#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <time.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "list.h"
#include <sys/time.h>
#include <sys/select.h>

#define LISTENING_PORT 1337
#define LISTENING_GROUP "224.0.0.42"
#define BUFLEN 512

main(int argc) {
	struct sockaddr_in addr, tcpaddr;
	int addrlen, tcpaddrlen, sock, tcpsock, cnt, maxfd, res, tcpport, newsock;
	struct ip_mreq mreq;
	struct timeval timeout;
	char message[BUFLEN];
	fd_set rset;
	List sockets;
	Position pos;

	//create the multicast udp socket to use
	sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

	//throw error when the multicast socket couldn't be opened
	if(sock<0) {
		perror("Socket couldn't be opened");
		exit(1);
	}

	//create the tcp communication socket to use
	tcpsock = socket(AF_INET, SOCK_STREAM, 0);

	//throw error when the multicast socket couldn't be opened
	if(tcpsock<0) {
		perror("TCP socket couldn't be opened");
		exit(1);
	}

	//fill string with zeros
	bzero((char *)&tcpaddr, sizeof(tcpaddr));
	//set the socket-family to ipv4 protocolfamily
	tcpaddr.sin_family = AF_INET;
	//enter the address of the host we're running on into the struct
	tcpaddr.sin_addr.s_addr = htonl(INADDR_ANY);
	//calculate the size of the address
	tcpaddrlen = sizeof(tcpaddr);

	//fill string with zeros
	bzero((char *)&addr, sizeof(addr));
	//set the socket-family to ipv4 protocolfamily
	addr.sin_family = AF_INET;
	//enter the address of the host we're running on into the struct
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	//calculate the size of the address
	addrlen = sizeof(addr);
	//enter the port to listen on into the struct
	addr.sin_port = htons(LISTENING_PORT);

	//bind the tcp communication socket to the address used
	if(bind(tcpsock, (struct sockaddr *)&tcpaddr, sizeof(tcpaddr))<0) {
		perror("Couldn't bind the multicast socket");
		exit(1);
	}
	
	//start to listen on that socket
	if(listen(tcpsock,3)<0) {
		perror("Couldn't listen on that socket");
		exit(1);
	}

	printf("%d is the tcpsock\n",tcpsock);

	//bind the multicast socket to the address used
	if(bind(sock, (struct sockaddr *)&addr, sizeof(addr))<0) {
		perror("Couldn't bind the multicast socket");
		exit(1);
	}
	
	//get the assigned port for the tcp communication socket
	if(getsockname(tcpsock, (struct sockaddr *)&tcpaddr, &tcpaddrlen)<0) {
		perror("Couldn't get the socketname");
		exit(1);
	}
	tcpport = tcpaddr.sin_port;
	printf("The TCP communication socket port is: %d\n",tcpport);

	//create the linked list to save the sockets
	sockets = MakeEmpty(NULL);
	pos = Header(sockets);
	Insert(sock, sockets, pos);
	Insert(tcpsock, sockets, pos);

	//set the address of the multicast group that we want to listen to
	mreq.imr_multiaddr.s_addr = inet_addr(LISTENING_GROUP);
	//set the address on which we will try to join the multicast group to the interface
	mreq.imr_interface.s_addr = htonl(INADDR_ANY);
	
	//request to join the multicast group to the interface 
	if(setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq))<0) {
		perror("Couldn't set the socket options for mreq");
		exit(1);
	}
	cnt = recvfrom(sock, message, sizeof(message)-1, 0, (struct sockaddr *)&addr, &addrlen);
	message[cnt] = '\0';
	printf("%s",message);
	bzero(message, sizeof(message));
	sprintf(message, "discovery_reply %d\n",tcpport);
	if(sendto(sock,message,BUFLEN,0,(struct sockaddr *)&addr,addrlen)<0) {
		perror("Couldn't answer multicast request");
		exit(1);
	}
	newsock = accept(tcpsock,(struct sockaddr *)&tcpaddr, &tcpaddrlen);
	printf("%d is teh shit",newsock);
}