#!/usr/bin/env python3
#
# Copyright (C) 2019-2020 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os

from glob import glob
from sys import exit

from vyos.config import Config
from vyos.configdict import get_interface_dict
from vyos.configverify import verify_address
from vyos.configverify import verify_dhcpv6
from vyos.configverify import verify_interface_exists
from vyos.configverify import verify_mtu
from vyos.configverify import verify_mtu_ipv6
from vyos.configverify import verify_vlan_config
from vyos.configverify import verify_vrf
from vyos.ifconfig import EthernetIf
from vyos.util import dict_search
from vyos import ConfigError
from vyos import airbag
airbag.enable()

def get_config(config=None):
    """
    Retrive CLI config as dictionary. Dictionary can never be empty, as at least the
    interface name will be added or a deleted flag
    """
    if config:
        conf = config
    else:
        conf = Config()
    base = ['interfaces', 'ethernet']
    ethernet = get_interface_dict(conf, base)

    return ethernet

def verify(ethernet):
    if 'deleted' in ethernet:
        return None

    verify_interface_exists(ethernet)

    if ethernet.get('speed', None) == 'auto':
        if ethernet.get('duplex', None) != 'auto':
            raise ConfigError('If speed is hardcoded, duplex must be hardcoded, too')

    if ethernet.get('duplex', None) == 'auto':
        if ethernet.get('speed', None) != 'auto':
            raise ConfigError('If duplex is hardcoded, speed must be hardcoded, too')

    verify_mtu(ethernet)
    verify_mtu_ipv6(ethernet)
    verify_dhcpv6(ethernet)
    verify_address(ethernet)
    verify_vrf(ethernet)

    # XDP requires multiple TX queues
    if dict_search('offload.xdp', ethernet) != None:
        queues = glob('/sys/class/net/{ifname}/queues/tx-*'.format(**ethernet))
        if len(queues) < 2:
            raise ConfigError('XDP requires additional TX queues, too few available!')

    if {'is_bond_member', 'mac'} <= set(ethernet):
        print(f'WARNING: changing mac address "{mac}" will be ignored as "{ifname}" '
              f'is a member of bond "{is_bond_member}"'.format(**ethernet))

    # use common function to verify VLAN configuration
    verify_vlan_config(ethernet)
    return None

def generate(ethernet):
    return None

def apply(ethernet):
    e = EthernetIf(ethernet['ifname'])
    if 'deleted' in ethernet:
        # delete interface
        e.remove()
    else:
        e.update(ethernet)


if __name__ == '__main__':
    try:
        c = get_config()
        verify(c)
        generate(c)
        apply(c)
    except ConfigError as e:
        print(e)
        exit(1)