const loadObserver = (handler: () => void, src = '') => {
  let waiting = 0;
  
  return (el: HTMLImageElement) => {
    waiting++;

    const path = el.src;

    el.onload = function () {
      waiting--;

      if (waiting === 0) {
        handler();
        if(src !== '') {
          // const timeout = setTimeout(() => {
          //   el.src = src;
          //   clearTimeout(timeout);
          // }, 100);
          el.src = src;
        }
      }
    };

    el.onerror = function () {
      waiting--;

      if (waiting === 0) {
        handler();
      }
    };

    el.src = path;
  };
};

export default loadObserver;