app.ts

import { Client, Collection, Message } from 'discord.js';
import * as fs from 'fs';
const config = require('./config.json');

export interface Command {
	default: Command;
	name: string;
	guildOnly: boolean;
	args: string[];
	usage: string;
	aliases: string[];
	cooldown: number;
	execute(message: Message, args: string[]);
}

const client = new Client();

const cooldowns: Collection<string, Collection<string, number>> = new Collection();
const commands: Collection<string, Command> = new Collection();

const commandFiles = fs.readdirSync('./commands').filter(file => file.endsWith('.ts'));

commandFiles.forEach(async (file) => {
	if (file.includes('template') || file.includes('category_info')) return;
	const command: Command = await import(`./commands/${file}`).then((v: Command) => v.default);
	commands.set(command.name, command);
});

client.on('ready', () => {
	console.log(`Logged in as ${client.user.tag}!`);
});

client.on('message', message => {
	if (!message.content.startsWith(config.prefix) || message.author.bot) return;

	const args: Array<string> = message.content.slice(config.prefix.length).split(/ +/);
	const commandName: string = args.shift().toLowerCase();

	if (!commands.has(commandName)) return;

	const command = commands.get(commandName) || commands.find(cmd => cmd.aliases && cmd.aliases.includes(commandName));

	if (command.guildOnly && message.channel.type !== 'text') {
		return message.reply('I can\'t execute that command in DMs!');
	}

	if (command.args && !args.length) {
		let reply = `You didn't provide any arguments, ${message.author}`;

		if (command.usage) {
			reply += `\nThe proper usage would be: \`${config.prefix}${command.name} ${command.usage}\``;
		}

		return message.channel.send(reply);
	}

	if (!cooldowns.has(command.name)) {
		cooldowns.set(command.name, new Collection());
	}

	const now = Date.now();
	const timestamps = cooldowns.get(command.name);
	const cooldownAmount = (command.cooldown || 3) * 1000;

	if (timestamps.has(message.author.id)) {
		const expirationTime = timestamps.get(message.author.id) + cooldownAmount;

		if (now < expirationTime) {
			const timeLeft = (expirationTime - now) / 1000;
			return message.reply(`Please wait ${timeLeft.toFixed(1)} more second(s) before reusing the \`${command.name}\` command`);
		}

		timestamps.set(message.author.id, now);
		setTimeout(() => timestamps.delete(message.author.id), cooldownAmount);
	}

	try {
		command.execute(message, args);
	}
	catch (error) {
		console.error(error);
		message.reply('There was an error trying to execute that command!');
	}

});

client.login(config.token);