# Copyright 2013 Netease Corporation
# 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 availability zones
"""

import mock
import six

from nova import availability_zones as az
import nova.conf
from nova import context
from nova import db
from nova import objects
from nova import test

CONF = nova.conf.CONF


class AvailabilityZoneTestCases(test.TestCase):
    """Test case for aggregate based availability zone."""

    def setUp(self):
        super(AvailabilityZoneTestCases, self).setUp()
        self.host = 'me'
        self.availability_zone = 'nova-test'
        self.default_az = CONF.default_availability_zone
        self.default_in_az = CONF.internal_service_availability_zone
        self.context = context.get_admin_context()
        self.agg = self._create_az('az_agg', self.availability_zone)

    def tearDown(self):
        db.aggregate_delete(self.context, self.agg['id'])
        super(AvailabilityZoneTestCases, self).tearDown()

    def _create_az(self, agg_name, az_name):
        agg_meta = {'name': agg_name}
        agg = db.aggregate_create(self.context, agg_meta)

        metadata = {'availability_zone': az_name}
        db.aggregate_metadata_add(self.context, agg['id'], metadata)

        return agg

    def _update_az(self, aggregate, az_name):
        metadata = {'availability_zone': az_name}
        db.aggregate_update(self.context, aggregate['id'], metadata)

    def _create_service_with_topic(self, topic, host, disabled=False):
        values = {
            'binary': 'bin',
            'host': host,
            'topic': topic,
            'disabled': disabled,
        }
        return db.service_create(self.context, values)

    def _destroy_service(self, service):
        return db.service_destroy(self.context, service['id'])

    def _add_to_aggregate(self, service, aggregate):
        return db.aggregate_host_add(self.context,
                                     aggregate['id'], service['host'])

    def _delete_from_aggregate(self, service, aggregate):
        return db.aggregate_host_delete(self.context,
                                        aggregate['id'], service['host'])

    def test_rest_availability_zone_reset_cache(self):
        az._get_cache().add('cache', 'fake_value')
        az.reset_cache()
        self.assertIsNone(az._get_cache().get('cache'))

    def test_update_host_availability_zone_cache(self):
        """Test availability zone cache could be update."""
        service = self._create_service_with_topic('compute', self.host)

        # Create a new aggregate with an AZ and add the host to the AZ
        az_name = 'az1'
        cache_key = az._make_cache_key(self.host)
        agg_az1 = self._create_az('agg-az1', az_name)
        self._add_to_aggregate(service, agg_az1)
        az.update_host_availability_zone_cache(self.context, self.host)
        self.assertEqual('az1', az._get_cache().get(cache_key))
        az.update_host_availability_zone_cache(self.context, self.host, 'az2')
        self.assertEqual('az2', az._get_cache().get(cache_key))

    def test_set_availability_zone_compute_service(self):
        """Test for compute service get right availability zone."""
        service = self._create_service_with_topic('compute', self.host)
        services = db.service_get_all(self.context)

        # The service is not add into aggregate, so confirm it is default
        # availability zone.
        new_service = az.set_availability_zones(self.context, services)[0]
        self.assertEqual(self.default_az, new_service['availability_zone'])

        # The service is added into aggregate, confirm return the aggregate
        # availability zone.
        self._add_to_aggregate(service, self.agg)
        new_service = az.set_availability_zones(self.context, services)[0]
        self.assertEqual(self.availability_zone,
                         new_service['availability_zone'])

        self._destroy_service(service)

    def test_set_availability_zone_unicode_key(self):
        """Test set availability zone cache key is unicode."""
        service = self._create_service_with_topic('network', self.host)
        services = db.service_get_all(self.context)
        az.set_availability_zones(self.context, services)
        self.assertIsInstance(services[0]['host'], six.text_type)
        cached_key = az._make_cache_key(services[0]['host'])
        self.assertIsInstance(cached_key, str)
        self._destroy_service(service)

    def test_set_availability_zone_not_compute_service(self):
        """Test not compute service get right availability zone."""
        service = self._create_service_with_topic('network', self.host)
        services = db.service_get_all(self.context)
        new_service = az.set_availability_zones(self.context, services)[0]
        self.assertEqual(self.default_in_az, new_service['availability_zone'])
        self._destroy_service(service)

    def test_get_host_availability_zone(self):
        """Test get right availability zone by given host."""
        self.assertEqual(self.default_az,
                        az.get_host_availability_zone(self.context, self.host))

        service = self._create_service_with_topic('compute', self.host)
        self._add_to_aggregate(service, self.agg)

        self.assertEqual(self.availability_zone,
                        az.get_host_availability_zone(self.context, self.host))

    def test_update_host_availability_zone(self):
        """Test availability zone could be update by given host."""
        service = self._create_service_with_topic('compute', self.host)

