#    Copyright 2012 IBM Corp.
#
#    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.

"""Handles all requests to the conductor service."""

from oslo.config import cfg
from oslo import messaging

from nova import baserpc
from nova.conductor import manager
from nova.conductor import rpcapi
from nova.i18n import _
from nova.openstack.common import log as logging
from nova import utils

conductor_opts = [
    cfg.BoolOpt('use_local',
                default=False,
                help='Perform nova-conductor operations locally'),
    cfg.StrOpt('topic',
               default='conductor',
               help='The topic on which conductor nodes listen'),
    cfg.StrOpt('manager',
               default='nova.conductor.manager.ConductorManager',
               help='Full class name for the Manager for conductor'),
    cfg.IntOpt('workers',
               help='Number of workers for OpenStack Conductor service. '
                    'The default will be the number of CPUs available.')
]
conductor_group = cfg.OptGroup(name='conductor',
                               title='Conductor Options')
CONF = cfg.CONF
CONF.register_group(conductor_group)
CONF.register_opts(conductor_opts, conductor_group)

LOG = logging.getLogger(__name__)


class LocalAPI(object):
    """A local version of the conductor API that does database updates
    locally instead of via RPC.
    """

    def __init__(self):
        # TODO(danms): This needs to be something more generic for
        # other/future users of this sort of functionality.
        self._manager = utils.ExceptionHelper(manager.ConductorManager())

    def wait_until_ready(self, context, *args, **kwargs):
        # nothing to wait for in the local case.
        pass

    def instance_update(self, context, instance_uuid, **updates):
        """Perform an instance update in the database."""
        return self._manager.instance_update(context, instance_uuid,
                                             updates, 'compute')

    def instance_get_all_by_host(self, context, host, columns_to_join=None):
        return self._manager.instance_get_all_by_host(
            context, host, None, columns_to_join=columns_to_join)

    def instance_get_all_by_host_and_node(self, context, host, node):
        return self._manager.instance_get_all_by_host(context, host, node,
                None)

    def migration_get_in_progress_by_host_and_node(self, context, host, node):
        return self._manager.migration_get_in_progress_by_host_and_node(
            context, host, node)

    def aggregate_metadata_get_by_host(self, context, host,
                                       key='availability_zone'):
        return self._manager.aggregate_metadata_get_by_host(context,
                                                            host,
                                                            key)

    def bw_usage_get(self, context, uuid, start_period, mac):
        return self._manager.bw_usage_update(context, uuid, mac, start_period,
                None, None, None, None, None, False)

    def bw_usage_update(self, context, uuid, mac, start_period,
                        bw_in, bw_out, last_ctr_in, last_ctr_out,
                        last_refreshed=None, update_cells=True):
        return self._manager.bw_usage_update(context, uuid, mac, start_period,
                                             bw_in, bw_out,
                                             last_ctr_in, last_ctr_out,
                                             last_refreshed,
                                             update_cells=update_cells)

    def provider_fw_rule_get_all(self, context):
        return self._manager.provider_fw_rule_get_all(context)

    def block_device_mapping_create(self, context, values):
        return self._manager.block_device_mapping_update_or_create(context,
                                                                   values,
                                                                   create=True)

    def block_device_mapping_update(self, context, bdm_id, values):
        values = dict(values)
        values['id'] = bdm_id
        return self._manager.block_device_mapping_update_or_create(
            context, values, create=False)

    def block_device_mapping_update_or_create(self, context, values):
        return self._manager.block_device_mapping_update_or_create(context,
                                                                   values,
                                                                   create=None)

    def block_device_mapping_get_all_by_instance(self, context, instance,
                                                 legacy=True):
        return self._manager.block_device_mapping_get_all_by_instance(
            context, instance, legacy)

    def vol_get_usage_by_time(self, context, start_time):
        return self._manager.vol_get_usage_by_time(context, start_time)

    def vol_usage_update(self, context, vol_id, rd_req, rd_bytes, wr_req,
                         wr_bytes, instance, last_refreshed=None,
                         update_totals=False):
        return self._manager.vol_usage_update(context, vol_id,
                                              rd_req, rd_bytes,
                                              wr_req, wr_bytes,
                                              instance, last_refreshed,
                                              update_totals)

    def service_get_all(self, context):
        return self._manager.service_get_all_by(context, host=None, topic=None,
                binary=None)

    def service_get_all_by_topic(self, context, topic):
        return self._manager.service_get_all_by(context, topic=topic,
                host=None, binary=None)

