/* 
 * Derived from Example 16-1, JavaScript: The Definitive Guide by David Flanagan. 
 *		Copyright 2002 O'Reilly & Associates.
 *
 * While copyrighted, using them is here is ok according to:
 *		http://www.oreilly.com/pub/a/oreilly/ask_tim/2001/codepolicy.html
 *
 * You can test this routine by using the CookieTest.html
 */

/* The constructor function: creates a cookie object for the specified
 * document, with a specified name and optional attributes.
 * Arguments:
 *   document: The Document object that the cookie is stored for. Required.
 *   name:     A string that specifies a name for the cookie. Required.
 *   hours:    An optional number that specifies the number of hours from now
 *             that the cookie should expire.
 *   path:     An optional string that specifies the cookie path attribute.
 *   domain:   An optional string that specifies the cookie domain attribute.
 *   secure:   An optional Boolean value that, if true, requests a secure cookie.
 */
function Cookie(document, name, hours, path, domain, secure)
{
    // All the predefined properties of this object begin with '$'
    // to distinguish them from other properties which are the values to
    // be stored in the cookie.
    this.$document = document;
    this.$name = name;
    if (hours)
        this.$expiration = new Date((new Date()).getTime() + hours*60*60*1000); // one Hour
    else this.$expiration = null;
    if (path) this.$path = path; else this.$path = null;
    if (domain) this.$domain = domain; else this.$domain = null;
    if (secure) this.$secure = true; else this.$secure = false;
}

/*
 * This function is the store() method of the Cookie object.
 */
Cookie.prototype.store = function () {
    // First, loop through the properties of the Cookie object and
    // put together the value of the cookie. Since cookies use the
    // equals sign and semicolons as separators, we'll use colons
    // and ampersands for the individual state variables we store 
    // within a single cookie value. Note that we escape the value
    // of each state variable, in case it contains punctuation or other
    // illegal characters.
    var cookieval = "";
    for(var prop in this) {
        // Ignore properties with names that begin with '$' and also methods.
        if ((prop.charAt(0) == '$') || ((typeof this[prop]) == 'function')) 
            continue;
        if (cookieval != "") cookieval += '&';
        cookieval += prop + ':' + escape(this[prop]);
    }

    // Now that we have the value of the cookie, put together the 
    // complete cookie string, which includes the name and the various
    // attributes specified when the Cookie object was created.
    var cookie = this.$name + '=' + cookieval;
    if (this.$expiration)
        cookie += '; expires=' + this.$expiration.toGMTString();
    if (this.$path) cookie += '; path=' + this.$path;
    if (this.$domain) cookie += '; domain=' + this.$domain;
    if (this.$secure) cookie += '; secure';

    // Now store the cookie by setting the magic Document.cookie property.
    this.$document.cookie = cookie;
}

/*
 * This function is the load() method of the Cookie object.
 */
Cookie.prototype.load = function() { 
    // First, get a list of all cookies that pertain to this document.
    // We do this by reading the magic Document.cookie property.
    var allcookies = this.$document.cookie;
    if (allcookies == "") return false;

    // Now extract just the named cookie from that list.
    var start = allcookies.indexOf(this.$name + '=');
    if (start == -1) return false;   // Cookie not defined for this page.
    start += this.$name.length + 1;  // Skip name and equals sign.
    var end = allcookies.indexOf(';', start);
    if (end == -1) end = allcookies.length;
    var cookieval = allcookies.substring(start, end);

    // Now that we've extracted the value of the named cookie, we've
    // got to break that value down into individual state variable 
    // names and values. The name/value pairs are separated from each
    // other by ampersands, and the individual names and values are
    // separated from each other by colons. We use the split method
    // to parse everything.
    var a = cookieval.split('&');    // Break it into array of name/value pairs.
    for(var i=0; i < a.length; i++)  // Break each pair into an array.
        a[i] = a[i].split(':');

    // Now that we've parsed the cookie value, set all the names and values
    // of the state variables in this Cookie object. Note that we unescape()
    // the property value, because we called escape() when we stored it.
    for(var i = 0; i < a.length; i++) {
        this[a[i][0]] = unescape(a[i][1]);
    }

    // We're done, so return the success code.
    return true;
}

/* 
 * This function is the remove() method of the Cookie object.
 */
Cookie.prototype.remove = function() {
    var cookie;
    cookie = this.$name + '=';
    if (this.$path) cookie += '; path=' + this.$path;
    if (this.$domain) cookie += '; domain=' + this.$domain;
    cookie += '; expires=Fri, 02-Jan-1970 00:00:00 GMT';

    this.$document.cookie = cookie;
}

/**
 *	Client-side general Cookie management functions (Original)
 * 
 *  Note these are the original cookie functions. For some reason 
 *  the set function and delete functions were never used.  Rather
 *  than guessing at the reasons, using the above scripts from 
 *  O'Reilly makes sense.
 **/

function getCookieVal (offset) 
   {
        var endstr = document.cookie.indexOf (";", offset);
   	if (endstr == -1)
      	   endstr = document.cookie.length;
   	return unescape(document.cookie.substring(offset, endstr));
   }

function getCookie (name) 
   {
   	var arg = name + "=";
   	var alen = arg.length;
   	var clen = document.cookie.length;
   	var i = 0;
   	while (i < clen) {
	      var j = i + alen;
	      if (document.cookie.substring(i, j) == arg)
   		return getCookieVal (j);
    	      i = document.cookie.indexOf(" ", i) + 1;
	      if (i == 0) break; 
        }
   	return null;
   }
   
// Alert box for Test Cookie
function displayCookie(cookieName)
{
   if (getCookie(cookieName) != null) {
      alert(cookieName + " = " + getCookie(cookieName));
   }
   else
   {
      alert("Cookie " + cookieName + " is not defined.");
   }
}

// function setCookie (name, value) 
// {
//   var argv = setCookie.arguments;
//   var argc = setCookie.arguments.length;
//   var expires = (argc > 2) ? argv[2] : null;
//   var path = (argc > 3) ? argv[3] : null;
//   var domain = (argc > 4) ? argv[4] : null;
//   var secure = (argc > 5) ? argv[5] : false;
//   document.cookie = name + "=" + escape (value) +
//        ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) +
//        ((path == null) ? "" : ("; path=" + path)) +
//        ((domain == null) ? "" : ("; domain=" + domain)) +
//        ((secure == true) ? "; secure" : "");
// }

// function deleteCookie () 
// {
// var exp = new Date();
//   exp.setTime (exp.getTime() - 1000000000); // This cookie is history (changed -1 to make it previous time)
//   var cval = getCookie ('PipePrefs');
//   document.cookie ='PipePrefs' + "=" + cval + "; expires=" + exp.toGMTString();
//   alert("The cookie has been deleted.");
// }