$(document).ready(function() {
  console.log("ready");

  var _current_pages = -1,
      _page_left_bg, _page_right_bg,
      _$page_left = $('#page-left'), _$page_right = $('#page-right'),
      _bgs_prefix = "images/pages/";

  //     ____      _ __
  //    /  _/___  (_) /_
  //    / // __ \/ / __/
  //  _/ // / / / / /_
  // /___/_/ /_/_/\__/

  function init(){
    console.log("init", _$page_left);
    initkeyboard();
    changePages();
  };

  //     ____
  //    / __ \____ _____ ____  _____
  //   / /_/ / __ `/ __ `/ _ \/ ___/
  //  / ____/ /_/ / /_/ /  __(__  )
  // /_/    \__,_/\__, /\___/____/
  //             /____/

  function nextPages(){
    if(_current_pages < _PAGES.length-2){
      _current_pages+=2;
      changePages();
    }
  };

  function prevPages(){
    if(_current_pages > -1){
      _current_pages-=2;
      changePages();
    }
  };

  function changePages(){
    console.log("changePages");
    _page_left_bg  = _bgs_prefix+_PAGES[_current_pages];
    _page_right_bg = _bgs_prefix+_PAGES[_current_pages+1];
    console.log(_page_left_bg+" | "+_page_right_bg);

    _$page_left.css({'background-image': "url("+_page_left_bg+")"});
    _$page_right.css({'background-image': "url("+_page_right_bg+")"});

  };

  //     __ __           __                         __
  //    / //_/__  __  __/ /_  ____  ____ __________/ /
  //   / ,< / _ \/ / / / __ \/ __ \/ __ `/ ___/ __  /
  //  / /| /  __/ /_/ / /_/ / /_/ / /_/ / /  / /_/ /
  // /_/ |_\___/\__, /_.___/\____/\__,_/_/   \__,_/
  //           /____/
  function initkeyboard(){
    keyboardJS.bind('right', function(event) {
      // console.log(event);
      nextPages();
    });
    keyboardJS.bind('left', function(event) {
      // console.log(event);
      prevPages();
    });
  };

  init();
});