#!/usr/bin/python3
import argparse
# ==============================================================================
# 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 sys
import cfnbootstrap
from cfnbootstrap.cfn_client import CloudFormationClient
from optparse import OptionParser
from cfnbootstrap.construction import Contractor, WorkLog
from cfnbootstrap import util
import logging
import os
import json

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

# user can also specify a file as a positional argument (args[0])
# or pipe in data through stdin (using '-' as an argument)

parser.usage = ("%prog [options]\n"
                "  or:  %prog [options] <filename>\n"
                "  or:  cat <filename> | %prog [options] -")

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("-c", "--configsets", help='An optional list of configSets (default: "default")',
                  type="string", dest="configsets")

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")

parser.add_option("-t", "--strict", help=argparse.SUPPRESS,
                  action="store_true", dest="strict")

if os.name == "nt":
    parser.add_option("", "--resume", help="Resume from a previous cfn-init run",
                      action="store_true", dest="resume")

(options, args) = parser.parse_args()

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

strict_mode = options.strict

worklog = WorkLog()

if os.name == "nt" and options.resume:

    if not worklog.has_key('metadata'):
        print("Error: cannot resume from previous session; no metadata stored", file=sys.stderr)
        sys.exit(1)

    try:
        worklog.resume()
    except Exception as e:
        print("Error occurred during resume: {}".format(str(e)), file=sys.stderr)
        logging.exception("Unhandled exception during resume: %s", str(e))
        sys.exit(1)
    sys.exit(0)

read_from_file = (len(args) > 0) and (args[0] != '-')
read_from_stdin = (len(args) > 0) and (args[0] == '-')
stack_arg_present = bool(options.stack_name or options.logical_resource_id)
read_from_stack = bool(options.stack_name and options.logical_resource_id)

if read_from_file or read_from_stdin:
    if (len(args) > 1) or (read_from_file and read_from_stdin) or (stack_arg_present):
        print("Error: You cannot specify more than one input source for metadata", file=sys.stderr)
        parser.print_help(sys.stderr)
        sys.exit(1)
elif not stack_arg_present:
    print("Error: You must specify an input source for metadata: a stack name and logical resource id, or a file", file=sys.stderr)
    parser.print_help(sys.stderr)
    sys.exit(1)
elif not read_from_stack:
    print("Error: You must specify both a stack name and logical resource id", 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

configSets = ["default"]
if options.configsets:
    configSets = options.configsets.split(',')

proxyinfo = util.get_proxyinfo(options)

if read_from_stdin:
    try:
        metadata = json.load(sys.stdin)
    except Exception as e:    # the type of exception thrown when reading bad JSON depends on whether json or simplejson was imported
        if type(e).__name__ == "ValueError" or type(e).__name__ == "JSONDecodeError":
            print("Error decoding JSON from stdin: {}".format(
                str(e)), file=sys.stderr)
        else:
            print("Unknown error reading metadata from stdin", file=sys.stderr)
        sys.exit(1)
elif read_from_file:
    try:
        with open(args[0], 'r+') as f:
            metadata = json.load(f)
    except IOError as e:
        if e.strerror:
            print(e.strerror, file=sys.stderr)
        else:
            print("Unknown error reading from file {}".format(
                args[0]), file=sys.stderr)
        sys.exit(1)
    except Exception as e:
        if type(e).__name__ == "ValueError" or type(e).__name__ == "JSONDecodeError":
            print("Error decoding JSON from {0}: {1}".format(
                args[0], str(e)), file=sys.stderr)
        else:
            print("Unknown error reading from file {}".format(
                args[0]), file=sys.stderr)
        sys.exit(1)
else:
    try:
        detail = CloudFormationClient(creds, url=url, region=options.region, proxyinfo=proxyinfo).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 = detail.metadata

if os.name == 'nt':
    data_dir = os.path.expandvars(r'${SystemDrive}\cfn\cfn-init\data')
else:
    data_dir = '/var/lib/cfn-init/data'
if not os.path.isdir(data_dir) and not os.path.exists(data_dir):
    os.makedirs(data_dir)

if os.path.isdir(data_dir):
    with open(os.path.join(data_dir, "metadata.json"), "w") as f:
        json.dump(metadata, f, indent=4)
else:
    print("Could not create {} to store metadata".format(
        data_dir), file=sys.stderr)
    logging.error("Could not create {} to store metadata".format(data_dir))

if Contractor.metadataValid(metadata):
    try:
        logging.info("Starting build".center(60, '-'))
        worklog.build(metadata, configSets, strict_mode)
    except Exception as e:
        logging.error("BUILD FAILED!".center(60, '-'))
        print("Error occurred during build: {}".format(str(e)), file=sys.stderr)
        logging.exception("Unhandled exception during build: %s" % str(e))
        sys.exit(1)
    else:
        logging.info("Build complete".center(60, '-'))
else:
    if read_from_stack:
        print("Could not find 'AWS::CloudFormation::Init' key in metadata for {}.".format(options.logical_resource_id),
              file=sys.stderr)
    elif read_from_file:
        print("Could not find 'AWS::CloudFormation::Init' key in {}.".format(
            args[0]), file=sys.stderr)
    else:
        print("Could not find 'AWS::CloudFormation::Init' key in stdin input.", file=sys.stderr)
    sys.exit(0)