# Copyright 2016 Red Hat, Inc.
# 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.
import netaddr

from neutron_lib.api.definitions import provider_net
from tempest.common import utils
from tempest.common import waiters
from tempest.lib import decorators

from neutron_tempest_plugin.common import ssh
from neutron_tempest_plugin import config
from neutron_tempest_plugin.scenario import base
from neutron_tempest_plugin.scenario import constants

CONF = config.CONF


class NetworkMtuBaseTest(base.BaseTempestTestCase):
    credentials = ['primary', 'admin']
    servers = []
    networks = []

    @classmethod
    def skip_checks(cls):
        super(NetworkMtuBaseTest, cls).skip_checks()
        if ("vxlan" not in
                config.CONF.neutron_plugin_options.available_type_drivers
            or "gre" not in
                config.CONF.neutron_plugin_options.available_type_drivers):
            raise cls.skipException("GRE or VXLAN type_driver is not enabled")

    @classmethod
    @utils.requires_ext(extension=provider_net.ALIAS, service="network")
    def resource_setup(cls):
        super(NetworkMtuBaseTest, cls).resource_setup()
        # setup basic topology for servers we can log into it
        cls.router = cls.create_router_by_client()
        cls.keypair = cls.create_keypair()
        cls.secgroup = cls.os_primary.network_client.create_security_group(
            name='secgroup_mtu')
        cls.security_groups.append(cls.secgroup['security_group'])
        cls.create_loginable_secgroup_rule(
            secgroup_id=cls.secgroup['security_group']['id'])
        cls.create_pingable_secgroup_rule(
            secgroup_id=cls.secgroup['security_group']['id'])

    def _create_setup(self):
        self.admin_client = self.os_admin.network_client
        net_kwargs = {'tenant_id': self.client.tenant_id}
        for sub, net_type in (
                ('10.100.0.0/16', 'vxlan'), ('10.200.0.0/16', 'gre')):
            net_kwargs['name'] = '-'.join([net_type, 'net'])
            net_kwargs['provider:network_type'] = net_type
            network = self.admin_client.create_network(**net_kwargs)[
                'network']
            self.networks.append(network)
            self.addCleanup(self.admin_client.delete_network, network['id'])
            cidr = netaddr.IPNetwork(sub)
            subnet = self.create_subnet(network, cidr=cidr)
            self.create_router_interface(self.router['id'], subnet['id'])
            self.addCleanup(self.client.remove_router_interface_with_subnet_id,
                            self.router['id'], subnet['id'])
        # check that MTUs are different for 2 networks
        self.assertNotEqual(self.networks[0]['mtu'], self.networks[1]['mtu'])
        self.networks.sort(key=lambda net: net['mtu'])
        server1, fip1 = self.create_pingable_vm(self.networks[0])
        server_ssh_client1 = ssh.Client(
            self.floating_ips[0]['floating_ip_address'],
            CONF.validation.image_ssh_user,
            pkey=self.keypair['private_key'])
        server2, fip2 = self.create_pingable_vm(self.networks[1])
        server_ssh_client2 = ssh.Client(
            self.floating_ips[0]['floating_ip_address'],
            CONF.validation.image_ssh_user,
            pkey=self.keypair['private_key'])
        for fip in (fip1, fip2):
            self.check_connectivity(fip['floating_ip_address'],
                                    CONF.validation.image_ssh_user,
                                    self.keypair['private_key'])
        return server_ssh_client1, fip1, server_ssh_client2, fip2

    def create_pingable_vm(self, net):
        server = self.create_server(
            flavor_ref=CONF.compute.flavor_ref,
            image_ref=CONF.compute.image_ref,
            key_name=self.keypair['name'],
            networks=[{'uuid': net['id']}],
            security_groups=[{'name': self.secgroup[
                'security_group']['name']}])
        waiters.wait_for_server_status(
            self.os_primary.servers_client, server['server']['id'],
            constants.SERVER_STATUS_ACTIVE)
        port = self.client.list_ports(
            network_id=net['id'], device_id=server['server']['id'])['ports'][0]
        fip = self.create_and_associate_floatingip(port['id'])
        return server, fip

    @decorators.idempotent_id('3d73ec1a-2ec6-45a9-b0f8-04a273d9d344')
    def test_connectivity_min_max_mtu(self):
        server_ssh_client, _, _, fip2 = self._create_setup()
        # ping with min mtu of 2 networks succeeds even when
        # fragmentation is disabled
        self.check_remote_connectivity(
            server_ssh_client, fip2['fixed_ip_address'],
            mtu=self.networks[0]['mtu'], fragmentation=False)

        # ping with the size above min mtu of 2 networks
        # fails when fragmentation is disabled
        self.check_remote_connectivity(
            server_ssh_client, fip2['fixed_ip_address'], should_succeed=False,
            mtu=self.networks[0]['mtu'] + 1, fragmentation=False)

        # ping with max mtu of 2 networks succeeds when
        # fragmentation is enabled
        self.check_remote_connectivity(
            server_ssh_client, fip2['fixed_ip_address'],
            mtu=self.networks[1]['mtu'])

        # ping with max mtu of 2 networks fails when fragmentation is disabled
        self.check_remote_connectivity(
            server_ssh_client, fip2['fixed_ip_address'], should_succeed=False,
            mtu=self.networks[1]['mtu'], fragmentation=False)