#!/usr/bin/env python3
#
# Copyright VyOS maintainers and contributors <maintainers@vyos.io>
#
# 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/>.

# T7646: restore behavior of IPv6 default route if only dhcpv6 was defined but
#        not "ipv6 address autoconf"

from vyos.configtree import ConfigTree

def migrate(config: ConfigTree) -> None:
    for type in config.list_nodes(['interfaces']):
        for interface in config.list_nodes(['interfaces', type]):
            iface_base_path = ['interfaces', type, interface]
            dhcpv6_addr_path = iface_base_path + ['address']

            if config.exists(dhcpv6_addr_path) and 'dhcpv6' in config.return_values(dhcpv6_addr_path):
                autoconf_path = iface_base_path + ['ipv6', 'address', 'autoconf']
                if not config.exists(autoconf_path):
                    config.set(autoconf_path)

            vif_path = iface_base_path + ['vif']
            if config.exists(vif_path):
                for vif in config.list_nodes(vif_path):
                    vif_dhcpv6_addr_path = vif_path + [vif, 'address']
                    if config.exists(vif_dhcpv6_addr_path) and 'dhcpv6' in config.return_values(vif_dhcpv6_addr_path):
                        vif_autoconf_path = vif_path + [vif, 'ipv6', 'address', 'autoconf']
                        if not config.exists(vif_autoconf_path):
                            config.set(vif_autoconf_path)

            vif_s_path = iface_base_path + ['vif-s']
            if config.exists(vif_s_path):
                for vif_s in config.list_nodes(vif_s_path):
                    vif_s_dhcpv6_addr_path = vif_s_path + [vif_s, 'address']
                    if config.exists(vif_s_dhcpv6_addr_path) and 'dhcpv6' in config.return_values(vif_s_dhcpv6_addr_path):
                        vif_s_autoconf_path = vif_s_path + [vif_s, 'ipv6', 'address', 'autoconf']
                        if not config.exists(vif_s_autoconf_path):
                            config.set(vif_s_autoconf_path)

                    vif_c_path = iface_base_path + ['vif-s', vif_s, 'vif-c']
                    if config.exists(vif_c_path):
                        for vif_c in config.list_nodes(vif_c_path):
                            vif_c_dhcpv6_addr_path = vif_c_path + [vif_c, 'address']
                            if config.exists(vif_c_dhcpv6_addr_path) and 'dhcpv6' in config.return_values(vif_c_dhcpv6_addr_path):
                                vif_c_autoconf_path = vif_c_path + [vif_c, 'ipv6', 'address', 'autoconf']
                                if not config.exists(vif_c_autoconf_path):
                                    config.set(vif_c_autoconf_path)