#!/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/>.
#
# T3871: interface names are no longer derived from 'hw-id'. Carry the existing
# bindings over to the mapping store - anchored to the slot the MAC sits in, so
# nothing is renamed - then drop the node. Hardware which is not present is
# skipped: the configuration may well originate from another machine.

from vyos.configtree import ConfigTree
from vyos.ifconfig.ifname_store import discover_devices
from vyos.ifconfig.ifname_store import load_store
from vyos.ifconfig.ifname_store import save_store
from vyos.ifconfig.ifname_store import sync_link_files

bases = (['interfaces', 'ethernet'], ['interfaces', 'wireless'])


def migrate(config: ConfigTree) -> None:
    bindings = {}
    for base in bases:
        if not config.exists(base):
            continue
        for intf in config.list_nodes(base):
            path = base + [intf, 'hw-id']
            if config.exists(path):
                bindings[intf] = config.return_value(path).lower()
                config.delete(path)

    if not bindings:
        return

    devices = {device['mac']: device for device in discover_devices()}
    store = load_store()
    entries = store['interfaces']
    added = False

    taken = set(entries.values())

    for name, hwid in bindings.items():
        device = devices.get(hwid)
        if device is None or not device['key']:
            continue
        # an entry already in the store is authoritative, and a slot already
        # spoken for must not gain a second name - only one of them could
        # ever be filled
        if name in entries or device['key'] in taken:
            continue
        entries[name] = device['key']
        taken.add(device['key'])
        added = True

    if added and save_store(store):
        try:
            sync_link_files(store, devices=list(devices.values()))
        except OSError:
            pass