#!/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.
# ==============================================================================

import cfnbootstrap
from cfnbootstrap.cfn_client import CloudFormationClient
from cfnbootstrap import util
from optparse import OptionParser
from optparse import OptionGroup
import base64
import re
from cfnbootstrap.packages import requests
import socket
import sys
import json

default_id = util.get_instance_id()
if not default_id:
    default_id = socket.getfqdn()

parser = OptionParser(usage="usage: %prog [options] [WaitConditionHandle URL]")
parser.add_option_group(util.get_cred_options(parser))
parser.add_option_group(util.get_proxy_options(parser))

parser.add_option("-s", "--success",
                  help="If true, signal success to CloudFormation; if false, signal failure. Default: true",
                  dest="success", type="choice", choices=["true", "false"], action="store", default="true")
parser.add_option("-i", "--id", help="A unique ID to send with the signal",
                  dest="id", type="string", action="store", default=default_id)
parser.add_option("-e", "--exit-code", help="Derive success or failure from specified exit code",
                  dest="exit_code", type="int", action="store")

wch_group = OptionGroup(parser, "WaitConditionHandle Signal Options")
wch_group.add_option("-r", "--reason", help="The reason for success/failure",
                     dest="reason", type="string", action="store", default="")
wch_group.add_option("-d", "--data", help="Data to include with the WaitCondition signal",
                     dest="data", type="string", action="store", default="")
parser.add_option_group(wch_group)

rs_group = OptionGroup(parser, "Resource Signal Options")
rs_group.add_option("", "--stack", help="A CloudFormation stack",
                    dest="stack_name", type="string", action="store")
rs_group.add_option("", "--resource", help="A CloudFormation logical resource ID",
                    dest="logical_resource_id", type="string", action="store")
rs_group.add_option("", "--url",
                    help="The CloudFormation service URL. The endpoint URL must match the region option. Use of this parameter is discouraged.",
                    dest="endpoint", type="string", action="store")
rs_group.add_option("", "--region", help="The CloudFormation region. Default: us-east-1.",
                    dest="region", type="string", default="us-east-1")
parser.add_option_group(rs_group)

(options, args) = parser.parse_args()

signal_success = True

if options.exit_code:
    signal_success = False
elif options.success != "true":
    signal_success = False

cfnbootstrap.configureLogging("DEBUG")


def get_status(signal_success):
    return 'SUCCESS' if signal_success else 'FAILURE'


@util.retry_on_failure()
@util.timeout()
def send(url, data):
    requests.put(url,
                 data=json.dumps(data),
                 headers={"Content-Type": ""},
                 verify=True,
                 proxies=util.get_proxyinfo(options),
                 timeout=util.REQUEST_TIMEOUT).raise_for_status()


def signal_wch(options, args):
    if not options.reason and not signal_success:
        options.reason = "Configuration failed."

    data = {'Status': get_status(signal_success),
            'Reason': options.reason,
            'Data': options.data,
            'UniqueId': options.id}

    try:
        url = args[0] if re.match(
            r'https?://.*', args[0]) else base64.b64decode(args[0])
    except TypeError:
        print("Error: Invalid WaitConditionHandle URL specified: %s" %
              args[0], file=sys.stderr)
        sys.exit(1)

    if isinstance(url, bytes):
        url = url.decode('utf8')

    if not re.match(r'https?://.*', url):
        print("Error: Invalid WaitConditionHandle URL specified: %s" %
              args[0], file=sys.stderr)
        sys.exit(1)

    try:
        send(url, data)
        print('CloudFormation signaled successfully with %s.'.format(
            data['Status']))
        sys.exit(0)
    except IOError as e:
        print('Error signaling CloudFormation: %s' % str(e), file=sys.stderr)
        sys.exit(1)


def signal_resource(options, args):
    if not options.stack_name:
        print("Error: You must specify a stack name when signaling a resource", file=sys.stderr)
        parser.print_help(sys.stderr)
        sys.exit(1)

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

    proxyinfo = util.get_proxyinfo(options)
    status = get_status(signal_success)

    try:
        CloudFormationClient(creds, url=url, region=options.region, proxyinfo=proxyinfo).signal_resource(
            options.logical_resource_id, options.stack_name, options.id, status)
    except IOError as e:
        if e.strerror:
            print(e.strerror, file=sys.stderr)
        else:
            print("Unknown error signaling %s" %
                  options.logical_resource_id, file=sys.stderr)
        sys.exit(1)


is_wch_signal = args and args[0]
is_resource_signal = options.logical_resource_id is not None

if is_wch_signal and is_resource_signal:
    print("Error: Cannot specify both a WaitConditionHandle URL and a logical resource id", file=sys.stderr)
    sys.exit(1)

if is_wch_signal:
    signal_wch(options, args)
elif is_resource_signal:
    signal_resource(options, args)
else:
    print("Error: No WaitConditionHandle URL or logical resource id specified", file=sys.stderr)
    parser.print_help(sys.stderr)
    sys.exit(1)