import {
  Component,
  Input,
  OnInit,
} from '@angular/core';
import { Observable } from 'rxjs';

import { SearchService } from '../../../../core/shared/search/search.service';
import { ViewMode } from '../../../../core/shared/view-mode.model';
import { hasValue } from '../../../empty.util';

@Component({
  selector: 'ds-search-results-skeleton',
  templateUrl: './search-results-skeleton.component.html',
  styleUrls: ['./search-results-skeleton.component.scss'],
})
/**
 * Component to show placeholders for search results while loading, to give a loading feedback to the user without layout shifting.
 */
export class SearchResultsSkeletonComponent implements OnInit {
  /**
   * Whether the search result contains thumbnail
   */
  @Input()
  showThumbnails: boolean;
  /**
   * The number of search result loaded in the current page
   */
  @Input()
  numberOfResults = 0;
  /**
   * How many placeholder are displayed for the search result text
   */
  @Input()
  textLineCount = 2;
  /**
   * The view mode of the search page
   */
  public viewMode$: Observable<ViewMode>;
  /**
   * Array built from numberOfResults to count and iterate based on index
   */
  public loadingResults: number[];

  protected readonly ViewMode = ViewMode;

  constructor(private searchService: SearchService) {
    this.viewMode$ = this.searchService.getViewMode();
  }

  ngOnInit() {
    this.loadingResults = Array.from({ length: this.numberOfResults }, (_, i) => i + 1);

    if (!hasValue(this.showThumbnails)) {
      // this is needed as the default value of show thumbnails is true but set in lower levels of the DOM.
      this.showThumbnails = true;
    }
  }
}
