// src/hooks/useAssetLoader.ts
import { useState, useEffect } from 'react';

// Defines the structure for our asset map
export type AssetSource = {
  id: string;
  label: string;
  src: string;
};

// The hook returns the loaded images and the loading status
export const useAssetLoader = (assets: AssetSource[]) => {
  const [loadedImages, setLoadedImages] = useState<
    Record<string, HTMLImageElement>
  >({});
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    // Reset state when assets change
    setIsLoading(true);
    setLoadedImages({});
    setError(null);

    if (assets.length === 0) {
      setIsLoading(false);
      return;
    }

    const loadImages = async () => {
      try {
        const promises = assets.map((asset) => {
          return new Promise<void>((resolve, reject) => {
            const img = new Image();
            // --- THIS IS THE CRITICAL FIX ---
            // This attribute tells the browser it's okay to use this cross-origin image on a canvas
            // that you intend to capture a stream from.
            img.crossOrigin = "anonymous";
            // --------------------------------

            img.src = asset.src;
            img.onload = () => {
              setLoadedImages((prev) => ({ ...prev, [asset.id]: img }));
              resolve();
            };
            img.onerror = (err) => {
              console.error(
                `Failed to load asset: ${asset.label} from ${asset.src}`,
                err
              );
              reject(new Error(`Failed to load ${asset.label}`));
            };
          });
        });

        await Promise.all(promises);
      } catch (err: unknown) {
        console.error("Failed to load one or more assets:", err);
        if (err instanceof Error) {
          setError(err.message);
        } else {
          setError("An unknown error occurred during asset loading.");
        }
      } finally {
        setIsLoading(false);
      }
    };

    loadImages();
  }, [JSON.stringify(assets)]); // Use stringify to deep-compare the assets array dependency

  return { loadedImages, isLoading, error };
};