#!/usr/bin/env python3
#
# Copyright (C) 2017-2024 VyOS maintainers and contributors
#
# 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/>.

import os

from sys import exit

from vyos.base import Warning
from vyos.config import Config
from vyos.utils.network import is_addr_assigned
from vyos.utils.network import is_loopback_addr
from vyos.version import get_version_data
from vyos.utils.process import call
from vyos.template import render
from vyos import ConfigError
from vyos import airbag
airbag.enable()

config_file = "/etc/default/lldpd"
vyos_config_file = "/etc/lldpd.d/01-vyos.conf"
base = ['service', 'lldp']

def get_config(config=None):
    if config:
        conf = config
    else:
        conf = Config()

    if not conf.exists(base):
        return {}

    lldp = conf.get_config_dict(base, key_mangling=('-', '_'),
                                no_tag_node_value_mangle=True,
                                get_first_key=True,
                                with_recursive_defaults=True)

    if conf.exists(['service', 'snmp']):
        lldp['system_snmp_enabled'] = ''

    version_data = get_version_data()
    lldp['version'] = version_data['version']

    # prune location information if not set by user
    for interface in lldp.get('interface', []):
        if lldp.from_defaults(['interface', interface, 'location']):
            del lldp['interface'][interface]['location']
        elif lldp.from_defaults(['interface', interface, 'location','coordinate_based']):
            del lldp['interface'][interface]['location']['coordinate_based']

    return lldp

def verify(lldp):
    # bail out early - looks like removal from running config
    if lldp is None:
        return

    if 'management_address' in lldp:
        for address in lldp['management_address']:
            message = f'LLDP management address "{address}" is invalid'
            if is_loopback_addr(address):
                Warning(f'{message} - loopback address')
            elif not is_addr_assigned(address):
                Warning(f'{message} - not assigned to any interface')

    if 'interface' in lldp:
        for interface, interface_config in lldp['interface'].items():
            # bail out early if no location info present in interface config
            if 'location' not in interface_config:
                continue
            if 'coordinate_based' in interface_config['location']:
                if not {'latitude', 'latitude'} <= set(interface_config['location']['coordinate_based']):
                    raise ConfigError(f'Must define both longitude and latitude for "{interface}" location!')

    # check options
    if 'snmp' in lldp:
        if 'system_snmp_enabled' not in lldp:
            raise ConfigError('SNMP must be configured to enable LLDP SNMP!')


def generate(lldp):
    # bail out early - looks like removal from running config
    if lldp is None:
        return

    render(config_file, 'lldp/lldpd.j2', lldp)
    render(vyos_config_file, 'lldp/vyos.conf.j2', lldp)

def apply(lldp):
    systemd_service = 'lldpd.service'
    if lldp:
        # start/restart lldp service
        call(f'systemctl restart {systemd_service}')
    else:
        # LLDP service has been terminated
        call(f'systemctl stop {systemd_service}')
        if os.path.isfile(config_file):
            os.unlink(config_file)
        if os.path.isfile(vyos_config_file):
            os.unlink(vyos_config_file)

if __name__ == '__main__':
    try:
        c = get_config()
        verify(c)
        generate(c)
        apply(c)
    except ConfigError as e:
        print(e)
        exit(1)