features

features.ts

import { Injectable, isDevMode, NgModule, Pipe } from "@angular/core";
import { Observable } from "rxjs/Observable";
import { BehaviorSubject } from "rxjs/BehaviorSubject";


export type AvailableFeatures = keyof { "FEATURE_FROM_BACK", "PAID_PLAN": false }
export type AvailableFeaturesObj = {[key in AvailableFeatures]: any};

export const Features: AvailableFeaturesObj = {
  "PAID_PLAN": true,
}


@Injectable()
export class FeaturesService {
  constructor(private httpClient: HttpClient, private user: User) {
    this.updateQuotes();
    this.user.status$.subscribe(loggedId => {
      if (!loggedId) {
        this.featuresCache.next(Features);
      }
    })
  }

  private featuresCache = new BehaviorSubject<AvailableFeaturesObj>(Features);

  updateQuotes() {
    this.httpClient.get(`api/users/quotas`).subscribe(res => {
      if (isDevMode()) {
        console.assert(JSON.stringify(Object.keys(Features)) === JSON.stringify(Object.keys(res)), `FeaturesService: go check  check available features`);
      }
      this.featuresCache.next(res);
    });
  }

  isFeatureAvailable(feature: AvailableFeatures): Observable<number> {
    return this.featuresCache.map(res => res && res[feature]);
  }


}


@Pipe({
  name: 'isAvailableFeature',
  pure: false,
})
export class IsAvailableFeaturePipe {

  constructor(private service: FeaturesService) {
  }

  transform(featureName: AvailableFeatures) {
    return this.service.isFeatureAvailable(featureName);
  }
}

@NgModule({
  imports: [],
  declarations: [IsAvailableFeaturePipe],
  exports: [IsAvailableFeaturePipe],
})
export class FeaturesModule {
  static forRoot() {
    return {
      ngModule: FeaturesModule,
      providers: [FeaturesService],
    }
  }
}