#    Copyright (C) 2014 AT&T Labs 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.

import contextlib

from kazoo import exceptions as kazoo_exceptions
from oslo_utils import uuidutils
import testtools

from taskflow import exceptions as exc
from taskflow.persistence import backends
from taskflow.persistence.backends import impl_zookeeper
from taskflow import test
from taskflow.tests.unit.persistence import base
from taskflow.tests import utils as test_utils
from taskflow.utils import kazoo_utils

TEST_PATH_TPL = '/taskflow/persistence-test/%s'
_ZOOKEEPER_AVAILABLE = test_utils.zookeeper_available(
    impl_zookeeper.MIN_ZK_VERSION
)


def clean_backend(backend, conf):
    with contextlib.closing(backend.get_connection()) as conn:
        try:
            conn.clear_all()
        except exc.NotFound:
            pass
    client = kazoo_utils.make_client(conf)
    client.start()
    try:
        client.delete(conf['path'], recursive=True)
    except kazoo_exceptions.NoNodeError:
        pass
    finally:
        kazoo_utils.finalize_client(client)


@testtools.skipIf(not _ZOOKEEPER_AVAILABLE, 'zookeeper is not available')
class ZkPersistenceTest(test.TestCase, base.PersistenceTestMixin):
    def _get_connection(self):
        return self.backend.get_connection()

    def setUp(self):
        super().setUp()
        conf = test_utils.ZK_TEST_CONFIG.copy()
        # Create a unique path just for this test (so that we don't overwrite
        # what other tests are doing).
        conf['path'] = TEST_PATH_TPL % (uuidutils.generate_uuid())
        self.backend = impl_zookeeper.ZkBackend(conf)
        self.addCleanup(self.backend.close)
        self.addCleanup(clean_backend, self.backend, conf)
        with contextlib.closing(self.backend.get_connection()) as conn:
            conn.upgrade()

    def test_zk_persistence_entry_point(self):
        conf = {'connection': 'zookeeper:'}
        with contextlib.closing(backends.fetch(conf)) as be:
            self.assertIsInstance(be, impl_zookeeper.ZkBackend)
