import { emitEvent } from '../dom/event.js';
import { createPromiseResolver } from './create-promise-resolver.js';
import { waitForPromiseSet } from './wait-for-promise.js';


export type PauseableEvent = CustomEvent<{
	id: string;
	addPromise: (promise: Promise<any>) => void;
}>


export const pauseableEvent = async (element: HTMLElement, eventName: string) => {
	const [ promise, resolve, , id ] = createPromiseResolver();
	const promises = new Set([ promise ]);
	promise.finally(() => promises.delete(promise));

	const addPromise = (promise: Promise<any>) => {
		promises.add(promise);
		promise.finally(() => promises.delete(promise));
	};

	const windowResolve = (ev: CustomEvent<{id: string;}>) => ev.detail.id === id && resolve();

	window.addEventListener(eventName, windowResolve as any);

	emitEvent(element, eventName, { detail: { id, addPromise } });

	await waitForPromiseSet(promises);

	window.removeEventListener(eventName, windowResolve as any);
};