client/src/app/videos/recommendations/recent-videos-recommendation.service.ts

   1 import { Injectable } from '@angular/core'
   2 import { RecommendationService } from '@app/videos/recommendations/recommendations.service'
   3 import { Video } from '@app/shared/video/video.model'
   4 import { RecommendationInfo } from '@app/shared/video/recommendation-info.model'
   5 import { VideoService } from '@app/shared/video/video.service'
   6 import { map } from 'rxjs/operators'
   7 import { Observable } from 'rxjs'
   8 import { SearchService } from '@app/search/search.service'
   9 import { AdvancedSearch } from '@app/search/advanced-search.model'
  10
  11 /**
  12  * Provides "recommendations" by providing the most recently uploaded videos.
  13  */
  14 @Injectable()
  15 export class RecentVideosRecommendationService implements RecommendationService {
  16
  17   readonly pageSize = 5
  18
  19   constructor (
  20     private videos: VideoService,
  21     private searchService: SearchService
  22   ) { }
  23
  24   getRecommendations (recommendation: RecommendationInfo): Observable<Video[]> {
  25     return this.fetchPage(1, recommendation)
  26       .pipe(
  27         map(videos => {
  28           const otherVideos = videos.filter(v => v.uuid !== recommendation.uuid)
  29           return otherVideos.slice(0, this.pageSize)
  30         })
  31       )
  32   }
  33
  34   private fetchPage (page: number, recommendation: RecommendationInfo): Observable<Video[]> {
  35     let pagination = { currentPage: page, itemsPerPage: this.pageSize + 1 }
  36     if (!recommendation.tags) {
  37       return this.videos.getVideos(pagination, '-createdAt')
  38         .pipe(
  39           map(v => v.videos)
  40         )
  41     }
  42     if (recommendation.tags.length === 0) {
  43       return this.videos.getVideos(pagination, '-createdAt')
  44         .pipe(
  45           map(v => v.videos)
  46         )
  47     }
  48     return this.searchService.searchVideos('',
  49       pagination,
  50       new AdvancedSearch({ tagsOneOf: recommendation.tags.join(','), sort: '-createdAt' })
  51     ).pipe(
  52       map(v => v.videos)
  53     )
  54   }
  55 }