# vim: tabstop=4 shiftwidth=4 softtabstop=4

# 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.
#
# @author: Bob Melander, Cisco Systems, Inc.

from oslo.config import cfg

from neutron.api.rpc.agentnotifiers import l3_rpc_agent_api
from neutron.common import constants as q_const
from neutron.common import rpc as q_rpc
from neutron.common import topics
from neutron.db import api as qdbapi
from neutron.db import db_base_plugin_v2
from neutron.db import extraroute_db
from neutron.db import l3_agentschedulers_db
from neutron.db import l3_gwmode_db
from neutron.db import l3_rpc_base
from neutron.db import model_base
from neutron.openstack.common import importutils
from neutron.openstack.common import rpc
from neutron.plugins.common import constants


class L3RouterPluginRpcCallbacks(l3_rpc_base.L3RpcCallbackMixin):

    # Set RPC API version to 1.0 by default.
    RPC_API_VERSION = '1.0'

    def create_rpc_dispatcher(self):
        """Get the rpc dispatcher for this manager.

        If a manager would like to set an rpc API version, or support more than
        one class as the target of rpc messages, override this method.
        """
        return q_rpc.PluginRpcDispatcher([self])


class L3RouterPlugin(db_base_plugin_v2.CommonDbMixin,
                     extraroute_db.ExtraRoute_db_mixin,
                     l3_gwmode_db.L3_NAT_db_mixin,
                     l3_agentschedulers_db.L3AgentSchedulerDbMixin):

    """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 and extraroute_db.ExtraRoute_db_mixin.
    """
    supported_extension_aliases = ["router", "ext-gw-mode",
                                   "extraroute", "l3_agent_scheduler"]

    def __init__(self):
        qdbapi.register_models(base=model_base.BASEV2)
        self.setup_rpc()
        self.router_scheduler = importutils.import_object(
            cfg.CONF.router_scheduler_driver)

    def setup_rpc(self):
        # RPC support
        self.topic = topics.L3PLUGIN
        self.conn = rpc.create_connection(new=True)
        self.agent_notifiers.update(
            {q_const.AGENT_TYPE_L3: l3_rpc_agent_api.L3AgentNotify})
        self.callbacks = L3RouterPluginRpcCallbacks()
        self.dispatcher = self.callbacks.create_rpc_dispatcher()
        self.conn.create_consumer(self.topic, self.dispatcher,
                                  fanout=False)
        self.conn.consume_in_thread()

    def get_plugin_type(self):
        return constants.L3_ROUTER_NAT

    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.")