#!/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/>.

# T6079: Disable duplicate static mappings

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']
config = ConfigTree(config_file)

if not config.exists(base + ['shared-network-name']):
    # Nothing to do
    exit(0)

# Run this for every instance if 'shared-network-name'
for network in config.list_nodes(base + ['shared-network-name']):
    base_network = base + ['shared-network-name', network]

    if not config.exists(base_network + ['subnet']):
        continue

    for subnet in config.list_nodes(base_network + ['subnet']):
        base_subnet = base_network + ['subnet', subnet]

        if config.exists(base_subnet + ['static-mapping']):
            used_mac = []
            used_ip = []

            for mapping in config.list_nodes(base_subnet + ['static-mapping']):
                base_mapping = base_subnet + ['static-mapping', mapping]

                if config.exists(base_mapping + ['mac-address']):
                    mac = config.return_value(base_mapping + ['mac-address'])

                    if mac in used_mac:
                        config.set(base_mapping + ['disable'])
                    else:
                        used_mac.append(mac)

                if config.exists(base_mapping + ['ip-address']):
                    ip = config.return_value(base_mapping + ['ip-address'])

                    if ip in used_ip:
                        config.set(base_subnet + ['static-mapping', mapping, 'disable'])
                    else:
                        used_ip.append(ip)

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)