04. Stopwatch

function stopwatch() {
  const currentTime = document.querySelector('#time');
  const startButton = document.querySelector('#startBtn');
  const stopButton = document.querySelector('#stopBtn');
  let time = 0;
  let intervalId;

  const formatTime = (timeValue) => {
    const min = Math.floor(timeValue / 60);
    const sec = timeValue % 60;
    return `${(`0${min}`).slice(-2)}:${(`0${sec}`).slice(-2)}`;
  };

  const startButtonHandler = () => {
    time = 0;
    currentTime.innerText = formatTime(0);
    stopButton.removeAttribute('disabled');
    startButton.setAttribute('disabled', true);

    intervalId = setInterval(() => {
      time++;
      currentTime.innerText = formatTime(time);
    }, 1000);
  };

  const stopButtonHandler = () => {
    stopButton.setAttribute('disabled', true);
    startButton.removeAttribute('disabled');
    clearInterval(intervalId);
  };

  startButton.addEventListener('click', startButtonHandler);

  stopButton.addEventListener('click', stopButtonHandler);
}