#   Copyright 2012-2013 OpenStack Foundation
#
#   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.
#

"""Limits Action Implementation"""

import itertools

from osc_lib.command import command
from osc_lib import utils

from openstackclient.i18n import _
from openstackclient.identity import common as identity_common


def _format_absolute_limit(absolute_limits):
    info = {}

    for key in set(absolute_limits):
        if key in ('id', 'name', 'location'):
            continue

        info[key] = absolute_limits[key]

    return info


def _format_rate_limit(rate_limits):
    # flatten this:
    #
    #   {'uri': '<uri>', 'limit': [{'value': '<value>', ...], ...}
    #
    # to this:
    #
    #   {'uri': '<uri>', 'value': '<value>', ...}, ...}
    return itertools.chain(
        *[[{'uri': x['uri'], **y} for y in x['limit']] for x in rate_limits]
    )


class ShowLimits(command.Lister):
    _description = _("Show compute and block storage limits")

    def get_parser(self, prog_name):
        parser = super().get_parser(prog_name)
        type_group = parser.add_mutually_exclusive_group(required=True)
        type_group.add_argument(
            "--absolute",
            dest="is_absolute",
            action="store_true",
            default=False,
            help=_("Show absolute limits"),
        )
        type_group.add_argument(
            "--rate",
            dest="is_rate",
            action="store_true",
            default=False,
            help=_(
                'Show rate limits. This is not supported by the compute '
                'service since the 12.0.0 (Liberty) release and is only '
                'supported by the block storage service when the '
                'rate-limiting middleware is enabled. It is therefore a no-op '
                'in most deployments.'
            ),
        )
        parser.add_argument(
            "--reserved",
            dest="is_reserved",
            action="store_true",
            default=False,
            help=_("Include reservations count (only valid with --absolute)"),
        )
        parser.add_argument(
            '--project',
            metavar='<project>',
            help=_(
                'Show limits for a specific project (name or ID) '
                '(only valid with --absolute)'
            ),
        )
        parser.add_argument(
            '--domain',
            metavar='<domain>',
            help=_(
                'Domain the project belongs to (name or ID) '
                '(only valid with --absolute)'
            ),
        )
        return parser

    def take_action(self, parsed_args):
        project_id = None
        if parsed_args.project is not None:
            identity_client = self.app.client_manager.identity
            if parsed_args.domain is not None:
                domain = identity_common.find_domain(
                    identity_client, parsed_args.domain
                )
                project_id = utils.find_resource(
                    identity_client.projects,
                    parsed_args.project,
                    domain_id=domain.id,
                ).id
            else:
                project_id = utils.find_resource(
                    identity_client.projects, parsed_args.project
                ).id

        compute_limits = None
        volume_limits = None

        if self.app.client_manager.is_compute_endpoint_enabled():
            compute_client = self.app.client_manager.sdk_connection.compute
            compute_limits = compute_client.get_limits(
                reserved=parsed_args.is_reserved, tenant_id=project_id
            )

        if self.app.client_manager.is_volume_endpoint_enabled():
            volume_client = self.app.client_manager.sdk_connection.volume
            volume_limits = volume_client.get_limits(
                project=project_id,
            )

        if parsed_args.is_absolute:
            columns = ["Name", "Value"]
            info = {}
            if compute_limits:
                info.update(_format_absolute_limit(compute_limits.absolute))
            if volume_limits:
                info.update(_format_absolute_limit(volume_limits.absolute))

            return (columns, sorted(info.items(), key=lambda x: x[0]))
        else:  # parsed_args.is_rate
            data = []
            if compute_limits:
                data.extend(_format_rate_limit(compute_limits.rate))
            if volume_limits:
                data.extend(_format_rate_limit(volume_limits.rate))
            columns = [
                "Verb",
                "URI",
                "Value",
                "Remain",
                "Unit",
                "Next Available",
            ]

            return (
                columns,
                [
                    (
                        s['verb'],
                        s['uri'],
                        s['value'],
                        s['remaining'],
                        s['unit'],
                        s.get('next-available') or s['next_available'],
                    )
                    for s in data
                ],
            )
