From 6bfd167122eea6ccc739e8f5583ceb3f5662c6be Mon Sep 17 00:00:00 2001
From: Chneemann <andre-kempf@mailbox.org>
Date: Thu, 1 May 2025 08:03:32 +0200
Subject: [PATCH] feat: create GenreService to load film genres from API

---
 backend/video_app/views.py                    | 10 ++++
 backend/videoflix/urls.py                     |  3 +-
 .../home/categories/categories.component.ts   | 49 ++++++++++---------
 frontend/src/app/services/genre.service.ts    | 33 +++++++++++++
 4 files changed, 72 insertions(+), 23 deletions(-)
 create mode 100644 frontend/src/app/services/genre.service.ts

diff --git a/backend/video_app/views.py b/backend/video_app/views.py
index 3ce53f0..142b1c3 100644
--- a/backend/video_app/views.py
+++ b/backend/video_app/views.py
@@ -3,6 +3,7 @@ from rest_framework.permissions import IsAuthenticated
 from rest_framework.response import Response
 from .serializer import VideoSerializer
 from .models import Video
+from .class_assets import FILM_GENRES
 from django.core.cache.backends.base import DEFAULT_TIMEOUT 
 from django.views.decorators.cache import cache_page 
 from django.conf import settings
@@ -24,6 +25,15 @@ def video_list(request):
     serializer = VideoSerializer(videos, many=True)
     return Response(serializer.data)
 
+@api_view(['GET'])
+@permission_classes([IsAuthenticated])
+def genre_list(request):
+    """
+    Return a list of film genres from static choices.
+    """
+    genres = [{'code': code, 'name': name} for code, name in FILM_GENRES]
+    return Response(genres)
+
 @api_view(['GET'])
 @permission_classes([IsAuthenticated])
 def check_video_resolutions(request, id):
diff --git a/backend/videoflix/urls.py b/backend/videoflix/urls.py
index f880856..1574283 100644
--- a/backend/videoflix/urls.py
+++ b/backend/videoflix/urls.py
@@ -23,8 +23,9 @@ urlpatterns = [
     # Content URLs
     path('videos/', video_views.video_list, name='video_list'),
     path('video/upload/', video_views.video_upload, name='video_upload'),
+    path('video/genres/', video_views.genre_list, name='genre_list'),
     path('video/<int:id>/', video_views.check_video_resolutions, name='check_video_resolutions'),
- 
+    
     # Users URLs
     path('users/', user_views.user_list, name='user_list'),
     path('users/<int:id>/', user_views.user_detail, name='user_detail'),
diff --git a/frontend/src/app/components/home/categories/categories.component.ts b/frontend/src/app/components/home/categories/categories.component.ts
index 3eafbf4..10c98c3 100644
--- a/frontend/src/app/components/home/categories/categories.component.ts
+++ b/frontend/src/app/components/home/categories/categories.component.ts
@@ -5,10 +5,13 @@ import {
   EventEmitter,
   HostListener,
   Input,
+  OnInit,
   Output,
 } from '@angular/core';
 import { environment } from '../../../../environments/environment';
 import { VideoListComponent } from './video-list/video-list.component';
+import { FilmGenre, GenreService } from '../../../services/genre.service';
+import { Subject, takeUntil } from 'rxjs';
 
 @Component({
   selector: 'app-categories',
@@ -17,7 +20,7 @@ import { VideoListComponent } from './video-list/video-list.component';
   templateUrl: './categories.component.html',
   styleUrl: './categories.component.scss',
 })
-export class CategoriesComponent implements AfterViewInit {
+export class CategoriesComponent implements OnInit, AfterViewInit {
   @Input() videos: any[] = [];
   @Input() currentVideo: number = 0;
   @Input() favoriteVideos: any[] = [];
@@ -26,32 +29,34 @@ export class CategoriesComponent implements AfterViewInit {
 
   environmentBaseUrl: string = environment.baseUrl;
   isScrollable: boolean = false;
+  filmGenres: FilmGenre[] = [];
 
-  filmGenres = [
-    { code: 'action', name: 'Action' },
-    { code: 'adventure', name: 'Adventure' },
-    { code: 'animation', name: 'Animation' },
-    { code: 'anime', name: 'Anime' },
-    { code: 'comedy', name: 'Comedy' },
-    { code: 'crime', name: 'Crime' },
-    { code: 'documentary', name: 'Documentary' },
-    { code: 'drama', name: 'Drama' },
-    { code: 'fantasy', name: 'Fantasy' },
-    { code: 'horror', name: 'Horror' },
-    { code: 'musical', name: 'Musical' },
-    { code: 'mystery', name: 'Mystery' },
-    { code: 'other', name: 'Miscellaneous' },
-    { code: 'romance', name: 'Romance' },
-    { code: 'science_fiction', name: 'Science Fiction' },
-    { code: 'thriller', name: 'Thriller' },
-    { code: 'war', name: 'War' },
-    { code: 'western', name: 'Western' },
-  ];
+  private destroy$ = new Subject<void>();
 
-  ngAfterViewInit() {
+  constructor(private genreService: GenreService) {}
+
+  ngOnInit(): void {
+    this.getFilmGenreNames();
+  }
+
+  ngAfterViewInit(): void {
     this.checkScroll();
   }
 
+  ngOnDestroy(): void {
+    this.destroy$.next();
+    this.destroy$.complete();
+  }
+
+  getFilmGenreNames(): void {
+    this.genreService
+      .getGenres()
+      .pipe(takeUntil(this.destroy$))
+      .subscribe((genres) => {
+        this.filmGenres = genres;
+      });
+  }
+
   openCurrentVideo(videoId: number) {
     this.currentVideo = videoId;
     this.currentVideoId.emit(videoId);
diff --git a/frontend/src/app/services/genre.service.ts b/frontend/src/app/services/genre.service.ts
new file mode 100644
index 0000000..626b53c
--- /dev/null
+++ b/frontend/src/app/services/genre.service.ts
@@ -0,0 +1,33 @@
+import { Injectable } from '@angular/core';
+import { Observable, of, tap } from 'rxjs';
+import { ApiService } from './api.service';
+
+export interface FilmGenre {
+  code: string;
+  name: string;
+}
+
+@Injectable({
+  providedIn: 'root',
+})
+export class GenreService {
+  private genres: FilmGenre[] = [];
+
+  constructor(private apiService: ApiService) {}
+
+  /**
+   * Returns the genres either from the cache or from the API endpoint.
+   * @returns observable of movie genres
+   */
+  getGenres(): Observable<FilmGenre[]> {
+    if (this.genres.length > 0) {
+      return of(this.genres);
+    }
+
+    return this.apiService.get<FilmGenre[]>('/video/genres/', true).pipe(
+      tap((data) => {
+        this.genres = data;
+      })
+    );
+  }
+}