#!/usr/bin/env python3
#
# Copyright (C) 2020-2024 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/>.

# - remove primary/secondary identifier from nameserver
# - TODO: remove radius server req-limit

from sys import argv, exit
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()

config = ConfigTree(config_file)
base = ['vpn', 'l2tp', 'remote-access']
if not config.exists(base):
    # Nothing to do
    exit(0)
else:
    # Migrate IPv4 DNS servers
    dns_base = base + ['dns-servers']
    if config.exists(dns_base):
        for server in ['server-1', 'server-2']:
          if config.exists(dns_base + [server]):
            dns = config.return_value(dns_base + [server])
            config.set(base + ['name-server'], value=dns, replace=False)

        config.delete(dns_base)

    # Migrate IPv6 DNS servers
    dns_base = base + ['dnsv6-servers']
    if config.exists(dns_base):
        for server in config.return_values(dns_base):
            config.set(base + ['name-server'], value=server, replace=False)

        config.delete(dns_base)

    # Migrate IPv4 WINS servers
    wins_base = base + ['wins-servers']
    if config.exists(wins_base):
        for server in ['server-1', 'server-2']:
          if config.exists(wins_base + [server]):
            wins = config.return_value(wins_base + [server])
            config.set(base + ['wins-server'], value=wins, replace=False)

        config.delete(wins_base)


    # Remove RADIUS server req-limit node
    radius_base = base + ['authentication', 'radius']
    if config.exists(radius_base):
        for server in config.list_nodes(radius_base + ['server']):
            if config.exists(radius_base + ['server', server, 'req-limit']):
                config.delete(radius_base + ['server', server, 'req-limit'])

    # Migrate IPv6 prefixes
    ipv6_base = base + ['client-ipv6-pool']
    if config.exists(ipv6_base + ['prefix']):
        prefix_old = config.return_values(ipv6_base + ['prefix'])
        # delete old prefix CLI nodes
        config.delete(ipv6_base + ['prefix'])
        # create ned prefix tag node
        config.set(ipv6_base + ['prefix'])
        config.set_tag(ipv6_base + ['prefix'])

        for p in prefix_old:
            prefix = p.split(',')[0]
            mask = p.split(',')[1]
            config.set(ipv6_base + ['prefix', prefix, 'mask'], value=mask)

    if config.exists(ipv6_base + ['delegate-prefix']):
        prefix_old = config.return_values(ipv6_base + ['delegate-prefix'])
        # delete old delegate prefix CLI nodes
        config.delete(ipv6_base + ['delegate-prefix'])
        # create ned delegation tag node
        config.set(ipv6_base + ['delegate'])
        config.set_tag(ipv6_base + ['delegate'])

        for p in prefix_old:
            prefix = p.split(',')[0]
            mask = p.split(',')[1]
            config.set(ipv6_base + ['delegate', prefix, 'delegate-prefix'], value=mask)

    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)