import uuid

import jwt
from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from sqlmodel import Session, select

from app.database import get_session
from app.models.user import User
from app.auth.jwt import decode_token

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


async def get_current_user(
    token: str = Depends(oauth2_scheme),
    session: Session = Depends(get_session),
) -> User:
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = decode_token(token)
        user_id_str: str | None = payload.get("sub")
        if user_id_str is None:
            raise credentials_exception
        user_id = uuid.UUID(user_id_str)
    except (jwt.PyJWTError, ValueError):
        raise credentials_exception

    user = session.get(User, user_id)
    if user is None:
        raise credentials_exception
    return user