/*
 * $Id: base64.js,v 2.15 2014/04/05 12:58:57 dankogai Exp dankogai $
 *
 *  Licensed under the BSD 3-Clause License.
 *    http://opensource.org/licenses/BSD-3-Clause
 *
 *  References:
 *    http://en.wikipedia.org/wiki/Base64
 */

(function(global) {
	'use strict';
	// existing version for noConflict()
	var _Base64 = global.Base64;
	var version = "2.1.9";
	// if node.js, we use Buffer
	var buffer;
	if (typeof module !== 'undefined' && module.exports) {
		try {
			buffer = require('buffer').Buffer;
		} catch (err) {
		}
	}
	// constants
	var b64chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
	var b64tab = function(bin) {
		var t = {};
		for (var i = 0, l = bin.length; i < l; i++)
			t[bin.charAt(i)] = i;
		return t;
	}(b64chars);
	var fromCharCode = String.fromCharCode;
	// encoder stuff
	var cb_utob = function(c) {
		if (c.length < 2) {
			var cc = c.charCodeAt(0);
			return cc < 0x80 ? c
					: cc < 0x800 ? (fromCharCode(0xc0 | (cc >>> 6)) + fromCharCode(0x80 | (cc & 0x3f)))
							: (fromCharCode(0xe0 | ((cc >>> 12) & 0x0f))
									+ fromCharCode(0x80 | ((cc >>> 6) & 0x3f)) + fromCharCode(0x80 | (cc & 0x3f)));
		} else {
			var cc = 0x10000 + (c.charCodeAt(0) - 0xD800) * 0x400
					+ (c.charCodeAt(1) - 0xDC00);
			return (fromCharCode(0xf0 | ((cc >>> 18) & 0x07))
					+ fromCharCode(0x80 | ((cc >>> 12) & 0x3f))
					+ fromCharCode(0x80 | ((cc >>> 6) & 0x3f)) + fromCharCode(0x80 | (cc & 0x3f)));
		}
	};
	var re_utob = /[\uD800-\uDBFF][\uDC00-\uDFFFF]|[^\x00-\x7F]/g;
	var utob = function(u) {
		return u.replace(re_utob, cb_utob);
	};
	var cb_encode = function(ccc) {
		var padlen = [ 0, 2, 1 ][ccc.length % 3], ord = ccc.charCodeAt(0) << 16
				| ((ccc.length > 1 ? ccc.charCodeAt(1) : 0) << 8)
				| ((ccc.length > 2 ? ccc.charCodeAt(2) : 0)), chars = [
				b64chars.charAt(ord >>> 18),
				b64chars.charAt((ord >>> 12) & 63),
				padlen >= 2 ? '=' : b64chars.charAt((ord >>> 6) & 63),
				padlen >= 1 ? '=' : b64chars.charAt(ord & 63) ];
		return chars.join('');
	};
	var btoa = global.btoa ? function(b) {
		return global.btoa(b);
	} : function(b) {
		return b.replace(/[\s\S]{1,3}/g, cb_encode);
	};
	var _encode = buffer ? function(u) {
		return (u.constructor === buffer.constructor ? u : new buffer(u))
				.toString('base64')
	} : function(u) {
		return btoa(utob(u))
	};
	var encode = function(u, urisafe) {
		return !urisafe ? _encode(String(u)) : _encode(String(u)).replace(
				/[+\/]/g, function(m0) {
					return m0 == '+' ? '-' : '_';
				}).replace(/=/g, '');
	};
	var encodeURI = function(u) {
		return encode(u, true)
	};
	// decoder stuff
	var re_btou = new RegExp([ '[\xC0-\xDF][\x80-\xBF]',
			'[\xE0-\xEF][\x80-\xBF]{2}', '[\xF0-\xF7][\x80-\xBF]{3}' ]
			.join('|'), 'g');
	var cb_btou = function(cccc) {
		switch (cccc.length) {
		case 4:
			var cp = ((0x07 & cccc.charCodeAt(0)) << 18)
					| ((0x3f & cccc.charCodeAt(1)) << 12)
					| ((0x3f & cccc.charCodeAt(2)) << 6)
					| (0x3f & cccc.charCodeAt(3)), offset = cp - 0x10000;
			return (fromCharCode((offset >>> 10) + 0xD800) + fromCharCode((offset & 0x3FF) + 0xDC00));
		case 3:
			return fromCharCode(((0x0f & cccc.charCodeAt(0)) << 12)
					| ((0x3f & cccc.charCodeAt(1)) << 6)
					| (0x3f & cccc.charCodeAt(2)));
		default:
			return fromCharCode(((0x1f & cccc.charCodeAt(0)) << 6)
					| (0x3f & cccc.charCodeAt(1)));
		}
	};
	var btou = function(b) {
		return b.replace(re_btou, cb_btou);
	};
	var cb_decode = function(cccc) {
		var len = cccc.length, padlen = len % 4, n = (len > 0 ? b64tab[cccc
				.charAt(0)] << 18 : 0)
				| (len > 1 ? b64tab[cccc.charAt(1)] << 12 : 0)
				| (len > 2 ? b64tab[cccc.charAt(2)] << 6 : 0)
				| (len > 3 ? b64tab[cccc.charAt(3)] : 0), chars = [
				fromCharCode(n >>> 16), fromCharCode((n >>> 8) & 0xff),
				fromCharCode(n & 0xff) ];
		chars.length -= [ 0, 0, 2, 1 ][padlen];
		return chars.join('');
	};
	var atob = global.atob ? function(a) {
		return global.atob(a);
	} : function(a) {
		return a.replace(/[\s\S]{1,4}/g, cb_decode);
	};
	var _decode = buffer ? function(a) {
		return (a.constructor === buffer.constructor ? a : new buffer(a,
				'base64')).toString();
	} : function(a) {
		return btou(atob(a))
	};
	var decode = function(a) {
		return _decode(String(a).replace(/[-_]/g, function(m0) {
			return m0 == '-' ? '+' : '/'
		}).replace(/[^A-Za-z0-9\+\/]/g, ''));
	};
	var noConflict = function() {
		var Base64 = global.Base64;
		global.Base64 = _Base64;
		return Base64;
	};
	// export Base64
	global.Base64 = {
		VERSION : version,
		atob : atob,
		btoa : btoa,
		fromBase64 : decode,
		toBase64 : encode,
		utob : utob,
		encode : encode,
		encodeURI : encodeURI,
		btou : btou,
		decode : decode,
		noConflict : noConflict
	};
	// if ES5 is available, make Base64.extendString() available
	if (typeof Object.defineProperty === 'function') {
		var noEnum = function(v) {
			return {
				value : v,
				enumerable : false,
				writable : true,
				configurable : true
			};
		};
		global.Base64.extendString = function() {
			Object.defineProperty(String.prototype, 'fromBase64',
					noEnum(function() {
						return decode(this)
					}));
			Object.defineProperty(String.prototype, 'toBase64',
					noEnum(function(urisafe) {
						return encode(this, urisafe)
					}));
			Object.defineProperty(String.prototype, 'toBase64URI',
					noEnum(function() {
						return encode(this, true)
					}));
		};
	}
	// that's it!
	if (global['Meteor']) {
		Base64 = global.Base64; // for normal export in Meteor.js
	}
})(this);