#!/usr/bin/env python3
#
# Copyright (C) 2024 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/>.

# T3316:
# - Migrate dhcp options under new option node
# - Add subnet IDs to existing subnets

import sys
from vyos.configtree import ConfigTree

if len(sys.argv) < 2:
    print("Must specify file name!")
    sys.exit(1)

file_name = sys.argv[1]

with open(file_name, 'r') as f:
    config_file = f.read()

base = ['service', 'dhcp-server', 'shared-network-name']
config = ConfigTree(config_file)

if not config.exists(base):
    # Nothing to do
    sys.exit(0)

option_nodes = ['bootfile-name', 'bootfile-server', 'bootfile-size', 'captive-portal',
                'client-prefix-length', 'default-router', 'domain-name', 'domain-search',
                'name-server', 'ip-forwarding', 'ipv6-only-preferred', 'ntp-server',
                'pop-server', 'server-identifier', 'smtp-server', 'static-route',
                'tftp-server-name', 'time-offset', 'time-server', 'time-zone',
                'vendor-option', 'wins-server', 'wpad-url']

subnet_id = 1

for network in config.list_nodes(base):
    for option in option_nodes:
        if config.exists(base + [network, option]):
            config.set(base + [network, 'option'])
            config.copy(base + [network, option], base + [network, 'option', option])
            config.delete(base + [network, option])

    if config.exists(base + [network, 'subnet']):
        for subnet in config.list_nodes(base + [network, 'subnet']):
            base_subnet = base + [network, 'subnet', subnet]

            for option in option_nodes:
                if config.exists(base_subnet + [option]):
                    config.set(base_subnet + ['option'])
                    config.copy(base_subnet + [option], base_subnet + ['option', option])
                    config.delete(base_subnet + [option])

            config.set(base_subnet + ['subnet-id'], value=subnet_id)
            subnet_id += 1

try:
    with open(file_name, 'w') as f:
        f.write(config.to_string())
except OSError as e:
    print("Failed to save the modified config: {}".format(e))
    exit(1)