$(document).ready(function() { //perform actions when DOM is ready
  var galleryTimer;
  var z = 10; //for setting the initial z-index's
  var inAnimation = false; //flag for testing if we are in a animation
  var $currImg = $('#gallery #pictures img:first');
  
  $($('#gallery #pictures img').get().reverse()).each(function() { //set the initial z-index's
    z++; //at the end we have the highest z-index value stored in the z variable
    $(this).css('z-index', z); //apply increased z-index to <img>
  });

  function swapFirstLast(isFirst) {
    if(inAnimation) return false; //if already swapping pictures just return
    else inAnimation = true; //set the flag that we process a image
    
    var processZindex, direction, newZindex, inDeCrease; //change for previous or next image
    
    if(isFirst) { processZindex = z; direction = '-'; newZindex = 11; inDeCrease = 1; } //set variables for "next" action
    else { processZindex = 11; direction = ''; newZindex = z; inDeCrease = -1; } //set variables for "previous" action
    
    $('#pictures img').each(function() { //process each image
      if($(this).css('z-index') == processZindex) { //if its the image we need to process
        $(this).animate({ 'top' : direction + $(this).height() + 'px' }, 'slow', function() { //animate the img above/under the gallery (assuming all pictures are equal height)
          $(this).css('z-index', newZindex) //set new z-index
            .animate({ 'top' : '0' }, 'slow', function() { //animate the image back to its original position
              inAnimation = false; //reset the flag
            });
        });
      } else { //not the image we need to process, only in/de-crease z-index
      	if($(this).css('z-index') == z-1) {
      		$currImg = $(this);
	      	$("#gallery #galleryText").fadeOut('slow',function(){adjustDescription();});
      	}
        $(this).animate({ 'top' : '0' }, 'slow', function() { //make sure to wait swapping the z-index when image is above/under the gallery
          $(this).css('z-index', parseInt($(this).css('z-index')) + inDeCrease); //in/de-crease the z-index by one
        });
      }
    });
    return false; //don't follow the clicked link
  }
  
  $('#gallery #next a,#gallery #pictures img').click(function() {
    return swapFirstLast(true); //swap first image to last position
  });
  
  $('#gallery #prev a').click(function() {
    return swapFirstLast(false); //swap last image to first position
  });
  
  
  $("#gallery #controller")
  	.find('#play, #playback, #stop')
  	.click(function(){
  	  var isFirst = true, $this = $(this), restart = true;
  	  if($this.attr('id') == "playback") isFirst = false;
  	  if($this.attr('id') == "stop") restart = false;
	  $this.parent().find(".active").removeClass("active");
	  $this.addClass("active");
	  clearInterval(galleryTimer);
	  if(restart)
	  	galleryTimer = setInterval(function(){swapFirstLast(isFirst);}, 2500);
	  return false;
  });
  adjustDescription()
  function adjustDescription()
  {
	  $("#gallery #galleryText #header").text($currImg.attr('alt'));
	  $("#gallery #galleryText #description").text(
	  	$currImg.parent().parent()
	  		.find("#picturesDescription #" + $currImg.attr('id') + "Desc").text()
	  );
	  $("#gallery #galleryText").fadeIn('slow');
  }
  
});