Finish Favorites UI and jumping

frontend/src/api/player.tsx

@@ -61,6 +61,16 @@ export const API = {
       body: JSON.stringify({ url }),
     });
   },
+
+  async replaceCurrentFile(url: string): Promise<void> {
+    await fetch('/api/playlist/replace', {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify({ url }),
+    });
+  },
   
   async removeFromPlaylist(index: number): Promise<void> {
     await fetch(`/api/playlist/${index}`, {
@@ -116,5 +126,38 @@ export const API = {
     };
 
     return ws;
+  },
+
+  async getFavorites(): Promise<PlaylistItem[]> {
+    const response = await fetch('/api/favorites');
+    return response.json();
+  },
+
+  async addToFavorites(url: string): Promise<void> {
+    // Maybe a little weird to make an empty PlaylistItem here, but we do want to support adding
+    // known PlaylistItems to favorites in the future. 
+    const playlistItem: PlaylistItem = {
+      filename: url,
+      title: null,
+      id: 0,
+      playing: null,
+      metadata: undefined,
+    };
+
+    await fetch('/api/favorites', {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify(playlistItem),
+    });
+  },
+
+  async removeFromFavorites(id: number): Promise<void> {
+    await fetch(`/api/favorites/${id}`, { method: 'DELETE' });
+  },
+
+  async clearFavorites(): Promise<void> {
+    await fetch('/api/favorites', { method: 'DELETE' });
   }
 };