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

   1 import { Inject, 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
  25   getRecommendations (recommendation: RecommendationInfo): Observable<Video[]> {
  26     return this.fetchPage(1, recommendation)
  27       .pipe(
  28         map(videos => {
  29           const otherVideos = videos.filter(v => v.uuid !== recommendation.uuid)
  30           return otherVideos.slice(0, this.pageSize)
  31         })
  32       )
  33   }
  34
  35   private fetchPage (page: number, recommendation: RecommendationInfo): Observable<Video[]> {
  36     let pagination = { currentPage: page, itemsPerPage: this.pageSize + 1 }
  37     if (!recommendation.tags) {
  38       return this.videos.getVideos(pagination, '-createdAt')
  39         .pipe(
  40           map(v => v.videos)
  41         )
  42     }
  43     if (recommendation.tags.length === 0) {
  44       return this.videos.getVideos(pagination, '-createdAt')
  45         .pipe(
  46           map(v => v.videos)
  47         )
  48     }
  49     return this.searchService.searchVideos('',
  50       pagination,
  51       new AdvancedSearch({ tagsOneOf: recommendation.tags.join(','), sort: '-createdAt' })
  52     ).pipe(
  53       map(v => v.videos)
  54     )
  55   }
  56 }