#
# Copyright 2012 New Dream Network, LLC (DreamHost)
# Copyright 2013 eNovance
#
# Author: Doug Hellmann <doug.hellmann@dreamhost.com>
#         Julien Danjou <julien@danjou.info>
#
# 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.

"""Base classes for API tests."""
import fixtures
import os
import uuid
import warnings

import six
from six.moves.urllib import parse as urlparse
import testscenarios.testcase
from testtools import testcase

from ceilometer.openstack.common.fixture import config
import ceilometer.openstack.common.fixture.mockpatch as oslo_mock
from ceilometer import storage
from ceilometer.tests import base as test_base


class MongoDbManager(fixtures.Fixture):

    def __init__(self, url):
        self._url = url

    def setUp(self):
        super(MongoDbManager, self).setUp()
        with warnings.catch_warnings():
            warnings.filterwarnings(
                action='ignore',
                message='.*you must provide a username and password.*')
            try:
                self.connection = storage.get_connection(self.url)
            except storage.StorageBadVersion as e:
                raise testcase.TestSkipped(six.text_type(e))

    @property
    def url(self):
        return '%(url)s_%(db)s' % {
            'url': self._url,
            'db': uuid.uuid4().hex
        }


class HBaseManager(fixtures.Fixture):
    def __init__(self, url):
        self._url = url

    def setUp(self):
        super(HBaseManager, self).setUp()
        self.connection = storage.get_connection(self.url)

    @property
    def url(self):
        return '%s?table_prefix=%s' % (
            self._url,
            uuid.uuid4().hex
        )


class SQLiteManager(fixtures.Fixture):

    def __init__(self, url):
        self.url = url

    def setUp(self):
        super(SQLiteManager, self).setUp()
        self.connection = storage.get_connection(self.url)


class TestBase(testscenarios.testcase.WithScenarios, test_base.BaseTestCase):

    DRIVER_MANAGERS = {
        'mongodb': MongoDbManager,
        'db2': MongoDbManager,
        'sqlite': SQLiteManager,
        'hbase': HBaseManager,
    }

    db_url = 'sqlite://'  # NOTE(Alexei_987) Set default db url

    def setUp(self):
        super(TestBase, self).setUp()

        engine = urlparse.urlparse(self.db_url).scheme

        # NOTE(Alexei_987) Shortcut to skip expensive db setUp
        test_method = self._get_test_method()
        if (hasattr(test_method, '_run_with')
                and engine not in test_method._run_with):
            raise testcase.TestSkipped(
                'Test is not applicable for %s' % engine)

        self.db_manager = self._get_driver_manager(engine)(self.db_url)
        self.useFixture(self.db_manager)

        self.conn = self.db_manager.connection
        self.conn.upgrade()

        self.useFixture(oslo_mock.Patch('ceilometer.storage.get_connection',
                                        return_value=self.conn))

        self.CONF = self.useFixture(config.Config()).conf
        self.CONF([], project='ceilometer')

        # Set a default location for the pipeline config file so the
        # tests work even if ceilometer is not installed globally on
        # the system.
        self.CONF.import_opt('pipeline_cfg_file', 'ceilometer.pipeline')
        self.CONF.set_override(
            'pipeline_cfg_file',
            self.path_get('etc/ceilometer/pipeline.yaml')
        )

    def tearDown(self):
        self.conn.clear()
        self.conn = None
        super(TestBase, self).tearDown()

    def _get_driver_manager(self, engine):
        manager = self.DRIVER_MANAGERS.get(engine)
        if not manager:
            raise ValueError('No manager available for %s' % engine)
        return manager


def run_with(*drivers):
    """Used to mark tests that are only applicable for certain db driver.
    Skips test if driver is not available
    """
    def decorator(test):
        if isinstance(test, type) and issubclass(test, TestBase):
            # Decorate all test methods
            for attr in dir(test):
                value = getattr(test, attr)
                if callable(value) and attr.startswith('test_'):
                    value.__func__._run_with = drivers
        else:
            test._run_with = drivers
        return test
    return decorator


@six.add_metaclass(test_base.SkipNotImplementedMeta)
class MixinTestsWithBackendScenarios(object):

    scenarios = [
        ('sqlite', {'db_url': 'sqlite://'}),
        ('mongodb', {'db_url': os.environ.get('CEILOMETER_TEST_MONGODB_URL')}),
        ('hbase', {'db_url': os.environ.get('CEILOMETER_TEST_HBASE_URL',
                                            'hbase://__test__')}),
        ('db2', {'db_url': (os.environ.get('CEILOMETER_TEST_DB2_URL') or
                            os.environ.get('CEILOMETER_TEST_MONGODB_URL'))})
    ]