# Copyright 2010 Jacob Kaplan-Moss
# Copyright 2011 OpenStack LLC.
# 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 Nova API.
"""

import argparse
import glob
import httplib2
import imp
import itertools
import os
import pkgutil
import sys
import logging

import novaclient
from novaclient import client
from novaclient import exceptions as exc
import novaclient.extension
from novaclient import utils
from novaclient.v1_1 import shell as shell_v1_1

DEFAULT_OS_COMPUTE_API_VERSION = "1.1"
DEFAULT_NOVA_ENDPOINT_TYPE = 'publicURL'
DEFAULT_NOVA_SERVICE_TYPE = 'compute'

logger = logging.getLogger(__name__)


class NovaClientArgumentParser(argparse.ArgumentParser):

    def __init__(self, *args, **kwargs):
        super(NovaClientArgumentParser, self).__init__(*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 OpenStackComputeShell(object):

    def get_base_parser(self):
        parser = NovaClientArgumentParser(
            prog='nova',
            description=__doc__.strip(),
            epilog='See "nova 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=novaclient.__version__)

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

        parser.add_argument('--no-cache',
            default=utils.env('OS_NO_CACHE', default=False),
            action='store_true',
            help="Don't use the auth token cache.")
        parser.add_argument('--no_cache',
            help=argparse.SUPPRESS)

        parser.add_argument('--timings',
            default=False,
            action='store_true',
            help="Print call timing info")

        parser.add_argument('--os-username',
            metavar='<auth-user-name>',
            default=utils.env('OS_USERNAME', 'NOVA_USERNAME'),
            help='Defaults to env[OS_USERNAME].')
        parser.add_argument('--os_username',
            help=argparse.SUPPRESS)

        parser.add_argument('--os-password',
            metavar='<auth-password>',
            default=utils.env('OS_PASSWORD', 'NOVA_PASSWORD'),
            help='Defaults to env[OS_PASSWORD].')
        parser.add_argument('--os_password',
            help=argparse.SUPPRESS)

        parser.add_argument('--os-tenant-name',
            metavar='<auth-tenant-name>',
            default=utils.env('OS_TENANT_NAME', 'NOVA_PROJECT_ID'),
            help='Defaults to env[OS_TENANT_NAME].')
        parser.add_argument('--os_tenant_name',
            help=argparse.SUPPRESS)

        parser.add_argument('--os-auth-url',
            metavar='<auth-url>',
            default=utils.env('OS_AUTH_URL', 'NOVA_URL'),
            help='Defaults to env[OS_AUTH_URL].')
        parser.add_argument('--os_auth_url',
            help=argparse.SUPPRESS)

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

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

        parser.add_argument('--service-type',
            metavar='<service-type>',
            help='Defaults to compute for most actions')
        parser.add_argument('--service_type',
            help=argparse.SUPPRESS)

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

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

        parser.add_argument('--endpoint-type',
            metavar='<endpoint-type>',
            default=utils.env('NOVA_ENDPOINT_TYPE',
                        default=DEFAULT_NOVA_ENDPOINT_TYPE),
            help='Defaults to env[NOVA_ENDPOINT_TYPE] or '
                    + DEFAULT_NOVA_ENDPOINT_TYPE + '.')
        # NOTE(dtroyer): We can't add --endpoint_type here due to argparse
        #                thinking usage-list --end is ambiguous; but it
        #                works fine with only --endpoint-type present
        #                Go figure.  I'm leaving this here for doc purposes.
        #parser.add_argument('--endpoint_type',
        #    help=argparse.SUPPRESS)

        parser.add_argument('--os-compute-api-version',
            metavar='<compute-api-ver>',
            default=utils.env('OS_COMPUTE_API_VERSION',
                default=DEFAULT_OS_COMPUTE_API_VERSION),
            help='Accepts 1.1, defaults to env[OS_COMPUTE_API_VERSION].')
        parser.add_argument('--os_compute_api_version',
            help=argparse.SUPPRESS)

        parser.add_argument('--insecure',
            default=utils.env('NOVACLIENT_INSECURE', default=False),
            action='store_true',
            help="Explicitly allow novaclient to perform \"insecure\" "
                 "SSL (https) requests. The server's certificate will "
                 "not be verified against any certificate authorities. "
                 "This option should be used with caution.")

        # FIXME(dtroyer): The args below are here for diablo compatibility,
        #                 remove them in folsum cycle

        # alias for --os-username, left in for backwards compatibility
        parser.add_argument('--username',
            help=argparse.SUPPRESS)

        # alias for --os-region-name, left in for backwards compatibility
        parser.add_argument('--region_name',
            help=argparse.SUPPRESS)

        # alias for --os-password, left in for backwards compatibility
        parser.add_argument('--apikey', '--password', dest='apikey',
            default=utils.env('NOVA_API_KEY'),
            help=argparse.SUPPRESS)

        # alias for --os-tenant-name, left in for backward compatibility
        parser.add_argument('--projectid', '--tenant_name', dest='projectid',
            default=utils.env('NOVA_PROJECT_ID'),
            help=argparse.SUPPRESS)

