# Copyright (c) 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.

from oslo_utils import uuidutils
from oslo_utils import versionutils

from nova.compute import utils as compute_utils
from nova import db
from nova import exception
from nova import objects
from nova.objects import base
from nova.objects import fields


LAZY_LOAD_FIELDS = ['hosts']


# TODO(berrange): Remove NovaObjectDictCompat
@base.NovaObjectRegistry.register
class InstanceGroup(base.NovaPersistentObject, base.NovaObject,
                    base.NovaObjectDictCompat):
    # Version 1.0: Initial version
    # Version 1.1: String attributes updated to support unicode
    # Version 1.2: Use list/dict helpers for policies, metadetails, members
    # Version 1.3: Make uuid a non-None real string
    # Version 1.4: Add add_members()
    # Version 1.5: Add get_hosts()
    # Version 1.6: Add get_by_name()
    # Version 1.7: Deprecate metadetails
    # Version 1.8: Add count_members_by_user()
    # Version 1.9: Add get_by_instance_uuid()
    # Version 1.10: Add hosts field
    VERSION = '1.10'

    fields = {
        'id': fields.IntegerField(),

        'user_id': fields.StringField(nullable=True),
        'project_id': fields.StringField(nullable=True),

        'uuid': fields.UUIDField(),
        'name': fields.StringField(nullable=True),

        'policies': fields.ListOfStringsField(nullable=True),
        'members': fields.ListOfStringsField(nullable=True),
        'hosts': fields.ListOfStringsField(nullable=True),
        }

    def obj_make_compatible(self, primitive, target_version):
        target_version = versionutils.convert_version_to_tuple(target_version)
        if target_version < (1, 7):
            # NOTE(danms): Before 1.7, we had an always-empty
            # metadetails property
            primitive['metadetails'] = {}

    @staticmethod
    def _from_db_object(context, instance_group, db_inst):
        """Method to help with migration to objects.

        Converts a database entity to a formal object.