introduce fluent observable and per minute rate limit

web/src/engine/Observable.ts

@@ -51,15 +51,17 @@ export class Observable<TValue, TOwner = null> implements IObservable<TValue, TO
     /**
      * Register a {@link callback} that gets invoked whenever the {@link Value} is changed or a notification is forced via {@link Dispatch}.
      */
-    public Subscribe(callback: SubscriberCallback<TValue, TOwner>): void {
+    public Subscribe(callback: SubscriberCallback<TValue, TOwner>): typeof this {
         this.subscribers.add(callback);
+        return this;
     }
 
     /**
      * Unregister the {@link callback} from any further notifications.
      */
-    public Unsubscribe(callback: SubscriberCallback<TValue, TOwner>): void {
+    public Unsubscribe(callback: SubscriberCallback<TValue, TOwner>): typeof this {
         this.subscribers.delete(callback);
+        return this;
     }
 }
 

web/src/engine/taskpool/RateLimit.ts

@@ -15,6 +15,14 @@ export class RateLimit {
     public get Throttle() {
         return this.amount > 0 && this.interval > 0 ? this.interval * 1000 / this.amount : 0;
     }
+
+    /**
+     * Create a new {@link RateLimit} instance.
+     * @param amount - Maximum number of units within an interval of 60 seconds.
+     */
+    public static PerMinute(amount: number) {
+        return new RateLimit(amount, 60);
+    }
 }
 
 export const Unlimited = new RateLimit(0, 0);

web/src/engine/websites/MangaDex.ts

@@ -5,8 +5,6 @@ import { MangaScraper, type MangaPlugin, Manga, Chapter, Page } from '../provide
 import { TaskPool, Priority } from '../taskpool/TaskPool';
 import { RateLimit } from '../taskpool/RateLimit';
 import * as Common from './decorators/Common';
-import { Numeric } from '../SettingsManager';
-import { WebsiteResourceKey as R } from '../../i18n/ILocale';
 
 type CachedManga = {
     id: string,
@@ -101,13 +99,10 @@ const chapterLanguageMap = new Map([
 export default class extends MangaScraper {
 
     private readonly api = 'https://api.mangadex.org';
-    private readonly mangasTaskPool = new TaskPool(1, new RateLimit(2, 1));
     private readonly chaptersTaskPool = new TaskPool(1, new RateLimit(4, 1));
 
     public constructor() {
         super('mangadex', 'MangaDex', 'https://mangadex.org', Tags.Media.Manga, Tags.Media.Manhwa, Tags.Media.Manhua, Tags.Language.Multilingual, Tags.Source.Aggregator, Tags.Source.Scanlator);
-        this.Settings.throttle = new Numeric('throttle.mangas', R.Plugin_Settings_ThrottlingInteraction, R.Plugin_Settings_ThrottlingInteractionInfo, 60, 6, 240);
-        (this.Settings.throttle as Numeric).Subscribe(value => this.mangasTaskPool.RateLimit = new RateLimit(value, 60));
     }
 
     public override get Icon() {

web/src/engine/websites/ReaperScans.ts

@@ -36,12 +36,11 @@ type LaravelLivewireMessage = {
 @Common.ImageAjax()
 export default class extends DecoratableMangaScraper {
 
-    private readonly interactionTaskPool = new TaskPool(1, new RateLimit(15, 60));
+    private readonly interactionTaskPool = new TaskPool(1, RateLimit.PerMinute(15));
 
     public constructor() {
         super('reaperscans', 'Reaper Scans', 'https://reaperscans.com', Tags.Media.Manhwa, Tags.Media.Manhua, Tags.Language.English);
-        this.Settings.throttle = new Numeric('throttle.interactive', R.Plugin_Settings_ThrottlingInteraction, R.Plugin_Settings_ThrottlingInteractionInfo, 15, 1, 60);
-        (this.Settings.throttle as Numeric).Subscribe(value => this.interactionTaskPool.RateLimit = new RateLimit(value, 60));
+        this.Settings.throttle = new Numeric('throttle.interactive', R.Plugin_Settings_ThrottlingInteraction, R.Plugin_Settings_ThrottlingInteractionInfo, 15, 1, 60).Subscribe(value => this.interactionTaskPool.RateLimit = RateLimit.PerMinute(value));
     }
 
     public override get Icon() {

web/src/engine/websites/TruyenQQ.ts

@@ -21,13 +21,11 @@ function PageExtractor(element: HTMLElement): string {
 @Common.ImageAjax()
 export default class extends DecoratableMangaScraper {
 
-    private readonly interactionTaskPool = new TaskPool(1, new RateLimit(30, 60));
+    private readonly interactionTaskPool = new TaskPool(1, RateLimit.PerMinute(30));
 
     public constructor() {
         super('truyenqq', 'TruyenQQ', 'https://truyenqqviet.com', Tags.Media.Manhwa, Tags.Media.Manhua, Tags.Language.Vietnamese, Tags.Source.Aggregator);
-        const throttle = new Numeric('throttle.interactive', R.Plugin_Settings_ThrottlingInteraction, R.Plugin_Settings_ThrottlingInteractionInfo, 30, 1, 60);
-        throttle.Subscribe(value => this.interactionTaskPool.RateLimit = new RateLimit(value, 60));
-        this.Settings.throttle = throttle;
+        this.Settings.throttle = new Numeric('throttle.interactive', R.Plugin_Settings_ThrottlingInteraction, R.Plugin_Settings_ThrottlingInteractionInfo, 30, 1, 60).Subscribe(value => this.interactionTaskPool.RateLimit = RateLimit.PerMinute(value));
     }
 
     public override get Icon() {