import { Injectable } from '@angular/core';
import { Subject } from 'rxjs';
import { debounceTime, distinctUntilChanged, startWith, switchMap } from 'rxjs/operators';

import { CarsRemoteService } from './cars-remote.service';

@Injectable()
export class CarsV2Service {

  constructor(private carsRemoteService: CarsRemoteService) { }

  getCarsStream(querySubject: Subject<string>) {
    const carsQuery$ = querySubject.pipe(
      debounceTime(250),
      distinctUntilChanged(),
      startWith('')
    );

    return carsQuery$.pipe(
      switchMap(query => this.carsRemoteService.loadCars(query))
    );
  }
}