var ddaccordion={
    //object to store corresponding contentclass name based on headerclass
    contentclassname:{},
    //PUBLIC function to expand a particular header
    expandone:function(headerclass, selected){
        this.toggleone(headerclass, selected, "expand")
    },
    //PUBLIC function to collapse a particular header
    collapseone:function(headerclass, selected){
        this.toggleone(headerclass, selected, "collapse")
    },
    //PUBLIC function to expand all headers based on their shared CSS classname
    expandall:function(headerclass){
        var $=jQuery
        var $headers=$('.'+headerclass)
        $('.'+this.contentclassname[headerclass]+':hidden').each(function(){
                   $headers.eq(parseInt($(this).attr('contentindex'))).trigger("evt_accordion")
        })
    },
    //PUBLIC function to collapse all headers based on their shared CSS classname
    collapseall:function(headerclass){
        var $=jQuery
        var $headers=$('.'+headerclass)
        $('.'+this.contentclassname[headerclass]+':visible').each(function(){
                   $headers.eq(parseInt($(this).attr('contentindex'))).trigger("evt_accordion")
        })
    },
    //PUBLIC function to expand/ collapse a particular header
    toggleone:function(headerclass, selected, optstate){
        var $=jQuery
        var $targetHeader=$('.'+headerclass).eq(selected)
        var $subcontent=$('.'+this.contentclassname[headerclass]).eq(selected)
        if (typeof optstate=="undefined" || optstate=="expand" && $subcontent.is(":hidden") ||
                   optstate=="collapse" && $subcontent.is(":visible"))
            $targetHeader.trigger("evt_accordion")
    },

    expandit:function($targetHeader, $targetContent, config, useractivated){
        $targetContent.slideDown(config.animatespeed, function(){
        config.onopenclose($targetHeader.get(0), parseInt($targetHeader.attr('headerindex')),
        $targetContent.css('display'), useractivated)})
        this.transformHeader($targetHeader, config, "expand")
    },

    collapseit:function($targetHeader, $targetContent, config, isuseractivated){
        $targetContent.slideUp(config.animatespeed, function(){
        config.onopenclose($targetHeader.get(0), parseInt($targetHeader.attr('headerindex')),
        $targetContent.css('display'), isuseractivated)})
        this.transformHeader($targetHeader, config, "collapse")
    },

    transformHeader:function($targetHeader, config, state){
        //alternate btw "expand" and "collapse" CSS classes
        $targetHeader.addClass((state=="expand")? config.cssclass.expand : config.cssclass.collapse)
        .removeClass((state=="expand")? config.cssclass.collapse : config.cssclass.expand)
        //Change header image (assuming header is an image)?
        if (config.htmlsetting.location=='src'){
            //Set target to either header itself, or first image within header
            $targetHeader=($targetHeader.is("img"))? $targetHeader : $targetHeader.find('img').eq(0)
            $targetHeader.attr('src', (state=="expand")?
            config.htmlsetting.expand : config.htmlsetting.collapse) //change header image
        }
        //if change "prefix" HTML, locate dynamically added ".accordprefix" span tag and change it
        else if (config.htmlsetting.location=="prefix")
            $targetHeader.find('.accordprefix').html((state=="expand")?
            config.htmlsetting.expand : config.htmlsetting.collapse)
        else if (config.htmlsetting.location=="suffix")
            $targetHeader.find('.accordsuffix').html((state=="expand")?
            config.htmlsetting.expand : config.htmlsetting.collapse)
    },

    urlparamselect:function(headerclass){
        //check for "?headerclass=2,3,4" in URL
        var result=window.location.search.match(new RegExp(headerclass+"=((\\d+)(,(\\d+))*)", "i"))
        if (result!=null) result=RegExp.$1.split(',')
        //returns null, [index], or [index1,index2,etc], where index are the desired selected header indices
        return result
    },

    getCookie:function(Name){
        var re=new RegExp(Name+"=[^;]+", "i") //construct RE to search for target name/value pair
        if (document.cookie.match(re)) //if cookie found
            return document.cookie.match(re)[0].split("=")[1] //return its value
        return null
    },

    setCookie:function(name, value){document.cookie = name + "=" + value + "; path=/"},

