# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
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"""Session authentication backend."""

from __future__ import annotations

import warnings
from functools import wraps
from typing import Any, Callable, TypeVar, cast

from flask import Response

from airflow.exceptions import RemovedInAirflow3Warning
from airflow.www.extensions.init_auth_manager import get_auth_manager

CLIENT_AUTH: tuple[str, str] | Any | None = None

warnings.warn(
    "This module is deprecated. Please use `airflow.providers.fab.auth_manager.api.auth.backend.session` instead.",
    RemovedInAirflow3Warning,
    stacklevel=2,
)


def init_app(_):
    """Initialize authentication backend."""


T = TypeVar("T", bound=Callable)


def requires_authentication(function: T):
    """Decorate functions that require authentication."""

    @wraps(function)
    def decorated(*args, **kwargs):
        if not get_auth_manager().is_logged_in():
            return Response("Unauthorized", 401, {})
        return function(*args, **kwargs)

    return cast(T, decorated)