index.ts

const base64Chars = "-0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz";
const base = 64;
let previousTime = 0;
const counter = new Array(12).fill(0);

function toBase64(num: number, length: number): string {
  let result = "";
  for (let i = 0; i < length; i++) {
    result = base64Chars[num % base] + result;
    num = Math.floor(num / base);
  }
  return result;
}

function generateRandomBase64(length: number): string {
  let result = "";
  for (let i = 0; i < length; i++) {
    result += base64Chars[Math.floor(Math.random() * base)];
  }
  return result;
}

function generateUUID(): string {
  const currentTime = Date.now();
  const timeBase64 = toBase64(currentTime, 8);
  let randomOrCounterBase64 = "";

  if (currentTime === previousTime) {
    // Increment the counter
    for (let i = counter.length - 1; i >= 0; i--) {
      counter[i]++;
      if (counter[i] < base) {
        break;
      } else {
        counter[i] = 0;
      }
    }
    randomOrCounterBase64 = counter.map(index => base64Chars[index]).join("");
  } else {
    // Generate new random values and initialize counter with random starting values
    randomOrCounterBase64 = generateRandomBase64(12);
    // Initialize counter with random values instead of zeros to avoid hyphen-heavy sequences
    for (let i = 0; i < counter.length; i++) {
      counter[i] = Math.floor(Math.random() * base);
    }
    previousTime = currentTime;
  }

  return timeBase64 + randomOrCounterBase64;
}

function generateRowID(): string {
  return generateUUID().replace(/_/g, "Z");
}

export default {
  generateUUID,
  generateRowID,
};