        # alias for --os-auth-url, left in for backward compatibility
        parser.add_argument('--url', '--auth_url', dest='url',
            default=utils.env('NOVA_URL'),
            help=argparse.SUPPRESS)

        parser.add_argument('--bypass-url',
            metavar='<bypass-url>',
            dest='bypass_url',
            help="Use this API endpoint instead of the Service Catalog")
        parser.add_argument('--bypass_url',
            help=argparse.SUPPRESS)

        return parser

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

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

        try:
            actions_module = {
                '1.1': shell_v1_1,
                '2': shell_v1_1,
            }[version]
        except KeyError:
            actions_module = shell_v1_1

        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)):

            extension = novaclient.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_novaclient_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)
                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('.', '_')
        ext_path = os.path.join(module_path, version_str, '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 _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 hypen-separated instead of underscores.
            command = attr[3:].replace('_', '-')
            callback = getattr(actions_module, attr)
            desc = callback.__doc__ or ''
            action_help = desc.strip().split('\n')[0]
            arguments = getattr(callback, 'arguments', [])

            subparser = subparsers.add_parser(command,
                help=action_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

        streamhandler = logging.StreamHandler()
        streamformat = "%(levelname)s (%(module)s:%(lineno)d) %(message)s"
        streamhandler.setFormatter(logging.Formatter(streamformat))
        logger.setLevel(logging.DEBUG)
        logger.addHandler(streamhandler)

        httplib2.debuglevel = 1

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

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

        # NOTE(dtroyer): Hackery to handle --endpoint_type due to argparse
        #                thinking usage-list --end is ambiguous; but it
        #                works fine with only --endpoint-type present
        #                Go figure.
        if '--endpoint_type' in argv:
            spot = argv.index('--endpoint_type')
            argv[spot] = '--endpoint-type'

        subcommand_parser = self.get_subcommand_parser(
                options.os_compute_api_version)
        self.parser = subcommand_parser

        if options.help and len(args) == 0:
            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, os_password, os_tenant_name, os_auth_url,
                os_region_name, os_auth_system, endpoint_type, insecure,
                service_type, service_name, volume_service_name,
                username, apikey, projectid, url, region_name,
                bypass_url, no_cache) = (
                        args.os_username, args.os_password,
                        args.os_tenant_name, args.os_auth_url,
                        args.os_region_name, args.os_auth_system,
                        args.endpoint_type, args.insecure, args.service_type,
                        args.service_name, args.volume_service_name,
                        args.username, args.apikey, args.projectid,
                        args.url, args.region_name,
                        args.bypass_url, args.no_cache)

        if not endpoint_type:
            endpoint_type = DEFAULT_NOVA_ENDPOINT_TYPE

        if not service_type:
            service_type = DEFAULT_NOVA_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 not os_username:
                if not username:
                    raise exc.CommandError("You must provide a username "
                            "via either --os-username or env[OS_USERNAME]")
                else:
                    os_username = username

            if not os_password:
                if not apikey:
                    raise exc.CommandError("You must provide a password "
                            "via either --os-password or via "
                            "env[OS_PASSWORD]")
                else:
                    os_password = apikey

            if not os_tenant_name:
                if not projectid:
                    raise exc.CommandError("You must provide a tenant name "
                            "via either --os-tenant-name or "
                            "env[OS_TENANT_NAME]")
                else:
                    os_tenant_name = projectid

            if not os_auth_url:
                if not url:
                    if os_auth_system and os_auth_system != 'keystone':
                        os_auth_url = \
                            client.get_auth_system_url(os_auth_system)
                else:
                    os_auth_url = url

            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")

            if not os_region_name and region_name:
                os_region_name = region_name

        if (options.os_compute_api_version and
                options.os_compute_api_version != '1.0'):
            if not os_tenant_name:
                raise exc.CommandError("You must provide a tenant name "
                        "via either --os-tenant-name or env[OS_TENANT_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]")

        self.cs = client.Client(options.os_compute_api_version, os_username,
                os_password, os_tenant_name, os_auth_url, insecure,
                region_name=os_region_name, endpoint_type=endpoint_type,
                extensions=self.extensions, service_type=service_type,
                service_name=service_name, auth_system=os_auth_system,
                volume_service_name=volume_service_name,
                timings=args.timings, bypass_url=bypass_url,
                no_cache=no_cache, http_log_debug=options.debug)

        try:
            if not utils.isunauthenticated(args.func):
                self.cs.authenticate()
        except exc.Unauthorized:
            raise exc.CommandError("Invalid OpenStack Nova credentials.")
        except exc.AuthorizationFailure:
            raise exc.CommandError("Unable to authorize user")

        args.func(self.cs, args)

        if args.timings:
            self._dump_timings(self.cs.get_timings())

    def _dump_timings(self, timings):
        class Tyme(object):
            def __init__(self, url, seconds):
                self.url = url
                self.seconds = seconds
        results = [Tyme(url, end - start) for url, start, end in timings]
        total = 0.0
        for tyme in results:
            total += tyme.seconds
        results.append(Tyme("Total", total))
        utils.print_list(results, ["url", "seconds"], sortby_index=None)

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


# I'm picky about my shell help.
class OpenStackHelpFormatter(argparse.HelpFormatter):
    def start_section(self, heading):
        # Title-case the headings
        heading = '%s%s' % (heading[0].upper(), heading[1:])
        super(OpenStackHelpFormatter, self).start_section(heading)


def main():
    try:
        OpenStackComputeShell().main(sys.argv[1:])

    except Exception, e:
        logger.debug(e, exc_info=1)
        print >> sys.stderr, "ERROR: %s" % str(e)
        sys.exit(1)


if __name__ == "__main__":
    main()
