safetwitch/server/util/scraping/chat/chat.ts

import { EventEmitter } from 'stream';
import WebSocket from 'ws'
import { TwitchChatOptions, Metadata, MessageType, MessageTypes } from '../../../types/scraping/Chat'
import { parseUsername } from './utils';

export declare interface TwitchChat {
    on(event: 'PRIVMSG', listener: (username: string, messageType: MessageType, channel: string, message: string) => void): this
}

export class TwitchChat extends EventEmitter{
    public channels: string[]
    private url = 'wss://irc-ws.chat.twitch.tv:443'
    private ws: WebSocket | null;

    constructor(options: TwitchChatOptions) {
        super()
        this.channels = options.channels
        this.ws = null
    }

    private parser() {
        this.ws?.on('message', (data) => {
            let normalData = data.toString()
            let splitted = normalData.split(":")
            
            let metadata = splitted[1].split(' ')
            let message = splitted[2]

            if(!MessageTypes.includes(metadata[1])) return;

            let parsedMetadata: Metadata = {
                username: parseUsername(metadata[0]),
                messageType: metadata[1],
                channel: metadata[2],
                message: message
            }

            this.createEmit(parsedMetadata)
        })
    }

    private createEmit(data: Metadata) {
        this.emit(data.messageType, ...Object.values(data))
    }

    public async connect() {
        this.ws = new WebSocket(this.url)
        
        this.ws.on('open', () => {
            if(this.ws) {
                this.ws.send('PASS none')
                this.ws.send('NICK justinfan333333333333')
                
                for(let channel of this.channels) {
                    this.ws.send(`JOIN #${channel}`)
                }

                this.parser()
                return Promise.resolve()
            }
        })

    }

}