Synnefo

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from optparse import make_option

from django.core.management.base import BaseCommand, CommandError

from django.utils import simplejson as json

from astakos.im.models import Resource

from astakos.im.resources import update_resource

from ._common import show_resource_value, style_options, check_style, units

class Command(BaseCommand):

    args = "<resource name>"

    help = ("Modify a resource (currently only change the default base quota)."

            "\nIf no resource is specified, all resources are considered.")

    option_list = BaseCommand.option_list + (

        make_option('--limit',

                    dest='limit',

                    help="Specify default base quota"),

        make_option('--interactive',

                    action='store_true',

                    dest='interactive',

                    default=None,

                    help="Prompt user to change default base quotas"),

        make_option('--from-file',

                    dest='from_file',

                    metavar='<limits_file.json>',

                    help="Read default base quotas from a json file"),

        make_option('--unit-style',

                    default='mb',

                    help=("Specify display unit for resource values "

                          "(one of %s); defaults to mb") % style_options),

    )

    def handle(self, *args, **options):

        resource_name = args[0] if len(args) > 0 else None

        actions = {

            'limit': self.change_limit,

            'interactive': self.change_interactive,

            'from_file': self.change_from_file,

        }

        opts = [(key, value)

                for (key, value) in options.items()

                if key in actions and value is not None]

        if len(opts) != 1:

            raise CommandError("Please provide exactly one of the options: %s."

                               % ", ".join(actions.keys()))

        self.unit_style = options['unit_style']

        check_style(self.unit_style)

        key, value = opts[0]

        action = actions[key]

        action(resource_name, value)

    def get_resource(self, resource_name):

        try:

            return Resource.objects.get_for_update(name=resource_name)

        except Resource.DoesNotExist:

            raise CommandError("Resource %s does not exist."

                               % resource_name)

    def change_limit(self, resource_name, limit):

        if resource_name is None:

            raise CommandError("Please provide a resource name.")

        resource = self.get_resource(resource_name)

        self.change_resource_limit(resource, limit)

    def change_from_file(self, resource_name, filename):

        with open(filename) as file_data:

            try:

                config = json.load(file_data)

            except json.JSONDecodeError:

                raise CommandError("Malformed JSON file.")

            if not isinstance(config, dict):

                raise CommandError("Malformed JSON file.")

            self.change_with_conf(resource_name, config)

    def change_with_conf(self, resource_name, config):

        if resource_name is None:

            resources = Resource.objects.all().select_for_update()

        else:

            resources = [self.get_resource(resource_name)]

        for resource in resources:

            limit = config.get(resource.name)

            if limit is not None:

                self.change_resource_limit(resource, limit)

    def change_interactive(self, resource_name, _placeholder):

        if resource_name is None:

            resources = Resource.objects.all().select_for_update()

        else:

            resources = [self.get_resource(resource_name)]

        for resource in resources:

            self.stdout.write("Resource '%s' (%s)\n" %

                              (resource.name, resource.desc))

            value = show_resource_value(resource.uplimit, resource.name,

                                        self.unit_style)

            self.stdout.write("Current limit: %s\n" % value)

            while True:

                self.stdout.write("New limit (leave blank to keep current): ")

                response = raw_input()

                if response == "":

                    break

                else:

                    try:

                        value = units.parse(response)

                    except units.ParseError:

                        continue

                    update_resource(resource, value)

                    break

    def change_resource_limit(self, resource, limit):

        if not isinstance(limit, (int, long)):

            try:

                limit = units.parse(limit)

            except units.ParseError:

                m = ("Limit should be an integer, optionally followed "

                     "by a unit.")

                raise CommandError(m)

            update_resource(resource, limit)