lib.js

const Discord   = require('discord.js');
const snekfetch = require('snekfetch');
const _         = require('lodash/core');
const fs        = require('fs');
const config    = require('./config.json');

// Helper Functions
class Lib {
  embed(text,message){
    return ({embed:new Discord.RichEmbed().setDescription(text).setColor(`${message.guild.me.displayHexColor!=='#000000' ? message.guild.me.displayHexColor : config.hexColour}`)});
  }

  checkOwner(message){
    return (message.author.id===config.ownerID);
  }

  compareVersion(v1, v2) {
    if(v1===v2) return 0;
    var a1 = v1.toString().split(".");
    var a2 = v2.toString().split(".");
    for( var i = 0; i < a1.length && i < a2.length; i++ ) {
        var diff = parseInt(a1[i],10) - parseInt(a2[i],10);
        if( diff>0 ) {
            return 1;
        }
        else if( diff<0 ) {
            return -1;
        }
    }
    diff = a1.length - a2.length;
    return (diff>0) ? 1 : (diff<0) ? -1 : 0;
  }

  postDiscordBots() {
    snekfetch
      .post(`https://discordbots.org/api/bots/${client.user.id}/stats`)
      .set('Authorization', config.discordbots.token)
      .send({"server_count":client.guilds.size})
      .then(() => console.log(`Posted Guild Size (${client.guilds.size}) to DiscordBots API`))
      .catch(e => console.error(`Failed Posting to DiscordBots - ${e.stack}`));
  }

  // execute a single shell command where "cmd" is a string
  exec(cmd, cb){
    var child_process = require('child_process');
    var parts = cmd.split(/\s+/g);
    var p = child_process.spawn(parts[0], parts.slice(1), {stdio: 'inherit'});
    p.on('exit', function(code){
      var err = null;
      if (code) {
        err = new Error('command "'+ cmd +'" exited with wrong status code "'+ code +'"');
        err.code = code;
        err.cmd = cmd;
      }
      if (cb) cb(err);
    });
  };

  // execute multiple commands in series
  series(cmds, cb){
    var ex = this.exec;
    var execNext = function(){
      ex(cmds.shift(), function(err){
        if (err) {
          cb(err);
        } else {
          if (cmds.length) execNext();
          else cb(null);
        }
      });
    };
    execNext();
  };

  durstenfeldShuffle(array) {
    for (var i = array.length - 1; i > 0; i--) {
        var j = Math.floor(Math.random() * (i + 1));
        var temp = array[i];
        array[i] = array[j];
        array[j] = temp;
    }
    return array;
  }

  map_to_object(map) {
    const out = Object.create(null);
    map.forEach((value, key) => {
      if (value instanceof Map) {
        out[key] = map_to_object(value);
      }
      else {
        out[key] = value;
      }
    })
    return out;
  }

  object_to_map(obj) {
    let map = new Map();
    Object.keys(obj).forEach(key => {
        map.set(key, obj[key]);
    });
    return map;
  }

  writeMapToFile(guildsMap){
    var guildObj = this.map_to_object(guildsMap);
    Object.keys(guildObj).forEach(function(key) {
      var guild = guildObj[key];
      delete guild.playing;
      delete guild.songQueue;
    });
    fs.writeFile('guildRecords.json', JSON.stringify(guildObj, null, '\t'), 'utf8', function (err,data) {
      if (err){
        console.log(err);
      }
    });
  }

  readFileToMap(){
    var guildObj = JSON.parse(fs.readFileSync('guildRecords.json', 'utf8'));
    return this.object_to_map(guildObj);
  }

  queuePlayback(ytdl,guildsMap,voiceChannel,client,message,initMsg,playlistDetails,playlistLength){
    voiceChannel.join().then(connnection => {
      var poppedSong = guildsMap.get(message.guild.id).songQueue.pop();
      var dispatcher = connnection.playStream(ytdl(poppedSong.contentDetails.videoId, {filter : 'audioonly'}), {passes:2});
      initMsg.edit({embed:new Discord.MessageEmbed().setDescription(`:pager: **Playlist:** [${playlistDetails.snippet.title}](https://www.youtube.com/playlist?list=${playlistDetails.id}) - ${playlistLength.pos+1}/${playlistLength.pSize}\n:headphones: **Playing:** ${poppedSong.snippet.title}`).setThumbnail(poppedSong.snippet.thumbnails.default.url).setColor(`${message.guild.me.displayHexColor!=='#000000' ? message.guild.me.displayHexColor : config.hexColour}`)});
      dispatcher.on('end', () => {
        if (guildsMap.get(message.guild.id).songQueue && guildsMap.get(message.guild.id).songQueue.length!==0) {
          this.queuePlayback(ytdl,guildsMap,voiceChannel,client,message,initMsg,playlistDetails,{pos:playlistLength.pos+1,pSize:playlistLength.pSize});
        }
      });
    })
  }

  clearQueue(guildsMap,client,message){
    var gm = guildsMap.get(message.guild.id);
    delete gm.songQueue;
    guildsMap.set(message.guild.id,gm);
  }

}

module.exports = new Lib();