# Copyright VyOS maintainers and contributors <maintainers@vyos.io>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this library.  If not, see <http://www.gnu.org/licenses/>.

# Backfill IPv6 peer IID secret for legacy calling-sid configuration.

from secrets import token_hex

from vyos.configtree import ConfigTree

base = ['vpn', 'sstp']
peer_id_path = base + ['ppp-options', 'ipv6-peer-interface-id']
peer_id_secret_path = base + ['ppp-options', 'ipv6-peer-interface-id-secret']


def migrate(config: ConfigTree) -> None:
    if not config.exists(base):
        return

    if not config.exists(peer_id_path):
        return

    if config.return_value(peer_id_path) != 'calling-sid':
        return

    if config.exists(peer_id_secret_path):
        return

    config.set(peer_id_secret_path, value=token_hex(32))