#include "geostat.h"
#include <math.h>
#include <stdlib.h>
#include <time.h>
#include "log.h"
#include "memory.h"

/* GENERATION OF A GAUSSIAN WHITE NOISE VECTOR    */
/*input:                                          */
/* seed: seed                                     */
/* n: number of components in the vector          */
/*output:                                         */
/* realization: structure defining the realization*/

void generate(long* seed, int n, struct realization_mod* realization, int cores) {
    double* used_ram_t0 = malloc(sizeof(double));
    getVirtualMemUsed(used_ram_t0);

    log_info("RESULT = in progress, n = %d", n);

    struct cpustat initial[cores];
    struct cpustat final[cores];

    for (int i = 0; i < cores; i++) {
        get_stats(&initial[i], i - 1);
    }

    clock_t t = clock();

    int i;
    long idum2 = 123456789, iy = 0;
    long* iv;
    int iset = 0;

    iv = (long*)malloc(NTAB * sizeof(long));

    /*negative seed*/
    if (*seed > 0.0)
        *seed = -(*seed);

    /*realization definition*/
    (*realization).n = n;
    (*realization).code = 0;
    (*realization).vector_2 = chunk_array_create("realization1.txt", n, 32);
    if ((*realization).vector_2 == NULL) {
        log_error("RESULT = failed - No memory available in generate");
        exit(1);
    }

    /*Gaussian white noise generation*/
    for (i = 0; i < n; i++) {
        double value = gasdev(seed, &idum2, &iy, iv, cores);
        chunk_array_save((*realization).vector_2, i, value);
    }

    chunk_array_flush((*realization).vector_2);

    t = clock() - t;
    double time_taken = ((double)t)/CLOCKS_PER_SEC; // calculate the elapsed time

    for (int i = 0; i < cores; i++) {
        get_stats(&final[i], i - 1);
    }

    for (int i = 0; i < cores; i++) {
        log_info("CPU %d: %lf%%", i, calculate_load(&initial[i], &final[i]));
    }

    double* used_ram_tf = malloc(sizeof(double));
    getVirtualMemUsed(used_ram_tf);

    free(iv);

    log_info("RESULT = success, ELAPSED = %f seconds, DIF USED VIRTUAL MEM = %5.1f MB", time_taken, *used_ram_tf - *used_ram_t0);

    free(used_ram_t0);
    free(used_ram_tf);
}