#  Copyright (c) 2016 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 oslo_log import log as logging

from neutron.db import api as db_api
from neutron.db import common_db_mixin
from neutron.db import extraroute_db
from neutron.db import l3_agentschedulers_db
from neutron.db import l3_dvr_db
from neutron.db import l3_gwmode_db
from neutron.plugins.common import constants
from neutron_lib import constants as q_const

from networking_odl.common import config  # noqa
from networking_odl.common import constants as odl_const
from networking_odl.db import db
from networking_odl.journal import journal

LOG = logging.getLogger(__name__)


class OpenDaylightL3RouterPlugin(
    common_db_mixin.CommonDbMixin,
    extraroute_db.ExtraRoute_db_mixin,
    l3_dvr_db.L3_NAT_with_dvr_db_mixin,
    l3_gwmode_db.L3_NAT_db_mixin,
    l3_agentschedulers_db.L3AgentSchedulerDbMixin):

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

    This class implements a L3 service plugin that provides
    router and floatingip resources and manages associated
    request/response.
    """
    supported_extension_aliases = ["dvr", "router", "ext-gw-mode",
                                   "extraroute"]

    def __init__(self):
        super(OpenDaylightL3RouterPlugin, self).__init__()

        # TODO(rcurran): Continue investigation into how many journal threads
        # to run per neutron controller deployment.
        self.journal = journal.OpendaylightJournalThread()

    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 "
                "using OpenDaylight.")

    @journal.call_thread_on_end
    def create_router(self, context, router):
        session = db_api.get_session()
        with session.begin(subtransactions=True):
            router_dict = super(
                OpenDaylightL3RouterPlugin, self).create_router(context,
                                                                router)
            db.create_pending_row(context.session, odl_const.ODL_ROUTER,
                                  router_dict['id'], odl_const.ODL_CREATE,
                                  router_dict)
        return router_dict

    @journal.call_thread_on_end
    def update_router(self, context, router_id, router):
        session = db_api.get_session()
        with session.begin(subtransactions=True):
            router_dict = super(
                OpenDaylightL3RouterPlugin, self).update_router(
                    context, router_id, router)
            db.create_pending_row(context.session, odl_const.ODL_ROUTER,
                                  router_id, odl_const.ODL_UPDATE, router_dict)
        return router_dict

    @journal.call_thread_on_end
    def delete_router(self, context, router_id):
        session = db_api.get_session()
        router_dict = self.get_router(context, router_id)
        dependency_list = [router_dict['gw_port_id']]
        with session.begin(subtransactions=True):
            super(OpenDaylightL3RouterPlugin, self).delete_router(context,
                                                                  router_id)
            db.create_pending_row(context.session, odl_const.ODL_ROUTER,
                                  router_id, odl_const.ODL_DELETE,
                                  dependency_list)

    @journal.call_thread_on_end
    def create_floatingip(self, context, floatingip,
                          initial_status=q_const.FLOATINGIP_STATUS_ACTIVE):
        session = db_api.get_session()
        with session.begin(subtransactions=True):
            fip_dict = super(
                OpenDaylightL3RouterPlugin, self).create_floatingip(
                    context, floatingip, initial_status)
            db.create_pending_row(context.session, odl_const.ODL_FLOATINGIP,
                                  fip_dict['id'], odl_const.ODL_CREATE,
                                  fip_dict)
        return fip_dict

    @journal.call_thread_on_end
    def update_floatingip(self, context, floatingip_id, floatingip):
        session = db_api.get_session()
        with session.begin(subtransactions=True):
            fip_dict = super(
                OpenDaylightL3RouterPlugin, self).update_floatingip(
                    context, floatingip_id, floatingip)

            # Update status based on association
            if fip_dict.get('port_id') is None:
                fip_dict['status'] = q_const.FLOATINGIP_STATUS_DOWN
            else:
                fip_dict['status'] = q_const.FLOATINGIP_STATUS_ACTIVE
            self.update_floatingip_status(context, floatingip_id,
                                          fip_dict['status'])

            db.create_pending_row(context.session, odl_const.ODL_FLOATINGIP,
                                  floatingip_id, odl_const.ODL_UPDATE,
                                  fip_dict)
        return fip_dict

    @journal.call_thread_on_end
    def delete_floatingip(self, context, floatingip_id):
        session = db_api.get_session()
        floatingip_dict = self.get_floatingip(context, floatingip_id)
        dependency_list = [floatingip_dict['router_id']]
        dependency_list.append(floatingip_dict['floating_network_id'])
        with session.begin(subtransactions=True):
            super(OpenDaylightL3RouterPlugin, self).delete_floatingip(
                context, floatingip_id)
            db.create_pending_row(context.session, odl_const.ODL_FLOATINGIP,
                                  floatingip_id, odl_const.ODL_DELETE,
                                  dependency_list)

    @journal.call_thread_on_end
    def add_router_interface(self, context, router_id, interface_info):
        session = db_api.get_session()
        with session.begin(subtransactions=True):
            new_router = super(
                OpenDaylightL3RouterPlugin, self).add_router_interface(
                    context, router_id, interface_info)
            router_dict = self._generate_router_dict(router_id, interface_info,
                                                     new_router)
            db.create_pending_row(context.session, odl_const.ODL_ROUTER_INTF,
                                  odl_const.ODL_UUID_NOT_USED,
                                  odl_const.ODL_ADD, router_dict)
        return new_router

    @journal.call_thread_on_end
    def remove_router_interface(self, context, router_id, interface_info):
        session = db_api.get_session()
        with session.begin(subtransactions=True):
            new_router = super(
                OpenDaylightL3RouterPlugin, self).remove_router_interface(
                    context, router_id, interface_info)
            router_dict = self._generate_router_dict(router_id, interface_info,
                                                     new_router)
            db.create_pending_row(context.session, odl_const.ODL_ROUTER_INTF,
                                  odl_const.ODL_UUID_NOT_USED,
                                  odl_const.ODL_REMOVE, router_dict)
        return new_router

    def _generate_router_dict(self, router_id, interface_info, new_router):
        # Get network info for the subnet that is being added to the router.
        # Check if the interface information is by port-id or subnet-id.
        add_by_port, add_by_sub = self._validate_interface_info(interface_info)
        if add_by_sub:
            _port_id = new_router['port_id']
            _subnet_id = interface_info['subnet_id']
        elif add_by_port:
            _port_id = interface_info['port_id']
            _subnet_id = new_router['subnet_id']

        router_dict = {'subnet_id': _subnet_id,
                       'port_id': _port_id,
                       'id': router_id,
                       'tenant_id': new_router['tenant_id']}

        return router_dict

    dvr_deletens_if_no_port_warned = False

    def dvr_deletens_if_no_port(self, context, port_id):
        # TODO(yamahata): implement this method or delete this logging
        # For now, this is defined to avoid attribute exception
        # Since ODL L3 does not create namespaces, this is always going to
        # be a noop. When it is confirmed, delete this comment and logging
        if not self.dvr_deletens_if_no_port_warned:
            LOG.debug('dvr is not suported yet. '
                      'this method needs to be implemented')
            self.dvr_deletens_if_no_port_warned = True
        return []
