#!/usr/bin/env python3

# Copyright (C) 2023 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/>.

# T5708:
# - migrate "service dns dynamic timeout ..."
#        to "service dns dynamic interval ..."
# - remove "service dns dynamic address <interface> web-options ..." when <interface> != "web"
# - migrate "service dns dynamic address <interface> service <service> protocol dnsexit"
#        to "service dns dynamic address <interface> service <service> protocol dnsexit2"

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()

config = ConfigTree(config_file)

base_path = ['service', 'dns', 'dynamic']
timeout_path = base_path + ['timeout']
address_path = base_path + ['address']

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

# Migrate "service dns dynamic timeout ..."
#      to "service dns dynamic interval ..."
if config.exists(timeout_path):
    config.rename(timeout_path, 'interval')

# Remove "service dns dynamic address <interface> web-options ..." when <interface> != "web"
for address in config.list_nodes(address_path):
    if config.exists(address_path + [address, 'web-options']) and address != 'web':
        config.delete(address_path + [address, 'web-options'])

# Migrate "service dns dynamic address <interface> service <service> protocol dnsexit"
#      to "service dns dynamic address <interface> service <service> protocol dnsexit2"
for address in config.list_nodes(address_path):
    for svc_cfg in config.list_nodes(address_path + [address, 'service']):
        if config.exists(address_path + [address, 'service', svc_cfg, 'protocol']):
            protocol = config.return_value(address_path + [address, 'service', svc_cfg, 'protocol'])
            if protocol == 'dnsexit':
                config.set(address_path + [address, 'service', svc_cfg, 'protocol'], 'dnsexit2')

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))
    sys.exit(1)