Use IoC, impliment queue

src/services/player.ts

@@ -0,0 +1,88 @@
+import {inject, injectable} from 'inversify';
+import {VoiceConnection, VoiceChannel} from 'discord.js';
+import {TYPES} from '../types';
+import Queue from './queue';
+import getYouTubeStream from '../utils/get-youtube-stream';
+
+export enum Status {
+  Playing,
+  Paused,
+  Disconnected
+}
+
+export interface GuildPlayer {
+  status: Status;
+  voiceConnection: VoiceConnection | null;
+}
+
+@injectable()
+export default class {
+  private readonly guildPlayers = new Map<string, GuildPlayer>();
+  private readonly queue: Queue;
+
+  constructor(@inject(TYPES.Services.Queue) queue: Queue) {
+    this.queue = queue;
+  }
+
+  async connect(guildId: string, channel: VoiceChannel): Promise<void> {
+    this.initGuild(guildId);
+
+    const guildPlayer = this.guildPlayers.get(guildId);
+
+    const conn = await channel.join();
+
+    guildPlayer!.voiceConnection = conn;
+
+    this.guildPlayers.set(guildId, guildPlayer!);
+  }
+
+  disconnect(guildId: string): void {
+    this.initGuild(guildId);
+
+    const guildPlayer = this.guildPlayers.get(guildId);
+
+    if (guildPlayer?.voiceConnection) {
+      guildPlayer.voiceConnection.disconnect();
+    }
+  }
+
+  async play(guildId: string): Promise<void> {
+    const guildPlayer = this.get(guildId);
+    if (guildPlayer.voiceConnection === null) {
+      throw new Error('Not connected to a voice channel.');
+    }
+
+    if (guildPlayer.status === Status.Playing) {
+      // Already playing, return
+      return;
+    }
+
+    const songs = this.queue.get(guildId);
+
+    if (songs.length === 0) {
+      throw new Error('Queue empty.');
+    }
+
+    const song = songs[0];
+
+    const stream = await getYouTubeStream(song.url);
+
+    this.get(guildId).voiceConnection!.play(stream, {type: 'webm/opus'});
+
+    guildPlayer.status = Status.Playing;
+
+    this.guildPlayers.set(guildId, guildPlayer);
+  }
+
+  get(guildId: string): GuildPlayer {
+    this.initGuild(guildId);
+
+    return this.guildPlayers.get(guildId) as GuildPlayer;
+  }
+
+  private initGuild(guildId: string): void {
+    if (!this.guildPlayers.get(guildId)) {
+      this.guildPlayers.set(guildId, {status: Status.Disconnected, voiceConnection: null});
+    }
+  }
+}