export default function calcCRC16CCITT(payload: string): string {
  let result = 0xffff;

  if (payload.length > 0) {
    for (let offset = 0; offset < payload.length; offset++) {
      result ^= payload.charCodeAt(offset) << 8;
      for (let bitwise = 0; bitwise < 8; bitwise++) {
        if ((result <<= 1) & 0x10000) result ^= 0x1021;
        result &= 0xffff;
      }
    }
  }

  return result.toString(16).toUpperCase();
}