# Copyright 2011 Justin Santa Barbara
# 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.

"""
Provides common functionality for integrated unit tests
"""

import random
import string
import uuid

from oslo_config import cfg
from oslo_log import log as logging

from nova import crypto
import nova.image.glance
from nova import service
from nova import test
from nova.tests import fixtures as nova_fixtures
from nova.tests.functional.api import client
from nova.tests.unit import cast_as_call
from nova.tests.unit import fake_crypto
import nova.tests.unit.image.fake


CONF = cfg.CONF
LOG = logging.getLogger(__name__)
CONF.import_opt('manager', 'nova.cells.opts', group='cells')


def generate_random_alphanumeric(length):
    """Creates a random alphanumeric string of specified length."""
    return ''.join(random.choice(string.ascii_uppercase + string.digits)
                   for _x in range(length))


def generate_random_numeric(length):
    """Creates a random numeric string of specified length."""
    return ''.join(random.choice(string.digits)
                   for _x in range(length))


def generate_new_element(items, prefix, numeric=False):
    """Creates a random string with prefix, that is not in 'items' list."""
    while True:
        if numeric:
            candidate = prefix + generate_random_numeric(8)
        else:
            candidate = prefix + generate_random_alphanumeric(8)
        if candidate not in items:
            return candidate
        LOG.debug("Random collision on %s" % candidate)


class _IntegratedTestBase(test.TestCase):
    REQUIRES_LOCKING = True

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

        f = self._get_flags()
        self.flags(**f)
        self.flags(verbose=True)

        nova.tests.unit.image.fake.stub_out_image_service(self.stubs)
        self.stubs.Set(crypto, 'ensure_ca_filesystem',
                       fake_crypto.ensure_ca_filesystem)
        self.stubs.Set(crypto, 'fetch_ca',
                       fake_crypto.fetch_ca)
        self.stubs.Set(crypto, 'generate_x509_cert',
                       fake_crypto.generate_x509_cert)
        self.flags(scheduler_driver='nova.scheduler.'
                    'chance.ChanceScheduler')
        self._setup_services()

        self.api_fixture = self.useFixture(
            nova_fixtures.OSAPIFixture(self._api_version))
        self.api = self.api_fixture.api

        self.useFixture(cast_as_call.CastAsCall(self.stubs))

        self.addCleanup(nova.tests.unit.image.fake.FakeImageService_reset)

    def _setup_services(self):
        self.conductor = self.start_service('conductor',
                                            manager=CONF.conductor.manager)
        self.compute = self.start_service('compute')
        self.cert = self.start_service('cert')
        self.consoleauth = self.start_service('consoleauth')

        self.network = self.start_service('network')
        self.scheduler = self.start_service('scheduler')
        self.cells = self.start_service('cells', manager=CONF.cells.manager)

    def _get_test_client(self):
        return client.TestOpenStackClient('fake', 'fake', self.auth_url)

    def _start_api_service(self):
        self.osapi = service.WSGIService("osapi_compute")
        self.osapi.start()
        self.auth_url = 'http://%(host)s:%(port)s/%(api_version)s' % ({
            'host': self.osapi.host, 'port': self.osapi.port,
            'api_version': self._api_version})

    def _get_flags(self):
        """Allow subclass to modify global config before we start services."""
        # NOTE(sdague): _get_flags is used by about 13 tests that
        # subclass this mostly to modify the extensions list. We
        # should instead make that declarative in the future, at which
        # point we can get rid of this.
        return {}

    def get_unused_server_name(self):
        servers = self.api.get_servers()
        server_names = [server['name'] for server in servers]
        return generate_new_element(server_names, 'server')

    def get_invalid_image(self):
        return str(uuid.uuid4())

    def _build_minimal_create_server_request(self):
        server = {}

        image = self.api.get_images()[0]
        LOG.debug("Image: %s" % image)

        if self._image_ref_parameter in image:
            image_href = image[self._image_ref_parameter]
        else:
            image_href = image['id']
            image_href = 'http://fake.server/%s' % image_href

        # We now have a valid imageId
        server[self._image_ref_parameter] = image_href

        # Set a valid flavorId
        flavor = self.api.get_flavors()[0]
        LOG.debug("Using flavor: %s" % flavor)
        server[self._flavor_ref_parameter] = ('http://fake.server/%s'
                                              % flavor['id'])

        # Set a valid server name
        server_name = self.get_unused_server_name()
        server['name'] = server_name
        return server
