/*
---

script: Base64.js

description: String methods for encoding and decoding Base64 data

license: MIT-style license.

authors: Ryan Florence (http://ryanflorence.com), webtoolkit.info

requires:
 - core:1.2.4: [String]

provides: [String.toBase64, String.decodeBase64]

...
*/


(function(){
		
		// Base64 string methods taken from http://www.webtoolkit.info/
		var Base64 = {
			
			_keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
			
			encode : function (input) {
				var output = "";
				var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
				var i = 0;
				input = Base64._utf8_encode(input);
				while (i < input.length) {
					chr1 = input.charCodeAt(i++);
					chr2 = input.charCodeAt(i++);
					chr3 = input.charCodeAt(i++);
					enc1 = chr1 >> 2;
					enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
					enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
					enc4 = chr3 & 63;
					if (isNaN(chr2)) {
						enc3 = enc4 = 64;
					} else if (isNaN(chr3)) {
						enc4 = 64;
					};
					output = output +
					this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
						this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);
				};
				return output;
			},

			decode : function (input) {
				var output = "";
				var chr1, chr2, chr3;
				var enc1, enc2, enc3, enc4;
				var i = 0;
				input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
				while (i < input.length) {
					enc1 = this._keyStr.indexOf(input.charAt(i++));
					enc2 = this._keyStr.indexOf(input.charAt(i++));
					enc3 = this._keyStr.indexOf(input.charAt(i++));
					enc4 = this._keyStr.indexOf(input.charAt(i++));
					chr1 = (enc1 << 2) | (enc2 >> 4);
					chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
					chr3 = ((enc3 & 3) << 6) | enc4;
					output = output + String.fromCharCode(chr1);
					if (enc3 != 64) {
						output = output + String.fromCharCode(chr2);
					};
					if (enc4 != 64) {
						output = output + String.fromCharCode(chr3);
					};
				};
				output = Base64._utf8_decode(output);
				return output;
			},

			// private method for UTF-8 encoding
			_utf8_encode : function (string) {
				string = string.replace(/\r\n/g,"\n");
				var utftext = "";
				for (var n = 0; n < string.length; n++) {
				var c = string.charCodeAt(n);
				if (c < 128) {
					utftext += String.fromCharCode(c);
				} else if((c > 127) && (c < 2048)) {
					utftext += String.fromCharCode((c >> 6) | 192);
					utftext += String.fromCharCode((c & 63) | 128);
				}	else {
					utftext += String.fromCharCode((c >> 12) | 224);
					utftext += String.fromCharCode(((c >> 6) & 63) | 128);
					utftext += String.fromCharCode((c & 63) | 128);
				};

			};
			return utftext;
			},


		_utf8_decode : function (utftext) {
			var string = "";
			var i = 0;
			var c = c1 = c2 = 0;
			while ( i < utftext.length ) {
				c = utftext.charCodeAt(i);
				if (c < 128) {
					string += String.fromCharCode(c);
					i++;
				}	else if((c > 191) && (c < 224)) {
					c2 = utftext.charCodeAt(i+1);
					string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
					i += 2;
				}	else {
					c2 = utftext.charCodeAt(i+1);
					c3 = utftext.charCodeAt(i+2);
					string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
					i += 3;
				};
			};
			return string;
		}

	};
    
	String.implement({
		encodeBase64: function(){
			return Base64.encode(this);
		},

		fromBase64: function(){
			return Base64.decode(this);
		}
	});

	String.alias('decodeBase64','fromBase64');
	String.alias('toBase64','encodeBase64');
    
})();