#!/usr/bin/env python3
import importlib.util
import json
import re
from pathlib import Path


ROOT = Path(__file__).resolve().parents[1]


def load_client():
    path = ROOT / "public" / "kem_client.py"
    spec = importlib.util.spec_from_file_location("nullroute_client", path)
    module = importlib.util.module_from_spec(spec)
    assert spec.loader is not None
    spec.loader.exec_module(module)
    return module


def main() -> None:
    client = load_client()
    capsule = json.loads((ROOT / "public" / "capsule.json").read_text())
    plaintext = client.decrypt_capsule(capsule).decode()
    match = re.search(r"caplag\{[^}]+\}", plaintext)
    if not match:
        raise SystemExit("flag not found")
    print(match.group(0))


if __name__ == "__main__":
    main()