#include "genlib.h"
#include "log.h"
#include "memory.h"

/*determines the greatest prime factor of an integer*/
int maxfactor(int n, int cores) {
    double* used_ram_t0 = malloc(sizeof(double));
    getVirtualMemUsed(used_ram_t0);

    clock_t t = clock();

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

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

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

    int test_fact(int* pnum, int fact, int* pmaxfac);
    int lnum, fact;
    int maxfac;

    maxfac = 1;
    lnum = n;

    if (lnum != 0 && lnum != 1) {
        fact = 2;
        if (test_fact(&lnum, fact, &maxfac)) {
            fact = 3;
            if (test_fact(&lnum, fact, &maxfac)) {
                fact = 5;
                for (;;) {
                    if (!test_fact(&lnum, fact, &maxfac))
                        break;
                    fact += 2;
                    if (!test_fact(&lnum, fact, &maxfac))
                        break;
                    fact += 4;
                }
            }
        }
        if (lnum != 1) {
            if (lnum > maxfac)
                maxfac = lnum;
        }
    }
    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);

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

    free(used_ram_t0);
    free(used_ram_tf);
    
    return maxfac;
}