# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright (c) 2011 OpenStack, LLC.
# All Rights Reserved.
#
# Licensed 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 "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

"""Policy Engine For Kwapi"""

import os

from oslo.config import cfg

from kwapi.openstack.common import policy
from kwapi import utils

_POLICY_PATH = None
_POLICY_CACHE = {}


def init():
    global _POLICY_PATH
    global _POLICY_CACHE
    if not _POLICY_PATH:
        _POLICY_PATH = cfg.CONF.policy_file
        if not os.path.exists(_POLICY_PATH):
            _POLICY_PATH = cfg.CONF.find_file(_POLICY_PATH)
        if not _POLICY_PATH:
            raise cfg.ConfigFilesNotFoundError([cfg.CONF.policy_file])
    utils.read_cached_file(_POLICY_PATH, _POLICY_CACHE,
                           reload_func=_set_rules)


def _set_rules(data):
    default_rule = cfg.CONF.policy_default_rule
    policy.set_rules(policy.Rules.load_json(data, default_rule))


def check_is_admin(roles):
    """Whether or not roles contains 'admin' role according to policy setting.

    """
    init()

    return policy.check('context_is_admin', {}, {'roles': roles})