import { Injectable, EventEmitter } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class ProgressBarService {

  public updateProgressBar: EventEmitter<any>;
  private requestsRunning = 0;

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

  public getRequestsRunning(): number {
    return this.requestsRunning;
  }

  public increase(): void {
    this.requestsRunning++;
    if (this.requestsRunning === 1) {
      this.updateProgressBar.emit('indeterminate');
    }
  }

  public decrease(): void {
    if (this.requestsRunning > 0) {
      this.requestsRunning--;
      if (this.requestsRunning === 0) {
        this.updateProgressBar.emit('none');
      }
    }
  }

}