/**
 * @author Stéphane Roucheray 
 * @extends jquery
 */


jQuery.fn.carousel = function(previous, next, options){
	var sliderList = jQuery(this).children()[0];
	
	if (sliderList) {
	 /*
		var increment = jQuery(sliderList).children().outerWidth("true"),
		elmnts = jQuery(sliderList).children(),
		numElmts = elmnts.length,
		sizeFirstElmnt = increment,
		shownInViewport = Math.round(jQuery(this).width() / sizeFirstElmnt),
		firstElementOnViewPort = 1,
		isAnimating = false;
		*/
		var increment = 0;
		var elmnts = null;
		var numElmts = 0
		var sizeFirstElmnt = 0;
		var shownInViewport = 0;
		var firstElementOnViewPort = 0;
		var isAnimating = false;
    var This = this;
    
  	var init = function(carousel){
	 	  increment = jQuery(sliderList).children().outerWidth("true");
		  elmnts = jQuery(sliderList).children();
		  numElmts = elmnts.length;
		  sizeFirstElmnt = increment;
		  shownInViewport = Math.round(jQuery(carousel).width() / sizeFirstElmnt);
		  firstElementOnViewPort = 1;
		  isAnimating = false;
  		for (i = 0; i < shownInViewport; i++) {
	 		  jQuery(sliderList).css('width',(numElmts+shownInViewport)*increment + increment + "px");
			  jQuery(sliderList).append(jQuery(elmnts[i]).clone());
		  }
	 }

		
		
		jQuery(previous).click(function(event){
		  if(increment == 0){
		    init(This);
		  }
			if (!isAnimating) {
				if (firstElementOnViewPort == 1) {
					jQuery(sliderList).css('left', "-" + numElmts * sizeFirstElmnt + "px");
					firstElementOnViewPort = numElmts;
				}
				else {
					firstElementOnViewPort--;
				}
				jQuery(sliderList).animate({
					left: "+=" + increment,
					y: 0,
					queue: true
				}, "swing", function(){isAnimating = false;});
				isAnimating = true;
			}
			
		});
		
		jQuery(next).click(function(event){
		  if(increment == 0){
		    init(This);
		  }
			if (!isAnimating) {
				if (firstElementOnViewPort > numElmts) {
					firstElementOnViewPort = 2;
					jQuery(sliderList).css('left', "0px");
				}
				else {
					firstElementOnViewPort++;
				}
				jQuery(sliderList).animate({
					left: "-=" + increment,
					y: 0,
					queue: true
				}, "swing", function(){isAnimating = false;});
				isAnimating = true;
			}
		});
	}
};