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

key_t key1, key2, key3;           // klucz dla semaforow
int   semid1, semid2, semid3;   // ID semaforow
union semun ctl;            // unia do kontroli semafora

FILE* input;
FILE* temporary;
int pdes[2];

union semun
{
    int val;
    struct semid_ds *buf;
    unsigned short int *array;
    struct seminfo *__buf;
};

int semlock(int semid)
{

    struct sembuf opr;
    opr.sem_num =  0;
    opr.sem_op  = -1;
    opr.sem_flg =  0;

    if (semop(semid, &opr, 1) == -1){
        warn("Blad blokowania semafora!");
        return 0;
    }else{
        return 1;
    }
}

int semunlock(int semid)
{
    struct sembuf opr;

    opr.sem_num = 0;
    opr.sem_op  = 1;
    opr.sem_flg = 0;

    if (semop(semid, &opr, 1) == -1)
    {
        warn("Blad odblokowania semafora!");
        return 0;
    }
    else
    {
        return 1;
    }
}
void charToHex(unsigned char c, char * hex) {
	sprintf(hex, "%x", c);
}
void process1Interactive() {
	char dane[256];
	char c;
	while(1){
		sleep(1);
		printf("Podaj dane: ");
		scanf("%s", dane);
		int i = 0;
		while(dane[i]!= '\0'){
			semlock(semid1);
			//printf("Process 1: %c\n", dane[i]);
			//fflush(stdout);
			fputc(dane[i], temporary);
			fflush(temporary);
			fseek(temporary, -1, SEEK_CUR);
			i++;
			semunlock(semid2);
		}

	}


}
void process1File() {
	char c; int i;
	while((c = fgetc(input))!= EOF) {
		semlock(semid1);
		//printf("Process 1: %c\n", c);
		//fflush(stdout);
		fputc(c, temporary);
		fflush(temporary);
		fseek(temporary, -1, SEEK_CUR);
		semunlock(semid2);
	}
}
void process1Random() {

	unsigned char c; int i;
	while((c = fgetc(input))!= EOF) {
		semlock(semid1);
		//printf("Process 1: %c\n", c);
		//fflush(stdout);
		fputc(c, temporary);
		fflush(temporary);
		fseek(temporary, -1, SEEK_CUR);
		semunlock(semid2);
	}

}
void process2() {
	unsigned char c;
	char hex[3];
	close(pdes[0]);
	while(1) {
		semlock(semid2);
		c = fgetc(temporary);
		charToHex(c, hex);
		printf("Hex = %s", hex);
		//printf("Process 2: %c\n", c);
		fflush(stdout);
		write(pdes[1], hex, sizeof(hex));//write(pdes[1], &c, 1);
		semunlock(semid3);
	}
	//remove("file");
}
void process3() { // mozna zakonczyc ten proces normalnie za pomoca sygnalu, jak cos
	unsigned char c;
	char heks[3];
	close(pdes[1]);
	while(1) {
		semlock(semid3);
		read(pdes[0], heks, sizeof(heks));//read(pdes[0], &c, 1);
		//printf("In process 3: %c\n", c);
		printf(" , %s\n", heks);
		fflush(stdout);
		semunlock(semid1);
	}

}

int main(int argc, char **argv)
{									//////////////
    if ((key1 = ftok(".", 'A')) == -1)
        errx(1, "Blad tworzenia klucza!");

    if ((semid1 = semget(key1, 1, IPC_CREAT | 0600)) == -1)
        errx(2, "Blad tworzenia semafora!");

    ctl.val = 1;
    if (semctl(semid1, 0, SETVAL, ctl) == -1)
        errx(3, "Blad ustawiania semafora!");

    if ((key2 = ftok(".", 'B')) == -1)
        errx(1, "Blad tworzenia klucza!");

    if ((semid2 = semget(key2, 1, IPC_CREAT | 0600)) == -1)
        errx(2, "Blad tworzenia semafora!");

    ctl.val = 1;
    if (semctl(semid2, 0, SETVAL, ctl) == -1)
        errx(3, "Blad ustawiania semafora!");
	if ((key3 = ftok(".", 'C')) == -1)
        errx(1, "Blad tworzenia klucza!");

    if ((semid3 = semget(key3, 1, IPC_CREAT | 0600)) == -1)
        errx(2, "Blad tworzenia semafora!");

    ctl.val = 1;
    if (semctl(semid3, 0, SETVAL, ctl) == -1)
        errx(3, "Blad ustawiania semafora!");

	semlock(semid3);
	semlock(semid2);

	pipe(pdes);
	///////////////////files opening
	if(argc>1) {
		input = fopen(argv[1], "r"); //FILE* input = fopen(argv[1], "r"); /dev/urandom
		if(input == NULL) {
			printf("Blad przy otwieraniu pliku do odczytu!");
			return -1;
		}
	}
	temporary = fopen("file", "w+");
	if(temporary == NULL) {
		printf("Blad przy otwieraniu pliku do zapisu!");
		return -2;
	}


	/////////////////// processes
	if( fork() == 0 ) {         /////////////////////////////////////////////// proces 1 -> przekazuje dane do procesu 2 poprzez file
		if(argc == 1) { // interaktywny
			printf("Interactive");
			process1Interactive();
		}
		else if( strcmp(argv[1], "/dev/urandom") == 0 ){  // random
			printf("Random");
			process1Random();
		}
		else { // plik
			printf("File");
			process1File();
		}

	}
	else if(fork() == 0) {     /////////////////////////////////// proces 2 -> pobiera dane z procesu 1 poprzez file i przekazuje do procesu 3 poprzez pipe
		process2();
	}
	else if(fork() == 0) {     ////////////////////////////////// proces 3 -> pobiera dane z procesu 3 poprzez pipe
		process3();
	}

	while(1)
		pause();
	return 0;
}
// /dev/urandom