        # Create a new aggregate with an AZ and add the host to the AZ
        az_name = 'az1'
        agg_az1 = self._create_az('agg-az1', az_name)
        self._add_to_aggregate(service, agg_az1)
        self.assertEqual(az_name,
                    az.get_host_availability_zone(self.context, self.host))
        # Update AZ
        new_az_name = 'az2'
        self._update_az(agg_az1, new_az_name)
        self.assertEqual(new_az_name,
                    az.get_host_availability_zone(self.context, self.host))

    def test_delete_host_availability_zone(self):
        """Test availability zone could be deleted successfully."""
        service = self._create_service_with_topic('compute', self.host)

        # Create a new aggregate with an AZ and add the host to the AZ
        az_name = 'az1'
        agg_az1 = self._create_az('agg-az1', az_name)
        self._add_to_aggregate(service, agg_az1)
        self.assertEqual(az_name,
                    az.get_host_availability_zone(self.context, self.host))
        # Delete the AZ via deleting the aggregate
        self._delete_from_aggregate(service, agg_az1)
        self.assertEqual(self.default_az,
                    az.get_host_availability_zone(self.context, self.host))

    def test_get_availability_zones(self):
        """Test get_availability_zones."""

        # When the param get_only_available of get_availability_zones is set
        # to default False, it returns two lists, zones with at least one
        # enabled services, and zones with no enabled services,
        # when get_only_available is set to True, only return a list of zones
        # with at least one enabled services.
        # Use the following test data:
        #
        # zone         host        enabled
        # nova-test    host1       Yes
        # nova-test    host2       No
        # nova-test2   host3       Yes
        # nova-test3   host4       No
        # <default>    host5       No

        agg2 = self._create_az('agg-az2', 'nova-test2')
        agg3 = self._create_az('agg-az3', 'nova-test3')

        service1 = self._create_service_with_topic('compute', 'host1',
                                                   disabled=False)
        service2 = self._create_service_with_topic('compute', 'host2',
                                                   disabled=True)
        service3 = self._create_service_with_topic('compute', 'host3',
                                                   disabled=False)
        service4 = self._create_service_with_topic('compute', 'host4',
                                                   disabled=True)
        self._create_service_with_topic('compute', 'host5',
                                        disabled=True)

        self._add_to_aggregate(service1, self.agg)
        self._add_to_aggregate(service2, self.agg)
        self._add_to_aggregate(service3, agg2)
        self._add_to_aggregate(service4, agg3)

        zones, not_zones = az.get_availability_zones(self.context)

        self.assertEqual(['nova-test', 'nova-test2'], zones)
        self.assertEqual(['nova-test3', 'nova'], not_zones)

        zones = az.get_availability_zones(self.context, True)

        self.assertEqual(['nova-test', 'nova-test2'], zones)

        zones, not_zones = az.get_availability_zones(self.context,
                                                     with_hosts=True)

        self.assertJsonEqual(zones,
                         [(u'nova-test2', set([u'host3'])),
                                 (u'nova-test', set([u'host1']))])
        self.assertJsonEqual(not_zones,
                         [(u'nova-test3', set([u'host4'])),
                                 (u'nova', set([u'host5']))])

    def test_get_instance_availability_zone_default_value(self):
        """Test get right availability zone by given an instance."""
        fake_inst = objects.Instance(host=self.host,
                                     availability_zone=None)

        self.assertEqual(self.default_az,
                az.get_instance_availability_zone(self.context, fake_inst))

    def test_get_instance_availability_zone_from_aggregate(self):
        """Test get availability zone from aggregate by given an instance."""
        host = 'host170'
        service = self._create_service_with_topic('compute', host)
        self._add_to_aggregate(service, self.agg)

        fake_inst = objects.Instance(host=host,
                                     availability_zone=self.availability_zone)

        self.assertEqual(self.availability_zone,
                az.get_instance_availability_zone(self.context, fake_inst))

    @mock.patch.object(az._get_cache(), 'get')
    def test_get_instance_availability_zone_cache_differs(self, cache_get):
        host = 'host170'
        service = self._create_service_with_topic('compute', host)
        self._add_to_aggregate(service, self.agg)
        cache_get.return_value = self.default_az

        fake_inst = objects.Instance(host=host,
                                     availability_zone=self.availability_zone)
        self.assertEqual(
            self.availability_zone,
            az.get_instance_availability_zone(self.context, fake_inst))

    def test_get_instance_availability_zone_no_host(self):
        """Test get availability zone from instance if host not set."""
        fake_inst = objects.Instance(host=None, availability_zone='inst-az')

        result = az.get_instance_availability_zone(self.context, fake_inst)
        self.assertEqual('inst-az', result)

    def test_get_instance_availability_zone_no_host_no_az(self):
        """Test get availability zone if neither host nor az is set."""
        fake_inst = objects.Instance(host=None, availability_zone=None)

        result = az.get_instance_availability_zone(self.context, fake_inst)
        self.assertIsNone(result)