    def service_get_all_by_host(self, context, host):
        return self._manager.service_get_all_by(context, host=host, topic=None,
                binary=None)

    def service_get_by_host_and_topic(self, context, host, topic):
        return self._manager.service_get_all_by(context, topic, host,
                binary=None)

    def service_get_by_compute_host(self, context, host):
        result = self._manager.service_get_all_by(context, 'compute', host,
                binary=None)
        # FIXME(comstud): A major revision bump to 2.0 should return a
        # single entry, so we should just return 'result' at that point.
        return result[0]

    def service_get_by_args(self, context, host, binary):
        return self._manager.service_get_all_by(context, host=host,
                                                binary=binary, topic=None)

    def service_create(self, context, values):
        return self._manager.service_create(context, values)

    def service_destroy(self, context, service_id):
        return self._manager.service_destroy(context, service_id)

    def compute_node_create(self, context, values):
        return self._manager.compute_node_create(context, values)

    def compute_node_update(self, context, node, values, prune_stats=False):
        # NOTE(belliott) ignore prune_stats param, it's no longer relevant
        return self._manager.compute_node_update(context, node, values)

    def compute_node_delete(self, context, node):
        return self._manager.compute_node_delete(context, node)

    def service_update(self, context, service, values):
        return self._manager.service_update(context, service, values)

    def task_log_get(self, context, task_name, begin, end, host, state=None):
        return self._manager.task_log_get(context, task_name, begin, end,
                                          host, state)

    def task_log_begin_task(self, context, task_name, begin, end, host,
                            task_items=None, message=None):
        return self._manager.task_log_begin_task(context, task_name,
                                                 begin, end, host,
                                                 task_items, message)

    def task_log_end_task(self, context, task_name, begin, end, host,
                          errors, message=None):
        return self._manager.task_log_end_task(context, task_name,
                                               begin, end, host,
                                               errors, message)

    def notify_usage_exists(self, context, instance, current_period=False,
                            ignore_missing_network_data=True,
                            system_metadata=None, extra_usage_info=None):
        return self._manager.notify_usage_exists(
            context, instance, current_period, ignore_missing_network_data,
            system_metadata, extra_usage_info)

    def security_groups_trigger_handler(self, context, event, *args):
        return self._manager.security_groups_trigger_handler(context,
                                                             event, args)

    def security_groups_trigger_members_refresh(self, context, group_ids):
        return self._manager.security_groups_trigger_members_refresh(context,
                                                                     group_ids)

    def get_ec2_ids(self, context, instance):
        return self._manager.get_ec2_ids(context, instance)

    def object_backport(self, context, objinst, target_version):
        return self._manager.object_backport(context, objinst, target_version)


class LocalComputeTaskAPI(object):
    def __init__(self):
        # TODO(danms): This needs to be something more generic for
        # other/future users of this sort of functionality.
        self._manager = utils.ExceptionHelper(
                manager.ComputeTaskManager())

    def resize_instance(self, context, instance, extra_instance_updates,
                        scheduler_hint, flavor, reservations):
        # NOTE(comstud): 'extra_instance_updates' is not used here but is
        # needed for compatibility with the cells_rpcapi version of this
        # method.
        self._manager.migrate_server(
            context, instance, scheduler_hint, False, False, flavor,
            None, None, reservations)

    def live_migrate_instance(self, context, instance, host_name,
                              block_migration, disk_over_commit):
        scheduler_hint = {'host': host_name}
        self._manager.migrate_server(
            context, instance, scheduler_hint, True, False, None,
            block_migration, disk_over_commit, None)

    def build_instances(self, context, instances, image,
            filter_properties, admin_password, injected_files,
            requested_networks, security_groups, block_device_mapping,
            legacy_bdm=True):
        utils.spawn_n(self._manager.build_instances, context,
                instances=instances, image=image,
                filter_properties=filter_properties,
                admin_password=admin_password, injected_files=injected_files,
                requested_networks=requested_networks,
                security_groups=security_groups,
                block_device_mapping=block_device_mapping,
                legacy_bdm=legacy_bdm)

    def unshelve_instance(self, context, instance):
        utils.spawn_n(self._manager.unshelve_instance, context,
                instance=instance)

    def rebuild_instance(self, context, instance, orig_image_ref, image_ref,
                         injected_files, new_pass, orig_sys_metadata,
                         bdms, recreate=False, on_shared_storage=False,
                         preserve_ephemeral=False, host=None, kwargs=None):
        # kwargs unused but required for cell compatibility.
        utils.spawn_n(self._manager.rebuild_instance, context,
                instance=instance,
                new_pass=new_pass,
                injected_files=injected_files,
                image_ref=image_ref,
                orig_image_ref=orig_image_ref,
                orig_sys_metadata=orig_sys_metadata,
                bdms=bdms,
                recreate=recreate,
                on_shared_storage=on_shared_storage,
                host=host,
                preserve_ephemeral=preserve_ephemeral)


class API(LocalAPI):
    """Conductor API that does updates via RPC to the ConductorManager."""

