# Copyright 2012 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.
#

import argparse

from oslo_serialization import jsonutils

from neutronclient._i18n import _
from neutronclient.common import exceptions
from neutronclient.common import utils
from neutronclient.neutron import v2_0 as neutronV20


def _format_allocation_pools(subnet):
    try:
        return '\n'.join([jsonutils.dumps(pool) for pool in
                          subnet['allocation_pools']])
    except (TypeError, KeyError):
        return ''


def _format_dns_nameservers(subnet):
    try:
        return '\n'.join([jsonutils.dumps(server) for server in
                          subnet['dns_nameservers']])
    except (TypeError, KeyError):
        return ''


def _format_host_routes(subnet):
    try:
        return '\n'.join([jsonutils.dumps(route) for route in
                          subnet['host_routes']])
    except (TypeError, KeyError):
        return ''


def add_updatable_arguments(parser):
    parser.add_argument(
        '--name',
        help=_('Name of this subnet.'))
    parser.add_argument(
        '--description',
        help=_('Description of this subnet.'))
    gateway_sg = parser.add_mutually_exclusive_group()
    gateway_sg.add_argument(
        '--gateway', metavar='GATEWAY_IP',
        help=_('Gateway IP of this subnet.'))
    gateway_sg.add_argument(
        '--no-gateway',
        action='store_true',
        help=_('Do not configure a gateway for this subnet.'))
    parser.add_argument(
        '--allocation-pool', metavar='start=IP_ADDR,end=IP_ADDR',
        action='append', dest='allocation_pools',
        type=utils.str2dict_type(required_keys=['start', 'end']),
        help=_('Allocation pool IP addresses for this subnet '
               '(This option can be repeated).'))
    parser.add_argument(
        '--allocation_pool',
        action='append', dest='allocation_pools',
        type=utils.str2dict_type(required_keys=['start', 'end']),
        help=argparse.SUPPRESS)
    parser.add_argument(
        '--host-route', metavar='destination=CIDR,nexthop=IP_ADDR',
        action='append', dest='host_routes',
        type=utils.str2dict_type(required_keys=['destination', 'nexthop']),
        help=_('Additional route (This option can be repeated).'))
    parser.add_argument(
        '--dns-nameserver', metavar='DNS_NAMESERVER',
        action='append', dest='dns_nameservers',
        help=_('DNS name server for this subnet '
               '(This option can be repeated).'))
    parser.add_argument(
        '--disable-dhcp',
        action='store_true',
        help=_('Disable DHCP for this subnet.'))
    parser.add_argument(
        '--enable-dhcp',
        action='store_true',
        help=_('Enable DHCP for this subnet.'))
    # NOTE(ihrachys): yes, that's awful, but should be left as-is for
    # backwards compatibility for versions <=2.3.4 that passed the
    # boolean values through to the server without any argument
    # validation.
    parser.add_argument(
        '--enable-dhcp=True',
        action='store_true',
        dest='enable_dhcp',
        help=argparse.SUPPRESS)
    parser.add_argument(
        '--enable-dhcp=False',
        action='store_true',
        dest='disable_dhcp',
        help=argparse.SUPPRESS)


def updatable_args2body(parsed_args, body, for_create=True, ip_version=None):
    if parsed_args.disable_dhcp and parsed_args.enable_dhcp:
        raise exceptions.CommandError(_(
            "You cannot enable and disable DHCP at the same time."))

    neutronV20.update_dict(parsed_args, body,
                           ['name', 'allocation_pools',
                            'host_routes', 'dns_nameservers',
                            'description'])
    if parsed_args.no_gateway:
        body['gateway_ip'] = None
    elif parsed_args.gateway:
        body['gateway_ip'] = parsed_args.gateway
    if parsed_args.disable_dhcp:
        body['enable_dhcp'] = False
    if parsed_args.enable_dhcp:
        body['enable_dhcp'] = True
    if for_create and parsed_args.ipv6_ra_mode:
        if ip_version == 4:
            raise exceptions.CommandError(_("--ipv6-ra-mode is invalid "
                                            "when --ip-version is 4"))
        body['ipv6_ra_mode'] = parsed_args.ipv6_ra_mode
    if for_create and parsed_args.ipv6_address_mode:
        if ip_version == 4:
            raise exceptions.CommandError(_("--ipv6-address-mode is "
                                            "invalid when --ip-version "
                                            "is 4"))
        body['ipv6_address_mode'] = parsed_args.ipv6_address_mode


class ListSubnet(neutronV20.ListCommand):
    """List subnets that belong to a given tenant."""

