# Copyright 2019-2024 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/>.

# Change syntax of bond interface
# - move interface based bond-group to actual bond (de-nest)
# https://vyos.dev/T1614

from vyos.configtree import ConfigTree

base = ['interfaces', 'bonding']

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

    #
    # move interface based bond-group to actual bond (de-nest)
    #
    for intf in config.list_nodes(['interfaces', 'ethernet']):
        # check if bond-group exists
        if config.exists(['interfaces', 'ethernet', intf, 'bond-group']):
            # get configured bond interface
            bond = config.return_value(['interfaces', 'ethernet', intf, 'bond-group'])
            # delete old interface asigned (nested) bond group
            config.delete(['interfaces', 'ethernet', intf, 'bond-group'])
            # create new bond member interface
            config.set(base + [bond, 'member', 'interface'], value=intf, replace=False)

    #
    # some combinations were allowed in the past from a CLI perspective
    # but the kernel overwrote them - remove from CLI to not confuse the users.
    # In addition new consitency checks are in place so users can't repeat the
    # mistake. One of those nice issues is https://vyos.dev/T532
    for bond in config.list_nodes(base):
        if config.exists(base + [bond, 'arp-monitor', 'interval']) and config.exists(base + [bond, 'mode']):
            mode = config.return_value(base + [bond, 'mode'])
            if mode in ['802.3ad', 'transmit-load-balance', 'adaptive-load-balance']:
                intvl = int(config.return_value(base + [bond, 'arp-monitor', 'interval']))
                if intvl > 0:
                    # this is not allowed and the linux kernel replies with:
                    # option arp_interval: mode dependency failed, not supported in mode 802.3ad(4)
                    # option arp_interval: mode dependency failed, not supported in mode balance-alb(6)
                    # option arp_interval: mode dependency failed, not supported in mode balance-tlb(5)
                    #
                    # so we simply disable arp_interval by setting it to 0 and miimon will take care about the link
                    config.set(base + [bond, 'arp-monitor', 'interval'], value='0')