#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/wait.h>

int main(int argc, char const *argv[]) {
  int p1[2],p2[2],p3[2];
  pipe(p1); pipe(p2); pipe(p3);
  pid_t fiu = fork();
  pid_t fiu2 = fork();
  if(fiu==-1) {perror("nu"); exit(0);}
  if(fiu2==-1) {perror("nu"); exit(1);}

  if(fiu==0 && fiu2!=0)
  {
    printf("fiu1\n");
    close(p1[1]); close(p3[1]);
    close(p2[0]); close(p3[0]);
    char c;
    int r,w;
    while(1){
      r=read(p1[0],&c,1);
      if(r==-1) {perror("nu a putut citi date.txt"); exit(2);}
      if(c>='a' && c<='z')
       w=write(p2[1],&c,1);
      if(w==-1) {perror("nu a putut fi scris pe canalul dintre fiu1 si tata"); exit(2);}
      if(c=='\n') {write(p2[1],&c,1);break;}
    }
    close(p1[0]);
    close(p2[1]);
  }
  else if(fiu2==0 && fiu!=0)
  {
    printf("fiu2\n");
    int fd;
    int nr[100];
    for(int i=0;i<99;i++)nr[i]=0;
    if(-1==(fd=open("statistica.txt",O_CREAT | O_TRUNC | O_WRONLY,0600))) {perror("nu"); exit(3);}
    char c;
    int a;
    while(1){
      read(p2[0],&c,1);
      a=c-'a';
      nr[a]++;
      if(c=='\n') {break;}
    }

    char nrLitDif='0';
    int n='z'-'a'+1;
    for(int j=0;j<n;j++)
    {
      if(nr[j]>0)
      {
        nrLitDif++;
        c='a'+j;
        write(fd,&c,1);
        c=' ';
        write(fd,&c,1);
        c=nr[j]+'0';
        write(fd,&c,1);
        c='\n';
        write(fd,&c,1);
       // printf("%c %d\n",'a'+j,nr[j]);
      }
    }
    close(p2[1]);
    write(p3[1],&nrLitDif,1);
    close(p3[1]);
  }
  else if(fiu!=0 && fiu2!=0){
    printf("tata\n");
    close(p1[0]);
    close(p2[0]);
    close(p2[1]);
    close(p3[1]);
    int fd;
    if(-1==(fd=open("date.txt",O_RDONLY))) {perror("nu a putut citi date.txt"); exit(2);}
    char c;
    int r,w;
    while(1){
      r=read(fd,&c,1);
      if(r==-1) {perror("nu a putut citi date.txt"); exit(2);}
      w=write(p1[1],&c,1);
      if(w==-1) {perror("nu a putut fi scris pe canalul dintre fiu1 si tata"); exit(2);}
      if(c=='\n') break;
    }
    close(p1[1]);
    read(p3[0],&c,1);
    printf("NUMARUL DE CARA DIFERITE %c\n",c );
    close(p3[0]);
  }
  return 0;
}