    def __init__(self):
        self._manager = rpcapi.ConductorAPI()
        self.base_rpcapi = baserpc.BaseAPI(topic=CONF.conductor.topic)

    def wait_until_ready(self, context, early_timeout=10, early_attempts=10):
        '''Wait until a conductor service is up and running.

        This method calls the remote ping() method on the conductor topic until
        it gets a response.  It starts with a shorter timeout in the loop
        (early_timeout) up to early_attempts number of tries.  It then drops
        back to the globally configured timeout for rpc calls for each retry.
        '''
        attempt = 0
        timeout = early_timeout
        # if we show the timeout message, make sure we show a similar
        # message saying that everything is now working to avoid
        # confusion
        has_timedout = False
        while True:
            # NOTE(danms): Try ten times with a short timeout, and then punt
            # to the configured RPC timeout after that
            if attempt == early_attempts:
                timeout = None
            attempt += 1

            # NOTE(russellb): This is running during service startup. If we
            # allow an exception to be raised, the service will shut down.
            # This may fail the first time around if nova-conductor wasn't
            # running when this service started.
            try:
                self.base_rpcapi.ping(context, '1.21 GigaWatts',
                                      timeout=timeout)
                if has_timedout:
                    LOG.info(_('nova-conductor connection '
                               'established successfully'))
                break
            except messaging.MessagingTimeout:
                has_timedout = True
                LOG.warning(_('Timed out waiting for nova-conductor.  '
                              'Is it running? Or did this service start '
                              'before nova-conductor?  '
                              'Reattempting establishment of '
                              'nova-conductor connection...'))

    def instance_update(self, context, instance_uuid, **updates):
        """Perform an instance update in the database."""
        return self._manager.instance_update(context, instance_uuid,
                                             updates, 'conductor')


class ComputeTaskAPI(object):
    """ComputeTask API that queues up compute tasks for nova-conductor."""

    def __init__(self):
        self.conductor_compute_rpcapi = rpcapi.ComputeTaskAPI()

    def resize_instance(self, context, instance, extra_instance_updates,
                        scheduler_hint, flavor, reservations):
        # NOTE(comstud): 'extra_instance_updates' is not used here but is
        # needed for compatibility with the cells_rpcapi version of this
        # method.
        self.conductor_compute_rpcapi.migrate_server(
            context, instance, scheduler_hint, False, False, flavor,
            None, None, reservations)

    def live_migrate_instance(self, context, instance, host_name,
                              block_migration, disk_over_commit):
        scheduler_hint = {'host': host_name}
        self.conductor_compute_rpcapi.migrate_server(
            context, instance, scheduler_hint, True, False, None,
            block_migration, disk_over_commit, None)

    def build_instances(self, context, instances, image, filter_properties,
            admin_password, injected_files, requested_networks,
            security_groups, block_device_mapping, legacy_bdm=True):
        self.conductor_compute_rpcapi.build_instances(context,
                instances=instances, image=image,
                filter_properties=filter_properties,
                admin_password=admin_password, injected_files=injected_files,
                requested_networks=requested_networks,
                security_groups=security_groups,
                block_device_mapping=block_device_mapping,
                legacy_bdm=legacy_bdm)

    def unshelve_instance(self, context, instance):
        self.conductor_compute_rpcapi.unshelve_instance(context,
                instance=instance)

    def rebuild_instance(self, context, instance, orig_image_ref, image_ref,
                         injected_files, new_pass, orig_sys_metadata,
                         bdms, recreate=False, on_shared_storage=False,
                         preserve_ephemeral=False, host=None, kwargs=None):
        # kwargs unused but required for cell compatibility
        self.conductor_compute_rpcapi.rebuild_instance(context,
                instance=instance,
                new_pass=new_pass,
                injected_files=injected_files,
                image_ref=image_ref,
                orig_image_ref=orig_image_ref,
                orig_sys_metadata=orig_sys_metadata,
                bdms=bdms,
                recreate=recreate,
                on_shared_storage=on_shared_storage,
                preserve_ephemeral=preserve_ephemeral,
                host=host)
