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

(function () {
    'use strict';

    angular.module('base64', []).constant('$base64', (function () {

        // existing version for noConflict()
        var version = "2.1.8";
        // if node.js, we use Buffer
        var buffer;
        if (typeof module !== 'undefined' && module.exports) {
            buffer = require('buffer').Buffer;
        }
        // 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 = 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 = 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, ''));
        };

        return {
            encode: encode,
            decode: decode,
        };

    })());

})();