// A simple function to encrypt string
// to avoid being collected by robots.
function hide(seed, str) {
  const str_arr = new TextEncoder().encode(str);
  const res_arr = [];
  seed %= 1000000007;

  for (let i = 0; i < str_arr.length; i++) {
    res_arr.push((str_arr[i] + seed) % 256);
    seed = seed * seed % 1000000007;
  }


  return res_arr;
}

function unhide(seed, arr) {
  seed %= 1000000007;
  const str_arr = [];
  for (let i = 0; i < arr.length; i++) {
    str_arr.push((((arr[i] - seed) % 256) + 256) % 256)
    seed = seed * seed % 1000000007;
  }

  const ui8_arr = new Uint8Array(str_arr);
  const str = new TextDecoder().decode(ui8_arr);
  return str;
}

export {
  hide,
  unhide
}