(function(jQuery) {
    jQuery.fn.checkboxTree = function(settings) {

        settings = jQuery.extend({
            collapsedarrow: "img-arrow-collapsed.gif",
            expandedarrow: "img-arrow-expanded.gif",
            blankarrow: "img-arrow-blank.gif",
            activeClass: "checkboxtreeactive",
            hoverClass: "over",
            checkchildren: false,
            checkparents: true,
            collapsed: true,
            hidecbwithjs: false,
            checkedClass: "checked",
            onClick: function() { }
        }, settings);

        var $group = this;
        var $labels = jQuery(":checkbox + label", $group)
        var $checkboxes = jQuery(":checkbox", $group)

        //set up the tree
        jQuery("li", $group).each(function() {

            var $this = jQuery(this)
            var $collapseImage;

            if (settings.checkparents) {
                var checkedchildren = jQuery("ul li input:checked", $this).length
                var $firstcheckbox = $this.children("input:checkbox:first")

                if ((!$this.children("input:checkbox:first").is(":checked")) && (checkedchildren > 0)) {
                    $firstcheckbox.attr("checked", "checked")
                }
            }

            if ($this.is(":has(ul)")) {
                if (settings.collapsed) {
                    $this.find("ul").hide();
                    $collapseImage = jQuery('<img class="checkboxtreeimage" src="' + settings.collapsedarrow + '" / >')
                    $collapseImage.data("collapsedstate", 0)
                } else {
                    $collapseImage = jQuery('<img class="checkboxtreeimage" src="' + settings.expandedarrow + '" / >')
                    $collapseImage.data("collapsedstate", 1)
                }
            } else {
                $collapseImage = jQuery('<img src="' + settings.blankarrow + '" / >')
            }
            $this.prepend($collapseImage);

        })

        //add class signifying the tree has been setup
        $group.addClass(settings.activeClass);

        $group.bind("click.checkboxtree", function(e, a) {
            var $clicked = jQuery(e.target)
            var $clickedcheck = $clicked.prev()
            var $currrow = $clicked.parents("li:first")
            var $clickedparent = $currrow.parents("li:first").find(":checkbox:first");
            var $clickedparentlabel = $clickedparent.next("label");
            var clickedlabel = false;
            var clickedimage = false;
            if ($clicked.is(":checkbox + label")) {
                clickedlabel = true;
            }
            if ($clicked.is("img.checkboxtreeimage")) {
                clickedimage = true;
            }
            //when the label is clicked, set the checkbox to the opposite clicked state, and toggle the checked class
            if (clickedlabel) {
                $clicked.prev().attr({ checked: !$clickedcheck.attr("checked") }).end().toggleClass(settings.checkedClass);
                //check parents if that option is set
                if (settings.checkparents) {
                    var checkedchildren = jQuery("input:checked", $currrow).length

                    if ((!$clickedparent.is(":checked")) && (checkedchildren > 0)) {
                        $clickedparentlabel.trigger("click.checkboxtree", ["checkparents"])
                    }
                }
                //check child checkboxes if settings say so
                if (settings.checkchildren && a !== "checkparents") {
                    $currrow.find(":checkbox + label").prev().attr({ checked: $clickedcheck.attr("checked") ? "checked" : "" })
					.next()
					.addClass($clicked.hasClass(settings.checkedClass) ? settings.checkedClass : "")
					.removeClass($clicked.hasClass(settings.checkedClass) ? "" : settings.checkedClass)
                }
            }
            //handle expanding of levels
            if (clickedimage) {
                var clickstate = $clicked.data("collapsedstate")
                if (clickstate === 0) {
                    $currrow.children("ul").show();
                    $currrow.children("img").attr("src", settings.expandedarrow);
                    $clicked.data("collapsedstate", 1)
                } else if (clickstate === 1) {
                    $currrow.children("ul").hide();
                    $currrow.children("img").attr("src", settings.collapsedarrow);
                    $clicked.data("collapsedstate", 0)
                }
            }

            settings.onClick();
        })

        //set the class correctly for the labels that contain checked checkboxes
        jQuery("input:checked + label", $group).addClass(settings.checkedClass)

        //add hover class for labels if is ie 6
        if (jQuery.browser.msie && jQuery.browser.version < 7) {
            $labels.hover(
				function() { jQuery(this).addClass(settings.hoverClass) },
				function() { jQuery(this).removeClass(settings.hoverClass); }
			)
        }

        //hide the checkboxes with js if set option set to true
        if (settings.hidecbwithjs) {
            $checkboxes.hide();
        }

        /*
        jQuery("li",$group).each(function(){
        var $currentLi = jQuery(this);
        if($currentLi.is(":has(ul)")){
        //				//check the parent boxes if a child is selected
        //				if((!$currentLi.children("input:checkbox:first").is(":checked")) && (jQuery("ul li input:checked",$currentLi).length>0)){
        //					$currentLi.find("label:first").trigger("click");
        //				}
        this done				$currentLi.children("ul").hide();
        //				var $collapseImage = jQuery('<img src="' + settings.collapsedarrow + '" / >')
        //				$collapseImage.toggle(function(){
        //					$currentLi.children("ul").show();
        //					$currentLi.children("img").attr("src",settings.expandedarrow);
        //				},function(){
        //					$currentLi.children("ul").hide();
        //					$currentLi.children("img").attr("src",settings.collapsedarrow);
        //				})
        jQuery("ul li input:checkbox",$currentLi).next().click(function(){
        if((!$currentLi.children("input:checkbox:first").is(":checked")) && (jQuery("ul li input:checked",$currentLi).length>0)){
        $currentLi.find("label:first").addClass("checked").prev().attr("checked","checked")
        }
        });
        jQuery("input:checkbox",$currentLi).next().click(function(){
        if(jQuery("ul li input:checked",jQuery(this).parent("li")).length>0){
        jQuery(this).addClass("checked").prev().attr("checked","checked");
        }
        });
        $currentLi.prepend($collapseImage);
        }else{
        var $collapseImage = jQuery('<img src="' + settings.blankarrow + '" / >')
        $currentLi.prepend($collapseImage);
        }
        })
        */

        return $group;
    };
})(jQuery);