#!/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 optparse import OptionParser
from cfnbootstrap import util
import sys
import json

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")
parser.add_option("-r", "--resource", help="A CloudFormation logical resource ID",
                  type="string", dest="logical_resource_id")
parser.add_option("-k", "--key",
                  help="Retrieve the value at <key> in the Metadata object; must be in dotted object notation (parent.child.leaf)",
                  type="string", dest="key")

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()

if not options.stack_name or not options.logical_resource_id:
    print("Error: You must specify both a stack name and logical resource id", file=sys.stderr)
    parser.print_help(sys.stderr)
    sys.exit(1)

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:
    detail = client.describe_stack_resource(
        options.logical_resource_id, options.stack_name)
except IOError as e:
    if e.strerror:
        print(e.strerror, file=sys.stderr)
    else:
        print("Unknown error retrieving {}".format(
            options.logical_resource_id), file=sys.stderr)
    sys.exit(1)

if not detail.metadata:
    print("Error: {} does not specify any metadata".format(
        detail.logicalResourceId), file=sys.stderr)
    sys.exit(1)

metadata_to_dump = detail.metadata

if options.key:
    metadata_to_dump = util.extract_value(metadata_to_dump, options.key)
    if not metadata_to_dump:
        print("Error: %s is not present in the metadata for %s".format(
            options.key, detail.logicalResourceId), file=sys.stderr)
        sys.exit(1)

if isinstance(metadata_to_dump, str):
    print(metadata_to_dump, file=sys.stdout)
else:
    json.dump(metadata_to_dump, sys.stdout, indent=4)
    # This removes the annoying no-EOL symbols from some consoles, as json.dump does not end with a newline
    print("", file=sys.stdout)