// SERVER
#define WIN32_LEAN_AND_MEAN
#include <windows.h>

#include <winsock2.h>
#include <ws2tcpip.h>

#include <stdio.h>
#include <stdlib.h>

#define PORT 5276

int main() {
	fd_set master;
	fd_set read_fds;
	struct sockaddr_in myaddr;
	struct sockaddr_in remoteaddr;
	SOCKET fdmax;
	SOCKET listener;
	SOCKET newfd;
	char buf[256];
	int nbytes;
	bool yes = TRUE;
	socklen_t addrlen;
	SOCKET i;
	unsigned int j;

	FD_ZERO(&master);
	FD_ZERO(&read_fds);

	if((listener = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) == INVALID_SOCKET) {
		perror("socket");
		exit(1);
	}

	if(setsockopt(listener, SOL_SOCKET, SO_REUSEADDR, (char*)&yes, sizeof(bool)) == SOCKET_ERROR) {
		perror("setsockopt");
		exit(1);
	}

	memset(&myaddr, '\0', sizeof(myaddr));
	myaddr.sin_family = AF_INET;
	myaddr.sin_addr.s_addr = INADDR_ANY;
	myaddr.sin_port = htons(PORT);
	if(bind(listener, (struct sockaddr *)&myaddr, sizeof(myaddr)) == -1) {
		perror("bind");
		exit(1);
	}

	if(listen(listener, 15) == -1) {
		perror("listen");
		exit(1);
	}

	FD_SET(listener, &master);

	fdmax = listener;

	for(;;) {
		read_fds = master;
		if(select((int)fdmax +1, &read_fds, NULL, NULL, NULL) == -1) {
			perror("select");
			exit(1);
		}

		for(i=0;i<=fdmax;i++) {
			if(FD_ISSET(i, &read_fds)) {
				addrlen = sizeof(remoteaddr);
				if((newfd = accept(listener, (struct sockaddr *)&remoteaddr, &addrlen)) == -1) {
					perror("accept");
				} else {
					FD_SET(newfd, &master);
					if(newfd>fdmax) {
						fdmax = newfd;
					}
					printf("selectserver: new connection from %s on socket %d\n", inet_ntoa(remoteaddr.sin_addr), newfd);
				}
			} else {
				if((nbytes = recv(i, buf, sizeof(buf), 0)) <= 0) {
					if(nbytes==0) {
						printf("selectserver: socket %d hung up\n", i);
					} else {
						perror("recv");
					}
					closesocket(i);
					FD_CLR(i, &master);
				} else {
					for(j=0;j<=fdmax;j++) {
						if(FD_ISSET(j, &master)) {
							if(j!=listener && j!=i) {
								if(send(j, buf, nbytes, 0) == -1) {
									perror("send");
								}
							}
						}
					}
				}
			}
		}
	}
	return 0;
}