/**
 * The FlashSerializer serializes JavaScript variables of types object, array, string,
 * number, date, boolean, null or undefined into XML. 
 */

/**
 * Create a new instance of the FlashSerializer.
 * useCdata: Whether strings should be treated as character data. If false, strings are simply XML encoded.
 */
function FlashSerializer(useCdata)
{
    this.useCdata = useCdata;
}

/**
 * Serialize an array into a format that can be deserialized in Flash. Supported data types are object,
 * array, string, number, date, boolean, null, and undefined. Returns a string of serialized data.
 */
FlashSerializer.prototype.serialize = function(args)
{
    var qs = new String();

    for (var i = 0; i < args.length; ++i)
    {
        switch(typeof(args[i]))
        {
            case 'undefined':
                qs += 't'+(i)+'=undf';
                break;
            case 'string':
                qs += 't'+(i)+'=str&d'+(i)+'='+escape(args[i]);
                break;
            case 'number':
                qs += 't'+(i)+'=num&d'+(i)+'='+escape(args[i]);
                break;
            case 'boolean':
                qs += 't'+(i)+'=bool&d'+(i)+'='+escape(args[i]);
                break;
            case 'object':
                if (args[i] == null)
                {
                    qs += 't'+(i)+'=null';
                }
                else if (args[i] instanceof Date)
                {
                    qs += 't'+(i)+'=date&d'+(i)+'='+escape(args[i].getTime());
                }
                else // array or object
                {
                    try
                    {
                        qs += 't'+(i)+'=xser&d'+(i)+'='+escape(this._serializeXML(args[i]));
                    }
                    catch (exception)
                    {
                        throw new Exception("FlashSerializationException",
                                            "The following error occurred during complex object serialization: " + exception.getMessage());
                    }
                }
                break;
            default:
                throw new Exception("FlashSerializationException",
                                    "You can only serialize strings, numbers, booleans, dates, objects, arrays, nulls, and undefined.");
        }

        if (i != (args.length - 1))
        {
            qs += '&';
        }
    }

    return qs;
}

/**
 * Private
 */
FlashSerializer.prototype._serializeXML = function(obj)
{
    var doc = new Object();
    doc.xml = '<fp>'; 
    this._serializeNode(obj, doc, null);
    doc.xml += '</fp>'; 
    return doc.xml;
}

/**
 * Private
 */
FlashSerializer.prototype._serializeNode = function(obj, doc, name)
{
    switch(typeof(obj))
    {
        case 'undefined':
            doc.xml += '<undf'+this._addName(name)+'/>';
            break;
        case 'string':
            doc.xml += '<str'+this._addName(name)+'>'+this._escapeXml(obj)+'</str>';
            break;
        case 'number':
            doc.xml += '<num'+this._addName(name)+'>'+obj+'</num>';
            break;
        case 'boolean':
            doc.xml += '<bool'+this._addName(name)+' val="'+obj+'"/>';
            break;
        case 'object':
            if (obj == null)
            {
                doc.xml += '<null'+this._addName(name)+'/>';
            }
            else if (obj instanceof Date)
            {
                doc.xml += '<date'+this._addName(name)+'>'+obj.getTime()+'</date>';
            }
            else if (obj instanceof Array)
            {
                doc.xml += '<array'+this._addName(name)+'>';
                for (var i = 0; i < obj.length; ++i)
                {
                    this._serializeNode(obj[i], doc, null);
                }
                doc.xml += '</array>';
            }
            else
            {
                doc.xml += '<obj'+this._addName(name)+'>';
                for (var n in obj)
                {
                    if (typeof(obj[n]) == 'function')
                        continue;
                    this._serializeNode(obj[n], doc, n);
                }
                doc.xml += '</obj>';
            }
            break;
        default:
            throw new Exception("FlashSerializationException",
                                "You can only serialize strings, numbers, booleans, objects, dates, arrays, nulls and undefined");
            break;
    }
}

/**
 * Private
 */
FlashSerializer.prototype._addName= function(name)
{
    if (name != null)
    {
        return ' name="'+name+'"';
    }
    return '';
}

/**
 * Private
 */
FlashSerializer.prototype._escapeXml = function(str)
{
    if (this.useCdata)
        return '<![CDATA['+str+']]>';
    else
        return str.replace(/&/g,'&amp;').replace(/</g,'&lt;');
}