DHT InfoHash scraper

var DistributedHashTable = require( 'bittorrent-dht')
var BittorrentProtocol = require('bittorrent-protocol')
var TorrentDiscovery = require('torrent-discovery')
var ParseTorrent = require('parse-torrent')

var Net = require('net')
var RandomBytes = require('randombytes')


var UtP = require('ut_pex')
var UtM = require('ut_metadata')

class Client{
  constructor(){
    this.peerId = RandomBytes(20);
    this.DHT = new DistributedHashTable();
    this.torrents = [];
  }
  addInfohash(infohash){
    var torrent = new Torrent(infohash, this)
    torrent.discover()
    this.torrents.push(torrent)
  }
}

class Torrent{
  constructor(infoHash, client){
    this.infoHash = infoHash
    this.client = client
    this.discovery = null
    this.metadata = null
    this.peers = []
  }
  discover(){
    this.discovery = new TorrentDiscovery({
      infoHash: this.infoHash,
      peerId: this.client.peerId,
      dht: this.client.dht,
      tracker: false,
      port: 6000
    })

    this.discovery.on('peer', this._onPeer.bind(this))
  }
  _onPeer(address){
    var [host, port] = address.split(':')
    var Peer = {host: host, port: port}
    this._connectPeer(Peer)
  }
  _connectPeer(PeerAddress){
    //console.log("Creating new peer", PeerAddress)
    var match = false
    this.peers.forEach((peer)=>{
      if(peer.host === PeerAddress.host){
        match = true
      }
    })
    if(!match){
      var peer = new Peer(PeerAddress, this)
      this.peers.push(peer)
    }
  }
}

class Peer{
  constructor(address, torrent){
    this.host = address.host
    this.port = address.port
    this.torrent = torrent

    this.bitfield = null
    this.pieces = null

    this.wire = null
    this.conn = null

    this.connect()
  }

  connect(){
    this.wire = new BittorrentProtocol()
    this.wire.use(UtP())
    this.wire.ut_pex.on('peer', this.torrent._connectPeer.bind(this.torrent))

    this.wire.use(UtM())
    this.wire.ut_metadata.on('metadata', this._onMetadata.bind(this))
    this.wire.on('bitfield', this._onBitfield.bind(this))

    this.conn = new Net.createConnection({host: this.host, port: this.port})
    this.conn.on('error', (err)=>{
      console.log("Removing peer:",this.torrent.peers.indexOf(this))
      this.torrent.peers.splice(this.torrent.peers.indexOf(this), 1)
    })
    this.conn.pipe(this.wire).pipe(this.conn)
    this.wire.handshake(this.torrent.infoHash, this.torrent.client.peerId, {dht: true})

    if(!this.torrent.metadata){
      this.wire.ut_metadata.fetch()
    }

  }
  _onMetadata(meta){
    try{
      var metadata = ParseTorrent(meta)
      this.torrent.metadata = metadata
      for(var peer of this.torrent.peers){
        if(peer.wire && peer.wire.ut_metadata) peer.wire.ut_metadata.cancel()
      }
    }catch(err){
      console.error('Metadata failure', err)
    }
  }
  _onBitfield(bitfield){
    this.bitfield = bitfield
    var have = 0
    for(var i=0; i<bitfield.buffer.length << 3; i++){
      if(bitfield.get(i) === true){
        have += 1
      }
    }
    this.pieces = have
  }
}

setInterval(()=>{
  client.torrents.forEach((torrent)=>{
    torrent.peers.forEach((peer, i )=>{
      var status = ""
      if(torrent.metadata){
        status = peer.pieces === torrent.metadata.pieces.length ? "Seed" : "Leech"
        console.log(`[${i}] ${peer.host}:${peer.port} - ${peer.pieces}/${torrent.metadata.pieces.length} - ${status}`)

      }else{
        console.log(`[${i}] ${peer.host}:${peer.port}`)
      }
    })
  })
},1000)

var client = new Client()
// INSERT INFOHASH HERE
client.addInfohash('')