quiz.js

const request = require('request').defaults({
		encoding: null
	});
	const Discord = require('discord.js');
	const clientID = process.env.QUIZLET;
	
	module.exports = (message, content) => {
		if (content.match(/b!quiz\Whttps:\/\/quizlet\.com\/[0-9]+/gm)){
		var quizID = content.match(/\/[0-9]+\//gm)[0].match(/[0-9]+/gm)[0];
		request.get('https://api.quizlet.com/2.0/sets/'+quizID+'?client_id='+clientID+'&whitespace=1', function(err, res, body){
			var quiz = JSON.parse(body.toString());
			testQuestion(message, content, quiz, 0, 1)
		});
		}
		if (content.match(/b!quiz[0-9]+\Whttps:\/\/quizlet\.com\/[0-9]+/gm)){
		var len = parseInt(content.substring(6).match(/[0-9]+/gm)[0]);
		console.log(len);
		var quizID = content.match(/\/[0-9]+\//gm)[0].match(/[0-9]+/gm)[0];
		request.get('https://api.quizlet.com/2.0/sets/'+quizID+'?client_id='+clientID+'&whitespace=1', function(err, res, body){
			var quiz = JSON.parse(body.toString());
			len = Math.min(len, quiz.terms.length);
			testQuestion(message, content, quiz, 0, len)
		});
		}
		
		
	}
	
	function testQuestion(message, content, quiz, i, len){
		var q = quiz.terms[Math.floor(Math.random() * quiz.terms.length)];
			var question = q.term;
			var answer = q.definition.toLowerCase().replace(/[^ 0-9a-z]/gm, '');
			message.channel.send('\"' + question + '\"');
			const collector = new Discord.MessageCollector(message.channel, m => m.author.id === message.author.id, {
							time: 60000
						});
					collector.on('collect', message2 => {
						if (message2.user === message.user && message2.channel === message.channel) {	
							if (message2.cleanContent.toLowerCase().startsWith('b!quiz')){
								collector.stop();
							} else {
							var a = message2.cleanContent.toLowerCase().replace(/[^ 0-9a-z]/gm, '');
							if (a == answer){
								message2.react('✅');
							} else {
								message2.react('❌');
								message.channel.send('\"' + q.definition + '\"');
							}
							collector.stop();
							quiz.terms = quiz.terms.filter(function(item){
							return item.term !== question;
							});
							i++;
							if (i < len){
								testQuestion(message, content, quiz, i, len);
							}
							}
							
						}

					});
	}