import { Injectable } from '@angular/core';
import { Slide } from './slide.model';
import { Response, Http } from '@angular/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/catch';

@Injectable()
export class CarouselService {
  private _slidesUrl = 'assets/slides.json';

  constructor(private _http: Http) {}

  getSlides(): Observable<Slide[]> {
    return this._http.get(this._slidesUrl).map(this.extractData)
    .do(data => console.log('All: ' + JSON.stringify(data)))
    .catch(this.handleError);
  }

  private extractData(res: Response) {
    let body = res.json();
    return <Slide[]>(body.data || {});
  }

  private handleError(error: any) {
    let errMsg = (error.message) ? error.message :
      error.status ? (error.status + ' - ' + error.statusText) : 'Server error';
    console.error(errMsg);
    return Observable.throw(errMsg);
  }
}