feat: add collections (#484)

closes #418

server/api/themoviedb.ts

@@ -190,6 +190,12 @@ export interface TmdbMovieDetails {
     cast: TmdbCreditCast[];
     crew: TmdbCreditCrew[];
   };
+  belongs_to_collection?: {
+    id: number;
+    name: string;
+    poster_path?: string;
+    backdrop_path?: string;
+  };
   external_ids: TmdbExternalIds;
 }
 
@@ -344,6 +350,15 @@ export interface TmdbSeasonWithEpisodes extends TmdbTvSeasonResult {
   external_ids: TmdbExternalIds;
 }
 
+export interface TmdbCollection {
+  id: number;
+  name: string;
+  overview?: string;
+  poster_path?: string;
+  backdrop_path?: string;
+  parts: TmdbMovieResult[];
+}
+
 class TheMovieDb {
   private apiKey = 'db55323b8d3e4154498498a75642b381';
   private axios: AxiosInstance;
@@ -866,6 +881,29 @@ class TheMovieDb {
       );
     }
   }
+
+  public async getCollection({
+    collectionId,
+    language = 'en-US',
+  }: {
+    collectionId: number;
+    language?: string;
+  }): Promise<TmdbCollection> {
+    try {
+      const response = await this.axios.get<TmdbCollection>(
+        `/collection/${collectionId}`,
+        {
+          params: {
+            language,
+          },
+        }
+      );
+
+      return response.data;
+    } catch (e) {
+      throw new Error(`[TMDB] Failed to fetch collection: ${e.message}`);
+    }
+  }
 }
 
 export default TheMovieDb;