[ image polling ]

import { useState, useEffect } from 'react';

const checkImage = (url: string): Promise<boolean> => {
  return new Promise(resolve => {
    const image = new Image();
    image.onload = () => resolve(true);
    image.onerror = () => resolve(false);
    image.src = `${url}&r=${Math.random()}`; // 캐시 방지
  });
};

export const useImagePolling = (
  url: string,
  isGenerationComplete: boolean,
  interval: number = 5000,
): boolean => {
  const [imageLoaded, setImageLoaded] = useState<boolean>(false);

  useEffect(() => {
    let isMounted = true;
    let timeoutId: number;

    const pollImage = async (): Promise<void> => {
      if (!isGenerationComplete) {
        if (isMounted) {
          timeoutId = window.setTimeout(pollImage, interval);
        }
        return;
      }

      const exists = await checkImage(url);
      if (exists && isMounted) {
        setImageLoaded(true);
      } else if (isMounted) {
        timeoutId = window.setTimeout(pollImage, interval);
      }
    };

    pollImage();

    return () => {
      isMounted = false;
      if (timeoutId) {
        window.clearTimeout(timeoutId);
      }
    };
  }, [url, interval, isGenerationComplete]);

  return imageLoaded;
};