# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.

"""Base classes for our unit tests.

Allows overriding of flags for use of fakes, and some black magic for
inline callbacks.

"""

import eventlet
eventlet.monkey_patch(os=False)

import copy
import gettext
import inspect
import logging
import os
import shutil
import sys
import uuid

import fixtures
from oslo.concurrency import lockutils
from oslo.config import cfg
from oslo.config import fixture as config_fixture
from oslo.messaging import conffixture as messaging_conffixture
from oslo.utils import timeutils
import testtools

from nova import context
from nova import db
from nova.db import migration
from nova.db.sqlalchemy import api as session
from nova.network import manager as network_manager
from nova import objects
from nova.objects import base as objects_base
from nova.openstack.common.fixture import logging as log_fixture
from nova.openstack.common.fixture import moxstubout
from nova.openstack.common import log as nova_logging
from nova import paths
from nova import rpc
from nova import service
from nova.tests.unit import conf_fixture
from nova.tests.unit import policy_fixture
from nova import utils


test_opts = [
    cfg.StrOpt('sqlite_clean_db',
               default='clean.sqlite',
               help='File name of clean sqlite db'),
    ]

CONF = cfg.CONF
CONF.register_opts(test_opts)
CONF.import_opt('enabled', 'nova.api.openstack', group='osapi_v3')
CONF.set_override('use_stderr', False)

nova_logging.setup('nova')

# NOTE(comstud): Make sure we have all of the objects loaded. We do this
# at module import time, because we may be using mock decorators in our
# tests that run at import time.
objects.register_all()

_DB_CACHE = None
_TRUE_VALUES = ('True', 'true', '1', 'yes')


class Database(fixtures.Fixture):

    def __init__(self, db_session, db_migrate, sql_connection,
                    sqlite_db, sqlite_clean_db):
        self.sql_connection = sql_connection
        self.sqlite_db = sqlite_db
        self.sqlite_clean_db = sqlite_clean_db

        self.engine = db_session.get_engine()
        self.engine.dispose()
        conn = self.engine.connect()
        if sql_connection == "sqlite://":
            if db_migrate.db_version() > db_migrate.db_initial_version():
                return
        else:
            testdb = paths.state_path_rel(sqlite_db)
            if os.path.exists(testdb):
                return
        db_migrate.db_sync()
        if sql_connection == "sqlite://":
            conn = self.engine.connect()
            self._DB = "".join(line for line in conn.connection.iterdump())
            self.engine.dispose()
        else:
            cleandb = paths.state_path_rel(sqlite_clean_db)
            shutil.copyfile(testdb, cleandb)

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

        if self.sql_connection == "sqlite://":
            conn = self.engine.connect()
            conn.connection.executescript(self._DB)
            self.addCleanup(self.engine.dispose)
        else:
            shutil.copyfile(paths.state_path_rel(self.sqlite_clean_db),
                            paths.state_path_rel(self.sqlite_db))


class SampleNetworks(fixtures.Fixture):

    """Create sample networks in the database."""

    def __init__(self, host=None):
        self.host = host

    def setUp(self):
        super(SampleNetworks, self).setUp()
        ctxt = context.get_admin_context()
        network = network_manager.VlanManager(host=self.host)
        bridge_interface = CONF.flat_interface or CONF.vlan_interface
        network.create_networks(ctxt,
                                label='test',
                                cidr='10.0.0.0/8',
                                multi_host=CONF.multi_host,
                                num_networks=CONF.num_networks,
                                network_size=CONF.network_size,
                                cidr_v6=CONF.fixed_range_v6,
                                gateway=CONF.gateway,
                                gateway_v6=CONF.gateway_v6,
                                bridge=CONF.flat_network_bridge,
                                bridge_interface=bridge_interface,
                                vpn_start=CONF.vpn_start,
                                vlan_start=CONF.vlan_start,
                                dns1=CONF.flat_network_dns)
        for net in db.network_get_all(ctxt):
            network.set_network_host(ctxt, net)


class ReplaceModule(fixtures.Fixture):
    """Replace a module with a fake module."""

    def __init__(self, name, new_value):
        self.name = name
        self.new_value = new_value

    def _restore(self, old_value):
        sys.modules[self.name] = old_value

    def setUp(self):
        super(ReplaceModule, self).setUp()
        old_value = sys.modules.get(self.name)
        sys.modules[self.name] = self.new_value
        self.addCleanup(self._restore, old_value)


class ServiceFixture(fixtures.Fixture):
    """Run a service as a test fixture."""

