# Copyright 2011 OpenStack Foundation
# Copyright 2013 Rackspace Hosting
# 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.

"""
Command-line interface to the OpenStack Trove API.
"""

from __future__ import print_function

import argparse
import getpass
import glob
import imp
import itertools
import logging
import os
import pkgutil
import sys

from keystoneauth1.identity.generic import password
from keystoneauth1.identity.generic import token
from keystoneauth1 import loading
from oslo_utils import encodeutils
from oslo_utils import importutils
import pkg_resources
import six

from troveclient.apiclient import exceptions as exc
import troveclient.auth_plugin
from troveclient import client
import troveclient.extension
from troveclient.i18n import _  # noqa
from troveclient import utils
from troveclient.v1 import shell as shell_v1


DEFAULT_OS_DATABASE_API_VERSION = "1.0"
DEFAULT_TROVE_ENDPOINT_TYPE = 'publicURL'
DEFAULT_TROVE_SERVICE_TYPE = 'database'

LOG = logging.getLogger(__name__)
osprofiler_profiler = importutils.try_import("osprofiler.profiler")


class TroveClientArgumentParser(argparse.ArgumentParser):

    def __init__(self, *args, **kwargs):
        super(TroveClientArgumentParser, self).__init__(*args, **kwargs)

    def add_argument(self, *args, **kwargs):
        if kwargs.get('help') is None:
            raise Exception(_("An argument '%s' was specified without help.")
                            % args[0])
        super(TroveClientArgumentParser, self).add_argument(*args, **kwargs)

    def error(self, message):
        """error(message: string)

        Prints a usage message incorporating the message to stderr and
        exits.
        """
        self.print_usage(sys.stderr)
        # FIXME(lzyeval): if changes occur in argparse.ArgParser._check_value
        choose_from = ' (choose from'
        progparts = self.prog.partition(' ')
        self.exit(2, "error: %(errmsg)s\nTry '%(mainp)s help %(subp)s'"
                     " for more information.\n" %
                     {'errmsg': message.split(choose_from)[0],
                      'mainp': progparts[0],
                      'subp': progparts[2]})


class OpenStackTroveShell(object):

    def get_base_parser(self, argv):
        parser = TroveClientArgumentParser(
            prog='trove',
            description=__doc__.strip(),
            epilog=_('See "trove help COMMAND" '
                     'for help on a specific command.'),
            add_help=False,
            formatter_class=OpenStackHelpFormatter,
        )

        # Global arguments
        parser.add_argument('-h', '--help',
                            action='store_true',
                            help=argparse.SUPPRESS)

        parser.add_argument('--version',
                            action='version',
                            version=troveclient.__version__,
                            help=_("Show program's version number and exit."))

        parser.add_argument('--debug',
                            action='store_true',
                            default=utils.env('TROVECLIENT_DEBUG',
                                              default=False),
                            help=_("Print debugging output."))

        parser.add_argument('--os-auth-system',
                            metavar='<auth-system>',
                            default=utils.env('OS_AUTH_SYSTEM'),
                            help=argparse.SUPPRESS)

        parser.add_argument('--os_auth_system',
                            help=argparse.SUPPRESS)

        parser.add_argument('--service-type',
                            metavar='<service-type>',
                            default=utils.env('OS_SERVICE_TYPE',
                                              'TROVE_SERVICE_TYPE'),
                            help=_('Defaults to database for most actions.'))
        parser.add_argument('--service_type',
                            help=argparse.SUPPRESS)

        parser.add_argument('--service-name',
                            metavar='<service-name>',
                            default=utils.env('TROVE_SERVICE_NAME'),
                            help=_('Defaults to env[TROVE_SERVICE_NAME].'))
        parser.add_argument('--service_name',
                            help=argparse.SUPPRESS)

        parser.add_argument('--bypass-url',
                            metavar='<bypass-url>',
                            default=utils.env('TROVE_BYPASS_URL'),
                            help=_('Defaults to env[TROVE_BYPASS_URL].'))
        parser.add_argument('--bypass_url',
                            help=argparse.SUPPRESS)

