#   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.
#

"""Subnet action implementations"""
import copy

from json.encoder import JSONEncoder

from openstackclient.common import command
from openstackclient.common import parseractions
from openstackclient.common import utils
from openstackclient.identity import common as identity_common


def _format_allocation_pools(data):
    pool_formatted = ['%s-%s' % (pool.get('start', ''), pool.get('end', ''))
                      for pool in data]
    return ','.join(pool_formatted)


def _format_host_routes(data):
    try:
        return '\n'.join([JSONEncoder().encode(route) for route in data])
    except (TypeError, KeyError):
        return ''


_formatters = {
    'allocation_pools': _format_allocation_pools,
    'dns_nameservers': utils.format_list,
    'host_routes': _format_host_routes,
}


def _get_columns(item):
    columns = list(item.keys())
    if 'tenant_id' in columns:
        columns.remove('tenant_id')
        columns.append('project_id')
    return tuple(sorted(columns))


def convert_entries_to_nexthop(entries):
    # Change 'gateway' entry to 'nexthop'
    changed_entries = copy.deepcopy(entries)
    for entry in changed_entries:
        entry['nexthop'] = entry['gateway']
        del entry['gateway']

    return changed_entries


def convert_entries_to_gateway(entries):
    # Change 'nexhop' entry to 'gateway'
    changed_entries = copy.deepcopy(entries)
    for entry in changed_entries:
        entry['gateway'] = entry['nexthop']
        del entry['nexthop']

    return changed_entries


def _get_attrs(client_manager, parsed_args):
    attrs = {}
    if parsed_args.name is not None:
        attrs['name'] = str(parsed_args.name)

    if 'project' in parsed_args and parsed_args.project is not None:
        identity_client = client_manager.identity
        project_id = identity_common.find_project(
            identity_client,
            parsed_args.project,
            parsed_args.project_domain,
        ).id
        attrs['tenant_id'] = project_id

    client = client_manager.network
    attrs['network_id'] = client.find_network(parsed_args.network,
                                              ignore_missing=False).id

    if parsed_args.subnet_pool is not None:
        subnet_pool = client.find_subnet_pool(parsed_args.subnet_pool,
                                              ignore_missing=False)
        attrs['subnetpool_id'] = subnet_pool.id

    if parsed_args.use_default_subnet_pool:
        attrs['use_default_subnetpool'] = True
    if parsed_args.gateway.lower() != 'auto':
        if parsed_args.gateway.lower() == 'none':
            attrs['gateway_ip'] = None
        else:
            attrs['gateway_ip'] = parsed_args.gateway
    if parsed_args.prefix_length is not None:
        attrs['prefixlen'] = parsed_args.prefix_length
    if parsed_args.subnet_range is not None:
        attrs['cidr'] = parsed_args.subnet_range
    if parsed_args.ip_version is not None:
        attrs['ip_version'] = parsed_args.ip_version
    if parsed_args.ipv6_ra_mode is not None:
        attrs['ipv6_ra_mode'] = parsed_args.ipv6_ra_mode
    if parsed_args.ipv6_address_mode is not None:
        attrs['ipv6_address_mode'] = parsed_args.ipv6_address_mode
    if parsed_args.allocation_pools is not None:
        attrs['allocation_pools'] = parsed_args.allocation_pools
    if parsed_args.enable_dhcp is not None:
        attrs['enable_dhcp'] = parsed_args.enable_dhcp
    if parsed_args.dns_nameservers is not None:
        attrs['dns_nameservers'] = parsed_args.dns_nameservers
    if parsed_args.host_routes is not None:
        # Change 'gateway' entry to 'nexthop' to match the API
        attrs['host_routes'] = convert_entries_to_nexthop(
            parsed_args.host_routes)

    return attrs


class CreateSubnet(command.ShowOne):
    """Create a subnet"""

