type Closable = { close(): void } | (() => void) | Disposable;

/**
 * @see DisposableStack
 */
export class Closer implements Disposable {
	closers: Array<Closable> = [];

	defer(closer: Closable | null | undefined) {
		if (!closer) {
			return;
		}
		this.closers.push(closer);
	}

	add<T extends Closable | null | undefined>(closer: T): T {
		if (!closer) {
			return closer;
		}
		this.closers.push(closer);
		return closer;
	}

	[Symbol.dispose]() {
		for (let closer of this.closers) {
			if (typeof closer === 'function') {
				closer();
			} else if (Symbol.dispose in closer) {
				closer[Symbol.dispose]();
			} else {
				closer.close();
			}
		}
	}

	close() {
		this[Symbol.dispose]();
	}
}