var busy = false;
(function (c) {	
	
    c.fn.presentation = function (g) {
        var h = {
            slide: ".slide",
            pagerClass: "nav-pager",
            prevNextClass: "nav-prev-next",
            prevText: "Previous",
            nextText: "Next"
        };
        c(this).each(function () {
            var a = c(this);
            a.count = 1;
            a.changeSlide = function (b) {
        	
	                a.slides.filter(":visible").fadeOut(500);
	                $(".slides").css('height', a.slides.filter(":nth-child(" + b + ")").height());
	                $(".slides").css('overflow', 'hidden');
	                a.slides.filter(":nth-child(" + b + ")").delay(600).fadeIn(750);
	                a.find("." + a.options.pagerClass).children(".current").removeClass("current");                
	                a.find("." + a.options.pagerClass).children(":nth-child(" + b + ")").addClass("current");            	
            };
            a.pageClick = function (b) {
                if (!b.parent().hasClass("current")) {
                    a.changeSlide(b.parent().prevAll().length + 1);
                    a.count = b.parent().prevAll().length + 1;
                }
            };
            a.prevNextClick = function (b) {
            	if (!busy){
	            	busy = true;    
	                if (b === "prev") a.count === 1 ? (a.count = a.slides.length) : a.count--;
	                else a.count === a.slides.length ? (a.count = 1) : a.count++;
	                a.changeSlide(a.count);
	                window.location.hash = "#" + a.count;
	                setTimeout("busy = false",500 );
            	}
            };
            a.addControls = function () {
                a.numSlides = a.slides.length;
                for (var b = '<ol class="' + a.options.pagerClass + '">', d = 1; d < a.numSlides + 1; d++) b += '<li><a href="#' + d + '">' + d + "</a></li>";
                a.append(b);
                if (a.currentHash) {
                    a.find("." + a.options.pagerClass).children(":nth-child(" + a.currentHash + ")").addClass("current");
                    a.count = a.currentHash;
                } else {
                    a.find("." + a.options.pagerClass).children(":first-child").addClass("current");
                    a.count = 1;
                }
                a.append('<ul class="' + a.options.prevNextClass + '"><li><a href="#prev" class="prev">' + a.options.prevText + '</a></li><li><a href="#next" class="next">' + a.options.nextText + "</a></li>");
                a.find("." + a.options.pagerClass).find("a").bind("click", function () {
                    a.pageClick(c(this))
                });
                a.find("." + a.options.prevNextClass).find("a").click(function () {
                    a.prevNextClick(c(this).attr("class"));
                    return false
                });
                c(document).keyup(function (f) {
                    var e;
                    if (f.keyCode === 37) e = "prev";
                    else if (f.keyCode === 39) e = "next";
                    e !== "" && a.prevNextClick(e)
                })
            };
            a.init = function () {
                a.options = c.extend(h, g);
                a.slides = a.find(a.options.slide);
                a.currentHash = window.location.hash.substr(1);
                a.currentHash ? a.slides.filter(":not(:nth-child(" + a.currentHash + "))").hide() : a.slides.filter(":not(:first)").hide();
                a.addControls()
            };
            a.init()
        })
    }
})(jQuery);