# Copyright 2023-2024 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/>.

# T5708:
# - migrate "service dns dynamic timeout ..."
#        to "service dns dynamic interval ..."
# - remove "service dns dynamic address <interface> web-options ..." when <interface> != "web"
# - migrate "service dns dynamic address <interface> service <service> protocol dnsexit"
#        to "service dns dynamic address <interface> service <service> protocol dnsexit2"

# T6950:
# - add if statement to prevent processing of "service dns dynamic address" options if they don't exist
#        due to the fact they are no longer valid syntax

from vyos.configtree import ConfigTree

base_path = ['service', 'dns', 'dynamic']
timeout_path = base_path + ['timeout']
address_path = base_path + ['address']

def migrate(config: ConfigTree) -> None:
    if not config.exists(base_path):
        # Nothing to do
        return

    # Migrate "service dns dynamic timeout ..."
    #      to "service dns dynamic interval ..."
    if config.exists(timeout_path):
        config.rename(timeout_path, 'interval')

    # T6950: Can't migrate address if it doesn't exist
    if config.exists(address_path):

        # Remove "service dns dynamic address <interface> web-options ..." when <interface> != "web"
        for address in config.list_nodes(address_path):
            if config.exists(address_path + [address, 'web-options']) and address != 'web':
                config.delete(address_path + [address, 'web-options'])

        # Migrate "service dns dynamic address <interface> service <service> protocol dnsexit"
        #      to "service dns dynamic address <interface> service <service> protocol dnsexit2"
        for address in config.list_nodes(address_path):
            for svc_cfg in config.list_nodes(address_path + [address, 'service']):
                if config.exists(address_path + [address, 'service', svc_cfg, 'protocol']):
                    protocol = config.return_value(address_path + [address, 'service', svc_cfg, 'protocol'])
                    if protocol == 'dnsexit':
                        config.set(address_path + [address, 'service', svc_cfg, 'protocol'], 'dnsexit2')