#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>
#include <signal.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 f;
int msg_id;

void end()
{
    close(f);
    msgctl(msg_id, IPC_RMID, NULL);
    exit(0);
}

int main(int argc, char *argv[])
{
    signal(SIGTERM, end);
    signal(SIGINT, end);
    key_t key;
    if ((f = open(main_path, O_CREAT | O_RDWR, 0600)) == -1)
    {
        perror("open main file error");
        return -1;
    }
    else
    {
        close(f);
    }
    if ((key = ftok(main_path, 1)) == -1)
    {
        perror("main ftok error");
        return -1;
    }
    if ((msg_id = msgget(key, 0600 | IPC_CREAT)) == -1)
    {
        perror("msgget error");
        return -1;
    }
    printf("Created queue with id %d\n", msg_id);
    dane_pid pid_dane;
    dane_double dane_double;
    ssize_t bytes;
    for (;;)
    {
        if ((bytes = msgrcv(msg_id, (void *)&pid_dane, sizeof(pid_t), 1, 0)) == -1)
        {
            perror("msgrcv error");
            msgctl(msg_id, IPC_RMID, NULL);
            return -1;
        }
        printf("Received %d bytes\n", bytes);
        printf("Dane: %d\n", pid_dane.pid);
        pid_t pid;
        if ((pid = fork()) == -1)
        {
            msgctl(msg_id, IPC_RMID, NULL);
            return -1;
        }
        if (pid == 0)
        {
            key_t key;
            int f;
            if ((key = ftok(main_path, pid_dane.pid)) == -1)
            {
                perror("child ftok error");
                return -1;
            }
            int child_msg_id;
            if ((child_msg_id = msgget(key, 0600 | IPC_CREAT)) == -1)
            {
                perror("child msgget error");
                return -1;
            }
            printf("Created queue with id %d\n", child_msg_id);
            if ((bytes = msgrcv(child_msg_id, (void *)&dane_double, sizeof(double), 2, 0)) == -1)
            {
                perror("msgrcv error");
                msgctl(msg_id, IPC_RMID, NULL);
                return -1;
            }
            printf("Child received %d bytes and value %f\n", bytes, dane_double.n);
            dane_double.n = dane_double.n * dane_double.n;
            dane_double.mtype = 3;
            if (msgsnd(child_msg_id, (const void *)&dane_double, sizeof(double), 0) == -1)
            {
                perror("data send error");
                return -1;
            }
            printf("Sent %d bytes data: %f\n", sizeof(double), dane_double.n);
            if (msgctl(child_msg_id, IPC_RMID, NULL) == -1)
            {
                perror("child msgctl IPC_RMID error");
                return -1;
            }
        }
    }
    if (msgctl(msg_id, IPC_RMID, NULL) == -1)
    {
        perror("msgctl IPC_RMID error");
        return -1;
    }
}