#!/usr/bin/env python3
#
# Copyright (C) 2021 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 deprecated strongSwan options from VyOS CLI
# - vpn ipsec nat-traversal enable
# - vpn ipsec nat-networks allowed-network

from sys import argv
from sys import 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()

base = ['vpn', 'ipsec']
config = ConfigTree(config_file)

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

# Delete CLI nodes whose config options got removed by strongSwan
for cli_node in ['nat-traversal', 'nat-networks']:
    if config.exists(base + [cli_node]):
        config.delete(base + [cli_node])

# Remove options only valid in Openswan
if config.exists(base + ['site-to-site', 'peer']):
    for peer in config.list_nodes(base + ['site-to-site', 'peer']):
        if not config.exists(base + ['site-to-site', 'peer', peer, 'tunnel']):
            continue
        for tunnel in config.list_nodes(base + ['site-to-site', 'peer', peer, 'tunnel']):
            # allow-public-networks - Sets a value in ipsec.conf that was only ever valid in Openswan on kernel 2.6
            nat_networks = base + ['site-to-site', 'peer', peer, 'tunnel', tunnel, 'allow-nat-networks']
            if config.exists(nat_networks):
                config.delete(nat_networks)

            # allow-nat-networks - Also sets a value only valid in Openswan
            public_networks = base + ['site-to-site', 'peer', peer, 'tunnel', tunnel, 'allow-public-networks']
            if config.exists(public_networks):
                config.delete(public_networks)

# Rename "logging log-level" and "logging log-modes" to something more human friendly
log = base + ['logging']
if config.exists(log):
    config.rename(log, 'log')
    log = base + ['log']

log_level = log + ['log-level']
if config.exists(log_level):
    config.rename(log_level, 'level')

log_mode = log + ['log-modes']
if config.exists(log_mode):
    config.rename(log_mode, 'subsystem')

# Rename "ipsec-interfaces interface" to "interface"
base_interfaces = base + ['ipsec-interfaces', 'interface']
if config.exists(base_interfaces):
    config.copy(base_interfaces, base + ['interface'])
    config.delete(base + ['ipsec-interfaces'])

# Remove deprecated "auto-update" option
tmp = base + ['auto-update']
if config.exists(tmp):
    config.delete(tmp)

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)