        parser.add_argument('--database-service-name',
                            metavar='<database-service-name>',
                            default=utils.env('TROVE_DATABASE_SERVICE_NAME'),
                            help=_('Defaults to env'
                                   '[TROVE_DATABASE_SERVICE_NAME].'))
        parser.add_argument('--database_service_name',
                            help=argparse.SUPPRESS)

        default_trove_endpoint_type = utils.env(
            'OS_ENDPOINT_TYPE',
            default=DEFAULT_TROVE_ENDPOINT_TYPE)
        parser.add_argument('--endpoint-type',
                            metavar='<endpoint-type>',
                            default=utils.env(
                                'TROVE_ENDPOINT_TYPE',
                                default=default_trove_endpoint_type),
                            help=(_('Defaults to env[TROVE_ENDPOINT_TYPE] or '
                                    'env[OS_ENDPOINT_TYPE] or '
                                    '%(DEFAULT_TROVE_ENDPOINT_TYPE)s.') %
                                  {'DEFAULT_TROVE_ENDPOINT_TYPE':
                                   DEFAULT_TROVE_ENDPOINT_TYPE}))

        parser.add_argument('--endpoint_type',
                            help=argparse.SUPPRESS)

        parser.add_argument('--os-database-api-version',
                            metavar='<database-api-ver>',
                            default=utils.env(
                                'OS_DATABASE_API_VERSION',
                                default=DEFAULT_OS_DATABASE_API_VERSION),
                            help=_('Accepts 1, defaults '
                                   'to env[OS_DATABASE_API_VERSION].'))
        parser.add_argument('--os_database_api_version',
                            help=argparse.SUPPRESS)

        parser.add_argument('--retries',
                            metavar='<retries>',
                            type=int,
                            default=0,
                            help=_('Number of retries.'))

        parser.add_argument('--json', '--os-json-output',
                            dest='json',
                            action='store_true',
                            default=utils.env('OS_JSON_OUTPUT',
                                              default=False),
                            help=_('Output JSON instead of prettyprint. '
                                   'Defaults to env[OS_JSON_OUTPUT].'))

        if osprofiler_profiler:
            parser.add_argument('--profile',
                                metavar='HMAC_KEY',
                                default=utils.env('OS_PROFILE_HMACKEY',
                                                  default=None),
                                help=_('HMAC key used to encrypt context '
                                       'data when profiling the performance '
                                       'of an operation. This key should be '
                                       'set to one of the HMAC keys '
                                       'configured in Trove (they are found '
                                       'in configuration files, typically in '
                                       '/etc/trove). Without the key, '
                                       'profiling will not be triggered even '
                                       'if it is enabled on the server side. '
                                       'Defaults to env[OS_PROFILE_HMACKEY].'
                                       ))

        self._append_global_identity_args(parser, argv)

        # The auth-system-plugins might require some extra options
        troveclient.auth_plugin.load_auth_system_opts(parser)

        return parser

    def _append_global_identity_args(self, parser, argv):
        # Register CLI identity related arguments

        # Use keystoneauth to register common  CLI arguments
        loading.register_session_argparse_arguments(parser)
        default_auth_plugin = 'password'
        if 'os-token' in argv:
            default_auth_plugin = 'token'
        loading.register_auth_argparse_arguments(parser, argv,
                                                 default=default_auth_plugin)

        parser.set_defaults(insecure=utils.env('TROVECLIENT_INSECURE',
                            default=False))

        parser.set_defaults(os_auth_url=utils.env('OS_AUTH_URL'))

        parser.set_defaults(os_project_name=utils.env(
            'OS_PROJECT_NAME', 'OS_TENANT_NAME'))
        parser.set_defaults(os_project_id=utils.env(
            'OS_PROJECT_ID', 'OS_TENANT_ID'))

        parser.add_argument('--os_tenant_name',
                            help=argparse.SUPPRESS)

        parser.add_argument('--os_tenant_id',
                            help=argparse.SUPPRESS)

        parser.add_argument('--os-auth-token',
                            default=utils.env('OS_AUTH_TOKEN'),
                            help=argparse.SUPPRESS)

        parser.add_argument('--os-region-name',
                            metavar='<region-name>',
                            default=utils.env('OS_REGION_NAME'),
                            help=_('Specify the region to use. '
                                   'Defaults to env[OS_REGION_NAME].'))
        parser.add_argument('--os_region_name',
                            help=argparse.SUPPRESS)

