import { Loader } from "./Loader.ts";
import { DefaultLoadingManager } from "./LoadingManager.ts";

/** Loads an image as an ImageBitmap. */
export class ImageBitmapLoader extends Loader {
	#options: ImageBitmapOptions = {};

	setOptions(options: ImageBitmapOptions): this {
		this.#options = options;
		return this;
	}

	override load(
		url: string,
		onLoad?: (bitmap: ImageBitmap) => void,
		_onProgress?: (event: ProgressEvent) => void,
		onError?: (err: unknown) => void,
	): void {
		const manager = this.manager ?? DefaultLoadingManager;
		const fullUrl = this.path + url;
		const options = this.#options;

		manager.itemStart(fullUrl);

		fetch(fullUrl, { headers: { Accept: "image/*", ...this.requestHeader } })
			.then((response) => {
				if (!response.ok) {
					throw new Error(
						`ImageBitmapLoader: fetch failed - ${response.status} ${response.statusText}`,
					);
				}
				return response.blob();
			})
			.then((blob) => createImageBitmap(blob, options))
			.then((bitmap) => {
				onLoad?.(bitmap);
				manager.itemEnd(fullUrl);
			})
			.catch((err: unknown) => {
				onError?.(err);
				manager.itemError(fullUrl);
			});
	}
}