$(document).ready(function() {

  // navigation hovers
  $('#showcase-btn-prev').hover(function() {
    $(this).stop(true).animate({
        backgroundPosition: "0px 0px"
    }, 150);
  }, 
  function() {
    $(this).stop(true).animate({
      backgroundPosition: "10px 0px"
    }, 150);
  });

  $('#showcase-btn-next').hover(function() {
    $(this).stop(true).animate({
      backgroundPosition: "10px 0px"
    }, 150);
  }, 
  function() {
    $(this).stop(true).animate({
      backgroundPosition: "0px 0px"
    }, 150);
  });


  $('#showcase-btn-next').click(function() {
    showcase_next();
    return false;
  });

  $('#showcase-btn-prev').click(function() {
    showcase_prev();
    return false;
  });


  sc_items    = $('#showcase-items li.showcase-item');

  first_item  = $('#showcase-items li:first');
  first_item.addClass('showcase-item-active');

  showcase_adjust();

  first_item.css('visibility', 'visible');

  showcase_paging();
  showcase_check_dark();

	// bind resize event 
	$(window).resize(function() {
	
		showcase_adjust();
	});


});


function showcase_next() {

  var items         = $('li.showcase-item');
  var c_item        = $('li.showcase-item-active');  
  var c_index       = $(items).index(c_item);

  showcase_jump(c_index+1);  

}

function showcase_prev() {

  var items         = $('li.showcase-item');
  var c_item        = $('li.showcase-item-active');  
  var c_index       = $(items).index(c_item);

  showcase_jump(c_index-1);  

}


function showcase_jump(id) {

  var items       = $('li.showcase-item');
  if(id >= items.length || id < 0) { return; } 
  var new_item    = $(items[id]);
  var old_item    = $('li.showcase-item-active');

  new_item.fadeTo(0,0);
  new_item.css('visibility', 'visible');


  old_item.fadeTo('fast', 0, function() { $(this).css('visibility', 'hidden'); });
  new_item.fadeTo('fast', 1);
     

  old_item.removeClass('showcase-item-active');
  new_item.addClass('showcase-item-active');  

  showcase_paging();
  showcase_check_dark();

}


function showcase_paging() {

  var items         = $('li.showcase-item');
  var c_item        = $('li.showcase-item-active');  
  var c_index       = $(items).index(c_item);


  if(c_index <= 0) {
    $('#showcase-btn-prev').css('visibility', 'hidden');
  }
  else
  {
    $('#showcase-btn-prev').css('visibility', 'visible');
  }
   
  if(c_index == items.length - 1) {
    $('#showcase-btn-next').css('visibility', 'hidden');
  }
  else
  {
    
    $('#showcase-btn-next').css('visibility', 'visible');
  }

}

function showcase_check_dark() {

  var c_item        = $('li.showcase-item-active');
  if(c_item.hasClass('showcase-item-dark')) {

    $('#nav').addClass('navi-light');
    $('#showcase-btn-prev').addClass('btn-light');
    $('#showcase-btn-next').addClass('btn-light');
    $('.logo-dark').css('visibility', 'hidden');
    $('.logo-light').css('visibility', 'visible');
  }  
  else  
  {
    $('#nav').removeClass('navi-light');
    $('#showcase-btn-prev').removeClass('btn-light');
    $('#showcase-btn-next').removeClass('btn-light');

    $('.logo-light').css('visibility', 'hidden'); 
    $('.logo-dark').css('visibility', 'visible');
  }

}


function showcase_adjust() {

  // centering image

  var c_item        = $('li.showcase-item-active');
  if(c_item.length == 0) {
    c_item = $('li.showcase-item:first');
  }
 
  var sc_ul         = $('ul#showcase-items');
  var item_width    = $(c_item).width();

  if($(window).width() <= $(document).width()) {
    var max_width = $(document).width();
  } else {
    var max_width = $(window).width();
  } 


  var new_left = Math.floor((max_width - item_width)/2);  

  sc_ul.css('left', new_left + 'px');  
}