# Copyright (C) VyOS Inc.
#
# 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/>.

# T8865: When "address-family l2vpn-evpn advertise-all-vni" is
# configured remove the conflicting "vni" sub-node from each affected VRF
# because FRR returns "Failed to create VNI".

from vyos.configtree import ConfigTree

vrf_base = ['vrf', 'name']
bgp_base = ['protocols', 'bgp']
bgp_l2vpn_evpn = bgp_base + ['address-family', 'l2vpn-evpn']


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

    # Only act when advertise-all-vni is set in the default BGP instance
    if not config.exists(bgp_l2vpn_evpn + ['advertise-all-vni']):
        return

    for vrf in config.list_nodes(vrf_base):
        vni_path = vrf_base + [
            vrf,
            'protocols',
            'bgp',
            'address-family',
            'l2vpn-evpn',
            'vni',
        ]
        if config.exists(vni_path):
            config.delete(vni_path)