#!/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/>.

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)

# PEER changes
if config.exists(base + ['site-to-site', 'peer']):
    for peer in config.list_nodes(base + ['site-to-site', 'peer']):
        peer_base = base + ['site-to-site', 'peer', peer]

        # replace: 'ipsec site-to-site peer <tag> authentication pre-shared-secret xxx'
        #       => 'ipsec authentication psk <tag> secret xxx'
        if config.exists(peer_base + ['authentication', 'pre-shared-secret']):
            tmp = config.return_value(peer_base + ['authentication', 'pre-shared-secret'])
            config.delete(peer_base + ['authentication', 'pre-shared-secret'])
            config.set(base + ['authentication', 'psk', peer, 'secret'], value=tmp)
            # format as tag node to avoid loading problems
            config.set_tag(base + ['authentication', 'psk'])

            # Get id's from peers for "ipsec auth psk <tag> id xxx"
            if config.exists(peer_base + ['authentication', 'local-id']):
                local_id = config.return_value(peer_base + ['authentication', 'local-id'])
                config.set(base + ['authentication', 'psk', peer, 'id'], value=local_id, replace=False)
            if config.exists(peer_base + ['authentication', 'remote-id']):
                remote_id = config.return_value(peer_base + ['authentication', 'remote-id'])
                config.set(base + ['authentication', 'psk', peer, 'id'], value=remote_id, replace=False)

            if config.exists(peer_base + ['local-address']):
                tmp = config.return_value(peer_base + ['local-address'])
                config.set(base + ['authentication', 'psk', peer, 'id'], value=tmp, replace=False)
            if config.exists(peer_base + ['remote-address']):
                tmp = config.return_values(peer_base + ['remote-address'])
                if tmp:
                    for remote_addr in tmp:
                        if remote_addr == 'any':
                            remote_addr = '%any'
                        config.set(base + ['authentication', 'psk', peer, 'id'], value=remote_addr, replace=False)

            # get DHCP peer interface as psk dhcp-interface
            if config.exists(peer_base + ['dhcp-interface']):
                tmp = config.return_value(peer_base + ['dhcp-interface'])
                config.set(base + ['authentication', 'psk', peer, 'dhcp-interface'], value=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)