from config.constant import SecurityConstants
from externals.databases.pg_crud import get_user_by_id
from externals.databases.database import get_db
from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import jwt, JWTError
from sqlalchemy.ext.asyncio import AsyncSession


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


async def get_current_user(
    token: str = Depends(oauth2_scheme),
    db: AsyncSession = Depends(get_db),
):
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )

    try:
        payload = jwt.decode(
            token,
            SecurityConstants.JWT_SECRET_KEY,
            algorithms=[SecurityConstants.JWT_ALGORITHM],
        )
        user_id: str | None = payload.get("sub")
        if user_id is None:
            raise credentials_exception

    except JWTError:
        raise credentials_exception

    user = await get_user_by_id(db, user_id)
    if not user:
        raise credentials_exception

    return user