#!/usr/bin/env python3

# Copyright 2018-2024 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/>.

# Removes boolean operator from:
#   - "set service dhcp-server shared-network-name <xyz> subnet 172.31.0.0/24 ip-forwarding enable (true|false)"
#   - "set service dhcp-server shared-network-name <xyz> authoritative (true|false)"
#   - "set service dhcp-server disabled (true|false)"

from vyos.configtree import ConfigTree

def migrate(config: ConfigTree) -> None:
    if not config.exists(['service', 'dhcp-server']):
        # Nothing to do
        return
    else:
        base = ['service', 'dhcp-server']
        # Make node "set service dhcp-server dynamic-dns-update enable (true|false)" valueless
        if config.exists(base + ['dynamic-dns-update']):
            bool_val = config.return_value(base + ['dynamic-dns-update', 'enable'])

            # Delete the node with the old syntax
            config.delete(base + ['dynamic-dns-update'])
            if str(bool_val) == 'true':
                # Enable dynamic-dns-update with new syntax
                config.set(base + ['dynamic-dns-update'], value=None)

        # Make node "set service dhcp-server disabled (true|false)" valueless
        if config.exists(base + ['disabled']):
            bool_val = config.return_value(base + ['disabled'])

            # Delete the node with the old syntax
            config.delete(base + ['disabled'])
            if str(bool_val) == 'true':
                # Now disable DHCP server with the new syntax
                config.set(base + ['disable'], value=None)

        # Make node "set service dhcp-server hostfile-update (enable|disable) valueless
        if config.exists(base + ['hostfile-update']):
            bool_val = config.return_value(base + ['hostfile-update'])

            # Delete the node with the old syntax incl. all subnodes
            config.delete(base + ['hostfile-update'])
            if str(bool_val) == 'enable':
                # Enable hostfile update with new syntax
                config.set(base + ['hostfile-update'], value=None)

        # Run this for every instance if 'shared-network-name'
        for network in config.list_nodes(base + ['shared-network-name']):
            base_network = base + ['shared-network-name', network]
            # format as tag node to avoid loading problems
            config.set_tag(base + ['shared-network-name'])

            # Run this for every specified 'subnet'
            for subnet in config.list_nodes(base_network + ['subnet']):
                base_subnet = base_network + ['subnet', subnet]
                # format as tag node to avoid loading problems
                config.set_tag(base_network + ['subnet'])

                # Make node "set service dhcp-server shared-network-name <xyz> subnet 172.31.0.0/24 ip-forwarding enable" valueless
                if config.exists(base_subnet + ['ip-forwarding', 'enable']):
                    bool_val = config.return_value(base_subnet + ['ip-forwarding', 'enable'])
                    # Delete the node with the old syntax
                    config.delete(base_subnet + ['ip-forwarding'])
                    if str(bool_val) == 'true':
                        # Recreate node with new syntax
                        config.set(base_subnet + ['ip-forwarding'], value=None)

                # Rename node "set service dhcp-server shared-network-name <xyz> subnet 172.31.0.0/24 start <172.16.0.4> stop <172.16.0.9>
                if config.exists(base_subnet + ['start']):
                    # This is the new "range" id for DHCP lease ranges
                    r_id = 0
                    for range in config.list_nodes(base_subnet + ['start']):
                        range_start = range
                        range_stop = config.return_value(base_subnet + ['start', range_start, 'stop'])

                        # Delete the node with the old syntax
                        config.delete(base_subnet + ['start', range_start])

                        # Create the node for the new syntax
                        # Note: range is a tag node, counter is its child, not a value
                        config.set(base_subnet + ['range', r_id])
                        config.set(base_subnet + ['range', r_id, 'start'], value=range_start)
                        config.set(base_subnet + ['range', r_id, 'stop'], value=range_stop)

                        # format as tag node to avoid loading problems
                        config.set_tag(base_subnet + ['range'])

                        # increment range id for possible next range definition
                        r_id += 1

                    # Delete the node with the old syntax
                    config.delete(['service', 'dhcp-server', 'shared-network-name', network, 'subnet', subnet, 'start'])


            # Make node "set service dhcp-server shared-network-name <xyz> authoritative" valueless
            if config.exists(['service', 'dhcp-server', 'shared-network-name', network, 'authoritative']):
                authoritative = config.return_value(['service', 'dhcp-server', 'shared-network-name', network, 'authoritative'])

                # Delete the node with the old syntax
                config.delete(['service', 'dhcp-server', 'shared-network-name', network, 'authoritative'])

                # Recreate node with new syntax - if required
                if authoritative == "enable":
                    config.set(['service', 'dhcp-server', 'shared-network-name', network, 'authoritative'])