//Style Sheet Switcher version 1.1 Oct 10th, 2006
//Author: Dynamic Drive: http://www.dynamicdrive.com
//Usage terms: http://www.dynamicdrive.com/notice.htm

var manual_or_random = "manual" //"manual" or "random"
var randomsetting = "3 days" //"eachtime", "sessiononly", or "x days (replace x with desired integer)". Only applicable if mode is random.

//////No need to edit beyond here//////////////

function getCookie(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
}

function setCookie(name, value, days) {
    var expireDate = new Date()
    //set "expstring" to either future or past date, to set or delete cookie, respectively
    var expstring = (typeof days != "undefined") ? expireDate.setDate(expireDate.getDate() + parseInt(days)) : expireDate.setDate(expireDate.getDate() - 5)
    document.cookie = name + "=" + value + "; expires=" + expireDate.toGMTString() + "; path=/";
}

function deleteCookie(name) {
    setCookie(name, "moot")
}


function setStylesheet(title, randomize) { //Main stylesheet switcher function. Second parameter if defined causes a random alternate stylesheet (including none) to be enabled
    var i, cacheobj, altsheets = [""]
    for (i = 0; (cacheobj = document.getElementsByTagName("link")[i]); i++) {
        if (cacheobj.getAttribute("rel").toLowerCase() == "alternate stylesheet" && cacheobj.getAttribute("title")) { //if this is an alternate stylesheet with title
            cacheobj.disabled = true
            altsheets.push(cacheobj) //store reference to alt stylesheets inside array
            if (cacheobj.getAttribute("title") == title) //enable alternate stylesheet with title that matches parameter
                cacheobj.disabled = false //enable chosen style sheet
        }
    }
    if (typeof randomize != "undefined") { //if second paramter is defined, randomly enable an alt style sheet (includes non)
        var randomnumber = Math.floor(Math.random() * altsheets.length)
        altsheets[randomnumber].disabled = false
    }
    return (typeof randomize != "undefined" && altsheets[randomnumber] != "") ? altsheets[randomnumber].getAttribute("title") : "" //if in "random" mode, return "title" of randomly enabled alt stylesheet
}

function chooseStyle(styletitle, days) { //Interface function to switch style sheets plus save "title" attr of selected stylesheet to cookie
    if (document.getElementById) {
        setStylesheet(styletitle)
        setCookie("mysheet", styletitle, days)
        sessionStorage.setItem('mysheet', styletitle);
    }
}

function indicateSelected(element) { //Optional function that shows which style sheet is currently selected within group of radio buttons or select menu
    if (selectedtitle != null && (element.type == undefined || element.type == "select-one")) { //if element is a radio button or select menu
        var element = (element.type == "select-one") ? element.options : element
        for (var i = 0; i < element.length; i++) {
            if (element[i].value == selectedtitle) { //if match found between form element value and cookie value
                if (element[i].tagName == "OPTION") //if this is a select menu
                    element[i].selected = true
                else //else if it's a radio button
                    element[i].checked = true
                break
            }
        }
    }
}

if (manual_or_random == "manual") { //IF MANUAL MODE
    var selectedtitle = getCookie("mysheet")
    if (document.getElementById && selectedtitle != null) //load user chosen style sheet from cookie if there is one stored
        setStylesheet(selectedtitle)
    setCookie("mysheet", getCookie("mysheet"), 0)
}
else if (manual_or_random == "random") { //IF AUTO RANDOM MODE
    if (randomsetting == "eachtime")
        setStylesheet("", "random")
    else if (randomsetting == "sessiononly") { //if "sessiononly" setting
        if (getCookie("mysheet_s") == null) //if "mysheet_s" session cookie is empty
            document.cookie = "mysheet_s=" + setStylesheet("", "random") + "; path=/" //activate random alt stylesheet while remembering its "title" value
        else
            setStylesheet(getCookie("mysheet_s")) //just activate random alt stylesheet stored in cookie
    }
    else if (randomsetting.search(/^[1-9]+ days/i) != -1) { //if "x days" setting
        if (getCookie("mysheet_r") == null || parseInt(getCookie("mysheet_r_days")) != parseInt(randomsetting)) { //if "mysheet_r" cookie is empty or admin has changed number of days to persist in "x days" variable
            setCookie("mysheet_r", setStylesheet("", "random"), parseInt(randomsetting)) //activate random alt stylesheet while remembering its "title" value
            setCookie("mysheet_r_days", randomsetting, parseInt(randomsetting)) //Also remember the number of days to persist per the "x days" variable
        }
        else
            setStylesheet(getCookie("mysheet_r")) //just activate random alt stylesheet stored in cookie
    }
}

document.addEventListener('DOMContentLoaded', function () {
    if (!!sessionStorage.getItem('mysheet')) {
        chooseStyle(sessionStorage.getItem('mysheet'));
    }
}, true);