# Copyright (c) 2010 Cloud.com, Inc
# Copyright (c) 2012 Cloudbase Solutions Srl
#
#    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.

"""
A Hyper-V Nova Compute driver.
"""

import functools
import platform
import sys

from os_win import exceptions as os_win_exc
from os_win import utilsfactory
from oslo_log import log as logging
import six

from nova import exception
from nova.i18n import _, _LE
from nova.virt import driver
from nova.virt.hyperv import eventhandler
from nova.virt.hyperv import hostops
from nova.virt.hyperv import imagecache
from nova.virt.hyperv import livemigrationops
from nova.virt.hyperv import migrationops
from nova.virt.hyperv import rdpconsoleops
from nova.virt.hyperv import serialconsoleops
from nova.virt.hyperv import snapshotops
from nova.virt.hyperv import vmops
from nova.virt.hyperv import volumeops

LOG = logging.getLogger(__name__)


def convert_exceptions(function, exception_map):
    expected_exceptions = tuple(exception_map.keys())

    @functools.wraps(function)
    def wrapper(*args, **kwargs):
        try:
            return function(*args, **kwargs)
        except expected_exceptions as ex:
            raised_exception = exception_map.get(type(ex))
            if not raised_exception:
                # exception might be a subclass of an expected exception.
                for expected in expected_exceptions:
                    if isinstance(ex, expected):
                        raised_exception = exception_map[expected]
                        break

            exc_info = sys.exc_info()
            # NOTE(claudiub): Python 3 raises the exception object given as
            # the second argument in six.reraise.
            # The original message will be maintained by passing the original
            # exception.
            exc = raised_exception(six.text_type(exc_info[1]))
            six.reraise(raised_exception, exc, exc_info[2])
    return wrapper


def decorate_all_methods(decorator, *args, **kwargs):
    def decorate(cls):
        for attr in cls.__dict__:
            class_member = getattr(cls, attr)
            if callable(class_member):
                setattr(cls, attr, decorator(class_member, *args, **kwargs))
        return cls

    return decorate


exception_conversion_map = {
    # expected_exception: converted_exception
    os_win_exc.OSWinException: exception.NovaException,
    os_win_exc.HyperVVMNotFoundException: exception.InstanceNotFound,
}

# NOTE(claudiub): the purpose of the decorator below is to prevent any
# os_win exceptions (subclasses of OSWinException) to leak outside of the
# HyperVDriver.


@decorate_all_methods(convert_exceptions, exception_conversion_map)
class HyperVDriver(driver.ComputeDriver):
    capabilities = {
        "has_imagecache": True,
        "supports_recreate": False,
        "supports_migrate_to_same_host": True,
        "supports_attach_interface": True,
        "supports_device_tagging": True,
    }

    def __init__(self, virtapi):
        # check if the current version of Windows is supported before any
        # further driver initialisation.
        self._check_minimum_windows_version()

        super(HyperVDriver, self).__init__(virtapi)

        self._hostops = hostops.HostOps()
        self._volumeops = volumeops.VolumeOps()
        self._vmops = vmops.VMOps()
        self._snapshotops = snapshotops.SnapshotOps()
        self._livemigrationops = livemigrationops.LiveMigrationOps()
        self._migrationops = migrationops.MigrationOps()
        self._rdpconsoleops = rdpconsoleops.RDPConsoleOps()
        self._serialconsoleops = serialconsoleops.SerialConsoleOps()
        self._imagecache = imagecache.ImageCache()

    def _check_minimum_windows_version(self):
        if not utilsfactory.get_hostutils().check_min_windows_version(6, 2):
            # the version is of Windows is older than Windows Server 2012 R2.
            # Log an error, letting users know that this version is not
            # supported any longer.
            LOG.error(_LE('You are running nova-compute on an unsupported '
                          'version of Windows (older than Windows / Hyper-V '
                          'Server 2012). The support for this version of '
                          'Windows has been removed in Mitaka.'))
            raise exception.HypervisorTooOld(version='6.2')

