import type { MaybePromise } from '../../asyncs/MaybePromise';

export function polyfillFetch(nodeFetch: typeof import('node-fetch')): boolean;
export function polyfillFetch(nodeFetch?: undefined): Promise<boolean>;
export function polyfillFetch(nodeFetch?: typeof import('node-fetch')): MaybePromise<boolean> {
	if ('fetch' in globalThis) {
		return false;
	}
	// sync mode
	if (nodeFetch) {
		const { default: fetch, Response, Headers, Request, AbortError, FetchError, FormData, Blob, File } = nodeFetch;
		Object.assign(globalThis, { fetch, Response, Headers, Request, AbortError, FetchError, FormData, Blob, File });
		// abort controller
		return true;
	}
	return import('node-fetch').then((v) => polyfillFetch(v));
}