# Copyright 2022-2024 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/>.

# T2199: Migrate interface policy nodes to policy route <name> interface <ifname>

from vyos.configtree import ConfigTree

base4 = ['policy', 'route']
base6 = ['policy', 'route6']

def delete_orphaned_interface_policy(config, iftype, ifname, vif=None, vifs=None, vifc=None):
    """Delete unexpected policy on interfaces in cases when
       policy does not exist but inreface has a policy configuration
       Example T5941:
         set interfaces bonding bond0 vif 995 policy
    """
    if_path = ['interfaces', iftype, ifname]

    if vif:
        if_path += ['vif', vif]
    elif vifs:
        if_path += ['vif-s', vifs]
        if vifc:
            if_path += ['vif-c', vifc]

    if not config.exists(if_path + ['policy']):
        return

    config.delete(if_path + ['policy'])

def migrate_interface(config, iftype, ifname, vif=None, vifs=None, vifc=None):
    if_path = ['interfaces', iftype, ifname]
    ifname_full = ifname

    if vif:
        if_path += ['vif', vif]
        ifname_full = f'{ifname}.{vif}'
    elif vifs:
        if_path += ['vif-s', vifs]
        ifname_full = f'{ifname}.{vifs}'
        if vifc:
            if_path += ['vif-c', vifc]
            ifname_full = f'{ifname}.{vifs}.{vifc}'

    if not config.exists(if_path + ['policy']):
        return

    if config.exists(if_path + ['policy', 'route']):
        route_name = config.return_value(if_path + ['policy', 'route'])
        config.set(base4 + [route_name, 'interface'], value=ifname_full, replace=False)

    if config.exists(if_path + ['policy', 'route6']):
        route_name = config.return_value(if_path + ['policy', 'route6'])
        config.set(base6 + [route_name, 'interface'], value=ifname_full, replace=False)

    config.delete(if_path + ['policy'])

def migrate(config: ConfigTree) -> None:
    if not config.exists(base4) and not config.exists(base6):
        # Delete orphaned nodes on interfaces T5941
        for iftype in config.list_nodes(['interfaces']):
            for ifname in config.list_nodes(['interfaces', iftype]):
                delete_orphaned_interface_policy(config, iftype, ifname)

                if config.exists(['interfaces', iftype, ifname, 'vif']):
                    for vif in config.list_nodes(['interfaces', iftype, ifname, 'vif']):
                        delete_orphaned_interface_policy(config, iftype, ifname, vif=vif)

                if config.exists(['interfaces', iftype, ifname, 'vif-s']):
                    for vifs in config.list_nodes(['interfaces', iftype, ifname, 'vif-s']):
                        delete_orphaned_interface_policy(config, iftype, ifname, vifs=vifs)

                        if config.exists(['interfaces', iftype, ifname, 'vif-s', vifs, 'vif-c']):
                            for vifc in config.list_nodes(['interfaces', iftype, ifname, 'vif-s', vifs, 'vif-c']):
                                delete_orphaned_interface_policy(config, iftype, ifname, vifs=vifs, vifc=vifc)

        # Nothing to do
        return

    for iftype in config.list_nodes(['interfaces']):
        for ifname in config.list_nodes(['interfaces', iftype]):
            migrate_interface(config, iftype, ifname)

            if config.exists(['interfaces', iftype, ifname, 'vif']):
                for vif in config.list_nodes(['interfaces', iftype, ifname, 'vif']):
                    migrate_interface(config, iftype, ifname, vif=vif)

            if config.exists(['interfaces', iftype, ifname, 'vif-s']):
                for vifs in config.list_nodes(['interfaces', iftype, ifname, 'vif-s']):
                    migrate_interface(config, iftype, ifname, vifs=vifs)

                    if config.exists(['interfaces', iftype, ifname, 'vif-s', vifs, 'vif-c']):
                        for vifc in config.list_nodes(['interfaces', iftype, ifname, 'vif-s', vifs, 'vif-c']):
                            migrate_interface(config, iftype, ifname, vifs=vifs, vifc=vifc)