    def __init__(self, name, host=None, **kwargs):
        name = name
        host = host and host or uuid.uuid4().hex
        kwargs.setdefault('host', host)
        kwargs.setdefault('binary', 'nova-%s' % name)
        self.kwargs = kwargs

    def setUp(self):
        super(ServiceFixture, self).setUp()
        self.service = service.Service.create(**self.kwargs)
        self.service.start()
        self.addCleanup(self.service.kill)


class TranslationFixture(fixtures.Fixture):
    """Use gettext NullTranslation objects in tests."""

    def setUp(self):
        super(TranslationFixture, self).setUp()
        nulltrans = gettext.NullTranslations()
        gettext_fixture = fixtures.MonkeyPatch('gettext.translation',
                                               lambda *x, **y: nulltrans)
        self.gettext_patcher = self.useFixture(gettext_fixture)


class TestingException(Exception):
    pass


class NullHandler(logging.Handler):
    """custom default NullHandler to attempt to format the record.

    Used in conjunction with
    log_fixture.get_logging_handle_error_fixture to detect formatting errors in
    debug level logs without saving the logs.
    """
    def handle(self, record):
        self.format(record)

    def emit(self, record):
        pass

    def createLock(self):
        self.lock = None


class TestCase(testtools.TestCase):
    """Test case base class for all unit tests.

    Due to the slowness of DB access, please consider deriving from
    `NoDBTestCase` first.
    """
    USES_DB = True
    REQUIRES_LOCKING = False

    # NOTE(rpodolyaka): this attribute can be overridden in subclasses in order
    #                   to scale the global test timeout value set for each
    #                   test case separately. Use 0 value to disable timeout.
    TIMEOUT_SCALING_FACTOR = 1

    def setUp(self):
        """Run before each test method to initialize test environment."""
        super(TestCase, self).setUp()
        test_timeout = os.environ.get('OS_TEST_TIMEOUT', 0)
        try:
            test_timeout = int(test_timeout)
        except ValueError:
            # If timeout value is invalid do not set a timeout.
            test_timeout = 0

        if self.TIMEOUT_SCALING_FACTOR >= 0:
            test_timeout *= self.TIMEOUT_SCALING_FACTOR
        else:
            raise ValueError('TIMEOUT_SCALING_FACTOR value must be >= 0')

        if test_timeout > 0:
            self.useFixture(fixtures.Timeout(test_timeout, gentle=True))
        self.useFixture(fixtures.NestedTempfile())
        self.useFixture(fixtures.TempHomeDir())
        self.useFixture(TranslationFixture())
        self.useFixture(log_fixture.get_logging_handle_error_fixture())

        if os.environ.get('OS_STDOUT_CAPTURE') in _TRUE_VALUES:
            stdout = self.useFixture(fixtures.StringStream('stdout')).stream
            self.useFixture(fixtures.MonkeyPatch('sys.stdout', stdout))
        if os.environ.get('OS_STDERR_CAPTURE') in _TRUE_VALUES:
            stderr = self.useFixture(fixtures.StringStream('stderr')).stream
            self.useFixture(fixtures.MonkeyPatch('sys.stderr', stderr))

        rpc.add_extra_exmods('nova.test')
        self.addCleanup(rpc.clear_extra_exmods)
        self.addCleanup(rpc.cleanup)

        # set root logger to debug
        root = logging.getLogger()
        root.setLevel(logging.DEBUG)

        # supports collecting debug level for local runs
        if os.environ.get('OS_DEBUG') in _TRUE_VALUES:
            level = logging.DEBUG
        else:
            level = logging.INFO

        # Collect logs
        fs = '%(asctime)s %(levelname)s [%(name)s] %(message)s'
        self.useFixture(fixtures.FakeLogger(format=fs, level=None))
        root.handlers[0].setLevel(level)

        if level > logging.DEBUG:
            # Just attempt to format debug level logs, but don't save them
            handler = NullHandler()
            self.useFixture(fixtures.LogHandler(handler, nuke_handlers=False))
            handler.setLevel(logging.DEBUG)

