Add alarms api

src/utils.ts

@@ -16,3 +16,57 @@ export const rotateArray = <T>(arr: T[], reverse = false): T[] => {
 	else arr.push(arr.shift()!);
 	return arr;
 };
+
+type resolveCallback<T> = (value: T) => void;
+type rejectCallback = (reason?: unknown) => void;
+export const newPromise = <T>(): [
+	Promise<T>,
+	resolveCallback<T>,
+	rejectCallback
+] => {
+	let resolve: resolveCallback<T>;
+	let reject: rejectCallback;
+	const promise = new Promise(
+		(res: resolveCallback<T>, rej: rejectCallback) => {
+			resolve = res;
+			reject = rej;
+		}
+	);
+	return [promise, resolve!, reject!];
+};
+
+declare global {
+	interface Window {
+		alarmsMap?: Map<any, [Promise<void>, rejectCallback]>;
+	}
+}
+
+//Clone of the https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/alarms
+export namespace Alarms {
+	const getMap = () => {
+		window.alarmsMap ??= new Map();
+		return window.alarmsMap;
+	};
+
+	export const create = (delay: number, name?: any) => {
+		const map = getMap();
+		const alrm = map.get(name);
+		if (alrm) alrm[1]();
+
+		const [promise, resolve, reject] = newPromise<void>();
+		const timeout = setTimeout(resolve, delay);
+		promise.catch(() => window.clearTimeout(timeout));
+
+		if (name != undefined) map.set(name, [promise, reject]);
+		return promise;
+	};
+
+	export const get = (name: any) => (getMap().get(name) ?? [])[0];
+	export const getAll = () => Array.from(getMap().entries()).map((a) => a[0]);
+
+	export const clear = (name: any) => {
+		const alrm = getMap().get(name);
+		if (alrm) alrm[1]();
+	};
+	export const clearAll = () => getMap().forEach((a) => a[1]());
+}