#pragma once
#include <stddef.h>
#include <time.h>
#include <string.h>

#ifdef RATELIMIT_THREADSAFE
#include <pthread.h>
#endif

typedef struct {
    ratelimit_table_type value;
    int count;
    double window_start;
} ratelimit_t;

static struct {
    ratelimit_t data[256];
    size_t next;
#ifdef RATELIMIT_THREADSAFE
    pthread_mutex_t lock;
#endif
} ratelimit_table = { {0}, 0
#ifdef RATELIMIT_THREADSAFE
, PTHREAD_MUTEX_INITIALIZER
#endif
};

static int rate_limited(ratelimit_table_type value, float window, int rate_limit) {
    struct timespec ts;
    clock_gettime(CLOCK_MONOTONIC, &ts);
    double now = ts.tv_sec + ts.tv_nsec * 1e-9;

#ifdef RATELIMIT_THREADSAFE
    pthread_mutex_lock(&ratelimit_table.lock);
#endif

    ratelimit_t* e = (void*)0;
    for (size_t i = 0; i < 256; i++) {
        if (memcmp(ratelimit_table.data[i].value, value, sizeof(ratelimit_table_type)) == 0) {
            e = &ratelimit_table.data[i];
            break;
        }
    }

    if (!e) {
        e = &ratelimit_table.data[ratelimit_table.next++];
        memcpy(e->value, value, sizeof(ratelimit_table_type));
        e->window_start = now;
        e->count = 0;
    }

    if (now - e->window_start >= window) {
        e->window_start = now;
        e->count = 0;
    }

    const int allowed = e->count < rate_limit;
    if (allowed) e->count++;

#ifdef RATELIMIT_THREADSAFE
    pthread_mutex_unlock(&ratelimit_table.lock);
#endif

    return allowed ? 0 : 1;
}