#include <unistd.h> // Per les crides a fitxer

#include <stdio.h>  // Per l'I/O de stdin/stdout

#include <errno.h>  // Pels errors de les crides a fitxer

#include <string.h> // Per strerror()

#include <stdlib.h> // Per abort()

#include <sys/types.h>  // Per crides de fitxer

#include <sys/socket.h>  // Per les macros bool,true,false

#include <netinet/in.h>

#include <arpa/inet.h>

#include <stdbool.h>

#include <assert.h> // Per assert()

#include <sys/select.h> // Pel select()

#include "rfc3164.h"

#include "syslog.h"

#define LISTEN_QUEUE = 10;

void show_help(const char * restrict program)

{

	printf("Usage: %s <udp_port> (negative for enable ipv6)\n", program);

}

int listen_ipv6(int port)

{

	int socket_ipv6;

	struct sockaddr_in6 source_ipv6;

	int result;

	int on=1;

	socket_ipv6 = socket(PF_INET6, SOCK_DGRAM, 0);

	if (socket_ipv6 == -1)

	{

		fprintf(stderr, "IPv6 socket failed.\n");

		abort();

	}

	/* Fem que poguem reutilitzar l'adreça encara que no s'hagi acabat

	   el timeout després de tancar-se la connexió */

	if (setsockopt(socket_ipv6, SOL_SOCKET, SO_REUSEADDR,

	                         (char *)&on,sizeof(on)) < 0)

	{

		fprintf(stderr, "IPv6 setsockopt() failed: %s.\n",

			strerror(errno));

		abort();

	}

	/* IPv6 listen address */

	memset(&source_ipv6, 0, sizeof(source_ipv6));

	source_ipv6.sin6_family = AF_INET6;

	source_ipv6.sin6_flowinfo = 0;

	source_ipv6.sin6_port = htons(port);

	source_ipv6.sin6_addr = in6addr_any;

	result = bind(socket_ipv6, (struct sockaddr *) &source_ipv6,

		sizeof(source_ipv6));

	assert(result == 0);

	/*

	result = listen(socket_ipv6, const_listen_queue);

	if (result != 0)

	{

		printf("Error in listen() ipv6: %s\n", strerror(errno));

		abort();

	}

	*/

	return socket_ipv6;

}

int listen_ipv4(int port)

{

	int socket_ipv4;

	struct sockaddr_in source_ipv4;

	int result;

	int on=1;

	socket_ipv4 = socket(PF_INET, SOCK_DGRAM, 0);

	if (socket_ipv4 == -1)

	{

		fprintf(stderr, "IPv4 socket not supported.\n");

		abort();

	}

	/* Fem que poguem reutilitzar l'adreça encara que no s'hagi acabat

	   el timeout després de tancar-se la connexió */

	if (setsockopt(socket_ipv4, SOL_SOCKET, SO_REUSEADDR,

	                         (char *)&on,sizeof(on)) < 0)

	{

		fprintf(stderr, "IPv4 setsockopt() failed: %s.\n",

			strerror(errno));

		abort();

	}

	/* IPv4 listen address */

	memset(&source_ipv4, 0, sizeof(source_ipv4));

	source_ipv4.sin_family = AF_INET;

	source_ipv4.sin_port = htons(port);

	source_ipv4.sin_addr.s_addr = htonl(INADDR_ANY);

	result = bind(socket_ipv4, (struct sockaddr *) &source_ipv4,

		sizeof(source_ipv4));

	assert(result == 0);

	/*

	result = listen(socket_ipv4, const_listen_queue);

	if (result != 0)

	{

		printf("Error in listen() ipv4: %s\n", strerror(errno));

		abort();

	}

	*/

	return socket_ipv4;

}

void server_loop(const int port, const bool ipv6enabled)

{

	int socket_ipv6, socket_ipv4;

	fd_set listen_sockets;

	struct timeval wait_time;

	int result;

	int size;

	int high_socket;

	char message[MESSAGE_LENGTH+1];

	socket_ipv4 = listen_ipv4(port);

	if (ipv6enabled)

		socket_ipv6 = listen_ipv6(port);

	/* Mirem quin és el socket més alt pel select() */

	high_socket = socket_ipv4;

	if (ipv6enabled && (high_socket < socket_ipv6) )

		high_socket = socket_ipv6;

	high_socket += 1;

	result = 0;

	while (result >= 0)

	{

		/* Establim els FDs que volem esperar al select() */

		FD_ZERO(&listen_sockets);

		if (ipv6enabled)

			FD_SET(socket_ipv6, &listen_sockets);

		FD_SET(socket_ipv4, &listen_sockets);

		/* Establim el temporitzador pel select() */

		wait_time.tv_sec = 5;

		wait_time.tv_usec = 0;

		result = select(high_socket, &listen_sockets, NULL, NULL,

			&wait_time);

		if (result == 0)

			continue;

		else if (result == -1)

		{

			fprintf(stderr, "Error in select(): %s\n",

				strerror(errno));

			abort();

		}

		/* Algun FD té dades... */

		if (FD_ISSET(socket_ipv4, &listen_sockets))

		{

			size = recv(socket_ipv4, message, MESSAGE_LENGTH, 0);

			process_message(message);

			/* Debug */

			if(!strcmp(message,"close"))

				break;

			write(1, message, size);

		}

		if (ipv6enabled && FD_ISSET(socket_ipv6, &listen_sockets))

		{

			size = recv(socket_ipv6, message, MESSAGE_LENGTH, 0);

			process_message(message);

			/* Debug */

			if(!strcmp(message,"close"))

				break;

			write(1, message, size);

		}

	}

	/* Closing sockets at the end */

	close(socket_ipv4);

	if (ipv6enabled)

		close(socket_ipv6);

}

int main(int argn, char **argv)

{

	int port;

	bool use_ipv6 = false;

	/* Processem els paràmetres d'entrada */

	if (argn != 2) {

		show_help(argv[0]);

		return 2;

	}

	port=atoi(argv[1]);

	/* If a port number is typed as negative, it will start

	 * also the ipv6 server */

	if(port < 0)

	{

		port = -port;

		use_ipv6 = true;

	}

	if (port < 0 || port >65535)

	{

		show_help(argv[0]);

		return 2;

	}

	program_ignore_hup();

	server_loop(port, use_ipv6);

	return 0;

}