#include "random.h"

static uint32_t state = 1;

void set_random_seed(uint32_t seed) {
    state = seed ? seed : 1;
}

uint32_t random_u32(void) {
    state ^= state << 13;
    state ^= state >> 17;
    state ^= state << 5;
    return state;
}

uint32_t random_range(uint32_t max) {
    if (max == 0) return 0;
    uint32_t threshold = (0xFFFFFFFFU / max) * max;
    uint32_t r;
    do {
        r = random_u32();
    } while (r >= threshold);
    return r % max;
}

void advance_state(uint32_t n) {
    state += n;
}