    resource = 'subnet'
    _formatters = {'allocation_pools': _format_allocation_pools,
                   'dns_nameservers': _format_dns_nameservers,
                   'host_routes': _format_host_routes, }
    list_columns = ['id', 'name', 'cidr', 'allocation_pools']
    pagination_support = True
    sorting_support = True


class ShowSubnet(neutronV20.ShowCommand):
    """Show information of a given subnet."""

    resource = 'subnet'


class CreateSubnet(neutronV20.CreateCommand):
    """Create a subnet for a given tenant."""

    resource = 'subnet'

    def add_known_arguments(self, parser):
        add_updatable_arguments(parser)
        parser.add_argument(
            '--ip-version',
            type=int,
            default=4, choices=[4, 6],
            help=_('IP version to use, default is 4. '
                   'Note that when subnetpool is specified, '
                   'IP version is determined from the subnetpool '
                   'and this option is ignored.'))
        parser.add_argument(
            '--ip_version',
            type=int,
            choices=[4, 6],
            help=argparse.SUPPRESS)
        parser.add_argument(
            'network_id', metavar='NETWORK',
            help=_('Network ID or name this subnet belongs to.'))
        parser.add_argument(
            'cidr', nargs='?', metavar='CIDR',
            help=_('CIDR of subnet to create.'))
        parser.add_argument(
            '--ipv6-ra-mode',
            type=utils.convert_to_lowercase,
            choices=['dhcpv6-stateful', 'dhcpv6-stateless', 'slaac'],
            help=_('IPv6 RA (Router Advertisement) mode.'))
        parser.add_argument(
            '--ipv6-address-mode',
            type=utils.convert_to_lowercase,
            choices=['dhcpv6-stateful', 'dhcpv6-stateless', 'slaac'],
            help=_('IPv6 address mode.'))
        parser.add_argument(
            '--subnetpool', metavar='SUBNETPOOL',
            help=_('ID or name of subnetpool from which this subnet '
                   'will obtain a CIDR.'))
        parser.add_argument(
            '--use-default-subnetpool',
            action='store_true',
            help=_('Use default subnetpool for ip_version, if it exists.'))
        parser.add_argument(
            '--prefixlen', metavar='PREFIX_LENGTH',
            help=_('Prefix length for subnet allocation from subnetpool.'))
        parser.add_argument(
            '--segment', metavar='SEGMENT',
            help=_('ID of segment with which this subnet will be associated.'))

    def args2body(self, parsed_args):
        _network_id = neutronV20.find_resourceid_by_name_or_id(
            self.get_client(), 'network', parsed_args.network_id)
        body = {'network_id': _network_id}

        if parsed_args.prefixlen:
            body['prefixlen'] = parsed_args.prefixlen
        ip_version = parsed_args.ip_version
        if parsed_args.use_default_subnetpool:
            body['use_default_subnetpool'] = True
        if parsed_args.segment:
            body['segment_id'] = neutronV20.find_resourceid_by_name_or_id(
                self.get_client(), 'segment', parsed_args.segment)
        if parsed_args.subnetpool:
            if parsed_args.subnetpool == 'None':
                _subnetpool_id = None
            else:
                _subnetpool = neutronV20.find_resource_by_name_or_id(
                    self.get_client(), 'subnetpool', parsed_args.subnetpool)
                _subnetpool_id = _subnetpool['id']
                # Now that we have the pool_id - let's just have a check on the
                # ip version used in the pool
                ip_version = _subnetpool['ip_version']
            body['subnetpool_id'] = _subnetpool_id

        # IP version needs to be set as IP version can be
        # determined by subnetpool.
        body['ip_version'] = ip_version

        if parsed_args.cidr:
            # With subnetpool, cidr is now optional for creating subnet.
            cidr = parsed_args.cidr
            body['cidr'] = cidr
            unusable_cidr = '/32' if ip_version == 4 else '/128'
            if cidr.endswith(unusable_cidr):
                self.log.warning(_("An IPv%(ip)d subnet with a %(cidr)s CIDR "
                                   "will have only one usable IP address so "
                                   "the device attached to it will not have "
                                   "any IP connectivity."),
                                 {"ip": ip_version,
                                  "cidr": unusable_cidr})

        updatable_args2body(parsed_args, body, ip_version=ip_version)
        if parsed_args.tenant_id:
            body['tenant_id'] = parsed_args.tenant_id

        return {'subnet': body}


class DeleteSubnet(neutronV20.DeleteCommand):
    """Delete a given subnet."""

    resource = 'subnet'


class UpdateSubnet(neutronV20.UpdateCommand):
    """Update subnet's information."""

    resource = 'subnet'

    def add_known_arguments(self, parser):
        add_updatable_arguments(parser)

    def args2body(self, parsed_args):
        body = {}
        updatable_args2body(parsed_args, body, for_create=False)
        return {'subnet': body}