    def get_subcommand_parser(self, version, argv):
        parser = self.get_base_parser(argv)

        self.subcommands = {}
        subparsers = parser.add_subparsers(metavar='<subcommand>')

        try:
            actions_module = {
                '1.0': shell_v1,
            }[version]
        except KeyError:
            actions_module = shell_v1

        self._find_actions(subparsers, actions_module)
        self._find_actions(subparsers, self)

        for extension in self.extensions:
            self._find_actions(subparsers, extension.module)

        self._add_bash_completion_subparser(subparsers)

        return parser

    def _discover_extensions(self, version):
        extensions = []
        for name, module in itertools.chain(
                self._discover_via_python_path(),
                self._discover_via_contrib_path(version),
                self._discover_via_entry_points()):

            extension = troveclient.extension.Extension(name, module)
            extensions.append(extension)

        return extensions

    def _discover_via_python_path(self):
        for (module_loader, name, _ispkg) in pkgutil.iter_modules():
            if name.endswith('_python_troveclient_ext'):
                if not hasattr(module_loader, 'load_module'):
                    # Python 2.6 compat: actually get an ImpImporter obj
                    module_loader = module_loader.find_module(name)

                module = module_loader.load_module(name)
                if hasattr(module, 'extension_name'):
                    name = module.extension_name

                yield name, module

    def _discover_via_contrib_path(self, version):
        module_path = os.path.dirname(os.path.abspath(__file__))
        version_str = "v%s" % version.replace('.', '_')
        version_pkg = 'v1' if version_str == 'v1_0' else version_str
        ext_path = os.path.join(module_path, version_pkg, 'contrib')
        ext_glob = os.path.join(ext_path, "*.py")

        for ext_path in glob.iglob(ext_glob):
            name = os.path.basename(ext_path)[:-3]

            if name == "__init__":
                continue

            module = imp.load_source(name, ext_path)
            yield name, module

    def _discover_via_entry_points(self):
        for ep in pkg_resources.iter_entry_points('troveclient.extension'):
            name = ep.name
            module = ep.load()

            yield name, module

    def _add_bash_completion_subparser(self, subparsers):
        subparser = subparsers.add_parser(
            'bash_completion',
            add_help=False,
            formatter_class=OpenStackHelpFormatter)

        self.subcommands['bash_completion'] = subparser
        subparser.set_defaults(func=self.do_bash_completion)

    def _find_actions(self, subparsers, actions_module):
        for attr in (a for a in dir(actions_module) if a.startswith('do_')):
            # I prefer to be hyphen-separated instead of underscores.
            command = attr[3:].replace('_', '-')
            callback = getattr(actions_module, attr)
            desc = callback.__doc__ or ''
            help = desc.strip().split('\n')[0]
            arguments = getattr(callback, 'arguments', [])

            subparser = subparsers.add_parser(
                command,
                help=help,
                description=desc,
                add_help=False,
                formatter_class=OpenStackHelpFormatter)

            subparser.add_argument('-h', '--help',
                                   action='help',
                                   help=argparse.SUPPRESS,)

            self.subcommands[command] = subparser
            for (args, kwargs) in arguments:
                subparser.add_argument(*args, **kwargs)
            subparser.set_defaults(func=callback)

    def setup_debugging(self, debug):
        if not debug:
            return

        streamformat = "%(levelname)s (%(module)s:%(lineno)d) %(message)s"
        logging.basicConfig(level=logging.DEBUG,
                            format=streamformat)

    def main(self, argv):
        # Parse args once to find version and debug settings
        parser = self.get_base_parser(argv)
        (options, args) = parser.parse_known_args(argv)
        self.setup_debugging(options.debug)
        self.options = options

        # Discover available auth plugins
        troveclient.auth_plugin.discover_auth_systems()

        # build available subcommands based on version
        self.extensions = self._discover_extensions(
            options.os_database_api_version)
        self._run_extension_hooks('__pre_parse_args__')

        subcommand_parser = self.get_subcommand_parser(
            options.os_database_api_version, argv)
        self.parser = subcommand_parser

        if options.help or not argv:
            subcommand_parser.print_help()
            return 0

        args = subcommand_parser.parse_args(argv)
        self._run_extension_hooks('__post_parse_args__', args)

