(function(root, factory) {
	if(typeof define === "function" && define.amd) {
		define([], factory);
	} else if(typeof module === "object" && module.exports) {
		module.exports = factory();
	} else {
		root.Base = factory();
	}
}(this, function() {
	'use strict';

	function Base64() {
		// private property  
		this._keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	}
	//public method for encoding  
	Base64.prototype.encode = function(input) {
		var output = "",
			chr1, chr2, chr3, enc1, enc2, enc3, enc4, i = 0;
		input = this._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;
	}

	// public method for decoding  
	Base64.prototype.decode = function(input) {
		var output = "",
			chr1, chr2, chr3, enc1, enc2, enc3, enc4, 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 = this._utf8_decode(output);
		return output;
	}

	// private method for UTF-8 encoding  
	Base64.prototype._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;
	}

	// private method for UTF-8 decoding  
	Base64.prototype._utf8_decode = function(utftext) {
		var string = "",
			i = 0,
			c = 0,
			c1 = 0,
			c2 = 0,
			c3 = 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;
	}

	var Base = new Base64();

	return Base;
}));