# Copyright 2015 Hewlett-Packard Development Company, L.P.
#
# Author: Endre Karlson <endre.karlson@hp.com>
#
# 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.
import mock
from oslo_config import cfg

from designate import coordination
from designate import service
from designate.tests import fixtures
from designate.tests import TestCase

cfg.CONF.register_group(cfg.OptGroup("service:dummy"))

cfg.CONF.register_opts([
], group="service:dummy")


class CoordinatedService(coordination.CoordinationMixin, service.Service):
    @property
    def service_name(self):
        return "dummy"


class TestCoordinationMixin(TestCase):
    def setUp(self):
        super(TestCoordinationMixin, self).setUp()
        self.config(backend_url="zake://", group="coordination")

    def test_start(self):
        service = CoordinatedService()
        service.start()

        self.assertTrue(service._coordination_started)
        self.assertIn(service.service_name.encode('utf-8'),
                      service._coordinator.get_groups().get())
        self.assertIn(service._coordination_id.encode('utf-8'),
                      service._coordinator.get_members(
                            service.service_name).get())
        service.stop()

    def test_stop(self):
        service = CoordinatedService()
        service.start()
        service.stop()
        self.assertFalse(service._coordination_started)

    def test_start_no_coordination(self):
        self.config(backend_url=None, group="coordination")
        service = CoordinatedService()
        service.start()
        self.assertIsNone(service._coordinator)

    def test_stop_no_coordination(self):
        self.config(backend_url=None, group="coordination")
        service = CoordinatedService()
        self.assertIsNone(service._coordinator)
        service.start()
        service.stop()


class TestPartitioner(TestCase):
    def _get_partitioner(self, partitions, host=b'a'):
        fixture = self.useFixture(fixtures.CoordinatorFixture(
            'zake://', host))
        group = 'group'
        fixture.coordinator.create_group(group)
        fixture.coordinator.join_group(group)

        return coordination.Partitioner(fixture.coordinator, group, host,
                                        partitions), fixture.coordinator

    def test_callbacks(self):
        cb1 = mock.Mock()
        cb2 = mock.Mock()
        partitions = list(range(0, 10))

        p_one, c_one = self._get_partitioner(partitions)
        p_one.start()
        p_one.watch_partition_change(cb1)
        p_one.watch_partition_change(cb2)

        # Initial partitions are calucated upon service bootup
        cb1.assert_called_with(partitions, None, None)
        cb2.assert_called_with(partitions, None, None)

        cb1.reset_mock()
        cb2.reset_mock()

        # Startup a new partioner that will cause the cb's to be called
        p_two, c_two = self._get_partitioner(partitions, host=b'b')
        p_two.start()

        # We'll get the 5 first partition ranges
        c_one.run_watchers()
        cb1.assert_called_with(partitions[:5], [b'a', b'b'], mock.ANY)
        cb2.assert_called_with(partitions[:5], [b'a', b'b'], mock.ANY)

    def test_two_even_partitions(self):
        partitions = list(range(0, 10))

        p_one, c_one = self._get_partitioner(partitions)
        p_two, c_two = self._get_partitioner(partitions, host=b'b')

        p_one.start()
        p_two.start()

        # Call c_one watchers making it refresh it's partitions
        c_one.run_watchers()

        self.assertEqual([0, 1, 2, 3, 4], p_one.my_partitions)
        self.assertEqual([5, 6, 7, 8, 9], p_two.my_partitions)

    def test_two_odd_partitions(self):
        partitions = list(range(0, 11))

        p_one, c_one = self._get_partitioner(partitions)
        p_two, c_two = self._get_partitioner(partitions, host=b'b')

        p_one.start()
        p_two.start()

        # Call c_one watchers making it refresh it's partitions
        c_one.run_watchers()

        self.assertEqual([0, 1, 2, 3, 4, 5], p_one.my_partitions)
        self.assertEqual([6, 7, 8, 9, 10], p_two.my_partitions)

    def test_three_even_partitions(self):
        partitions = list(range(0, 10))

        p_one, c_one = self._get_partitioner(partitions)
        p_two, c_two = self._get_partitioner(partitions, host=b'b')
        p_three, c_three = self._get_partitioner(partitions, host=b'c')

        p_one.start()
        p_two.start()
        p_three.start()

