/**
* alea.js
* Alea library is a pseudo-random number generator (PRNG).
* @module alea
*/

(function (root, factory) {
    if (typeof exports === 'object') {
        module.exports = factory();
    } else if (typeof define === 'function' && define.amd) {
        define(factory);
    } else {
        root.Alea = factory();
    }
}(this, function () {

    'use strict';

    // From http://baagoe.com/en/RandomMusings/javascript/

    // importState to sync generator states
    Alea.importState = function (i) {
        var random = new Alea();
        random.importState(i);
        return random;
    };

    return Alea;

    function Alea() {
        return (function (args) {
            // Johannes Baagøe <baagoe@baagoe.com>, 2010
            var s0 = 0;
            var s1 = 0;
            var s2 = 0;
            var c = 1;

            if (args.length == 0) {
                args = [+new Date];
            }
            var mash = Mash();
            s0 = mash(' ');
            s1 = mash(' ');
            s2 = mash(' ');

            for (var i = 0; i < args.length; i++) {
                s0 -= mash(args[i]);
                if (s0 < 0) {
                    s0 += 1;
                }
                s1 -= mash(args[i]);
                if (s1 < 0) {
                    s1 += 1;
                }
                s2 -= mash(args[i]);
                if (s2 < 0) {
                    s2 += 1;
                }
            }
            mash = null;

            var random = function () {
                var t = 2091639 * s0 + c * 2.3283064365386963e-10; // 2^-32
                s0 = s1;
                s1 = s2;
                return s2 = t - (c = t | 0);
            };
            random.uint32 = function () {
                return random() * 0x100000000; // 2^32
            };
            random.fract53 = function () {
                return random() +
                    (random() * 0x200000 | 0) * 1.1102230246251565e-16; // 2^-53
            };
            random.version = 'Alea 0.9';
            random.args = args;

            // my own additions to sync state between two generators
            random.exportState = function () {
                return [s0, s1, s2, c];
            };
            random.importState = function (i) {
                s0 = +i[0] || 0;
                s1 = +i[1] || 0;
                s2 = +i[2] || 0;
                c = +i[3] || 0;
            };

            return random;

        }(Array.prototype.slice.call(arguments)));
    }

    function Mash() {
        var n = 0xefc8249d;

        var mash = function (data) {
            data = data.toString();
            for (var i = 0; i < data.length; i++) {
                n += data.charCodeAt(i);
                var h = 0.02519603282416938 * n;
                n = h >>> 0;
                h -= n;
                h *= n;
                n = h >>> 0;
                h -= n;
                n += h * 0x100000000; // 2^32
            }
            return (n >>> 0) * 2.3283064365386963e-10; // 2^-32
        };

        mash.version = 'Mash 0.9';
        return mash;
    }
}));