class MersenneTwister {
    constructor(seed = new Date().getTime()) {
        this.N          = 624;
        this.M          = 397;
        this.MATRIX_A   = 0x9908b0df;
        this.UPPER_MASK = 0x80000000;
        this.LOWER_MASK = 0x7fffffff;
        this.mt         = new Array(this.N);
        this.mti        = this.N + 1;

        this.init_genrand(seed);
    };

    init_genrand(s) {
        this.mt[0] = s >>> 0;

        for (this.mti = 1; this.mti < this.N; this.mti++) {
            let s             = this.mt[this.mti - 1] ^ (this.mt[this.mti - 1] >>> 30);
            this.mt[this.mti] = (((((s & 0xffff0000) >>> 16) * 1812433253) << 16) + (s & 0x0000ffff) * 1812433253) + this.mti;
            this.mt[this.mti] >>>= 0;
        }
    }

    init_by_array(init_key, key_length) {
        let i, j, k;

        this.init_genrand(19650218);

        i = 1;
        j = 0;
        k = (this.N > key_length ? this.N : key_length);

        for (; k; k--) {
            let s      = this.mt[i - 1] ^ (this.mt[i - 1] >>> 30)
            this.mt[i] = (this.mt[i] ^ (((((s & 0xffff0000) >>> 16) * 1664525) << 16) + ((s & 0x0000ffff) * 1664525))) + init_key[j] + j;
            this.mt[i] >>>= 0;

            i++;
            j++;

            if (i >= this.N) {
                this.mt[0] = this.mt[this.N - 1];
                i          = 1;
            }

            if (j >= key_length) j = 0;
        }

        for (k = this.N - 1; k; k--) {
            let s      = this.mt[i - 1] ^ (this.mt[i - 1] >>> 30);
            this.mt[i] = (this.mt[i] ^ (((((s & 0xffff0000) >>> 16) * 1566083941) << 16) + (s & 0x0000ffff) * 1566083941)) - i;
            this.mt[i] >>>= 0;

            i++;

            if (i >= this.N) {
                this.mt[0] = this.mt[this.N - 1];
                i = 1;
            }
        }

        this.mt[0] = 0x80000000;
    }

    genrand_int32() {
        let y;
        let mag01 = new Array(0x0, this.MATRIX_A);

        if (this.mti >= this.N) {
            let kk;

            if (this.mti == this.N + 1) {
                this.init_genrand(5489);
            }

            for (kk = 0; kk < this.N - this.M; kk++) {
                y           = (this.mt[kk] & this.UPPER_MASK) | (this.mt[kk + 1] & this.LOWER_MASK);
                this.mt[kk] = this.mt[kk + this.M] ^ (y >>> 1) ^ mag01[y & 0x1];
            }

            for (; kk < this.N - 1; kk++) {
                y           = (this.mt[kk] & this.UPPER_MASK) | (this.mt[kk + 1] & this.LOWER_MASK);
                this.mt[kk] = this.mt[kk + (this.M - this.N)] ^ (y >>> 1) ^ mag01[y & 0x1];
            }

            y                   = (this.mt[this.N - 1] & this.UPPER_MASK) | (this.mt[0] & this.LOWER_MASK);
            this.mt[this.N - 1] = this.mt[this.M - 1] ^ (y >>> 1) ^ mag01[y & 0x1];
            this.mti            = 0;
        }

        y = this.mt[this.mti++];
        y ^= (y >>> 11);
        y ^= (y << 7) & 0x9d2c5680;
        y ^= (y << 15) & 0xefc60000;
        y ^= (y >>> 18);

        return y >>> 0;
    }

    genrand_int31() {
        return (this.genrand_int32() >>> 1);
    }

    genrand_real1() {
        return this.genrand_int32() * (1.0 / 4294967295.0);
    }

    random() {
        return this.genrand_int32() * (1.0 / 4294967296.0);
    }

    genrand_real3() {
        return (this.genrand_int32() + 0.5) * (1.0 / 4294967296.0);
    }

    genrand_res53() {
        let a = this.genrand_int32() >>> 5,
            b = this.genrand_int32() >>> 6;
        return (a * 67108864.0 + b) * (1.0 / 9007199254740992.0);
    }
}

module.exports = MersenneTwister;