# Copyright 2011-2012 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.
"""
Tests For Capacity Weigher.
"""

import mock
from oslo_config import cfg

from manila import context
from manila.openstack.common.scheduler import weights
from manila.scheduler.weights import capacity
from manila.share import utils
from manila import test
from manila.tests.scheduler import fakes

CONF = cfg.CONF


class CapacityWeigherTestCase(test.TestCase):
    def setUp(self):
        super(CapacityWeigherTestCase, self).setUp()
        self.host_manager = fakes.FakeHostManager()
        self.weight_handler = weights.HostWeightHandler(
            'manila.scheduler.weights')

    def _get_weighed_host(self, hosts, weight_properties=None):
        if weight_properties is None:
            weight_properties = {}
        return self.weight_handler.get_weighed_objects(
            [capacity.CapacityWeigher],
            hosts,
            weight_properties)[0]

    @mock.patch('manila.db.sqlalchemy.api.service_get_all_by_topic')
    def _get_all_hosts(self, _mock_service_get_all_by_topic, disabled=False):
        ctxt = context.get_admin_context()
        fakes.mock_host_manager_db_calls(_mock_service_get_all_by_topic,
                                         disabled=disabled)
        host_states = self.host_manager.get_all_host_states_share(ctxt)
        _mock_service_get_all_by_topic.assert_called_once_with(
            ctxt, CONF.share_topic)
        return host_states

    def test_default_of_spreading_first(self):
        hostinfo_list = self._get_all_hosts()

        # host1: free_capacity_gb=1024, free=1024*(1-0.1)
        # host2: free_capacity_gb=300, free=300*(1-0.1)
        # host3: free_capacity_gb=512, free=512
        # host4: free_capacity_gb=200, free=200*(1-0.05)

        # so, host1 should win:
        weighed_host = self._get_weighed_host(hostinfo_list)
        self.assertEqual(weighed_host.weight, 1.0)
        self.assertEqual(
            'host1', utils.extract_host(weighed_host.obj.host))

    def test_capacity_weight_multiplier1(self):
        self.flags(capacity_weight_multiplier=-1.0)
        hostinfo_list = self._get_all_hosts()

        # host1: free_capacity_gb=1024, free=-1024*(1-0.1)
        # host2: free_capacity_gb=300, free=-300*(1-0.1)
        # host3: free_capacity_gb=512, free=-512
        # host4: free_capacity_gb=200, free=-200*(1-0.05)

        # so, host4 should win:
        weighed_host = self._get_weighed_host(hostinfo_list)
        self.assertEqual(weighed_host.weight, 0.0)
        self.assertEqual(
            'host4', utils.extract_host(weighed_host.obj.host))

    def test_capacity_weight_multiplier2(self):
        self.flags(capacity_weight_multiplier=2.0)
        hostinfo_list = self._get_all_hosts()

        # host1: free_capacity_gb=1024, free=1024*(1-0.1)*2
        # host2: free_capacity_gb=300, free=300*(1-0.1)*2
        # host3: free_capacity_gb=512, free=512*2
        # host4: free_capacity_gb=200, free=200*(1-0.05)*2

        # so, host1 should win:
        weighed_host = self._get_weighed_host(hostinfo_list)
        self.assertEqual(weighed_host.weight, 2.0)
        self.assertEqual(
            'host1', utils.extract_host(weighed_host.obj.host))
