from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.orm import Session
from jose import JWTError, jwt
from app.db.session import get_db
from app.db.models import User
from app.core.config import get_settings

settings = get_settings()
security = HTTPBearer()


def get_current_user(
    credentials: HTTPAuthorizationCredentials = Depends(security),
    db: Session = Depends(get_db),
) -> User:
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    
    try:
        payload = jwt.decode(credentials.credentials, settings.SECRET_KEY, algorithms=["HS256"])
        user_id: str = payload.get("sub")
        if user_id is None:
            raise credentials_exception
        user_id = int(user_id)  # Convert back to int for database query
    except (JWTError, ValueError):
        raise credentials_exception
    
    user = db.query(User).filter(User.id == user_id).first()
    if user is None:
        raise credentials_exception
    
    return user