        # Short-circuit and deal with help right away.
        if args.func == self.do_help:
            self.do_help(args)
            return 0
        elif args.func == self.do_bash_completion:
            self.do_bash_completion(args)
            return 0

        os_username = args.os_username
        os_password = args.os_password
        os_project_name = getattr(args, 'os_project_name',
                                  getattr(args, 'os_tenant_name', None))
        os_auth_url = args.os_auth_url
        os_region_name = args.os_region_name
        os_project_id = getattr(
            args, 'os_project_id',
            getattr(args, 'os_tenant_id', None))
        os_auth_system = args.os_auth_system

        if "v2.0" not in os_auth_url:
            if (not args.os_project_domain_id and
                    not args.os_project_domain_name):
                setattr(args, "os_project_domain_id", "default")
            if not args.os_user_domain_id and not args.os_user_domain_name:
                setattr(args, "os_user_domain_id", "default")

        endpoint_type = args.endpoint_type
        insecure = args.insecure
        service_type = args.service_type
        service_name = args.service_name
        database_service_name = args.database_service_name
        cacert = args.os_cacert
        bypass_url = args.bypass_url

        if os_auth_system and os_auth_system != "keystone":
            auth_plugin = troveclient.auth_plugin.load_plugin(os_auth_system)
        else:
            auth_plugin = None

        if not endpoint_type:
            endpoint_type = DEFAULT_TROVE_ENDPOINT_TYPE

        if not service_type:
            service_type = DEFAULT_TROVE_SERVICE_TYPE
            service_type = utils.get_service_type(args.func) or service_type

        # FIXME(usrleon): Here should be restrict for project id same as
        # for os_username or os_password but for compatibility it is not.

        if not utils.isunauthenticated(args.func):

            if auth_plugin:
                auth_plugin.parse_opts(args)

            if not auth_plugin or not auth_plugin.opts:
                if not os_username:
                    raise exc.CommandError(_(
                        "You must provide a username "
                        "via either --os-username or env[OS_USERNAME]"))

            if not os_password:
                os_password = getpass.getpass()

            if not os_auth_url:
                if os_auth_system and os_auth_system != 'keystone':
                    os_auth_url = auth_plugin.get_auth_url()

        # V3 stuff
        project_info_provided = (self.options.os_project_name or
                                 self.options.os_project_id)

        if (not project_info_provided):
            raise exc.CommandError(
                _("You must provide a "
                  "project_id or project_name (with "
                  "project_domain_name or project_domain_id) via "
                  "  --os-project-id (env[OS_PROJECT_ID])"
                  "  --os-project-name (env[OS_PROJECT_NAME]),"
                  "  --os-project-domain-id "
                  "(env[OS_PROJECT_DOMAIN_ID])"
                  "  --os-project-domain-name "
                  "(env[OS_PROJECT_DOMAIN_NAME])"))

        if not os_auth_url:
            raise exc.CommandError(_("You must provide an auth url "
                                     "via either --os-auth-url or "
                                     "env[OS_AUTH_URL] or specify an "
                                     "auth_system which defines a default "
                                     "url with --os-auth-system or "
                                     "env[OS_AUTH_SYSTEM]"))

        use_session = True
        if auth_plugin or bypass_url:
            use_session = False

        ks_session = None
        keystone_auth = None
        if use_session:
            project_id = args.os_project_id or args.os_tenant_id
            project_name = args.os_project_name or args.os_tenant_name

            ks_session = loading.load_session_from_argparse_arguments(args)
            keystone_auth = self._get_keystone_auth(
                ks_session,
                args.os_auth_url,
                username=args.os_username,
                user_id=args.os_user_id,
                user_domain_id=args.os_user_domain_id,
                user_domain_name=args.os_user_domain_name,
                password=args.os_password,
                auth_token=args.os_auth_token,
                project_id=project_id,
                project_name=project_name,
                project_domain_id=args.os_project_domain_id,
                project_domain_name=args.os_project_domain_name)

        profile = osprofiler_profiler and options.profile
        if profile:
            osprofiler_profiler.init(options.profile)

