var base64map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
let Crypto = {};
var util = Crypto.util = {
    rotl: function (n, b) {
        return (n << b) | (n >>> (32 - b));
    },
    rotr: function (n, b) {
        return (n << (32 - b)) | (n >>> b);
    },
    endian: function (n) {
        if (n.constructor == Number) {
            return util.rotl(n,  8) & 0x00FF00FF |
                   util.rotl(n, 24) & 0xFF00FF00;
        }
        for (var i = 0; i < n.length; i++)
            n[i] = util.endian(n[i]);
        return n;
    },
    randomBytes: function (n) {
        for (var bytes = []; n > 0; n--)
            bytes.push(Math.floor(Math.random() * 256));
        return bytes;
    },
    stringToBytes: function (str) {
        var bytes = [];
        for (var i = 0; i < str.length; i++)
            bytes.push(str.charCodeAt(i));
        return bytes;
    },
    bytesToString: function (bytes) {
        var str = [];
        for (var i = 0; i < bytes.length; i++)
            str.push(String.fromCharCode(bytes[i]));
        return str.join("");
    },
    stringToWords: function (str) {
        var words = [];
        for (var c = 0, b = 0; c < str.length; c++, b += 8)
            words[b >>> 5] |= str.charCodeAt(c) << (24 - b % 32);
        return words;
    },
    bytesToWords: function (bytes) {
        var words = [];
        for (var i = 0, b = 0; i < bytes.length; i++, b += 8)
            words[b >>> 5] |= bytes[i] << (24 - b % 32);
        return words;
    },
    wordsToBytes: function (words) {
        var bytes = [];
        for (var b = 0; b < words.length * 32; b += 8)
            bytes.push((words[b >>> 5] >>> (24 - b % 32)) & 0xFF);
        return bytes;
    },
    bytesToHex: function (bytes) {
        var hex = [];
        for (var i = 0; i < bytes.length; i++) {
            hex.push((bytes[i] >>> 4).toString(16));
            hex.push((bytes[i] & 0xF).toString(16));
        }
        return hex.join("");
    },
    hexToBytes: function (hex) {
        var bytes = [];
        for (var c = 0; c < hex.length; c += 2)
            bytes.push(parseInt(hex.substr(c, 2), 16));
        return bytes;
    },
    bytesToBase64: function (bytes) {
        if (typeof btoa == "function") return btoa(util.bytesToString(bytes));
        var base64 = [],
            overflow;
        for (var i = 0; i < bytes.length; i++) {
            switch (i % 3) {
                case 0:
                    base64.push(base64map.charAt(bytes[i] >>> 2));
                    overflow = (bytes[i] & 0x3) << 4;
                    break;
                case 1:
                    base64.push(base64map.charAt(overflow | (bytes[i] >>> 4)));
                    overflow = (bytes[i] & 0xF) << 2;
                    break;
                case 2:
                    base64.push(base64map.charAt(overflow | (bytes[i] >>> 6)));
                    base64.push(base64map.charAt(bytes[i] & 0x3F));
                    overflow = -1;
            }
        }
        if (overflow != undefined && overflow != -1)
            base64.push(base64map.charAt(overflow));
        while (base64.length % 4 != 0) base64.push("=");
        return base64.join("");
    },
    base64ToBytes: function (base64) {
        if (typeof atob == "function") return util.stringToBytes(atob(base64));
        base64 = base64.replace(/[^A-Z0-9+\/]/ig, "");
        var bytes = [];
        for (var i = 0; i < base64.length; i++) {
            switch (i % 4) {
                case 1:
                    bytes.push((base64map.indexOf(base64.charAt(i - 1)) << 2) |
                               (base64map.indexOf(base64.charAt(i)) >>> 4));
                    break;
                case 2:
                    bytes.push(((base64map.indexOf(base64.charAt(i - 1)) & 0xF) << 4) |
                               (base64map.indexOf(base64.charAt(i)) >>> 2));
                    break;
                case 3:
                    bytes.push(((base64map.indexOf(base64.charAt(i - 1)) & 0x3) << 6) |
                               (base64map.indexOf(base64.charAt(i))));
                    break;
            }
        }
        return bytes;
    }
};
Crypto.mode = {};
export default Crypto;