/**
 * @author feiwen
 */
(function($) {
    $.fn.textSlider = function(settings) {
        settings = jQuery.extend({
            speed: "normal",
            line: 2,
            timer: 1000
        }, settings);
        return new $.textSlider(this, settings);
    };
    $.extend({ textSlider: function($this, settings) {
        //alert($this.html());
        var ul = $("ul:eq(0)", $this);
        if ($this.length === 0)
            return null;
        var timerID;
        var li = ul.children();
        var total = li.length;
        if (total <= settings.line)
            return null;
        var _btnUp = $(".up:eq(0)", $this)
        var _btnDown = $(".down:eq(0)", $this)
        var liHight = $(li[0]).outerHeight();
        var upHeight = 0 - settings.line * liHight; //滚动的高度；
        if (total < settings.line * 2) {
            for (var i = 0; i < settings.line * 2 - total; i++) {
                ul.find("li:eq(" + i + ")").clone().appendTo(ul);
            }
        }
        ul.wrap($("<div></div>").css({ "overflow": "hidden", "white-space": "nowrap", "height": -upHeight }));
        var scrollUp = function() {
            _btnUp.unbind("click", scrollUp);
            ul.animate({ marginTop: upHeight }, settings.speed, function() {
                for (i = 0; i < settings.line; i++) {
                    //$(li[i]).appendTo(ul);
                    ul.find("li:first").appendTo(ul);
                    // alert(ul.html());
                }
                ul.css({ marginTop: 0 });
                _btnUp.bind("click", scrollUp); //Shawphy:绑定向上按钮的点击事件
            });
        };
        var scrollDown = function() {
            _btnDown.unbind("click", scrollDown);
            ul.css({ marginTop: upHeight });
            for (i = 0; i < settings.line; i++) {
                ul.find("li:last").prependTo(ul);
            }
            ul.animate({ marginTop: 0 }, settings.speed, function() {
                _btnDown.bind("click", scrollDown); //Shawphy:绑定向上按钮的点击事件
            });
        };
        var autoPlay = function() {
            timerID = window.setInterval(scrollUp, settings.timer);
            //alert(settings.timer);
        };
        var autoStop = function() {
            window.clearInterval(timerID);
        };
        //事件绑定
        ul.hover(autoStop, autoPlay).mouseout();
        _btnUp.css("cursor", "pointer").click(scrollUp);
        _btnUp.hover(autoStop, autoPlay);
        _btnDown.css("cursor", "pointer").click(scrollDown);
        _btnDown.hover(autoStop, autoPlay);

        this.halt = autoStop;
        this.fire = autoPlay;
        this.dispose = function() {
            this.halt();
            ul.unbind();
            _btnDown.unbind();
            _btnUp.unbind();
        };
    }
    });
})(jQuery);