#include <sys/types.h>
#include <signal.h>
#include <termios.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/ipc.h>
#include <sys/msg.h>


#define MSGSIZE 100
#define STRUCTMSGSIZE (MSGSIZE + sizeof(pid_t))
#define ERRCODE -1
#define NO_FLAGS 0
#define MSGJOINQ 1
#define MSGLEAVEQ 2
#define MSG_TYPE_DATA 3
#define MSG_ALL_TYPES 0
#define QUEUE_RIGHTS 0600
#define PROJECT_PREFIX 97
#define COUNT_MESSAGES 10
#define START_CHAR 32
#define END_CHAR 127
#define SLEEP_TIME 1

struct message {
  long mtype;
  pid_t pid;
  char mtext[MSGSIZE];
};


int qclose(int queue) {
  if(msgctl(queue,IPC_RMID,NULL) == ERRCODE) {
    perror("msgctl");
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}

int qrecv(int queue) {
  struct message buf;
  int count = 0;
  do {
    ssize_t length;
    if((length = msgrcv(queue, &buf, STRUCTMSGSIZE, MSG_ALL_TYPES, NO_FLAGS)) == ERRCODE) {
      perror("msgrcv");
      return EXIT_FAILURE;
    }

    switch(buf.mtype) {
      case MSGJOINQ:
        ++count;
        printf("new sender %d\n", buf.pid);
        break;

      case MSGLEAVEQ:
        --count;
        printf("del sender %d\n", buf.pid);
        break;

      default:
        printf("process %d: %s\n", buf.pid, buf.mtext);
    }
  } while (count > 0);

  return EXIT_SUCCESS;
}

int main() {
  key_t queueKey = ftok("master.c", PROJECT_PREFIX);
  if(queueKey == ERRCODE) {
    perror("ftok");
    return EXIT_FAILURE;
  }

  int queue;
  queue = msgget(queueKey, IPC_CREAT | QUEUE_RIGHTS);
  if(queue == ERRCODE) {
    perror("msgget");
    return EXIT_FAILURE;
  }

  printf("Queue was created\n");

  if(qrecv(queue) != EXIT_SUCCESS) {
    qclose(queue);
    return EXIT_FAILURE;
  }

  if(qclose(queue) != EXIT_SUCCESS) {
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}