import type { LoadingManager } from "./LoadingManager.ts";

/** Abstract base loader. */
export class Loader {
	#manager: LoadingManager | undefined;
	#path = "";
	#crossOrigin = "";
	#requestHeader: Record<string, string> = {};

	constructor(manager: LoadingManager | undefined = undefined) {
		this.#manager = manager;
	}

	get manager(): LoadingManager | undefined {
		return this.#manager;
	}

	get path(): string {
		return this.#path;
	}

	get crossOrigin(): string {
		return this.#crossOrigin;
	}

	get requestHeader(): Record<string, string> {
		return this.#requestHeader;
	}

	setPath(path: string): this {
		this.#path = path;
		return this;
	}

	setCrossOrigin(crossOrigin: string): this {
		this.#crossOrigin = crossOrigin;
		return this;
	}

	setRequestHeader(requestHeader: Record<string, string>): this {
		this.#requestHeader = requestHeader;
		return this;
	}

	/**
	 * Abstract - subclasses override.
	 */
	load(
		_url: string,
		_onLoad: ((data: unknown) => void) | undefined,
		_onProgress: ((event: ProgressEvent) => void) | undefined,
		_onError: ((err: unknown) => void) | undefined,
	): void {
		// Abstract
	}

	/**
	 * Promise-based wrapper around load().
	 */
	loadAsync(
		url: string,
		onProgress?: (event: ProgressEvent) => void,
	): Promise<unknown> {
		return new Promise((resolve, reject) => {
			this.load(url, resolve, onProgress, reject);
		});
	}
}