(function($) {

    $.fn.extend({
        draggable: function(options) {
            var args = Array.prototype.slice.call(arguments, 1);
            
            return this.each(function() {
                if (typeof options == "string") {
                    var drag = $.data(this, "ui-draggable");
                    drag[options].apply(drag, args);

                } else if(!$.data(this, "ui-draggable"))
                    new $.ui.draggable(this, options);
            });
        }
    });
    
    $.ui.draggable = function(element, options) {
        //Initialize needed constants
        var self = this;
        
        this.element = $(element);
        
        $.data(element, "ui-draggable", this);
        this.element.addClass("ui-draggable");
        
        //Prepare the passed options
        this.options = $.extend({}, options);
        var o = this.options;
        $.extend(o, {
            helper: o.ghosting == true ? 'clone' : (o.helper || 'original'),
            handle : o.handle ? ($(o.handle, element)[0] ? $(o.handle, element) : this.element) : this.element,
            appendTo: o.appendTo || 'parent'        
        });
        
        $(element).bind("setData.draggable", function(event, key, value){
            self.options[key] = value;
        }).bind("getData.draggable", function(event, key){
            return self.options[key];
        });

        //Initialize mouse events for interaction
        $(o.handle).mouseInteraction({
            executor: this,
            delay: o.delay,
            distance: o.distance || 0,
            dragPrevention: o.prevention ? o.prevention.toLowerCase().split(',') : ['input','textarea','button','select','option'],
            start: this.start,
            stop: this.stop,
            drag: this.drag,
            condition: function(e) { return !(e.target.className.indexOf("ui-resizable-handle") != -1 || this.disabled); }
        });

        //Position the node
        if(o.helper == 'original' && (this.element.css('position') == 'static' || this.element.css('position') == ''))
            this.element.css('position', 'relative');
    };
    
    $.extend($.ui.draggable.prototype, {
        plugins: {},
        ui: function(e) {
            return {
                helper: this.helper,
                position: this.position,
                absolutePosition: this.positionAbs,
                instance: this,
                options: this.options                   
            };
        },
        propagate: function(n,e) {
            $.ui.plugin.call(this, n, [e, this.ui()]);
            return this.element.triggerHandler(n == "drag" ? n : "drag"+n, [e, this.ui()], this.options[n]);
        },
        destroy: function() {
            this.handle.removeMouseInteraction();
            this.element
                .removeClass("ui-draggable ui-draggable-disabled")
                .removeData("ui-draggable")
                .unbind(".draggable");
        },
        enable: function() {
            this.element.removeClass("ui-draggable-disabled");
            this.disabled = false;
        },
        disable: function() {
            this.element.addClass("ui-draggable-disabled");
            this.disabled = true;
        },
        recallOffset: function(e) {
            var elementPosition = { left: this.elementOffset.left - this.offsetParentOffset.left, top: this.elementOffset.top - this.offsetParentOffset.top };
            var r = this.helper.css('position') == 'relative';

            //Generate the original position
            this.originalPosition = {
                left: (r ? parseInt(this.helper.css('left'),10) || 0 : elementPosition.left + (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollLeft)),
                top: (r ? parseInt(this.helper.css('top'),10) || 0 : elementPosition.top + (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollTop))
            };
            
            //Generate a flexible offset that will later be subtracted from e.pageX/Y
            this.offset = {left: this._pageX - this.originalPosition.left, top: this._pageY - this.originalPosition.top };
        },
        start: function(e) {
          
            var o = this.options;
            if($.ui.ddmanager) $.ui.ddmanager.current = this;
            
            //Create and append the visible helper
            this.helper = typeof o.helper == 'function' ? $(o.helper.apply(this.element[0], [e])) : (o.helper == 'clone' ? this.element.clone().appendTo((o.appendTo == 'parent' ? this.element[0].parentNode : o.appendTo)) : this.element);
            if(this.helper[0] != this.element[0]) this.helper.css('position', 'absolute');
            if(!this.helper.parents('body').length) this.helper.appendTo((o.appendTo == 'parent' ? this.element[0].parentNode : o.appendTo));

            //Find out the next positioned parent
            this.offsetParent = (function(cp) {
                while(cp) {
                    if(cp.style && (/(absolute|relative|fixed)/).test($.css(cp,'position'))) return $(cp);
                    cp = cp.parentNode ? cp.parentNode : null;
                }; return $("body");        
            })(this.helper[0].parentNode);
            
