/**
 * Cookies.js, providing easy access to cookies thru the cookiejar object. Enabling so-called "subcookies" thru the subcookiejar 
 * object.
 * See this related blogpost for more information on how to use these objects:
 *  <http://www.whatstyle.net/articles/28/subcookies>
 * Check out this other blogpost for information about the new version:
 *  <http://www.whatstyle.net/articles/46/subcookies_v2>
 * 
 * @author Harmen Janssen <http://www.whatstyle.net>
 * @version 2.0
 * 
 */

/* based on http://www.quirksmode.org/js/cookies.html, by Peter-Paul Koch */
var cookiejar = {
    /* set a cookie */
    bake: function(cookieName,cookieValue,days,path) {
        var expires='';
        if (days) {
            var date = new Date();
            date.setTime(date.getTime()+(days*24*60*60*1000));
            expires = "; expires="+date.toGMTString();
        }
        var thePath = '; path=/';
        if (path) {
            thePath = '; path=' + path;
        }
        document.cookie = cookieName+'='+escape(cookieValue)+expires+thePath;
        return true;
    },
    /* get a cookie value */
    fetch: function(cookieName) {
        var nameEQ = cookieName + '=';
        var ca = document.cookie.split(';');
        for (var i=0; i<ca.length; i++) {
            var c = ca[i];
            while (c.charAt(0) == ' ') {
                c = c.substring(1, c.length);
            }
            if (c.indexOf(nameEQ) == 0) {
                return unescape(c.substring(nameEQ.length, c.length));
            }
        }
        return null;
    },
    /* delete a cookie */
    crumble: function(cookieName) {
        return cookiejar.bake(cookieName,'',-1);
    }
};

/* circumventing browser restrictions on the number of cookies one can use */
var subcookiejar = {
    nameValueSeparator: '$$:$$',
    subcookieSeparator: '$$/$$',
    /* set a cookie. subcookieObj is a collection of cookies to be. Every member of subcookieObj is the name of the cookie, its value
     * the cookie value
     */
    bake: function(cookieName,subcookieObj,days,path) {
        var existingCookie;
        /* check for existing cookie */
        if (existingCookie = subcookiejar.fetch (cookieName)) {
            /* if a cookie by the same name is found, 
             * append its values to the subcookieObj.
             */
            for (var i in existingCookie) {
                if (!(i in subcookieObj)) {
                    subcookieObj[i] = existingCookie[i];
                }
            }
        }
        var cookieValue = '';
        for (var i in subcookieObj) {
            cookieValue += i + subcookiejar.nameValueSeparator;
            cookieValue += subcookieObj[i];
            cookieValue += subcookiejar.subcookieSeparator;
        }
        /* remove trailing subcookieSeparator */
        cookieValue = cookieValue.substring(0,cookieValue.length-subcookiejar.subcookieSeparator.length);
        return cookiejar.bake(cookieName,cookieValue,days,path);
    },
    /* get a subcookie */
    fetch: function(cookieName,subcookieName) {
        var cookieValue = cookiejar.fetch(cookieName);
        /* proceed only if a cookie was found */
        if (!cookieValue) {
            return null;
        }
        var subcookies = cookieValue.split(subcookiejar.subcookieSeparator);
        var cookieObj = {};
        for (var i=0,sclen=subcookies.length; i<sclen; i++) {
            var sc = subcookies[i].split(subcookiejar.nameValueSeparator);
            cookieObj [sc[0]] = sc[1];
        }
        /* if subcookieName is given, return that subcookie if available, or null.
         * else, return the entire cookie as an object literal
         */
        if (subcookieName != undefined) {
            if (subcookieName in cookieObj) {
                return cookieObj[subcookieName];
            }
            return null;
        }
        return cookieObj;
    },
    /* delete a subcookie */
    crumble: function(cookieName,subcookieName,days,path) {
        var cookieValue = cookiejar.fetch(cookieName);
        if (!cookieValue) {
            return false;
        }
        var newCookieObj = {};
        var subcookies = cookieValue.split(subcookiejar.subcookieSeparator);
        for (var i=0, sclen=subcookies.length; i<sclen; i++)    {
            var sc = subcookies[i].split(subcookiejar.nameValueSeparator);
            if (sc[0] != subcookieName) {
                newCookieObj[sc[0]] = sc[1];
            }
        }
        return subcookiejar.bake(cookieName,newCookieObj,days,path);
    }
};