    @property
    def need_legacy_block_device_info(self):
        return False

    def init_host(self, host):
        self._serialconsoleops.start_console_handlers()
        event_handler = eventhandler.InstanceEventHandler(
            state_change_callback=self.emit_event)
        event_handler.start_listener()

    def list_instance_uuids(self):
        return self._vmops.list_instance_uuids()

    def list_instances(self):
        return self._vmops.list_instances()

    def estimate_instance_overhead(self, instance_info):
        return self._vmops.estimate_instance_overhead(instance_info)

    def spawn(self, context, instance, image_meta, injected_files,
              admin_password, network_info=None, block_device_info=None):
        self._vmops.spawn(context, instance, image_meta, injected_files,
                          admin_password, network_info, block_device_info)

    def reboot(self, context, instance, network_info, reboot_type,
               block_device_info=None, bad_volumes_callback=None):
        self._vmops.reboot(instance, network_info, reboot_type)

    def destroy(self, context, instance, network_info, block_device_info=None,
                destroy_disks=True, migrate_data=None):
        self._vmops.destroy(instance, network_info, block_device_info,
                            destroy_disks)

    def cleanup(self, context, instance, network_info, block_device_info=None,
                destroy_disks=True, migrate_data=None, destroy_vifs=True):
        """Cleanup after instance being destroyed by Hypervisor."""
        pass

    def get_info(self, instance):
        return self._vmops.get_info(instance)

    def attach_volume(self, context, connection_info, instance, mountpoint,
                      disk_bus=None, device_type=None, encryption=None):
        return self._volumeops.attach_volume(connection_info,
                                             instance.name)

    def detach_volume(self, connection_info, instance, mountpoint,
                      encryption=None):
        return self._volumeops.detach_volume(connection_info,
                                             instance.name)

    def get_volume_connector(self, instance):
        return self._volumeops.get_volume_connector(instance)

    def get_available_resource(self, nodename):
        return self._hostops.get_available_resource()

    def get_available_nodes(self, refresh=False):
        return [platform.node()]

    def host_power_action(self, action):
        return self._hostops.host_power_action(action)

    def snapshot(self, context, instance, image_id, update_task_state):
        self._snapshotops.snapshot(context, instance, image_id,
                                   update_task_state)

    def pause(self, instance):
        self._vmops.pause(instance)

    def unpause(self, instance):
        self._vmops.unpause(instance)

    def suspend(self, context, instance):
        self._vmops.suspend(instance)

    def resume(self, context, instance, network_info, block_device_info=None):
        self._vmops.resume(instance)

    def power_off(self, instance, timeout=0, retry_interval=0):
        self._vmops.power_off(instance, timeout, retry_interval)

    def power_on(self, context, instance, network_info,
                 block_device_info=None):
        self._vmops.power_on(instance, block_device_info)

    def resume_state_on_host_boot(self, context, instance, network_info,
                                  block_device_info=None):
        """Resume guest state when a host is booted."""
        self._vmops.resume_state_on_host_boot(context, instance, network_info,
                                              block_device_info)

    def live_migration(self, context, instance, dest, post_method,
                       recover_method, block_migration=False,
                       migrate_data=None):
        self._livemigrationops.live_migration(context, instance, dest,
                                              post_method, recover_method,
                                              block_migration, migrate_data)

    def rollback_live_migration_at_destination(self, context, instance,
                                               network_info,
                                               block_device_info,
                                               destroy_disks=True,
                                               migrate_data=None):
        self.destroy(context, instance, network_info, block_device_info,
                     destroy_disks=destroy_disks)

    def pre_live_migration(self, context, instance, block_device_info,
                           network_info, disk_info, migrate_data):
        self._livemigrationops.pre_live_migration(context, instance,
                                                  block_device_info,
                                                  network_info)
        return migrate_data

