Unique key gennerator

key.ts

import dayjs from 'src/common/day';

const k = 'abcdefghijklmnopqustuvwxyz0123456789';

const generateBit = (word: number[], index: number) =>
  word[0] + index >= k.length
    ? k[(word[0] + index) % k.length]
    : k[word[0] + index];

const generateKey = (n: number, word: number[] = []) => {
  const left = Math.trunc(n / k.length);
  const right = n % k.length;

  word.push(right);

  if (left < k.length) {
    if (left > 0) {
      word.push(left);
    }

    const sec = generateBit(word, 1);
    const tri = generateBit(word, 2);
    const correct = word.reverse();

    return `${tri}${correct.map((c) => k[c]).join('')}${sec}`;
  }
  return generateKey(left, word);
};

export const getSurveyKey = (): string => {
  const dt = dayjs.utc().unix();
  const rnd = Math.floor(Math.random() * 999);
  const n = Number(`${dt}${rnd}`);
  return generateKey(n);
};