# Copyright 2018-2024 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/>.

# Converts "system gateway-address" option to "protocols static route 0.0.0.0/0 next-hop $gw"

from vyos.configtree import ConfigTree

def migrate(config: ConfigTree) -> None:
    if not config.exists(['system', 'gateway-address']):
        # Nothing to do
        return

    # Save the address
    gw = config.return_value(['system', 'gateway-address'])

    # Create the node for the new syntax
    # Note: next-hop is a tag node, gateway address is its child, not a value
    config.set(['protocols', 'static', 'route', '0.0.0.0/0', 'next-hop', gw])

    # Delete the node with the old syntax
    config.delete(['system', 'gateway-address'])

    # Now, the interesting part. Both route and next-hop are supposed to be tag nodes,
    # which you can verify with "cli-shell-api isTag $configPath".
    # They must be formatted as such to load correctly.
    config.set_tag(['protocols', 'static', 'route'])
    config.set_tag(['protocols', 'static', 'route', '0.0.0.0/0', 'next-hop'])