        # Call c_one watchers making it refresh it's partitions
        c_one.run_watchers()
        c_two.run_watchers()

        self.assertEqual([0, 1, 2, 3], p_one.my_partitions)
        self.assertEqual([4, 5, 6, 7], p_two.my_partitions)
        self.assertEqual([8, 9], p_three.my_partitions)

    def test_three_odd_partitions(self):
        partitions = list(range(0, 11))

        p_one, c_one = self._get_partitioner(partitions)
        p_two, c_two = self._get_partitioner(partitions, host=b'b')
        p_three, c_three = self._get_partitioner(partitions, host=b'c')

        p_one.start()
        p_two.start()
        p_three.start()

        c_one.run_watchers()
        c_two.run_watchers()

        self.assertEqual([0, 1, 2, 3], p_one.my_partitions)
        self.assertEqual([4, 5, 6, 7], p_two.my_partitions)
        self.assertEqual([8, 9, 10], p_three.my_partitions)


class TestPartitionerWithoutBackend(TestCase):
    def test_start(self):
        # We test starting the partitioner and calling the watch func first
        partitions = list(range(0, 10))

        cb1 = mock.Mock()
        cb2 = mock.Mock()
        partitioner = coordination.Partitioner(
            None, 'group', 'meme', partitions)
        partitioner.watch_partition_change(cb1)
        partitioner.watch_partition_change(cb2)
        partitioner.start()
        cb1.assert_called_with(partitions, None, None)
        cb2.assert_called_with(partitions, None, None)

    def test_cb_on_watch(self):
        partitions = list(range(0, 10))
        cb = mock.Mock()

        partitioner = coordination.Partitioner(
            None, 'group', 'meme', partitions)
        partitioner.start()
        partitioner.watch_partition_change(cb)
        cb.assert_called_with(partitions, None, None)


class TestLeaderElection(TestCase):
    def setUp(self):
        super(TestLeaderElection, self).setUp()

        self.coord_fixture = self.useFixture(fixtures.CoordinatorFixture(
            'zake://', b'InsertNameHere'))

        self.election = coordination.LeaderElection(
            self.coordinator, 'President')

    @property
    def coordinator(self):
        """Helper for quick access to the raw coordinator"""
        return self.coord_fixture.coordinator

    def test_is_leader(self):
        # We should not be leader until after we start the election.
        self.assertFalse(self.election.is_leader)

        # Start the election
        self.election.start()
        self.coordinator.run_watchers()

        # We should now be the leader.
        self.assertTrue(self.election.is_leader)

        # Stop the election
        self.election.stop()

        # We should no longer be the leader.
        self.assertFalse(self.election.is_leader)

    def test_callbacks(self):
        # We should not be leader until after we start the election.
        self.assertFalse(self.election.is_leader)

        # Create and attach a callback
        mock_callback_one = mock.Mock()
        self.election.watch_elected_as_leader(mock_callback_one)

        # Ensure the callback has not yet been called.
        self.assertFalse(mock_callback_one.called)

        # Start the election
        self.election.start()
        self.coordinator.run_watchers()

        # Ensure the callback has been called exactly once.
        self.assertEqual(1, mock_callback_one.call_count)

        # Create and attach a second callback after we start
        mock_callback_two = mock.Mock()
        self.election.watch_elected_as_leader(mock_callback_two)

        # Ensure the callback has been called exactly once.
        self.assertEqual(1, mock_callback_two.call_count)


class TestLeaderElectionWithoutBackend(TestCase):
    def setUp(self):
        super(TestLeaderElectionWithoutBackend, self).setUp()

        # coordinator = None indicates no coordination backend has been
        # configured
        coordinator = None
        self.election = coordination.LeaderElection(coordinator, 'President')

    def test_is_leader(self):
        # We should not be leader until after we start the election.
        self.assertFalse(self.election.is_leader)

        # Start the election
        self.election.start()

        # We should now be the leader.
        self.assertTrue(self.election.is_leader)

        # Stop the election
        self.election.stop()

        # We should no longer be the leader.
        self.assertFalse(self.election.is_leader)

    def test_callbacks(self):
        # We should not be leader until after we start the election.
        self.assertFalse(self.election.is_leader)

        # Create and attach a callback
        mock_callback_one = mock.Mock()
        self.election.watch_elected_as_leader(mock_callback_one)

        # Ensure the callback has not yet been called.
        self.assertFalse(mock_callback_one.called)

        # Start the election
        self.election.start()

        # Ensure the callback has been called exactly once.
        self.assertEqual(1, mock_callback_one.call_count)

        # Create and attach a second callback after we start
        mock_callback_two = mock.Mock()
        self.election.watch_elected_as_leader(mock_callback_two)

        # Ensure the callback has been called exactly once.
        self.assertEqual(1, mock_callback_two.call_count)