safetwitch-backend/routes/proxyRoute.ts

import { Router, Response, Request, NextFunction } from 'express'
import { TwitchAPI } from '../util/scraping/extractor';
import ws, { WebSocket } from 'ws';
import { TwitchChat } from '../util/scraping/chat/chat';
import { logger } from '../util/logger';

const proxyRouter = Router();
const twitch = new TwitchAPI()
     
proxyRouter.get('/img/:base64Url', async (req: Request, res: Response, next: NextFunction) => {
    const imageUrl = Buffer.from(req.params.base64Url, 'base64url').toString('utf-8')
    console.log(imageUrl)
    if(!imageUrl) return;

    const imageRes = await fetch(imageUrl)
      .catch(next)

    if(!imageRes) return;

    if(imageRes.status !== 200) {
      res.status(imageRes.status).send()
      const error = new Error('Image proxy fetch was not status 200')
      logger.warn(error)
    }

    const arrayBuffer = await imageRes.arrayBuffer()
    const buf = Buffer.from(arrayBuffer)

    res.send(buf)
})


proxyRouter.get('/stream/:username/hls.m3u8', async (req: Request, res: Response, next: NextFunction) => {
  let m3u8Data = await twitch.getStream(req.params.username)
  const urlRegex =/(\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/ig;
  const matches = m3u8Data.match(urlRegex)
  if (!matches) return next(new Error('Error proxying HLS'));

  for (let url of matches) {
    const base64data = Buffer.from(url).toString('base64url')
    m3u8Data = m3u8Data.replace(url, `${process.env.URL}/proxy/hls/${base64data}`)
  }

  res.setHeader('Content-type','application/vnd.apple.mpegurl')
  res.send(m3u8Data)
})

proxyRouter.get('/hls/:encodedUrl' , async (req: Request, res: Response, next: NextFunction) => {
  const unencodedUrl = Buffer.from(req.params.encodedUrl, 'base64url').toString()
  const m3u8Fetch = await fetch(unencodedUrl)
  var m3u8Data = await m3u8Fetch.text()
   
  res.send(m3u8Data)
})



// IRC PROXY
interface ExtWebSocket extends WebSocket {
  id: string;
}

const chat = new TwitchChat({
  login: {
    username: 'justinfan23423',
    password: 'none'
  },
  channels: []
})
chat.connect()

 const clients : { [k:string]: ExtWebSocket[] } = {}
import { randomUUID } from 'crypto';

const findClientsForStreamer = async (streamerName: string) => {
  if(!clients[streamerName]) return Promise.reject(new Error('No clients following streamer'))

  return clients[streamerName]
}

export const wsServer = new ws.Server({ noServer: true });
wsServer.on('connection', (ws: ExtWebSocket) => {
  const socket = ws as ExtWebSocket
  socket.on('message', (message) => {
    const data = message.toString()
    const splitted = data.split(' ')

    if(splitted.length > 2) socket.close()
    if(splitted[0] !== 'JOIN') socket.close()

    const streamersToJoin = splitted[1].split(',')
    if(streamersToJoin.length > 1) socket.close()

    const id = randomUUID()
    for (let streamer of streamersToJoin) {
      chat.addStreamer(streamer)
      
      if(clients[streamer]) {
        clients[streamer].push(socket)
      } else {
        clients[streamer] = [socket]
      }
    }
    socket.id = id
    socket.send('OK')
    

  });

  socket.on('close', () => {
    if(socket.id) {
    }
  })
});

chat.on('PRIVMSG', async (username, type, channel, message) => {
  const socketsToSend = await findClientsForStreamer(channel)
  for(let socket of socketsToSend) {
    let payload = {
      username,
      type,
      channel,
      message
    }
    socket.send(JSON.stringify(payload))
  }
})

 

export default proxyRouter