var Slider = Slider || {};
Slider.Utils = Slider.Utils || {};

var page = 1;
var incrementer = 3;
var itemcount = $('.slider-wrapper').find('.slider-item').length;
var perpage = 3;
var pagecount = Math.ceil(itemcount / perpage);
var itemwidth = $('.slider-wrapper').find('.slider-item').outerWidth();
var wrapwidth = itemwidth * itemcount;
var pagesize = itemwidth * perpage;
var lastpage = itemcount - incrementer;

Slider.Utils.init = function(){
    Slider.Utils.adjust();
    $('.next').click(function(){
        Slider.Utils.nextClick();
		console.log("next");
    });
    $('.prev').click(function(){
        Slider.Utils.prevClick();
    });
};
Slider.Utils.adjust = function(){
    //$('.slider-wrapper').width(pagesize);
    $('.slider-track').width(wrapwidth);
    $('.slider-item:odd').addClass('alt');
};
Slider.Utils.nextClick = function(){
    if (page >= 1 && page < pagecount) {
        $('.slider-track').animate({marginLeft: "-=" + itemwidth * incrementer});
        page = page + 1;
    }
    else 
        if (page === pagecount) {
            $('.slider-track').animate({marginLeft: 0});
            page = 1;
        }
};
Slider.Utils.prevClick = function(){
    if (page > 1 && page >= lastpage) {
        $('.slider-track').animate({
            marginLeft: "+=" + itemwidth * incrementer
        });
        page = page - 1;
    }
    else 
        if (page === 1) {
            $('.slider-track').animate({
                marginLeft: "-" + pagesize * lastpage
            });
            page = itemcount - incrementer;
        }
};


$(document).ready(function(){
	Slider.Utils.init();
});