    def get_parser(self, prog_name):
        parser = super(CreateSubnet, self).get_parser(prog_name)
        parser.add_argument(
            'name',
            help='New subnet name',
        )
        parser.add_argument(
            '--project',
            metavar='<project>',
            help="Owner's project (name or ID)",
        )
        identity_common.add_project_domain_option_to_parser(parser)
        subnet_pool_group = parser.add_mutually_exclusive_group()
        subnet_pool_group.add_argument(
            '--subnet-pool',
            metavar='<subnet-pool>',
            help='Subnet pool from which this subnet will obtain a CIDR '
                 '(Name or ID)',
        )
        subnet_pool_group.add_argument(
            '--use-default-subnet-pool',
            action='store_true',
            help='Use default subnet pool for --ip-version',
        )
        parser.add_argument(
            '--prefix-length',
            metavar='<prefix-length>',
            help='Prefix length for subnet allocation from subnetpool',
        )
        parser.add_argument(
            '--subnet-range',
            metavar='<subnet-range>',
            help='Subnet range in CIDR notation '
                 '(required if --subnet-pool is not specified, '
                 'optional otherwise)',
        )
        parser.add_argument(
            '--allocation-pool',
            metavar='start=<ip-address>,end=<ip-address>',
            dest='allocation_pools',
            action=parseractions.MultiKeyValueAction,
            required_keys=['start', 'end'],
            help='Allocation pool IP addresses for this subnet '
                 'e.g.: start=192.168.199.2,end=192.168.199.254 '
                 '(This option can be repeated)',
        )
        dhcp_enable_group = parser.add_mutually_exclusive_group()
        dhcp_enable_group.add_argument(
            '--dhcp',
            dest='enable_dhcp',
            action='store_true',
            default=True,
            help='Enable DHCP (default)',
        )
        dhcp_enable_group.add_argument(
            '--no-dhcp',
            dest='enable_dhcp',
            action='store_false',
            help='Disable DHCP',
        )
        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(
            '--gateway',
            metavar='<gateway>',
            default='auto',
            help="Specify a gateway for the subnet.  The three options are: "
                 "  <ip-address>: Specific IP address to use as the gateway "
                 "  'auto':       Gateway address should automatically be "
                 "                chosen from within the subnet itself "
                 "  'none':       This subnet will not use a gateway "
                 "e.g.: --gateway 192.168.9.1, --gateway auto, --gateway none"
                 "(default is 'auto')",
        )
        parser.add_argument(
            '--host-route',
            metavar='destination=<subnet>,gateway=<ip-address>',
            dest='host_routes',
            action=parseractions.MultiKeyValueAction,
            required_keys=['destination', 'gateway'],
            help='Additional route for this subnet '
                 'e.g.: destination=10.10.0.0/16,gateway=192.168.71.254 '
                 'destination: destination subnet (in CIDR notation) '
                 'gateway: nexthop IP address '
                 '(This option can be repeated)',
        )
        parser.add_argument(
            '--ip-version',
            type=int,
            default=4,
            choices=[4, 6],
            help='IP version (default is 4).  Note that when subnet pool is '
                 'specified, IP version is determined from the subnet pool '
                 'and this option is ignored.',
        )
        parser.add_argument(
            '--ipv6-ra-mode',
            choices=['dhcpv6-stateful', 'dhcpv6-stateless', 'slaac'],
            help='IPv6 RA (Router Advertisement) mode, '
                 'valid modes: [dhcpv6-stateful, dhcpv6-stateless, slaac]',
        )
        parser.add_argument(
            '--ipv6-address-mode',
            choices=['dhcpv6-stateful', 'dhcpv6-stateless', 'slaac'],
            help='IPv6 address mode, '
                 'valid modes: [dhcpv6-stateful, dhcpv6-stateless, slaac]',
        )
        parser.add_argument(
            '--network',
            required=True,
            metavar='<network>',
            help='Network this subnet belongs to (name or ID)',
        )

        return parser

    def take_action(self, parsed_args):
        client = self.app.client_manager.network
        attrs = _get_attrs(self.app.client_manager, parsed_args)
        obj = client.create_subnet(**attrs)
        columns = _get_columns(obj)
        data = utils.get_item_properties(obj, columns, formatters=_formatters)
        return (columns, data)


class DeleteSubnet(command.Command):
    """Delete subnet"""

    def get_parser(self, prog_name):
        parser = super(DeleteSubnet, self).get_parser(prog_name)
        parser.add_argument(
            'subnet',
            metavar="<subnet>",
            help="Subnet to delete (name or ID)",
        )
        return parser

    def take_action(self, parsed_args):
        client = self.app.client_manager.network
        client.delete_subnet(
            client.find_subnet(parsed_args.subnet))


class ListSubnet(command.Lister):
    """List subnets"""

    def get_parser(self, prog_name):
        parser = super(ListSubnet, self).get_parser(prog_name)
        parser.add_argument(
            '--long',
            action='store_true',
            default=False,
            help='List additional fields in output',
        )
        return parser

    def take_action(self, parsed_args):
        data = self.app.client_manager.network.subnets()

        headers = ('ID', 'Name', 'Network', 'Subnet')
        columns = ('id', 'name', 'network_id', 'cidr')
        if parsed_args.long:
            headers += ('Project', 'DHCP', 'Name Servers',
                        'Allocation Pools', 'Host Routes', 'IP Version',
                        'Gateway')
            columns += ('tenant_id', 'enable_dhcp', 'dns_nameservers',
                        'allocation_pools', 'host_routes', 'ip_version',
                        'gateway_ip')

        return (headers,
                (utils.get_item_properties(
                    s, columns,
                    formatters=_formatters,
                ) for s in data))


class ShowSubnet(command.ShowOne):
    """Show subnet details"""

    def get_parser(self, prog_name):
        parser = super(ShowSubnet, self).get_parser(prog_name)
        parser.add_argument(
            'subnet',
            metavar="<subnet>",
            help="Subnet to show (name or ID)",
        )
        return parser

    def take_action(self, parsed_args):
        obj = self.app.client_manager.network.find_subnet(parsed_args.subnet,
                                                          ignore_missing=False)
        columns = _get_columns(obj)
        data = utils.get_item_properties(obj, columns, formatters=_formatters)
        return (columns, data)