#!/usr/bin/env python3
import configparser
import subprocess
import re
import io

def offline():
    expr = re.compile("ips:[^()]+handshake")
    proc = subprocess.run(["wg", "show", "vpn"], capture_output=True, encoding="utf-8")
    return len(expr.findall(proc.stdout)) == 0

def rotate_conf():
    iface = None
    peers = []
    try:
        with open("/snacks/wireguard/wg.conf", "r") as f:
            pattern = re.compile("\[[^\[\]]+\][^\[\]]+")
            sections = []
            for section in re.findall(pattern, f.read()):
                sections.append(section.strip())
    except Exception as e:
        print(e)
    else:
        for section in sections:
            config = configparser.ConfigParser()
            config.read_string(section)
            if "Peer" in config.sections():
                peers.append(config)
            else:
                iface = config
    buf = io.StringIO()
    try:
        iface.write(buf)
    except Exception as e:
        print(e)
    else:
        first = peers.pop(0)
        peers.append(first)
        for peer in peers:
            peer.write(buf)
        try:
            with open("/snacks/wireguard/wg.conf", "w") as f:
                f.write(buf.getvalue())
        except Exception as e:
            print(e)

if offline():
    rotate_conf()
    subprocess.run(["systemctl", "restart", "vpnclient-wg"])