#!/usr/bin/python3

# ==============================================================================
# Copyright 2011 Amazon.com, Inc. or its affiliates. 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.
# ==============================================================================

from cfnbootstrap import util
from cfnbootstrap.cfn_client import CloudFormationClient
from optparse import OptionParser
import cfnbootstrap
import os
import sys

parser = OptionParser()
parser.add_option_group(util.get_cred_options(parser))
parser.add_option_group(util.get_proxy_options(parser))

parser.add_option("-s", "--stack", help="A CloudFormation stack",
                  type="string", dest="stack_name", default=os.environ.get('STACK_NAME'))
parser.add_option("-c", "--command-name", help="The command name",
                  type="string", dest="command_name", default=os.environ.get('CMD_NAME'))
parser.add_option("-i", "--invocation-id", help="The invocation ID",
                  type="string", dest="invocation_id", default=os.environ.get('INVOCATION_ID'))
parser.add_option("-l", "--listener-id", help="The listener ID",
                  type="string", dest="listener_id", default=os.environ.get('LISTENER_ID'))

parser.add_option("-u", "--url",
                  help="The CloudFormation service URL. The endpoint URL must match the region option. Use of this parameter is discouraged.",
                  type="string", dest="endpoint")
parser.add_option("", "--region", help="The CloudFormation region. Default: us-east-1.",
                  type="string", dest="region", default="us-east-1")

parser.add_option("-v", "--verbose", help="Enables verbose logging",
                  action="store_true", dest="verbose")

(options, args) = parser.parse_args()


def fail_on_unspecified(value, name):
    if not value:
        print("Error: You must specify %s" % name, file=sys.stderr)
        parser.print_help(sys.stderr)
        sys.exit(1)


fail_on_unspecified(options.stack_name, "StackName")
fail_on_unspecified(options.command_name, "CommandName")
fail_on_unspecified(options.invocation_id, "InvocationId")
fail_on_unspecified(options.listener_id, "ListenerId")

cfnbootstrap.configureLogging("DEBUG" if options.verbose else "INFO")

creds = util.get_creds_or_die(options)

url = CloudFormationClient.endpointForRegion(options.region)
if options.endpoint:
    url = options.endpoint

client = CloudFormationClient(
    creds, url=url, region=options.region, proxyinfo=util.get_proxyinfo(options))

try:
    leader = client.elect_command_leader(options.stack_name,
                                         options.command_name,
                                         options.invocation_id,
                                         options.listener_id)
    sys.exit(0 if leader == options.listener_id else 5)
except IOError as e:
    if e.strerror:
        print(e.strerror, file=sys.stderr)
    else:
        print("Unknown error electing command leader", file=sys.stderr)
    sys.exit(1)