#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(char argument)
{
   int pipa[2];
   int pipa_2[2];
   int des_fifo;
   const char* subor_fifo="FIFO_PIPA";
   char BUFFER_MAIN[BUFSIZ];
   char buffer[BUFSIZ];
   char buffer_B[BUFSIZ];
   pid_t fork_1;
   pid_t fork_2;

                                                             //   vytvorenie fifo + prist.prava
   des_fifo=mkfifo(subor_fifo,0777);
    if(des_fifo==0) printf("\nFIFO PIPA VYTVORENA\n");
   else { perror("\nNASTALA CHYBA V FIFO => ");
          printf("\n");  }

   if (pipe(pipa) != 0){                           //     pipa 1
    perror("\nNASTALA CHYBA V PIPE_1 => ");
    exit(EXIT_FAILURE); }
   else {printf("PIPA_1 VYTVORENA.");}

   if (pipe(pipa_2) != 0){
    perror("\nNASTALA CHYBA V PIPE_2 => ");             //  pipa 2
    printf("\n");
    exit(EXIT_FAILURE); }
    else {printf("\nPIPA_2 VYTVORENA.\n");}


    fork_1 = fork();                                  //     vytvorenie potomka 1

   if (fork_1 == -1) {
       printf("\nNASTALA CHYBA V PROCESE FORK_1 => ");
    printf("\n");
         exit(EXIT_FAILURE);
         }

   if (fork_1 == 0) {
         printf("\nPOTOMOK 1 BOL USPESNE VYTVORENY.\n");

    fork_2 = fork();                           //       vytvorenie potomka 2

    if (fork_2 == -1) {
            perror("\nNASTALA CHYBA V PROCESE FORK_2 => ");
        printf("\n");
            exit(EXIT_FAILURE);
            }
    if (fork_2 == 0){
                printf("POTOMOK 2 BOL USPESNE VYTVORENY.\n");

                                                               //        -- potomok2 --
        read(pipa_2[0], buffer, 1);

        if (buffer[0]=='2'){                   //    ak je "2", zapis do FIFA potomok 2
            int des = open(subor_fifo,O_WRONLY);
            if (des<0){
                perror("\nNASTALA CHYBA V OTVORENI FIFO => ");
                printf("\n");
                exit(EXIT_FAILURE);
            }
            write(des,"POTOMOK 2",9);
            close(des);
        }

            exit(EXIT_SUCCESS);
    }
    else {                                          //          -- potomok1 --

        read(pipa[0], buffer_B, 1);
        if (buffer_B[0]=='1'){
            int des = open(subor_fifo,O_WRONLY);
            if (des<0){
                perror("\nCHYBA FIFO : ");
                printf("\n");
                exit(EXIT_FAILURE);
            }
            write(des,"POTOMOK 1",9);
            close(des);
        }
        write(pipa_2[1], buffer_B, 1);

            exit(EXIT_SUCCESS);
    }

   }
   else {                                            //  --  RODIC  + argumenty--

    memset(BUFFER_MAIN, '\0', sizeof(BUFFER_MAIN));

     printf("\nVLOZTE ARGUMENT (1-2): ");
     scanf("%c",&argument);
          printf("\n");
           if (argument == '2' || argument == '1' ){
        write(pipa[1],&argument,1);
        int des = open(subor_fifo,O_RDONLY);
        if (des<0){
            perror("\nFIFO CHYBA : ");
            exit(EXIT_FAILURE);
        }

        read(des,BUFFER_MAIN,BUFSIZ);
                printf("-----------------------------------------------------\n");
            printf("Rodic z FIFA NACITAL HLASKU : >>>>  %s  <<<<\n" ,BUFFER_MAIN);
        printf("-----------------------------------------------------\n");
        close(des);
       }
      else printf("CHYBA - ZADAL SI INY ARGUMENT AKO {1} alebo {2}\n");
      printf("\n");
      exit(EXIT_FAILURE);
}
   exit(EXIT_SUCCESS);
}