#!/usr/bin/env python3
#
# Copyright (C) 2022-2024 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/>.

from sys import exit, argv
from vyos.configtree import ConfigTree

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

file_name = argv[1]
with open(file_name, 'r') as f:
    config_file = f.read()

base = ['system', 'ipv6']
config = ConfigTree(config_file)

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

# T4346: drop support to disbale IPv6 address family within the OS Kernel
if config.exists(base + ['disable']):
    config.delete(base + ['disable'])
    # IPv6 address family disable was the only CLI option set - we can cleanup
    # the entire tree
    if len(config.list_nodes(base)) == 0:
        config.delete(base)

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