RepVRT Music

const { Command } = require('discord.js-commando');
const { MessageEmbed } = require('discord.js');
const Youtube = require('simple-youtube-api');
const ytdl = require('ytdl-core');
const youtube = new Youtube(youtubeApiKey); // insert here your Youtube API key, you can also store it as an environment variable or in a config.json

var queue = []; // in this array we will store songs in queue
var isPlaying; // we will use this variable to determine if a song is playing

module.exports = class PlayCommand extends Command {
  constructor(client) {
    super(client, {
      name: 'play',
      aliases: ['play-song', 'add'],
      memberName: 'play',
      group: 'music', // this means the folder the file is inside
      description: 'Play any song from youtube',
      guildOnly: true, // make this command available only in servers not dm's
      clientPermissions: ['SPEAK', 'CONNECT'],
      throttling: { // limit the uses so users don't spam the command
        usages: 2,
        duration: 5
      },
      args: [
        {
          key: 'query', // here we name the variable that will hold the input
          prompt: 'What song would you like to listen to?', // send this msg if
          // the user hasn't provided any arg or if the arg was not a string
          type: 'string', // only permit string inputs
          validate: query => query.length > 0 && query.length < 200
        }
      ]
    });
  }
async run(message, { query }) {
    // determine if the user is in a voice channel when calling the command
    var voiceChannel = message.member.voice.channel;
    if (!voiceChannel) return message.say('Join a channel and try again');
    // if not, return the above message
if (query.match(/^(http(s)?:\/\/)?((w){3}.)?youtu(be|.be)?(\.com)?\/.+/)) {
      const url = query;
      try { // using try catch because there are many api calls and as a result -async await usage
        /*
        the 'replace' and 'split' methods create an array that looks
        like this: [ 'https://www.youtube.com/watch?', 'v=', 'dQw4w9WgXcQ' ]
        then we declare an 'id' variable and assign it to the 3rd element
        */
        query = query
          .replace(/(>|<)/gi, '')
          .split(/(vi\/|v=|\/v\/|youtu\.be\/|\/embed\/)/);
        const id = query[2].split(/[^0-9a-z_\-]/i)[0];
        const video = await youtube.getVideoByID(id); // getting a video object by calling
        // the getVideoByID provided to us by simple-youtube-api
        /*
        I didn't test live streams yet to determine if the bot is capable of
        playing them, also you can remove the second if statement if you want,
        I chose to keep it for now.
        */
        if (video.raw.snippet.liveBroadcastContent === 'live')
          return message.say("I don't support live streams!");
        if (video.duration.hours !== 0)
          return message.say('I cannot play videos longer than 1 hour');
        /*
        construct the song object, it has url, title and voiceChannel
        object that contains methods which are critical to us later on(join,
        dispatcher etc..)
        */
        const title = video.title;
        const song = {
          url,
          title,
          voiceChannel
        };
        // this if statement limits the queue size, can be removed if you wish
        if (queue.length > 6) {
          return message.say(
            'There are too many songs in the queue already, skip or wait a bit'
          );
        }
        queue.push(song); // push the song object to queue
        /*
        If there is no song playing, call the playSong method(we will see it
        later on :)
        else if there is a song playing, return a msg that says the song was
        added to queue
        */
        if (isPlaying == false || typeof isPlaying == 'undefined') {
          isPlaying = true;
          return playSong(queue, message);
        } else if (isPlaying == true) {
          return message.say(`${song.title} added to queue`);
        }
      // catches errors from getVideoByID method
      } catch (err) {
        console.error(err);
        return message.say('Something went wrong, please try later');
      }
    }
try {
      /*
      call 'searchVideos' method to get a list of 5 video objects that match the
      query. Then create an array of the 5 videos numbered from 1 to 5 with their
      titles.
      */
      const videos = await youtube.searchVideos(query, 5);
      const vidNameArr = [];
      for (let i = 0; i < videos.length; i++) {
        vidNameArr.push(`${i + 1}: ${videos[i].title}`);
      }
      vidNameArr.push('exit');
      /* construct a message embed that will be displayed to the chat, it
      contains the song titles fetched using 'searchVideos'.
      */
         const embed = new MessageEmbed()
        .setColor('#e9f931')
        .setTitle('Choose a song by commenting a number between 1 and 5')
        .addField('Song 1', vidNameArr[0])
        .addField('Song 2', vidNameArr[1])
        .addField('Song 3', vidNameArr[2])
        .addField('Song 4', vidNameArr[3])
        .addField('Song 5', vidNameArr[4])
        .addField('Exit', 'exit');
      var songEmbed = await message.say({ embed });
      try {
        /*
        assign 'response' variable whatever the user types. The correct
        responses are numbers between 1-5 or 'exit'. There is also a time limit
        of 1 minute to respond.
        */
          var response = await message.channel.awaitMessages(
          msg => (msg.content > 0 && msg.content < 6) || msg.content === 'exit',
          {
            max: 1,
            maxProcessed: 1,
            time: 60000,
            errors: ['time']
          }
        );
      } catch (err) { // catch errors from 'awaitMessages' and respond correctly
        console.error(err);
        songEmbed.delete()
        return message.say(
          'Please try again and enter a number between 1 and 5 or exit'
        );
      }
      if (response.first().content === 'exit') return songEmbed.delete();
      // assign videoIndex to the song number the user enters
      const videoIndex = parseInt(response.first().content);
      try {
        // fetch the video object using 'getVideoByID'
        var video = await youtube.getVideoByID(videos[videoIndex - 1].id);
        if (video.raw.snippet.liveBroadcastContent === 'live')
          return message.say("I don't support live streams!");
      } catch (err) { // catch errors from 'getVideoByID'
        console.error(err);
        songEmbed.delete()
        return message.say(
          'An error has occured when trying to get the video ID from youtube'
        );
      }
      const url = `https://www.youtube.com/watch?v=${video.raw.id}`;
      const title = video.title;

