#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/shm.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>

#include "header.h"

int msggen(char *buf) {
  int length = rand() % (MSGSIZE - 2) + 1;
  int i;
  for(i = 0; i < length; ++i) {
    buf[i] = (char)(rand() % (END_CHAR - START_CHAR) + START_CHAR);
  }
  buf[length] = '\0';
  ++length;

  return length;
}

int detachSharedMem(void *attachedMem) {
  if(shmdt(attachedMem) == ERRCODE) {
    perror("shmdt");
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}

int delSharedMem(int sharedMem) {
  if(shmctl(sharedMem, IPC_RMID, NULL) == ERRCODE) {
    perror("shmctl");
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}

int delSem(int sem) {
  if(semctl(sem, DUMMY, IPC_RMID, DUMMY) == ERRCODE) {
    perror("semctl");
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}

int produce(int sem, char *attachedMem) {
  struct sembuf waitReading = {SEM_PRODUCER, LOCK, SEM_UNDO};
  struct sembuf produced = {SEM_CONSUMER, UNLOCK, SEM_UNDO};

  int i;
  for(i = 0; i < MSGCOUNT; ++i) {
    msggen(attachedMem);

    printf("Send: %s\n", attachedMem);

    if(semop(sem, &produced, 1) == ERRCODE) {
      perror("semop");
      return EXIT_FAILURE;
    }

    if(semop(sem, &waitReading, 1) == ERRCODE) {
      perror("semop");
      return EXIT_FAILURE;
    }

//  sleep(1);
  }

  return EXIT_SUCCESS;
}

int main() {
  srand(time(NULL));

  key_t idKey = ftok("header.h", PROJECT_PREFIX);
  if(idKey == ERRCODE) {
    perror("ftok");
    return EXIT_FAILURE;
  }

  int sem = semget(idKey, SEMCOUNT, IPC_CREAT | ACCESS_RIGHTS);
  if(sem == ERRCODE) {
    perror("semget");
    return EXIT_FAILURE;
  }

  int sharedMem = shmget(idKey, MSGSIZE, IPC_CREAT | ACCESS_RIGHTS);
  if(sharedMem == ERRCODE) {
    perror("shmget");
    delSem(sem);
    return EXIT_FAILURE;
  }

  char *attachedMem = shmat(sharedMem, ANY_PLACE, NO_FLAGS);
  if(attachedMem == NULL) {
    delSem(sem);
    delSharedMem(sharedMem);
    perror("shmat");
    return EXIT_FAILURE;
  }

  if(produce(sem, attachedMem) != EXIT_SUCCESS) {
    delSem(sem);
    detachSharedMem(attachedMem);
    delSharedMem(sharedMem);
    return EXIT_FAILURE;
  }

  if(detachSharedMem(attachedMem) != EXIT_SUCCESS) {
    delSharedMem(sharedMem);
    delSem(sem);
    return EXIT_FAILURE;
  }

  if(delSharedMem(sharedMem) != EXIT_SUCCESS) {
    delSem(sem);
    return EXIT_FAILURE;
  }

  if(delSem(sem) != EXIT_SUCCESS) {
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}