        self.cs = client.Client(options.os_database_api_version, os_username,
                                os_password, os_project_name, os_auth_url,
                                insecure, region_name=os_region_name,
                                tenant_id=os_project_id,
                                endpoint_type=endpoint_type,
                                extensions=self.extensions,
                                service_type=service_type,
                                service_name=service_name,
                                database_service_name=database_service_name,
                                retries=options.retries,
                                http_log_debug=args.debug,
                                cacert=cacert,
                                bypass_url=bypass_url,
                                auth_system=os_auth_system,
                                auth_plugin=auth_plugin,
                                session=ks_session,
                                auth=keystone_auth)

        try:
            if not utils.isunauthenticated(args.func):
                # If Keystone is used, authentication is handled as
                # part of session.
                if not use_session:
                    self.cs.authenticate()
        except exc.Unauthorized:
            raise exc.CommandError(_("Invalid OpenStack Trove credentials."))
        except exc.AuthorizationFailure:
            raise exc.CommandError(_("Unable to authorize user"))

        endpoint_api_version = self.cs.get_database_api_version_from_endpoint()

        if endpoint_api_version != options.os_database_api_version:
            msg = (_("Database API version is set to %(db_ver)s "
                     "but you are accessing a %(ep_ver)s endpoint. "
                     "Change its value via either --os-database-api-version "
                     "or env[OS_DATABASE_API_VERSION]") %
                   {'db_ver': options.os_database_api_version,
                    'ep_ver': endpoint_api_version})
            # raise exc.InvalidAPIVersion(msg)
            raise exc.UnsupportedVersion(msg)

        # Override printing to json output
        if args.json:
            utils.json_output = True
        else:
            utils.json_output = False

        try:
            args.func(self.cs, args)
        finally:
            if profile:
                trace_id = osprofiler_profiler.get().get_base_id()
                print(_("Trace ID: %(trace_id)s") % {'trace_id': trace_id})
                print(_("To display the trace, use the following command:\n"
                        "osprofiler trace show --html %(trace_id)s")
                      % {'trace_id': trace_id})

    def _run_extension_hooks(self, hook_type, *args, **kwargs):
        """Run hooks for all registered extensions."""
        for extension in self.extensions:
            extension.run_hooks(hook_type, *args, **kwargs)

    def do_bash_completion(self, args):
        """Prints arguments for bash_completion.

        Prints all of the commands and options to stdout so that the
        trove.bash_completion script doesn't have to hard code them.
        """
        commands = set()
        options = set()
        for sc_str, sc in list(self.subcommands.items()):
            commands.add(sc_str)
            for option in list(sc._optionals._option_string_actions.keys()):
                options.add(option)

        commands.remove('bash-completion')
        commands.remove('bash_completion')
        print(' '.join(commands | options))

    @utils.arg('command', metavar='<subcommand>', nargs='?',
               help=_('Display help for <subcommand>.'))
    def do_help(self, args):
        """Displays help about this program or one of its subcommands."""
        if args.command:
            if args.command in self.subcommands:
                self.subcommands[args.command].print_help()
            else:
                raise exc.CommandError(_("'%s' is not a valid subcommand") %
                                       args.command)
        else:
            self.parser.print_help()

    def _get_keystone_auth(self, session, auth_url, **kwargs):
        auth_token = kwargs.pop('auth_token', None)
        if auth_token:
            return token.Token(auth_url, auth_token, **kwargs)
        else:
            return password.Password(
                auth_url,
                username=kwargs.pop('username'),
                user_id=kwargs.pop('user_id'),
                password=kwargs.pop('password'),
                user_domain_id=kwargs.pop('user_domain_id'),
                user_domain_name=kwargs.pop('user_domain_name'),
                **kwargs)


# I'm picky about my shell help.
class OpenStackHelpFormatter(argparse.HelpFormatter):
    def __init__(self, prog, indent_increment=2, max_help_position=34,
                 width=None):
        super(OpenStackHelpFormatter, self).__init__(prog, indent_increment,
                                                     max_help_position, width)

    def start_section(self, heading):
        # Title-case the headings
        heading = '%s%s' % (heading[0].upper(), heading[1:])
        super(OpenStackHelpFormatter, self).start_section(heading)

    def _format_usage(self, usage, actions, groups, prefix):
        """Formats the argument list to correct argument positions.

