export function randomNum(len: number, radix: number) {
  const chars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');
  const uuid: string[] = [];
  radix = radix ?? chars.length;

  if (len) {
    // Compact form
    for (let i = 0; i < len; i++) {
      uuid[i] = chars[0 | (Math.random() * radix)] ?? '';
    }
  } else {
    // rfc4122, version 4 form
    let r: number;

    // rfc4122 requires these characters
    uuid[8] = uuid[13] = uuid[18] = uuid[23] = '-';
    uuid[14] = '4';

    // Fill in random data.  At i==19 set the high bits of clock sequence as
    // per rfc4122, sec. 4.1.5
    for (let i = 0; i < 36; i++) {
      if (!uuid[i]) {
        r = 0 | (Math.random() * 16);
        uuid[i] = chars[i === 19 ? (r & 0x3) | 0x8 : r] ?? '';
      }
    }
  }
  return uuid.join('') + new Date().getTime();
}
