Add non-working fast-forward

See #15

src/bot.ts

@@ -88,6 +88,8 @@ import {
   playYouTubeLinkPrefixCommandPatterns,
   playYoutubeURLRequests,
 } from './music/play/youtube/constants';
+import { fastForwardPrefixCommandPatterns } from './music/ff/constants';
+import { fastForward } from './music/ff';
 
 const djBotus = new Client();
 
@@ -346,6 +348,16 @@ djBotus.on('message', async (message) => {
     }
   }
 
+  if (requestDetails.style === MsgBotRequestStyle.Prefix) {
+    const fastForwardTrackPrefixDetails = identifyRequest(
+      messageContent,
+      fastForwardPrefixCommandPatterns,
+    );
+    if (fastForwardTrackPrefixDetails.index !== -1) {
+      return fastForward(message);
+    }
+  }
+
   // Music: Playlist Management
   if (interpretRequest(message, playYoutubeURLRequests)) {
     return playAndOrAddYoutubeToPlaylist(message);

src/music/ff/constants.ts

@@ -0,0 +1,11 @@
+import { prefixCommandTerminatorPatternStr } from '../../constants';
+
+export const fastForwardPrefixKeywords = ['fast forward', 'fwd', 'ff'];
+const fastForwardPrefixCommands: string[] = [
+  `(?:${fastForwardPrefixKeywords
+    .map((k) => `(?:${k})`)
+    .join('|')})${prefixCommandTerminatorPatternStr}`,
+];
+export const fastForwardPrefixCommandPatterns = fastForwardPrefixCommands.map(
+  (prefixCommand) => new RegExp(prefixCommand, 'gim'),
+);

src/music/ff/index.ts

@@ -1,9 +1,11 @@
 import { Message } from 'discord.js';
+import floor from 'lodash/floor';
 import isNil from 'lodash/isNil';
+
 import logger from '../../logger';
 import { reactWithEmoji } from '../../social';
-
 import { songScaffold } from '../constants';
+import { play } from '../play/youtube';
 import { defaultPlaylistName, getPlaylist } from '../playlist';
 
 export const fastForward = (message: Message) => {
@@ -28,4 +30,14 @@ export const fastForward = (message: Message) => {
     });
     return;
   }
+  const streamTime = playlist.connection?.dispatcher?.streamTime ?? 0;
+  const streamTotalSecs = floor(streamTime / 1000);
+  const duration = floor(playlist.currentSong.duration);
+  const ffDuration = (() => {
+    if (streamTotalSecs + 10 < duration) {
+      return streamTotalSecs + 5;
+    }
+    return 0;
+  })();
+  play(message, { ff: ffDuration, track: playlist.currentSong });
 };

src/music/play/youtube/index.ts

@@ -61,10 +61,11 @@ export const onConnectionFinish = (message: Message) => {
 export const play = (
   message: Message,
   options: {
+    ff?: number;
     track: SongShape;
   },
 ) => {
-  const { track } = options;
+  const { ff, track } = options;
   if (!message.guild?.id) {
     reactWithEmoji.failed(message);
     logger.log({
@@ -109,8 +110,17 @@ export const play = (
     return;
   }
 
+  const trackUrl = (() => {
+    if (ff) {
+      const url = new URL(track.url);
+      url.searchParams.set('t', `${ff}s`);
+      return url.toString();
+    }
+    return track.url;
+  })();
+
   const dispatcher = playlist.connection
-    .play(ytdl(track.url, { filter: 'audioonly' }))
+    .play(ytdl(trackUrl, { filter: 'audioonly' }))
     .on('debug', (info) => {
       onDebug(message, { info });
     })