#include <unistd.h>
#include <stdio.h>
#include <sys/uio.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>

const char *main_path = "/tmp/serweripcmain";

typedef struct DanePid
{
    long mtype; /* Message type. */
    pid_t pid;  /* Message text. */
} dane_pid;

typedef struct DaneDouble
{
    long mtype; /* Message type. */
    double n;   /* Message text. */
} dane_double;

int main(int argc, char *argv[])
{
    key_t key;
    ssize_t bytes;
    if (access(main_path, F_OK) == -1)
    {
        perror("file inaccessible");
        return -1;
    }
    if ((key = ftok(main_path, 1)) == -1)
    {
        perror("main ftok error");
        return -1;
    }
    int msg_id;
    if ((msg_id = msgget(key, 0600)) == -1)
    {
        perror("msgget error");
        return -1;
    }
    dane_pid pid;
    pid.pid = getpid();
    pid.mtype = 1;
    dane_double test_dane;
    test_dane.n = 12;
    test_dane.mtype = 2;
    if (msgsnd(msg_id, (const void *)&pid, sizeof(pid_t), 0) == -1)
    {
        perror("pid error");
        return -1;
    }
    printf("Sent %d bytes pid: %d\n", sizeof(pid_t), pid.pid);
    key_t key2;
    if ((key2 = ftok(main_path, pid.pid)) == -1)
    {
        perror("data ftok error");
        return -1;
    }
    int msg_id_2;
    if ((msg_id_2 = msgget(key2, 0600 | IPC_CREAT | IPC_EXCL)) == -1)
    {
        perror("data msgget error");
        return -1;
    }
    printf("Opened queue with id %x\n", msg_id_2);
    if (msgsnd(msg_id_2, (const void *)&test_dane, sizeof(double), 0) == -1)
    {
        perror("data send error");
        return -1;
    }
    printf("Sent %d bytes data: %f\n", sizeof(double), test_dane.n);
    if ((bytes = msgrcv(msg_id_2, (void *)&test_dane, sizeof(double), 3, 0)) == -1)
    {
        perror("msgrcv error");
        msgctl(msg_id, IPC_RMID, NULL);
        return -1;
    }
    printf("Child received %d bytes and value %f\n", bytes, test_dane.n);
}