    def post_live_migration(self, context, instance, block_device_info,
                            migrate_data=None):
        self._livemigrationops.post_live_migration(context, instance,
                                                   block_device_info,
                                                   migrate_data)

    def post_live_migration_at_destination(self, context, instance,
                                           network_info,
                                           block_migration=False,
                                           block_device_info=None):
        self._livemigrationops.post_live_migration_at_destination(
            context,
            instance,
            network_info,
            block_migration)

    def check_can_live_migrate_destination(self, context, instance,
                                           src_compute_info, dst_compute_info,
                                           block_migration=False,
                                           disk_over_commit=False):
        return self._livemigrationops.check_can_live_migrate_destination(
            context, instance, src_compute_info, dst_compute_info,
            block_migration, disk_over_commit)

    def cleanup_live_migration_destination_check(self, context,
                                                 dest_check_data):
        self._livemigrationops.cleanup_live_migration_destination_check(
            context, dest_check_data)

    def check_can_live_migrate_source(self, context, instance,
                                      dest_check_data, block_device_info=None):
        return self._livemigrationops.check_can_live_migrate_source(
            context, instance, dest_check_data)

    def get_instance_disk_info(self, instance, block_device_info=None):
        pass

    def plug_vifs(self, instance, network_info):
        """Plug VIFs into networks."""
        msg = _("VIF plugging is not supported by the Hyper-V driver.")
        raise NotImplementedError(msg)

    def unplug_vifs(self, instance, network_info):
        """Unplug VIFs from networks."""
        msg = _("VIF unplugging is not supported by the Hyper-V driver.")
        raise NotImplementedError(msg)

    def ensure_filtering_rules_for_instance(self, instance, network_info):
        LOG.debug("ensure_filtering_rules_for_instance called",
                  instance=instance)

    def unfilter_instance(self, instance, network_info):
        LOG.debug("unfilter_instance called", instance=instance)

    def migrate_disk_and_power_off(self, context, instance, dest,
                                   flavor, network_info,
                                   block_device_info=None,
                                   timeout=0, retry_interval=0):
        return self._migrationops.migrate_disk_and_power_off(context,
                                                             instance, dest,
                                                             flavor,
                                                             network_info,
                                                             block_device_info,
                                                             timeout,
                                                             retry_interval)

    def confirm_migration(self, migration, instance, network_info):
        self._migrationops.confirm_migration(migration, instance, network_info)

    def finish_revert_migration(self, context, instance, network_info,
                                block_device_info=None, power_on=True):
        self._migrationops.finish_revert_migration(context, instance,
                                                   network_info,
                                                   block_device_info, power_on)

    def finish_migration(self, context, migration, instance, disk_info,
                         network_info, image_meta, resize_instance,
                         block_device_info=None, power_on=True):
        self._migrationops.finish_migration(context, migration, instance,
                                            disk_info, network_info,
                                            image_meta, resize_instance,
                                            block_device_info, power_on)

    def get_host_ip_addr(self):
        return self._hostops.get_host_ip_addr()

    def get_host_uptime(self):
        return self._hostops.get_host_uptime()

    def get_rdp_console(self, context, instance):
        return self._rdpconsoleops.get_rdp_console(instance)

    def get_serial_console(self, context, instance):
        return self._serialconsoleops.get_serial_console(instance.name)

    def get_console_output(self, context, instance):
        return self._serialconsoleops.get_console_output(instance.name)

    def manage_image_cache(self, context, all_instances):
        self._imagecache.update(context, all_instances)

    def attach_interface(self, instance, image_meta, vif):
        return self._vmops.attach_interface(instance, vif)

    def detach_interface(self, instance, vif):
        return self._vmops.detach_interface(instance, vif)

    def rescue(self, context, instance, network_info, image_meta,
               rescue_password):
        self._vmops.rescue_instance(context, instance, network_info,
                                    image_meta, rescue_password)

    def unrescue(self, instance, network_info):
        self._vmops.unrescue_instance(instance)
