#!/usr/bin/python3
# SPDX-License-Identifier: AGPL-3.0-or-later
"""
Configuration helper for WireGuard.
"""

import argparse
import json
import subprocess

SERVER_INTERFACE = 'wg0'


def parse_arguments():
    """Return parsed command line arguments as dictionary."""
    parser = argparse.ArgumentParser()
    subparsers = parser.add_subparsers(dest='subcommand', help='Sub command')

    subparsers.add_parser('get-info',
                          help='Get info for each configured interface')

    subparsers.required = True
    return parser.parse_args()


def _get_info():
    """Return info for each configured interface."""
    output = subprocess.check_output(['wg', 'show', 'all',
                                      'dump']).decode().strip()
    lines = output.split('\n')
    interfaces = {}
    for line in lines:
        if not line:
            continue

        fields = line.split()
        fields = [field if field != '(none)' else None for field in fields]
        interface_name = fields[0]
        if interface_name in interfaces:
            latest_handshake = int(fields[5]) if int(fields[5]) else None
            peer = {
                'public_key': fields[1],
                'preshared_key': fields[2],
                'endpoint': fields[3],
                'allowed_ips': fields[4],
                'latest_handshake': latest_handshake,
                'transfer_rx': fields[6],
                'transfer_tx': fields[7],
                'persistent_keepalive': fields[8],
            }
            interfaces[interface_name]['peers'].append(peer)

        else:
            interfaces[interface_name] = {
                'interface_name': interface_name,
                'private_key': fields[1],
                'public_key': fields[2],
                'listen_port': fields[3],
                'fwmark': fields[4],
                'peers': [],
            }

    return interfaces


def subcommand_get_info(_):
    """Print info for each configured interface."""
    print(json.dumps(_get_info()))


def main():
    """Parse arguments and perform all duties."""
    arguments = parse_arguments()

    subcommand = arguments.subcommand.replace('-', '_')
    subcommand_method = globals()['subcommand_' + subcommand]
    subcommand_method(arguments)


if __name__ == '__main__':
    main()