#include "stdlib.h"
#include "stdio.h"
#include "string.h"
#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <ctype.h>


#define blocksize 4096
int mypipe[2];
char file1[100],file2[100];

void sigusr1handler(int sig){
	if(sig == SIGUSR1){
		printf("I GOT SIGUSR1!\n");
		dup2(mypipe[1],1);
		execlp("cat","cat",file1,NULL);
		printf("Failed execlp on first child!\n");
		exit(-7);
	}
}
void fiu1(){
	struct sigaction s;
	s.sa_flags = 0;
	s.sa_handler = sigusr1handler;

	close(mypipe[0]);

	if(sigaction(SIGUSR1,&s,NULL)<0){//pregatim fiu1 sa primeasca SIGUSR1
		printf("Error at sigaction SIGUSR1!\n");
		exit(-6);
	}

	while(1){
		printf("Child 1: I have pid=%d\n",getpid());//afisam in fiu1 pid-ul lui pana primeste SIGUSR1
	}
}

void sigusr2handler(int sig){
	if(sig == SIGUSR2){
		printf("I GOT SIGUSR2!\n");
		dup2(mypipe[1],1);
		execlp("cat","cat",file2,NULL);
		printf("Failed execlp on first child!\n");
		exit(-7);
	}
}
void fiu2(){
	struct sigaction s;
	s.sa_flags = 0;
	s.sa_handler = sigusr2handler;

	close(mypipe[0]);
	if(sigaction(SIGUSR2,&s,NULL)<0){//pregatim fiu2 sa primeasca SIGUSR2
		printf("Error at sigaction SIGUSR2!\n");
		exit(-6);
	}

	while(1){
		printf("Child 2: I have pid=%d \n",getpid());//afisam pid-ul fiului2 pana primeste SIGUSR2
	}
}
void siginthandler(int sig){
	if(sig == SIGINT){//cand primeste fiul3 SIGINT
		printf("I GOT SIGINT!\n");
		char buffer[blocksize];
		char aux[blocksize];
		int r;
		int k;
		while((r=read(mypipe[0],buffer,blocksize))>0){//citim din pipe cat mai este
			strcpy(aux,"");//golim ce e in aux
			k=0;
			for(int i=0;i<r;i++){//parcurgem litera cu litera
				if(buffer[i] == ' ' || buffer[i]=='\n'){//daca am gasit spatiu sau newline inseamna ca s-o terminat un cuvant, si il afisam
					aux[k] = '\0';
					printf("%s\n",aux);
					strcpy(aux,"");
					k=0;
				}
				else{//daca ii altceva inafara de spatiu sau litera, adaugam caracteru ca sa construim cuvantul
					aux[k]=buffer[i];
					k++;
				}
			}//poate asta se putea face mai destept da nu stiu cum..oricum n-are relevanta pentru pipeuri lucratu cu stringuri
		}
		close(mypipe[0]);
		exit(0);
	}
}
void fiu3(){
	struct sigaction s;
	s.sa_flags = 0;
	s.sa_handler = siginthandler;

	close(mypipe[1]);

	if(sigaction(SIGINT,&s,NULL)<0){//pregatim fiu3 sa primeasca SIGINT
		printf("Error at sigaction SIGINT!\n");
		exit(-6);
	}

	while(1){
		printf("Child 3: I have pid=%d\n",getpid());//afisam pid-ul fiului 3 pana primeste SIGINT
	}
}

void sigalarmhandler(int sig){
	printf("BOO!\n");
	exit(0);
}
int pid1,pid2,pid3;

void parinte(){
	close(mypipe[0]);
	close(mypipe[1]);
	printf("Sending SIGUSR1 to %d, SIGUSR2 to %d, SIGINT to %d.\n",pid1,pid2,pid3);
	kill(pid1,SIGUSR1);
	kill(pid2,SIGUSR2);
	kill(pid3,SIGINT);
	//trimitem semnalele la copii
	struct sigaction s;
	s.sa_flags = 0;
	s.sa_handler=sigalarmhandler;
	if(sigaction(SIGALRM,&s,NULL)<0){//pregatim parintele sa primeasca SIGALRM
		printf("Error on sigaction SIGALRM!\n");
		exit(-10);
	}
	alarm(7);//trimitem peste 7 secunde semnalul SIGALRM
	while(1);
}
int main(int argc, char *argv[]){
	if(argc != 3){
		printf("Usage:./%s file1 file2\n",argv[0]);
		exit(-1);
	}

	strcpy(file1,argv[1]);
	strcpy(file2,argv[2]);

	if(pipe(mypipe)<0){
		printf("Error at creating pipe!\n");
		exit(-2);
	}


	if((pid1=fork())<0){
		printf("Error at first fork!\n");
		exit(-3);
	}
	if(pid1==0){
		fiu1();
	}


	if((pid2=fork())<0){
		printf("Error at second fork!\n");
		exit(-4);
	}
	if(pid2==0){
		fiu2();
	}

	if((pid3=fork())<0){
		printf("Error at third fork!\n");
		exit(-5);
	}
	if(pid3==0){
		fiu3();
	}
	sleep(0.5);//fara sleepu asta nu se intampla nimic
	parinte();
}