IMPORTANT!! `formatStrToTime` will show different result if you did `formatTimeToStr` with different depth

time-helper.ts

export const timeUnits = [
  // { name: "y", milliseconds: 31_536_000_000 },
  // { name: "mo", milliseconds: 2_592_000_000 },
  { name: "d", milliseconds: 86_400_000 },
  { name: "h", milliseconds: 3_600_000 },
  { name: "m", milliseconds: 60_000 },
  { name: "s", milliseconds: 1_000 },
  { name: "ms", milliseconds: 1 },
];

/**
 * @function formatTime
 * @param {number} time - unix timestamp
 * @param {number} depth - how many time units to show (default: 2)
 * @returns {string} formatted total time. Example: 15d 5h 25m 4s
 */
export function formatTimeToStr(time: number, depth = Infinity) {
  const formattedTime: string[] = [];
  let remainingTime = time;

  // TODO: calculate years and months by starting from the current date or provided date in param
  for (const timeUnit of timeUnits) {
    const timeUnitValue = Math.floor(remainingTime / timeUnit.milliseconds);

    if (timeUnitValue > 0) {
      formattedTime.push(`${timeUnitValue}${timeUnit.name}`);
      remainingTime -= timeUnitValue * timeUnit.milliseconds;
    }
  }

  return formattedTime.slice(0, depth).join(" ");
}

/**
 * @function formatTime
 * @param {string} str - string with all time formats joined with space. Example: "5h 21m 37s"
 * @returns {number} total time in milliseconds
 */
export function formatStrToTime(str: string) {
  const timeArr = str.split(" ");
  let time = 0;

  // TODO: calculate years and months by starting from the current date or provided date in param
  for (const timeUnit of timeUnits) {
    const timeUnitValue = timeArr.find((timeStr) =>
      timeStr.endsWith(timeUnit.name)
    );

    if (timeUnitValue) {
      time +=
        Number(timeUnitValue.slice(0, -timeUnit.name.length)) *
        timeUnit.milliseconds;
    }
  }

  return time;
}