/*jslint white: true, onevar: true, undef: true, nomen: true, eqeqeq: true, plusplus: true, bitwise: false, regexp: false, newcap: true, immed: true, strict: true */
/*global */
"use strict";

/**
*
*  Base64 encode / decode
*  http://www.webtoolkit.info/
*
**/

var Base64 = {

    // private property
    keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",

    // public method for encoding
    encode : function (input) {
        var output = "", chr1, chr2, chr3, enc1, enc2, enc3, enc4, i = 0;

        input = Base64.utf8_encode(input);

        while (i < input.length) {

            chr1 = input.charCodeAt(i);
            chr2 = input.charCodeAt(i += 1);
            chr3 = input.charCodeAt(i += 1);
            i += 1;

            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
    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 += 1));
            enc3 = this.keyStr.indexOf(input.charAt(i += 1));
            enc4 = this.keyStr.indexOf(input.charAt(i += 1));
            i += 1;

            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 = "", n, c;

        for (n = 0; n < string.length; n += 1) {

            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
    utf8_decode : function (utftext) {
        var string = "",
            i = 0,
            c = 0,
            c1 = 0,
            c2 = 0,
            c3;

        while (i < utftext.length) {

            c = utftext.charCodeAt(i);

            if (c < 128) {
                string += String.fromCharCode(c);
                i += 1;
            } 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;
    }

};