controller.js

var https = require('https');
var request = require('request');
var SECRET_TOKEN = process.env.DISTART_SECRET_TOKEN;

var TelegramBot = require('node-telegram-bot-api');

var bot = new TelegramBot(SECRET_TOKEN, {polling: false});

var fs = require('fs');

var file = fs.createWriteStream('./output');

module.exports = {
  auth: function () {
    return new Promise( function(resolve) {
      console.log('la');
      https.get('https://deepartapi.azurewebsites.net/create', function (r) {
        streamToString(r, function(string) {
          resolve(string);
        })
      })
    })
  },
  sendMessage: sendMessage,
  onImageDocReceived: function (token, document, user) {
    var id = document.file_id;
    getPhoto(token, id, user);
  },
  onImageReceived: function (token, photos, user) {
    var id = photos[photos.length-1].file_id;
    getPhoto(token, id, user);
  },
  onStart: function (token, users, username, params) {
    console.log(token);
    https.get('https://deepartapi.azurewebsites.net/start/' + token + '/300', function (r) {
      sendMessage('Thanks! You will receive your image as soon as it is done', users[username].chatID);
      moveUserToQueue (users, username);
    });
  }
}


function getPhoto (token, id, user) {
  console.log('https://api.telegram.org/bot' + SECRET_TOKEN + '/getFile?file_id=' + id);
  https.get('https://api.telegram.org/bot' + SECRET_TOKEN + '/getFile?file_id=' + id, function (res) {
    res.on('data', function (d) {
      console.log(JSON.parse(d.toString('utf8')));
      var path = JSON.parse(d.toString('utf8')).result.file_path;
      console.log('https://api.telegram.org/file/bot' + SECRET_TOKEN + '/' + path);
      https.get('https://api.telegram.org/file/bot' + SECRET_TOKEN + '/' + path, function (r) {
        r.pipe(request.post('https://deepartapi.azurewebsites.net/' + (user.content? 'content/'  : 'style/') + token));
        user.content++;
        if (user.content == 1) {
          sendMessage('Thanks! Please send the image on which you want to apply the style', user.chatID);
        } else {
          sendMessage('Thanks! Write start to start your job or delete to start again', user.chatID);
        }
        console.log("posted");
      });
    })
  });
  console.log(id);
}

function streamToString(s, cb) {
  var string = ''
  s.on('readable',function(buffer){
    var part = s.read().toString();
    string += part;
  });

  s.on('end',function(){
    cb(string);
  });
}

function sendMessage(text, chatID) {
  console.log('https://api.telegram.org/bot' + SECRET_TOKEN + '/sendMessage');
  request.post('https://api.telegram.org/bot' + SECRET_TOKEN + '/sendMessage', {form :{
    text : text,
    chat_id : chatID
  }});
}

function moveUserToQueue (users, username) {
  var user = users[username];
  delete users[username];
  queueListener(user);
}

function queueListener (user) {
  //poll the status of the query every second
  https.get('https://deepartapi.azurewebsites.net/status/' + user.token, function(r) {
    streamToString(r, function(s) {
      console.log(s);
      if (s !== 'SUCCESS') { // iterate
        setTimeout(function(){
          queueListener(user);
        }, 1000);
      } else {
        retrievePhoto(user);
      }
    });
  });
}

function retrievePhoto(user) {
  https.get('https://deepartapi.azurewebsites.net/get/' + user.token, function (r) {
    sendPhoto(user, r);
  });
}
function sendPhoto(user, photo) {
    // bot.sendPhoto(chatId, photo, {caption: 'Lovely kittens'});
    // console.log(photo);
    // streamToString(photo, function(s){
    //   console.log(s);
    // })
    // file.pipe(photo);
    sendMessage('https://deepartapi.azurewebsites.net/get/' + user.token, user.chatID);

    // photo.setHeader('Content-Type', 'image/jpeg');
    bot.sendPhoto(user.chatID, photo.toString());

    // request.post('https://api.telegram.org/bot' + SECRET_TOKEN + '/sendPhoto', {form :{
    //   chat_id: chatID,
    //   photo: photo
    // }}, function(e,r) {
    //   console.log('ah');
    //   console.log(e,r);
    // });
}