# 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.
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# 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/>.

# T4118: Change vpn ipsec syntax for IKE ESP and peer
# T4879: IPsec migration script remote-id for peer name eq address

import re

from vyos.configtree import ConfigTree

base = ['vpn', 'ipsec']

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

    # IKE changes, T4118:
    if config.exists(base + ['ike-group']):
        for ike_group in config.list_nodes(base + ['ike-group']):
            # replace 'ipsec ike-group <tag> mobike disable'
            #      => 'ipsec ike-group <tag> disable-mobike'
            mobike = base + ['ike-group', ike_group, 'mobike']
            if config.exists(mobike):
                if config.return_value(mobike) == 'disable':
                    config.set(base + ['ike-group', ike_group, 'disable-mobike'])
                config.delete(mobike)

            # replace 'ipsec ike-group <tag> ikev2-reauth yes'
            #      => 'ipsec ike-group <tag> ikev2-reauth'
            reauth = base + ['ike-group', ike_group, 'ikev2-reauth']
            if config.exists(reauth):
                if config.return_value(reauth) == 'yes':
                    config.delete(reauth)
                    config.set(reauth)
                else:
                    config.delete(reauth)

    # ESP changes
    # replace 'ipsec esp-group <tag> compression enable'
    #      => 'ipsec esp-group <tag> compression'
    if config.exists(base + ['esp-group']):
        for esp_group in config.list_nodes(base + ['esp-group']):
            compression = base + ['esp-group', esp_group, 'compression']
            if config.exists(compression):
                if config.return_value(compression) == 'enable':
                    config.delete(compression)
                    config.set(compression)
                else:
                    config.delete(compression)

    # PEER changes
    if config.exists(base + ['site-to-site', 'peer']):
        for peer in config.list_nodes(base + ['site-to-site', 'peer']):
            peer_base = base + ['site-to-site', 'peer', peer]

            # replace: 'peer <tag> id x'
            #       => 'peer <tag> local-id x'
            if config.exists(peer_base + ['authentication', 'id']):
                config.rename(peer_base + ['authentication', 'id'], 'local-id')

            # For the peer '@foo' set remote-id 'foo' if remote-id is not defined
            # For the peer '192.0.2.1' set remote-id '192.0.2.1' if remote-id is not defined
            if not config.exists(peer_base + ['authentication', 'remote-id']):
                tmp = peer.replace('@', '') if peer.startswith('@') else peer
                config.set(peer_base + ['authentication', 'remote-id'], value=tmp)

            # replace: 'peer <tag> force-encapsulation enable'
            #       => 'peer <tag> force-udp-encapsulation'
            force_enc = peer_base + ['force-encapsulation']
            if config.exists(force_enc):
                if config.return_value(force_enc) == 'enable':
                    config.delete(force_enc)
                    config.set(peer_base + ['force-udp-encapsulation'])
                else:
                    config.delete(force_enc)

            # add option: 'peer <tag> remote-address x.x.x.x'
            remote_address = peer
            if peer.startswith('@'):
                remote_address = 'any'
            config.set(peer_base + ['remote-address'], value=remote_address)
            # Peer name it is swanctl connection name and shouldn't contain dots or colons
            # rename peer:
            #   peer 192.0.2.1   => peer peer_192-0-2-1
            #   peer 2001:db8::2 => peer peer_2001-db8--2
            #   peer @foo        => peer peer_foo
            re_peer_name = re.sub(':|\.', '-', peer)
            if re_peer_name.startswith('@'):
                re_peer_name = re.sub('@', '', re_peer_name)
            new_peer_name = f'peer_{re_peer_name}'

            config.rename(peer_base, new_peer_name)

    # remote-access/road-warrior changes
    if config.exists(base + ['remote-access', 'connection']):
        for connection in config.list_nodes(base + ['remote-access', 'connection']):
            ra_base = base + ['remote-access', 'connection', connection]
            # replace: 'remote-access connection <tag> authentication id x'
            #       => 'remote-access connection <tag> authentication local-id x'
            if config.exists(ra_base + ['authentication', 'id']):
                config.rename(ra_base + ['authentication', 'id'], 'local-id')