# Copyright 2017 AT&T Intellectual Property.  All other 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.

import configparser
import logging
import time

from airflow.exceptions import AirflowException

from keystoneauth1.identity import v3 as keystone_v3
from keystoneauth1 import session as keystone_session


def ucp_keystone_session(shipyard_conf):

    # Read and parse shiyard.conf
    config = configparser.ConfigParser()
    config.read(shipyard_conf)

    # Initialize variables
    retry = 0
    sess = None
    keystone_auth = {}

    # We will allow 1 retry in getting the Keystone Session with a
    # backoff interval of 10 seconds in case there is a temporary
    # glitch in the network or transient problems with the keystone-api
    # pod
    while retry <= 1:
        # Construct Session Argument
        for attr in ('auth_url', 'password', 'project_domain_name',
                     'project_name', 'username', 'user_domain_name'):
            keystone_auth[attr] = config.get('keystone_authtoken', attr)

        # Set up keystone session
        logging.info("Get Keystone Session")
        auth = keystone_v3.Password(**keystone_auth)
        sess = keystone_session.Session(auth=auth)

        # Retry if we fail to get keystone session
        if sess:
            logging.info("Successfully Retrieved Keystone Session")
            break
        else:
            logging.info("Unable to get Keystone Session on first attempt")
            logging.info("Retrying after 10 seconds...")
            time.sleep(10)
            retry += 1

    # Raise Execptions if we fail to get the keystone session
    if not sess:
        raise AirflowException("Unable to get Keystone Session!")
    else:
        return sess