#ifndef XOROACC32_H
#define XOROACC32_H

#include <stdint.h>
#include "splitmix64.h"

#define xoroacc32_size 3
// state for xoroacc32
static uint16_t xoroacc32_s[xoroacc32_size];

static inline uint16_t rotl16(const uint16_t x, int k) {
	return (x << k) | (x >> (16 - k));
}

static inline void xoroacc32_seed(uint16_t seed) {
for (int k = 0; k < xoroacc32_size; k++)
    xoroacc32_s[k] = splitmix64_stateless(seed + k);
}

static inline uint16_t xoroshiro32pp(void) {
	uint16_t s0 = xoroacc32_s[0];
	uint16_t s1 = xoroacc32_s[1];
	uint16_t result = rotl16(s0 + s1, 9) + s0;
	s1 = s1 ^ s0;
	xoroacc32_s[0] = rotl16(s0, 13) ^ s1 ^ (s1 << 5);
	xoroacc32_s[1] = rotl16(s1, 10);
	return result;
}

// returns random number, modifies xoroacc32_s 
static inline uint32_t xoroacc32(void) {
	xoroacc32_s[2] = xoroacc32_s[2] + (xoroshiro32pp() + 1);
	uint32_t result = (uint32_t)xoroacc32_s[2];
	xoroacc32_s[2] = xoroacc32_s[2] + xoroshiro32pp();
	result = result | ((uint32_t)xoroacc32_s[2] << 16);
	return result;
}

#endif // XOROACC32_H