var TelegramBot = require('node-telegram-bot-api');
var exec = require('child_process').exec;
var BOT_TOKEN = '.';
var bot = new TelegramBot(BOT_TOKEN, {polling: true});

var photoQueue = [];

bot.onText(/\/photo/, function (msg) {
  console.log('photo');
    photoQueue.push(msg);
    takeAndSendPhoto(photoQueue[photoQueue.length - 1]);
});

function takeAndSendPhoto(msg) {
  bot.sendChatAction(msg.chat.id, 'upload_photo').then(function() {
    console.log('take photo');
    exec('raspistill -o /home/pi/pi-camera-bot/temp.jpg ', function photoTaken() {
      bot.sendPhoto(msg.chat.id, '/home/pi/pi-camera-bot/temp.jpg', {caption: new Date().toLocaleString()}).then(function nextPhoto() {
        photoQueue.pop();
        if (photoQueue.length > 0) {
          takeAndSendPhoto(photoQueue[photoQueue.length - 1]);
        }
     });
  })});
}