        # Don't log every single DB migration step
        logging.getLogger('migrate.versioning.api').setLevel(logging.WARNING)

        # NOTE(sdague): because of the way we were using the lock
        # wrapper we eneded up with a lot of tests that started
        # relying on global external locking being set up for them. We
        # consider all of these to be *bugs*. Tests should not require
        # global external locking, or if they do, they should
        # explicitly set it up themselves.
        #
        # The following REQUIRES_LOCKING class parameter is provided
        # as a bridge to get us there. No new tests should be added
        # that require it, and existing classes and tests should be
        # fixed to not need it.
        if self.REQUIRES_LOCKING:
            lock_path = self.useFixture(fixtures.TempDir()).path
            self.fixture = self.useFixture(
                config_fixture.Config(lockutils.CONF))
            self.fixture.config(lock_path=lock_path,
                                group='oslo_concurrency')

        self.useFixture(conf_fixture.ConfFixture(CONF))

        self.messaging_conf = messaging_conffixture.ConfFixture(CONF)
        self.messaging_conf.transport_driver = 'fake'
        self.useFixture(self.messaging_conf)

        rpc.init(CONF)

        if self.USES_DB:
            global _DB_CACHE
            if not _DB_CACHE:
                _DB_CACHE = Database(session, migration,
                        sql_connection=CONF.database.connection,
                        sqlite_db=CONF.database.sqlite_db,
                        sqlite_clean_db=CONF.sqlite_clean_db)

            self.useFixture(_DB_CACHE)

        # NOTE(danms): Make sure to reset us back to non-remote objects
        # for each test to avoid interactions. Also, backup the object
        # registry.
        objects_base.NovaObject.indirection_api = None
        self._base_test_obj_backup = copy.copy(
            objects_base.NovaObject._obj_classes)
        self.addCleanup(self._restore_obj_registry)

        # NOTE(mnaser): All calls to utils.is_neutron() are cached in
        # nova.utils._IS_NEUTRON.  We set it to None to avoid any
        # caching of that value.
        utils._IS_NEUTRON = None

        mox_fixture = self.useFixture(moxstubout.MoxStubout())
        self.mox = mox_fixture.mox
        self.stubs = mox_fixture.stubs
        self.addCleanup(self._clear_attrs)
        self.useFixture(fixtures.EnvironmentVariable('http_proxy'))
        self.policy = self.useFixture(policy_fixture.PolicyFixture())
        CONF.set_override('fatal_exception_format_errors', True)
        CONF.set_override('enabled', True, 'osapi_v3')
        CONF.set_override('force_dhcp_release', False)
        CONF.set_override('periodic_enable', False)

    def _restore_obj_registry(self):
        objects_base.NovaObject._obj_classes = self._base_test_obj_backup

    def _clear_attrs(self):
        # Delete attributes that don't start with _ so they don't pin
        # memory around unnecessarily for the duration of the test
        # suite
        for key in [k for k in self.__dict__.keys() if k[0] != '_']:
            del self.__dict__[key]

    def flags(self, **kw):
        """Override flag variables for a test."""
        group = kw.pop('group', None)
        for k, v in kw.iteritems():
            CONF.set_override(k, v, group)

    def start_service(self, name, host=None, **kwargs):
        svc = self.useFixture(ServiceFixture(name, host, **kwargs))
        return svc.service

    def assertPublicAPISignatures(self, baseinst, inst):
        def get_public_apis(inst):
            methods = {}
            for (name, value) in inspect.getmembers(inst, inspect.ismethod):
                if name.startswith("_"):
                    continue
                methods[name] = value
            return methods

        baseclass = baseinst.__class__.__name__
        basemethods = get_public_apis(baseinst)
        implmethods = get_public_apis(inst)

        extranames = []
        for name in sorted(implmethods.keys()):
            if name not in basemethods:
                extranames.append(name)

        self.assertEqual([], extranames,
                         "public APIs not listed in base class %s" %
                         baseclass)

        for name in sorted(implmethods.keys()):
            baseargs = inspect.getargspec(basemethods[name])
            implargs = inspect.getargspec(implmethods[name])

            self.assertEqual(baseargs, implargs,
                             "%s args don't match base class %s" %
                             (name, baseclass))


class APICoverage(object):

    cover_api = None

    def test_api_methods(self):
        self.assertTrue(self.cover_api is not None)
        api_methods = [x for x in dir(self.cover_api)
                       if not x.startswith('_')]
        test_methods = [x[5:] for x in dir(self)
                        if x.startswith('test_')]
        self.assertThat(
            test_methods,
            testtools.matchers.ContainsAll(api_methods))


class TimeOverride(fixtures.Fixture):
    """Fixture to start and remove time override."""

    def setUp(self):
        super(TimeOverride, self).setUp()
        timeutils.set_time_override()
        self.addCleanup(timeutils.clear_time_override)


class NoDBTestCase(TestCase):
    """`NoDBTestCase` differs from TestCase in that DB access is not supported.
    This makes tests run significantly faster. If possible, all new tests
    should derive from this class.
    """
    USES_DB = False


class BaseHookTestCase(NoDBTestCase):
    def assert_has_hook(self, expected_name, func):
        self.assertTrue(hasattr(func, '__hook_name__'))
        self.assertEqual(expected_name, func.__hook_name__)