# Copyright (C) 2014 eNovance SAS <licensing@enovance.com>
#
# 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.api import extensions
from neutron.api.v2 import attributes
from neutron.common import constants
from neutron.common import exceptions

HA_INFO = 'ha'
EXTENDED_ATTRIBUTES_2_0 = {
    'routers': {
        HA_INFO: {'allow_post': True, 'allow_put': False,
                  'default': attributes.ATTR_NOT_SPECIFIED, 'is_visible': True,
                  'enforce_policy': True,
                  'convert_to': attributes.convert_to_boolean_if_not_none}
    }
}


class DistributedHARouterNotSupported(NotImplementedError):
    message = _("Currenly distributed HA routers are "
                "not supported.")


class MaxVRIDAllocationTriesReached(exceptions.NeutronException):
    message = _("Failed to allocate a VRID in the network %(network_id)s "
                "for the router %(router_id)s after %(max_tries)s tries.")


class NoVRIDAvailable(exceptions.Conflict):
    message = _("No more Virtual Router Identifier (VRID) available when "
                "creating router %(router_id)s. The limit of number "
                "of HA Routers per tenant is 254.")


class HANetworkCIDRNotValid(exceptions.NeutronException):
    message = _("The HA Network CIDR specified in the configuration file "
                "isn't valid; %(cidr)s.")


class HANotEnoughAvailableAgents(exceptions.NeutronException):
    message = _("Not enough l3 agents available to ensure HA. Minimum "
                "required %(min_agents)s, available %(num_agents)s.")


class HAMinimumAgentsNumberNotValid(exceptions.NeutronException):
    message = (_("min_l3_agents_per_router config parameter is not valid. "
                 "It has to be equal to or more than %s for HA.") %
               constants.MINIMUM_AGENTS_FOR_HA)


class L3_ext_ha_mode(extensions.ExtensionDescriptor):
    """Extension class supporting virtual router in HA mode."""

    @classmethod
    def get_name(cls):
        return "HA Router extension"

    @classmethod
    def get_alias(cls):
        return constants.L3_HA_MODE_EXT_ALIAS

    @classmethod
    def get_description(cls):
        return "Add HA capability to routers."

    @classmethod
    def get_namespace(cls):
        return ""

    @classmethod
    def get_updated(cls):
        return "2014-04-26T00:00:00-00:00"

    def get_extended_resources(self, version):
        if version == "2.0":
            return EXTENDED_ATTRIBUTES_2_0
        else:
            return {}