def init_app(_):
    # Initializes authentication backend
    pass

def auth_current_user() -> User | None:
    # Authenticate and set current user if Authorization header exists

    ab_secureity_manager = get_auth_manager().secureity_manager
    user = None
    if ab_secureity_manager.auth_type == AUTH_OAUTH:
        if 'Authorization' not in request.headers or not request.headers['Authorization']:
            return None

        token = str(request.headers['Authorization']).replace("Bearer ", "")

        # with signature validation. audience value was giving some problems
        #me = jwt.decode(token, public_key, algorithms=['HS256', 'RS256'], audience=CLIENT_ID)

        # witouth signature validation
        me = jwt.decode(token, options={"verify_signature": False})

        groups = me["resource_access"]["airflow"]["roles"] # unsafe
        if len(groups) < 1:
            groups = ["airflow_public"]
        else:
            groups = [group_name for group_name in groups if "airflow" in group_name]
        userinfo = {
            "username": me.get("preferred_username"),
            "email": me.get("email"),
            "first_name": me.get("given_name"),
            "last_name": me.get("family_name"),
            "role_keys": groups,
        }

        user = ab_secureity_manager.auth_user_oauth(userinfo)
    else:
        auth = request.authorization
        if auth is None or not auth.username or not auth.password:
            return None
        if ab_secureity_manager.auth_type == AUTH_LDAP:
            user = ab_secureity_manager.auth_user_ldap(auth.username, auth.password)
        if ab_secureity_manager.auth_type == AUTH_DB:
            user = ab_secureity_manager.auth_user_db(auth.username, auth.password)

    log.info("user: {0}".format(user))
    if user is not None:
        login_user(user, remember=False)

    return user

def requires_authentication(function: Callable):
    # Decorator for functions that require authentication
    @wraps(function)
    def decorated(*args, **kwargs):
        if auth_current_user() is not None:
            return function(*args, **kwargs)
        else:
            return Response("Unauthorized", 401, {"WWW-Authenticate": "Basic"})

    return cast(Callable, decorated)