/*


Copyright (c) 2008 Fred Palmer fred.palmer_at_gmail.com





Permission is hereby granted, free of charge, to any person


obtaining a copy of this software and associated documentation


files (the "Software"), to deal in the Software without


restriction, including without limitation the rights to use,


copy, modify, merge, publish, distribute, sublicense, and/or sell


copies of the Software, and to permit persons to whom the


Software is furnished to do so, subject to the following


conditions:





The above copyright notice and this permission notice shall be


included in all copies or substantial portions of the Software.





THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,


EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES


OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND


NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT


HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,


WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING


FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR


OTHER DEALINGS IN THE SOFTWARE.


*/


function StringBuffer()


{ 


    this.buffer = []; 


} 





StringBuffer.prototype.append = function append(string)


{ 


    this.buffer.push(string); 


    return this; 


}; 





StringBuffer.prototype.toString = function toString()


{ 


    return this.buffer.join(""); 


}; 





var Base64 =


{


    codex : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",





    encode : function (input)


    {


        var output = new StringBuffer();





        var enumerator = new Utf8EncodeEnumerator(input);


        while (enumerator.moveNext())


        {


            var chr1 = enumerator.current;





            enumerator.moveNext();


            var chr2 = enumerator.current;





            enumerator.moveNext();


            var chr3 = enumerator.current;





            var enc1 = chr1 >> 2;


            var enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);


            var enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);


            var enc4 = chr3 & 63;





            if (isNaN(chr2))


            {


                enc3 = enc4 = 64;


            }


            else if (isNaN(chr3))


            {


                enc4 = 64;


            }





            output.append(this.codex.charAt(enc1) + this.codex.charAt(enc2) + this.codex.charAt(enc3) + this.codex.charAt(enc4));


        }





        return output.toString();


    },





    decode : function (input)


    {


        var output = new StringBuffer();





        var enumerator = new Base64DecodeEnumerator(input);


        while (enumerator.moveNext())


        {


            var charCode = enumerator.current;





            if (charCode < 128)


                output.append(String.fromCharCode(charCode));


            else if ((charCode > 191) && (charCode < 224))


            {


                enumerator.moveNext();


                var charCode2 = enumerator.current;





                output.append(String.fromCharCode(((charCode & 31) << 6) | (charCode2 & 63)));


            }


            else


            {


                enumerator.moveNext();


                var charCode2 = enumerator.current;





                enumerator.moveNext();


                var charCode3 = enumerator.current;





                output.append(String.fromCharCode(((charCode & 15) << 12) | ((charCode2 & 63) << 6) | (charCode3 & 63)));


            }


        }





        return output.toString();


    }


}








function Utf8EncodeEnumerator(input)


{


    this._input = input;


    this._index = -1;


    this._buffer = [];


}





Utf8EncodeEnumerator.prototype =


{


    current: Number.NaN,





    moveNext: function()


    {


        if (this._buffer.length > 0)


        {


            this.current = this._buffer.shift();


            return true;


        }


        else if (this._index >= (this._input.length - 1))


        {


            this.current = Number.NaN;


            return false;


        }


        else


        {


            var charCode = this._input.charCodeAt(++this._index);





            // "\r\n" -> "\n"


            //


            if ((charCode == 13) && (this._input.charCodeAt(this._index + 1) == 10))


            {


                charCode = 10;


                this._index += 2;


            }





            if (charCode < 128)


            {


                this.current = charCode;


            }


            else if ((charCode > 127) && (charCode < 2048))


            {


                this.current = (charCode >> 6) | 192;


                this._buffer.push((charCode & 63) | 128);


            }


            else


            {


                this.current = (charCode >> 12) | 224;


                this._buffer.push(((charCode >> 6) & 63) | 128);


                this._buffer.push((charCode & 63) | 128);


            }





            return true;


        }


    }


}





function Base64DecodeEnumerator(input)


{


    this._input = input;


    this._index = -1;


    this._buffer = [];


}





Base64DecodeEnumerator.prototype =


{


    current: 64,





    moveNext: function()


    {


        if (this._buffer.length > 0)


        {


            this.current = this._buffer.shift();


            return true;


        }


        else if (this._index >= (this._input.length - 1))


        {


            this.current = 64;


            return false;


        }


        else


        {


            var enc1 = Base64.codex.indexOf(this._input.charAt(++this._index));


            var enc2 = Base64.codex.indexOf(this._input.charAt(++this._index));


            var enc3 = Base64.codex.indexOf(this._input.charAt(++this._index));


            var enc4 = Base64.codex.indexOf(this._input.charAt(++this._index));





            var chr1 = (enc1 << 2) | (enc2 >> 4);


            var chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);


            var chr3 = ((enc3 & 3) << 6) | enc4;





            this.current = chr1;





            if (enc3 != 64)


                this._buffer.push(chr2);





            if (enc4 != 64)


                this._buffer.push(chr3);





            return true;


        }


    }


};