import { isPromise } from './isPromise';
import type { MaybePromise } from './MaybePromise';
import { nextOfAsyncIterator } from './nextOfAsyncIterator';

export function firstOfAsyncIterator<T>(it: MaybePromise<AsyncIterator<T> | Iterator<T> | T>): MaybePromise<T> {
	const next = nextOfAsyncIterator(it);
	if (isPromise(next)) {
		return next.then((v) => v[0]);
	}
	return next[0];
}