#define _POSIX_C_SOURCE 200809L

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#define ERR(source)                                     \
    do                                                  \
    {                                                   \
        fprintf(stderr, "%s:%d\n", __FILE__, __LINE__); \
        perror(source);                                 \
        kill(0, SIGKILL);                               \
        exit(EXIT_FAILURE);                             \
    } while (0)

#define MOTHERSHIP_FIFO "/tmp/mothership"
#define SUPPLIES_CAPACITY 4

typedef struct
{
    int id;        // 100, 99, ..., 1, 0
    int supplies;  // Current supplies
} expedition_t;

void usage(int argc, char* argv[])
{
    fprintf(stderr, "Usage: %s M\n", argv[0]);
    fprintf(stderr, "  M - size of the board (3 <= M <= 6)\n");
    exit(EXIT_FAILURE);
}

int set_handler(void (*f)(int), int sig)
{
    struct sigaction act = {0};
    act.sa_handler = f;
    if (sigaction(sig, &act, NULL) == -1)
        return -1;
    return 0;
}

int count_descriptors()
{
    int count = 0;
    DIR* dir;
    struct dirent* entry;
    struct stat stats;
    if ((dir = opendir("/proc/self/fd")) == NULL)
        ERR("opendir");
    char path[PATH_MAX];
    getcwd(path, PATH_MAX);
    chdir("/proc/self/fd");
    do
    {
        errno = 0;
        if ((entry = readdir(dir)) != NULL)
        {
            if (lstat(entry->d_name, &stats))
                ERR("lstat");
            if (!S_ISDIR(stats.st_mode))
                count++;
        }
    } while (entry != NULL);
    if (chdir(path))
        ERR("chdir");
    if (closedir(dir))
        ERR("closedir");
    return count - 1;  // one descriptor for open directory
}

void msleep(const int ms)
{
    struct timespec tt;
    tt.tv_sec = ms / 1000;
    tt.tv_nsec = (ms % 1000) * 1000000;
    while (nanosleep(&tt, &tt) == -1)
    {
    }
}

int main(int argc, char* argv[])
{
    return 0;
}