import { Injectable } from '@nestjs/common';
import { EventEmitter } from 'events';
import { fromEvent, Observable } from 'rxjs';

@Injectable()
export class EventsService {
  private readonly emitter: EventEmitter;

  constructor() {
    this.emitter = new EventEmitter();
  }

  private subscribe(event: string): Observable<unknown> {
    return fromEvent(this.emitter, event);
  }

  private emit(event: string, data: any): void {
    this.emitter.emit(event, data);
  }

  subscribeUserPrivilegeUpdate(vatsimId: string): Observable<unknown> {
    return this.subscribe(`/users/${vatsimId}`);
  }

  emitUserPrivilegeUpdate(vatsimId: string): void {
    this.emit(`/users/${vatsimId}`, {});
  }

  subscribeAirportRenew(): Observable<unknown> {
    return this.subscribe('/airports/renew');
  }

  emitAirportRenew(): void {
    this.emit('/airports/renew', {});
  }

  subscribeArrivalSequenceUpdate(icao: string): Observable<unknown> {
    return this.subscribe(`/airports/arrival/${icao}`);
  }

  emitArrivalSequenceUpdate(icao: string): void {
    this.emit(`/airports/arrival/${icao}`, {});
  }
}