      try {
        let song = { // construct the song object
          url,
          title,
          voiceChannel
        };
        if (queue.length > 6) {
          return message.say(
            'There are too many songs in the queue already, skip or wait a bit'
          );
        }
        queue.push(song); // push the song object to queue
        if (isPlaying == false || typeof isPlaying == 'undefined') {
          isPlaying = true;
          songEmbed.delete(); // delete the song list embed(so it wont spam chat)
          playSong(queue, message); // play the song
        } else if (isPlaying == true) {
          songEmbed.delete();
          return message.say(`${song.title} added to queue`);
        }
      } catch (err) {
        console.error(err);
        songEmbed.delete();
        return message.say('queue process gone wrong');
      }
    } catch (err) { // catch errors from playSong()
      console.error(err);
      if (songEmbed) { // if the songEmbed wasn't deleted because of an error related to playSong() - delete it
        songEmbed.delete();
      }
      return message.say(
        'Something went wrong with searching the video you requested :('
      );
    }
  }
};
function playSong(queue, message) {
  let voiceChannel;
  queue[0].voiceChannel
    .join() // join the voice channel the user is in
    .then(connection => {
      const dispatcher = connection // sends voice packet data to the voice connection
        .play(
          ytdl(queue[0].url, { // provide ytdl library with the song url
            volume: 0.1,
            quality: 'highestaudio', // highest audio quality
            highWaterMark: 1024 * 1024 * 10 // this line downloads part of the song before starting, it reduces stuttering
          })
        )
        .on('start', () => { // event emitted when the song starts
          /*
          export dispatcher and queue to other music commands, check out my bot
          repo on github to learn more
          */
          module.exports.dispatcher = dispatcher;
          module.exports.queue = queue;
          voiceChannel = queue[0].voiceChannel; // assign voiceChannel to the current one, incase the user moved channels in between songs
          return message.say(
            `:musical_note: Now playing: ${queue[0].title} :musical_note:`
          );
        })
        .on('finish', () => { // event emitted when the song ends
          queue.shift(); // remove the song from queue
          if (queue.length >= 1) { // if the queue has more songs, continue playing
            return playSong(queue, message);
          } else { // else if the queue is empty, assign isPlaying to false and leave the channel
            isPlaying = false;
            return voiceChannel.leave();
          }
        })
        .on('error', e => { // event emitted if an error occures
          message.say('Cannot play song');
          return console.log(e);
        });
    })
    .catch(err => { // catches dispatcher errors
      return console.log(err);
    });
}