#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <netdb.h>
#include <errno.h>
#include <signal.h>
extern int h_errno;

#define MAXBUF 80

void child_func(int childnum, struct in_addr servIP, int port);

void blad(char * message)
{
	fprintf(stderr, "%s\n", message);
	exit(1);
}

struct in_addr inet_addr_from_any(char * addr)
{
	struct hostent *host;
	struct in_addr in;

	in.s_addr = inet_addr(addr);

	if (in.s_addr == -1)
	{
		if ((host = gethostbyname(addr)))
		{
			in = *((struct in_addr *)(host->h_addr_list[0]));
			return in;
		} else {
			blad("nieprawidlowy adres");
		}
	}
	return in;
}

int isNumber(char * string)
{
	int i = 0;
	for (i = 0; string[i] != 0; ++i)
	{
		if (string[i] < '0' || string[i] > '9')
		{
			return 0;
		}
	}
	return 1;
}

int anyPort_to_int(char * string)
{
	FILE * potok;
	char buffer[MAXBUF];
	int readed;
	char * portStart;
	char * cp;

	if (isNumber(string))
	{
		portStart = string;
	} else {
		snprintf(buffer, sizeof(buffer), "getent services %s", string);
		potok = popen(buffer, "r");
		if (potok == NULL) blad("popen() error");
		if (feof(potok)) blad("can't find given port number");
		readed = fread(buffer, sizeof(char), sizeof(buffer), potok);
		if (ferror(potok)) blad("fread() error");
		if (readed == 0) blad("can't find given port number");
		buffer[readed - 1] = 0;

		for (cp = buffer; *cp != '/'; cp += sizeof(char))
		{
			if (*(cp - sizeof(char)) == ' ' && *cp >= '0' && *cp <= '9')
				portStart = cp;
		}
		cp = 0;
	}
	return atoi(portStart);
}

void handleSigPipe(int s)
{
	printf("[!] Otrzymalem sygnal PIPE\n");
	return;
}

int main(int argc, char *argv[])
{
	struct in_addr servIP;
	int port;
	int sock;
	struct sockaddr_in sAddr;
	char buffer2[MAXBUF];
	int ret;
	struct sigaction sigactionPipe;
	struct timeval selectTimeout;
	fd_set listaSelect;
	long timeout = 3;
	char c;
	int wyslalemPing = 0;
	int wyslanePingi = 0;
	int limitPingow = 3;

	sigactionPipe.sa_handler = handleSigPipe;
	sigaction(SIGPIPE, &sigactionPipe, NULL);

	if (argc < 3) {
		fprintf(stderr, "Uzycie: %s <serwer> <port>\n",
		        argv[0]);
		exit(1);
	}
	servIP = inet_addr_from_any(argv[1]);
	port = anyPort_to_int(argv[2]);
	printf("adres IP: %s\n", inet_ntoa(servIP)); /* DEBUG */
	printf("    port: %i\n", port); /* DEBUG */

	sock = socket(PF_INET, SOCK_STREAM, 0);
	sAddr.sin_family = AF_INET;
	sAddr.sin_addr.s_addr = servIP.s_addr;
	sAddr.sin_port = htons(port);

	if (connect(sock, (const struct sockaddr *) &sAddr, sizeof(sAddr)) != 0) {
		perror("klient");
		exit(1);
	}

	while (1)
	{
		if (wyslalemPing == 0)
		{
			printf("Wprowadz tekst do wyslania:\n");
		}
		wyslalemPing = 0;

		selectTimeout.tv_sec = timeout;
		selectTimeout.tv_usec = 0;
		FD_ZERO(&listaSelect);
		FD_SET(0, &listaSelect);
		FD_SET(sock, &listaSelect);

		errno = (int) NULL;
		ret = select(FD_SETSIZE, &listaSelect, NULL, NULL, &selectTimeout);
		if (ret == -1)
		{
			perror("select()");
			exit(EXIT_FAILURE);
		}

		if (FD_ISSET(0, &listaSelect)) {
			bzero(buffer2, sizeof(char) * sizeof(buffer2));
			ret = read(0, buffer2 + sizeof(char), sizeof(buffer2) - 1);
			buffer2[0] = 'N';
			printf("DEBUG: z klawiatury: read(): %i\n", ret);
			if (ret < 2)
			{
				printf("DEBUG: uzytkownik zazyczyl sobie wyjscie\n");
				break;
			}
			errno = (int) NULL;
			ret = write(sock, buffer2, strlen(buffer2));
			printf("DEBUG: write(): %i\n", ret);
			if (ret == -1)
			{
				perror("write()");
				exit(EXIT_FAILURE);
			}
		} else if (FD_ISSET(sock, &listaSelect)) {
			bzero(buffer2, sizeof(char) * sizeof(buffer2));
			errno = (int) NULL;
			ret = read(sock, buffer2, MAXBUF);
			printf("DEBUG: read(): %i\n", ret);
			if (ret == -1)
			{
				perror("read()");
				exit(EXIT_FAILURE);
			}
			if (buffer2[0] == 'N')
			{
				printf("Odczytano: %s", buffer2 + sizeof(char));
			} else if (buffer2[0] == 'O') {
				printf("DEBUG: otrzymalem pong\n");
				wyslanePingi = 0;
				wyslalemPing = 1;
			}
		} else {
			if (wyslanePingi == limitPingow)
			{
				printf("Serwer nie odpowiada. Koncze prace.\n");
				close(sock);
				exit(EXIT_FAILURE);
			}
			errno = (int) NULL;
			c = 'I';
			ret = write(sock, &c, 1);
			printf("DEBUG: write() ping: %i\n", ret);
			if (ret == -1)
			{
				perror("write() ping");
				exit(EXIT_FAILURE);
			}
			wyslalemPing = 1;
			wyslanePingi++;
		}

	}
	close(sock);
	return 0;
}