# Copyright (c) 2013 OpenStack Foundation.
# 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.

from neutron_lib.agent import topics
from neutron_lib.api.definitions import dvr
from neutron_lib.api.definitions import extraroute
from neutron_lib.api.definitions import extraroute_atomic
from neutron_lib.api.definitions import fip_port_details
from neutron_lib.api.definitions import floatingip_pools
from neutron_lib.api.definitions import l3 as l3_apidef
from neutron_lib.api.definitions import l3_ext_gw_mode
from neutron_lib.api.definitions import l3_ext_ha_mode
from neutron_lib.api.definitions import l3_flavors
from neutron_lib.api.definitions import l3_port_ip_change_not_allowed
from neutron_lib.api.definitions import qos_gateway_ip
from neutron_lib.api.definitions import router_availability_zone
from neutron_lib import constants as n_const
from neutron_lib.db import resource_extend
from neutron_lib.plugins import constants as plugin_constants
from neutron_lib import rpc as n_rpc
from neutron_lib.services import base as service_base
from oslo_config import cfg
from oslo_log import helpers as log_helpers
from oslo_log import log as logging
from oslo_utils import importutils

from neutron.api.rpc.agentnotifiers import l3_rpc_agent_api
from neutron.api.rpc.handlers import l3_rpc
from neutron.db import dns_db
from neutron.db import extraroute_db
from neutron.db import l3_dvr_ha_scheduler_db
from neutron.db import l3_dvrscheduler_db
from neutron.db import l3_fip_pools_db
from neutron.db import l3_fip_port_details
from neutron.db import l3_fip_qos
from neutron.db import l3_gateway_ip_qos
from neutron.db import l3_hamode_db
from neutron.db import l3_hascheduler_db
from neutron.db.models import l3 as l3_models
from neutron.extensions import _admin_state_down_before_update_lib
from neutron.quota import resource_registry
from neutron import service
from neutron.services.l3_router.service_providers import driver_controller


LOG = logging.getLogger(__name__)


def disable_dvr_extension_by_config(aliases):
    if not cfg.CONF.enable_dvr:
        LOG.info('Disabled DVR extension.')
        if 'dvr' in aliases:
            aliases.remove('dvr')


def disable_l3_qos_extension_by_plugins(ext, aliases):
    qos_class = 'neutron.services.qos.qos_plugin.QoSPlugin'
    if all(p not in cfg.CONF.service_plugins for p in ['qos', qos_class]):
        if ext in aliases:
            aliases.remove(ext)


@resource_extend.has_resource_extenders
class L3RouterPlugin(service_base.ServicePluginBase,
                     extraroute_db.ExtraRoute_db_mixin,
                     l3_hamode_db.L3_HA_NAT_db_mixin,
                     l3_gateway_ip_qos.L3_gw_ip_qos_db_mixin,
                     l3_dvr_ha_scheduler_db.L3_DVR_HA_scheduler_db_mixin,
                     dns_db.DNSDbMixin,
                     l3_fip_qos.FloatingQoSDbMixin,
                     l3_fip_port_details.Fip_port_details_db_mixin,
                     l3_fip_pools_db.FloatingIPPoolsMixin):

    """Implementation of the Neutron L3 Router Service Plugin.

    This class implements a L3 service plugin that provides
    router and floatingip resources and manages associated
    request/response.
    All DB related work is implemented in classes
    l3_db.L3_NAT_db_mixin, l3_hamode_db.L3_HA_NAT_db_mixin,
    l3_dvr_db.L3_NAT_with_dvr_db_mixin, and extraroute_db.ExtraRoute_db_mixin.
    """
    _supported_extension_aliases = [dvr.ALIAS, l3_apidef.ALIAS,
                                    l3_ext_gw_mode.ALIAS,
                                    extraroute.ALIAS,
                                    extraroute_atomic.ALIAS,
                                    n_const.L3_AGENT_SCHEDULER_EXT_ALIAS,
                                    l3_ext_ha_mode.ALIAS,
                                    router_availability_zone.ALIAS,
                                    l3_flavors.ALIAS, "qos-fip",
                                    fip_port_details.ALIAS,
                                    floatingip_pools.ALIAS,
                                    qos_gateway_ip.ALIAS,
                                    l3_port_ip_change_not_allowed.ALIAS,
                                    _admin_state_down_before_update_lib.ALIAS]

    __native_pagination_support = True
    __native_sorting_support = True
    __filter_validation_support = True

    IP_UPDATE_NOT_ALLOWED_LIST = [
        n_const.DEVICE_OWNER_ROUTER_INTF,
        n_const.DEVICE_OWNER_ROUTER_HA_INTF,
        n_const.DEVICE_OWNER_HA_REPLICATED_INT,
        n_const.DEVICE_OWNER_ROUTER_SNAT,
        n_const.DEVICE_OWNER_DVR_INTERFACE]

    @resource_registry.tracked_resources(router=l3_models.Router,
                                         floatingip=l3_models.FloatingIP)
    def __init__(self):
        self.router_scheduler = importutils.import_object(
            cfg.CONF.router_scheduler_driver)
        self.add_periodic_l3_agent_status_check()
        super(L3RouterPlugin, self).__init__()
        if 'dvr' in self.supported_extension_aliases:
            l3_dvrscheduler_db.subscribe()
        if 'l3-ha' in self.supported_extension_aliases:
            l3_hascheduler_db.subscribe()
        self.agent_notifiers.update(
            {n_const.AGENT_TYPE_L3: l3_rpc_agent_api.L3AgentNotifyAPI()})

        rpc_worker = service.RpcWorker([self], worker_process_count=0)

        self.add_worker(rpc_worker)
        self.l3_driver_controller = driver_controller.DriverController(self)

    @property
    def supported_extension_aliases(self):
        if not hasattr(self, '_aliases'):
            aliases = self._supported_extension_aliases[:]
            disable_dvr_extension_by_config(aliases)
            disable_l3_qos_extension_by_plugins('qos-fip', aliases)
            disable_l3_qos_extension_by_plugins('qos-gateway-ip', aliases)
            self._aliases = aliases
        return self._aliases

    @log_helpers.log_method_call
    def start_rpc_listeners(self):
        # RPC support
        self.topic = topics.L3PLUGIN
        self.conn = n_rpc.Connection()
        self.endpoints = [l3_rpc.L3RpcCallback()]
        self.conn.create_consumer(self.topic, self.endpoints,
                                  fanout=False)
        return self.conn.consume_in_threads()

    @classmethod
    def get_plugin_type(cls):
        return plugin_constants.L3

    def get_plugin_description(self):
        """returns string description of the plugin."""
        return ("L3 Router Service Plugin for basic L3 forwarding"
                " between (L2) Neutron networks and access to external"
                " networks via a NAT gateway.")

    def router_supports_scheduling(self, context, router_id):
        return self.l3_driver_controller.uses_scheduler(context, router_id)

    def create_floatingip(self, context, floatingip):
        """Create floating IP.

        :param context: Neutron request context
        :param floatingip: data for the floating IP being created
        :returns: A floating IP object on success

        As the l3 router plugin asynchronously creates floating IPs
        leveraging the l3 agent, the initial status for the floating
        IP object will be DOWN.
        """
        return super(L3RouterPlugin, self).create_floatingip(
            context, floatingip,
            initial_status=n_const.FLOATINGIP_STATUS_DOWN)

    @staticmethod
    @resource_extend.extends([l3_apidef.ROUTERS])
    def add_flavor_id(router_res, router_db):
        router_res['flavor_id'] = router_db['flavor_id']
