#!/usr/bin/env python3
import argparse
import os
import shutil
import subprocess
import sys
from pathlib import Path
from datetime import datetime

WG_DIR = Path("/etc/wireguard")
WG0 = WG_DIR / "wg0.conf"


def require_root():
    if os.geteuid() != 0:
        print("ERROR: run as root (sudo).", file=sys.stderr)
        sys.exit(1)


def run(cmd, check=True, capture=False):
    return subprocess.run(
        cmd,
        check=check,
        text=True,
        stdout=subprocess.PIPE if capture else None,
        stderr=subprocess.PIPE if capture else None,
    )


def backup_if_exists(p: Path):
    if p.exists():
        ts = datetime.now().strftime("%Y-%m-%d_%H%M%S")
        b = p.with_name(p.name + f".bak.{ts}")
        shutil.copy2(p, b)


def cmd_install(src: str):
    srcp = Path(src)
    if not srcp.exists():
        raise RuntimeError(f"Missing source config: {srcp}")
    WG_DIR.mkdir(parents=True, exist_ok=True)
    os.chmod(WG_DIR, 0o700)
    backup_if_exists(WG0)
    shutil.copy2(srcp, WG0)
    os.chmod(WG0, 0o600)
    os.chown(WG0, 0, 0)
    print(f"OK: installed {WG0}")


def cmd_up():
    run(["wg-quick", "up", "wg0"], check=True)


def cmd_down():
    run(["wg-quick", "down", "wg0"], check=False)


def cmd_status():
    run(["wg", "show"], check=False)
    run(["ip", "a", "show", "wg0"], check=False)


def main():
    require_root()
    p = argparse.ArgumentParser(prog="wg_client.py")
    sub = p.add_subparsers(dest="cmd", required=True)

    i = sub.add_parser("install")
    i.add_argument("config", help="Path to clientX.conf from server export")

    sub.add_parser("up")
    sub.add_parser("down")
    sub.add_parser("status")

    args = p.parse_args()

    try:
        if args.cmd == "install":
            cmd_install(args.config)
        elif args.cmd == "up":
            cmd_up()
        elif args.cmd == "down":
            cmd_down()
        elif args.cmd == "status":
            cmd_status()
    except Exception as e:
        print(f"ERROR: {e}", file=sys.stderr)
        sys.exit(1)


if __name__ == "__main__":
    main()