = Depends(get_db)) -> models.User:
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        user_id = payload.get("sub")
        if user_id is None:
            raise credentials_exception
        user_id = int(user_id)
    except (JWTError, ValueError, TypeError):
        raise credentials_exception

    user = db.query(models.User).filter(models.User.id == user_id).first()
    if user is None:
        raise credentials_exception
    return user