            //Prepare variables for position generation
            this.elementOffset = this.element.offset();
            this.offsetParentOffset = this.offsetParent.offset();
            var elementPosition = { left: this.elementOffset.left - this.offsetParentOffset.left, top: this.elementOffset.top - this.offsetParentOffset.top };
            this._pageX = e.pageX; this._pageY = e.pageY;
            this.clickOffset = { left: e.pageX - this.elementOffset.left, top: e.pageY - this.elementOffset.top };
            var r = this.helper.css('position') == 'relative';

            //Generate the original position
            this.originalPosition = {
                left: (r ? parseInt(this.helper.css('left'),10) || 0 : elementPosition.left + (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollLeft)),
                top: (r ? parseInt(this.helper.css('top'),10) || 0 : elementPosition.top + (this.offsetParent[0] == document.body ? 0 : this.offsetParent[0].scrollTop))
            };
            
            //If we have a fixed element, we must subtract the scroll offset again
            if(this.element.css('position') == 'fixed') {
                this.originalPosition.top -= this.offsetParent[0] == document.body ? $(document).scrollTop() : this.offsetParent[0].scrollTop;
                this.originalPosition.left -= this.offsetParent[0] == document.body ? $(document).scrollLeft() : this.offsetParent[0].scrollLeft;
            }
            
            //Generate a flexible offset that will later be subtracted from e.pageX/Y
            this.offset = {left: e.pageX - this.originalPosition.left, top: e.pageY - this.originalPosition.top };
            
            //Call plugins and callbacks
            this.propagate("start", e);

            this.helperProportions = { width: this.helper.outerWidth(), height: this.helper.outerHeight() };
            if ($.ui.ddmanager && !o.dropBehaviour) $.ui.ddmanager.prepareOffsets(this, e);
            
            //If we have something in cursorAt, we'll use it
            if(o.cursorAt) {
                if(o.cursorAt.top != undefined || o.cursorAt.bottom != undefined) {
                    this.offset.top -= this.clickOffset.top - (o.cursorAt.top != undefined ? o.cursorAt.top : (this.helperProportions.height - o.cursorAt.bottom));
                    this.clickOffset.top = (o.cursorAt.top != undefined ? o.cursorAt.top : (this.helperProportions.height - o.cursorAt.bottom));
                }
                if(o.cursorAt.left != undefined || o.cursorAt.right != undefined) {
                    this.offset.left -= this.clickOffset.left - (o.cursorAt.left != undefined ? o.cursorAt.left : (this.helperProportions.width - o.cursorAt.right));
                    this.clickOffset.left = (o.cursorAt.left != undefined ? o.cursorAt.left : (this.helperProportions.width - o.cursorAt.right));
                }
            }
            this.overMenu(e);
            return false;

        },
        clear: function() {
            if($.ui.ddmanager) $.ui.ddmanager.current = null;
            this.helper = null;
        },
        stop: function(e) {
        	
            this.overMenu(e);
            //If we are using droppables, inform the manager about the drop
            if ($.ui.ddmanager && !this.options.dropBehaviour)
                $.ui.ddmanager.drop(this, e);
                
            //Call plugins and trigger callbacks
            this.propagate("stop", e);
            
            if(this.cancelHelperRemoval) return false;          
            if(this.options.helper != 'original') this.helper.remove();
            this.clear();
            return false;
        },
        drag: function(e) {
           
            this.overMenu(e)
           
            //Compute the helpers position
            this.position = { top: e.pageY - this.offset.top, left: e.pageX - this.offset.left };
            this.positionAbs = { left: e.pageX - this.clickOffset.left, top: e.pageY - this.clickOffset.top };

            //Call plugins and callbacks            
            this.position = this.propagate("drag", e) || this.position;
            
            this.helper.css({ left: this.position.left+'px', top: this.position.top+'px' }); // Stick the helper to the cursor
            if($.ui.ddmanager) $.ui.ddmanager.drag(this, e);
         
            return false;
            
        },
        overMenu: function(e) {
        	// deals with going over the menu in IE 7 and FF
           
           
            this.container = $('#topmenu');
            if(typeof(this.container) == 'undefined' 
              || typeof(this.container.offset) == 'undefined') {
                
              return ;
            }
            var iMenuEnd = parseInt(this.container.offset().top)  + parseInt(this.container.height());
            
            if(this.element.offset().top <= iMenuEnd ) {
                var sTop = (parseInt(iMenuEnd) + 5) + "px";
                this.element.css({top: sTop })
                return true;
            }
            return false;
            
            
        }
    });

})(jQuery);