Add better caching, seek command

src/commands/seek.ts

@@ -0,0 +1,33 @@
+import {Message, TextChannel} from 'discord.js';
+import {TYPES} from '../types';
+import {inject, injectable} from 'inversify';
+import Player from '../services/player';
+import LoadingMessage from '../utils/loading-message';
+import Command from '.';
+
+@injectable()
+export default class implements Command {
+  public name = 'seek';
+  public description = 'seeks position in currently playing song';
+  private readonly player: Player;
+
+  constructor(@inject(TYPES.Services.Player) player: Player) {
+    this.player = player;
+  }
+
+  public async execute(msg: Message, args: string []): Promise<void> {
+    const seekTime = parseInt(args[0], 10);
+
+    const loading = new LoadingMessage(msg.channel as TextChannel, 'hold on a sec');
+
+    await loading.start();
+
+    try {
+      await this.player.seek(msg.guild!.id, seekTime);
+
+      await loading.stop('seeked');
+    } catch (_) {
+      await loading.stop('error somewhere');
+    }
+  }
+}