    init:function(config){
    document.write('<style type="text/css">\n')
    document.write('.'+config.contentclass+'{display: none}\n') //generate CSS to hide contents
    document.write('<\/style>')
    jQuery(document).ready(function($){
        ddaccordion.urlparamselect(config.headerclass)
        var persistedheaders=ddaccordion.getCookie(config.headerclass)
        ddaccordion.contentclassname[config.headerclass]=config.contentclass //remember contentclass name based on headerclass
        config.cssclass={collapse: config.toggleclass[0], expand: config.toggleclass[1]} //store expand and contract CSS classes as object properties
        config.revealtype=/^(click)|(mouseover)$/i.test(config.revealtype)? config.revealtype.replace(/mouseover/i, "mouseenter") : "click"
        config.htmlsetting={location: config.togglehtml[0], collapse: config.togglehtml[1], expand: config.togglehtml[2]} //store HTML settings as object properties
        config.oninit=(typeof config.oninit=="undefined")? function(){} : config.oninit //attach custom "oninit" event handler
        config.onopenclose=(typeof config.onopenclose=="undefined")? function(){} : config.onopenclose //attach custom "onopenclose" event handler
        var lastexpanded={} //object to hold reference to last expanded header and content (jquery objects)
        var expandedindices=ddaccordion.urlparamselect(config.headerclass) || ((config.persiststate && persistedheaders!=null)? persistedheaders : config.defaultexpanded)
        if (typeof expandedindices=='string') //test for string value (exception is config.defaultexpanded, which is an array)
                        expandedindices=expandedindices.replace(/c/ig, '').split(',') //transform string value to an array (ie: "c1,c2,c3" becomes [1,2,3]
        var $subcontents=$('.'+config["contentclass"])
        if (expandedindices.length==1 && expandedindices[0]=="-1") //check for expandedindices value of [-1], indicating persistence is on and no content expanded
                        expandedindices=[]
        if (config["collapseprev"] && expandedindices.length>1) //only allow one content open?
                        expandedindices=[expandedindices.pop()] //return last array element as an array (for sake of jQuery.inArray())
        if (config["onemustopen"] && expandedindices.length==0) //if at least one content should be open at all times and none are, open 1st header
                        expandedindices=[0]
        $('.'+config["headerclass"]).each(function(index){ //loop through all headers
                        if (/(prefix)|(suffix)/i.test(config.htmlsetting.location) && $(this).html()!=""){ //add a SPAN element to header depending on user setting and if header is a container tag
                                $('<span class="accordprefix"></span>').prependTo(this)
                                $('<span class="accordsuffix"></span>').appendTo(this)
                        }
                        $(this).attr('headerindex', index+'h') //store position of this header relative to its peers
                        $subcontents.eq(index).attr('contentindex', index+'c') //store position of this content relative to its peers
                        var $subcontent=$subcontents.eq(index)
                        var needle=(typeof expandedindices[0]=="number")? index : index+'' //check for data type within expandedindices array- index should match that type
                        if (jQuery.inArray(needle, expandedindices)!=-1){ //check for headers that should be expanded automatically (convert index to string first)
                                if (config.animatedefault==false)
                                        $subcontent.show()
                                ddaccordion.expandit($(this), $subcontent, config, false) //Last Boolean value sets 'isuseractivated' parameter
                                lastexpanded={$header:$(this), $content:$subcontent}
                        }  //end check
                        else{
                                $subcontent.hide()
                                config.onopenclose($(this).get(0), parseInt($(this).attr('headerindex')), $subcontent.css('display'), false) //Last Boolean value sets 'isuseractivated' parameter
                                ddaccordion.transformHeader($(this), config, "collapse")
                        }
                })
                $('.'+config["headerclass"]).bind("evt_accordion", function(){ //assign custom event handler that expands/ contacts a header
                                var $subcontent=$subcontents.eq(parseInt($(this).attr('headerindex'))) //get subcontent that should be expanded/collapsed
                                if ($subcontent.css('display')=="none"){
                                        ddaccordion.expandit($(this), $subcontent, config, true) //Last Boolean value sets 'isuseractivated' parameter
                                        if (config["collapseprev"] && lastexpanded.$header && $(this).get(0)!=lastexpanded.$header.get(0)){ //collapse previous content?
                                                ddaccordion.collapseit(lastexpanded.$header, lastexpanded.$content, config, true) //Last Boolean value sets 'isuseractivated' parameter
                                        }
                                        lastexpanded={$header:$(this), $content:$subcontent}
                                }
                                else if (!config["onemustopen"] || config["onemustopen"] && lastexpanded.$header && $(this).get(0)!=lastexpanded.$header.get(0)){
                                        ddaccordion.collapseit($(this), $subcontent, config, true) //Last Boolean value sets 'isuseractivated' parameter
                                }
                 })
                $('.'+config["headerclass"]).bind(config.revealtype, function(){
                        if (config.revealtype=="mouseenter"){
                                clearTimeout(config.revealdelay)
                                var headerindex=parseInt($(this).attr("headerindex"))
                                config.revealdelay=setTimeout(function(){ddaccordion.expandone(config["headerclass"], headerindex)}, config.mouseoverdelay || 0)
                        }
                        else{
                                $(this).trigger("evt_accordion")
                                return false //cancel default click behavior
                        }
                })
                $('.'+config["headerclass"]).bind("mouseleave", function(){
                        clearTimeout(config.revealdelay)
                })
                config.oninit($('.'+config["headerclass"]).get(), expandedindices)
                $(window).bind('unload', function(){ //clean up and persist on page unload
                        $('.'+config["headerclass"]).unbind()
                        var expandedindices=[]
                        $('.'+config["contentclass"]+":visible").each(function(index){ //get indices of expanded headers
                                expandedindices.push($(this).attr('contentindex'))
                        })
                        if (config.persiststate==true){ //persist state?
                                expandedindices=(expandedindices.length==0)? '-1c' : expandedindices //No contents expanded, indicate that with dummy '-1c' value?
                                ddaccordion.setCookie(config.headerclass, expandedindices)
                        }
                })
        })
        }
}