better-ttb/lib/bot.js

Create Twitch bots gooder

'use strict'

const tls = require('tls');
const assert = require('assert');
const EventEmitter = require('events').EventEmitter;

const parser = require('./parser');

const TwitchBot = class TwitchBot extends EventEmitter {

  constructor({ username, oauth, channels = [], port = 443, silence = false}) {
    
    // Initialize Emitters
    super()

    try {
      assert(username);
      assert(oauth);
    } catch (err) {
      throw new Error('Missing or invalid required arguments');
    }

    this.username = username;
    this.oauth = oauth;
    this.channels = channels.map(channel => parser.formatCHANNEL(channel));

    this.irc = new tls.TLSSocket();
    this.port = port;
    this.silence = silence;

    this._connect();

  }

  async _connect() {

    this.irc.connect({
      host: 'irc.chat.twitch.tv',
      port: this.port
    });

    this.irc.setEncoding('utf8');
    this.irc.once('connect', () => { this.afterConnect() });

  }

  afterConnect() {

    this.irc.on('error', err => this.emit('error', err));
    this.listen();
    this.writeIrcMessage("PASS " + this.oauth);
    this.writeIrcMessage("NICK " + this.username);;
    this.writeIrcMessage("CAP REQ :twitch.tv/tags");
    this.channels.forEach(c => this.join(c));

    this.writeIrcMessage("CAP REQ :twitch.tv/membership");
    this.writeIrcMessage("CAP REQ :twitch.tv/commands");

    this.emit('connected', this);
    
  }

  // TODO: Make this parsing better
  listen() {

    this.irc.on('data', data => {

      this.checkForError(data);

      /* Twitch sends keep-alive PINGs, need to respond with PONGs */
      if (data.includes('PING :tmi.twitch.tv')) {
        this.irc.write('PONG :tmi.twitch.tv\r\n');
      }

      if (data.includes('PRIVMSG')) {
        
        const message = parser.formatPRIVMSG(data);
        
        message.client = this;
        
        //TODO: Move these? IDK
        message.reply = (content, callback) => {
          this.send(`@${message.username}, ${content}`, message.channel.name, callback);
        }

        message.channel.send = (content, callback) => {
          this.send(content, message.channel.name, callback);
        }

        this.emit('message', message);

      }

      if (data.includes('CLEARCHAT')) {
        const event = parser.formatCLEARCHAT(data);
        if (event.type === 'timeout') this.emit('timeout', event);
        if (event.type === 'ban') this.emit('ban', event);
      }

      if (data.includes('USERNOTICE ')) {
        const event = parser.formatUSERNOTICE(data);
        if (['sub', 'resub'].includes(event.msg_id)) this.emit('subscription', event);
      }

      // https://dev.twitch.tv/docs/irc#join-twitch-membership
      // TODO: Use code 353 for detecting channel JOIN
      if (data.includes(`@${this.username}.tmi.twitch.tv JOIN`)) {
        const channel = parser.formatJOIN(data)
        if (channel) {
          if (!this.channels.includes(channel)) this.channels.push(channel);
          this.emit('join', channel);
        }
      }

      if (data.includes(`@${this.username}.tmi.twitch.tv PART`)) {
        const channel = parser.formatPART(data)
        if (channel) {
          if (this.channels.includes(channel)) this.channels.pop(channel);
          this.emit('part', channel);
        }
      }

    });

  }

  checkForError(event) {

    /* Login Authentication Failed */
    if (event.includes('Login authentication failed')) {
      this.irc.emit('error', {
        message: 'Login authentication failed'
      });
    }

    /* Auth formatting */
    if (event.includes('Improperly formatted auth')) {
      this.irc.emit('error', {
        message: 'Improperly formatted auth'
      });
    }

    /* Notice about blocked messages */
    if (event.includes('Your message was not sent because you are sending messages too quickly')) {
      this.irc.emit('error', {
        message: 'Your message was not sent because you are sending messages too quickly'
      });
    }

  }

  writeIrcMessage(text) {
    this.irc.write(text + "\r\n");
  }

  join(channel) {
    channel = parser.formatCHANNEL(channel);
    this.writeIrcMessage(`JOIN ${channel}`);
  }

  part(channel) {
    if (!channel && this.channels.length > 0) channel = this.channels[0];
    channel = parser.formatCHANNEL(channel);
    this.writeIrcMessage(`PART ${channel}`);
  }

  send(message, channel, callback) {

    if (!channel) channel = this.channels[0];
    if (message.length >= 500) {

      this.cb(callback, {
        sent: false,
        message: 'Exceeded PRIVMSG character limit (500)'
      });

    } else {
      this.writeIrcMessage('PRIVMSG ' + channel + ' :' + message);
    }

  }

  timeout(username, channel, duration = 600, reason = '') {

    if (!channel) channel = this.channels[0];
    this.send(`/timeout ${username} ${duration} ${reason}`, channel);

  }

  ban(username, channel, reason = '') {
    if (!channel) channel = this.channels[0];
    this.send(`/ban ${username} ${reason}`, channel);
  }

  close() {
    this.irc.destroy();
    this.emit('close');
  }

  cb(callback, obj) {

    if (!callback) return;
    obj.ts = new Date();
    callback(obj);

  }

}

module.exports = TwitchBot;