        Print positionals before optionals in the usage string to help
        users avoid argparse nargs='*' problems.

        ex: 'trove create --databases <db_name> <name> <flavor_id>'
        fails with 'error: too few arguments', but this succeeds:
        'trove create <name> <flavor_id> --databases <db_name>'
        """
        if prefix is None:
            prefix = _('usage: ')

        # if usage is specified, use that
        if usage is not None:
            usage = usage % dict(prog=self._prog)

        # if no optionals or positionals are available, usage is just prog
        elif usage is None and not actions:
            usage = '%(prog)s' % dict(prog=self._prog)

        # if optionals and positionals are available, calculate usage
        elif usage is None:
            prog = '%(prog)s' % dict(prog=self._prog)

            # split optionals from positionals
            optionals = []
            positionals = []
            for action in actions:
                if action.option_strings:
                    optionals.append(action)
                else:
                    positionals.append(action)

            # build full usage string
            format = self._format_actions_usage
            action_usage = format(optionals + positionals, groups)
            usage = ' '.join([s for s in [prog, action_usage] if s])

            # wrap the usage parts if it's too long
            text_width = self._width - self._current_indent
            if len(prefix) + len(usage) > text_width:

                # break usage into wrappable parts
                part_regexp = r'\(.*?\)+|\[.*?\]+|\S+'
                opt_usage = format(optionals, groups)
                pos_usage = format(positionals, groups)
                opt_parts = argparse._re.findall(part_regexp, opt_usage)
                pos_parts = argparse._re.findall(part_regexp, pos_usage)
                assert ' '.join(opt_parts) == opt_usage
                assert ' '.join(pos_parts) == pos_usage

                # helper for wrapping lines
                def get_lines(parts, indent, prefix=None):
                    lines = []
                    line = []
                    if prefix is not None:
                        line_len = len(prefix) - 1
                    else:
                        line_len = len(indent) - 1
                    for part in parts:
                        if line_len + 1 + len(part) > text_width:
                            lines.append(indent + ' '.join(line))
                            line = []
                            line_len = len(indent) - 1
                        line.append(part)
                        line_len += len(part) + 1
                    if line:
                        lines.append(indent + ' '.join(line))
                    if prefix is not None:
                        lines[0] = lines[0][len(indent):]
                    return lines

                # if prog is short, follow it with optionals or positionals
                if len(prefix) + len(prog) <= 0.75 * text_width:
                    indent = ' ' * (len(prefix) + len(prog) + 1)
                    if pos_parts:
                        if prog == 'trove':
                            # "trove help" called without any subcommand
                            lines = get_lines([prog] + opt_parts, indent,
                                              prefix)
                            lines.extend(get_lines(pos_parts, indent))
                        else:
                            lines = get_lines([prog] + pos_parts, indent,
                                              prefix)
                            lines.extend(get_lines(opt_parts, indent))
                    elif opt_parts:
                        lines = get_lines([prog] + opt_parts, indent, prefix)
                    else:
                        lines = [prog]

                # if prog is long, put it on its own line
                else:
                    indent = ' ' * len(prefix)
                    parts = pos_parts + opt_parts
                    lines = get_lines(parts, indent)
                    if len(lines) > 1:
                        lines = []
                        lines.extend(get_lines(pos_parts, indent))
                        lines.extend(get_lines(opt_parts, indent))
                    lines = [prog] + lines

                # join lines into usage
                usage = '\n'.join(lines)

        # prefix with 'usage:'
        return '%s%s\n\n' % (prefix, usage)


def main():
    try:
        if sys.version_info >= (3, 0):
            OpenStackTroveShell().main(sys.argv[1:])
        else:
            OpenStackTroveShell().main(map(encodeutils.safe_decode,
                                           sys.argv[1:]))
    except KeyboardInterrupt:
        print(_("... terminating trove client"), file=sys.stderr)
        sys.exit(130)
    except Exception as e:
        LOG.debug(e, exc_info=1)
        message = six.text_type(e)
        if not isinstance(message, six.string_types):
            message = str(message)
        print(_("ERROR: %s") % encodeutils.safe_encode(message),
              file=sys.stderr)
        sys.exit(1)


if __name__ == "__main__":
    main()
