/*
  This modules adds subslides support.
*/
(function($, deck, undefined) {

  var $d = $(document);
  
  /*
  Extends defaults/options.
  */
  $.extend(true, $[deck].defaults, {
  });

  var subSlidesCount = -1,
      subSlide = null;

  $d.bind('deck.init', function() {
    $('.incremental .highlight').addClass('subslide');
    $('.incremental .subslide').addClass('deck-offscreen');
  });

  $d.bind('deck.change', function(e, from, to) {
    var slide = $[deck]('getSlide', to);
    var parentSlide = slide.parent().closest('.slide');
    var subSlides = parentSlide.find('.subslide');
    if (parentSlide.is('.incremental') && subSlides.length) {
      if (subSlide) {
        subSlide.hide();
      } else if (!subSlide && from > to) {
        subSlidesCount = subSlides.length-1;
      }
      if (from < to) {
        subSlidesCount++;
      } else {
        subSlidesCount--;
      }
      subSlide = subSlides.eq(subSlidesCount);
      if (subSlide.is('.deck-offscreen')) {
        subSlide.removeClass('deck-offscreen').hide().slideDown();
      } else {
        subSlide.slideDown();
      }
    } else {
      if (subSlide) { subSlide.hide(); }
      subSlide = null;
      subSlidesCount = -1;
    }
  });

})(jQuery, 'deck', this);