import { Subject, Subscription, TeardownLogic } from "rxjs";

export interface EventBusType {
    type: string;
    payload: PayloadEventBus;
}

export interface PayloadEventBus {
    type: "resolve" | "reject";
    data: any;
  }

export default class EventBus {
    private static instance: EventBus;
    private eventSubject = new Subject<EventBusType>();
    private subscription = new Subscription();

    static getInstance(): EventBus {
        if (!EventBus.instance) {
            EventBus.instance = new EventBus();
        }
        return EventBus.instance;
    }

    get events() {
        return this.eventSubject.asObservable();
    }

    post(event: EventBusType) {
        this.eventSubject.next(event);
    }

    postEvent = (event: string, payload: PayloadEventBus) => {
        this.post({
          type: event,
          payload,
        });
      };

    unsubcribe() {
        this.subscription.unsubscribe();
    }

    add(teardown: TeardownLogic): Subscription {
        return this.subscription.add(teardown);
    }
}