#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <string.h>
#include <errno.h>

#define die(MSG) { fprintf(stderr, "%s %s. (%i)\n", MSG, strerror(errno), errno); return errno; }
#define SVPORT 8081
#define MAXCONN 2000000

int main(int argc, char *argv[]) {
	int			sock_fd;
	struct sockaddr_in	serv_addr;
	// Open socket and die if invalid file descriptor is returned
	if ((sock_fd = socket(AF_INET,SOCK_STREAM, 0)) < 0)
		die("Failed to open socket.");
	// Set server address and port
	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sin_family		= AF_INET;
	serv_addr.sin_addr.s_addr	= htonl(INADDR_ANY);
	serv_addr.sin_port		= htons(SVPORT);
	// Bind to socket
	if (bind(sock_fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
		die("Couldn't bind to socket.");
	// Go in passive(LISTEN) mode
	if ((listen(sock_fd, MAXCONN)) < 0)
		die("Failed to listen on socket.");
	printf("Now listening for connections.\n");
	// Accept connections
	char buffer[] = "Hello, fellow navigator!\n";
	for (int conncount=0;; conncount++) {
		int			conn_fd;
		socklen_t		client_len;
		struct sockaddr_in	client_addr;
		client_len = sizeof(client_addr);
		if ((conn_fd = accept(sock_fd, (struct sockaddr *) &client_addr, &client_len)) < 0)
			die("Failed to accept connection.");
		printf("Processed %i connections, last from %15s on port %5i.\r", conncount, inet_ntoa(client_addr.sin_addr), client_addr.sin_port);
		setvbuf(stdout, NULL, _IONBF, 0);
		if (send(conn_fd, buffer, strlen(buffer),0) < 0)
			fprintf(stderr, "\nFailed to send data. %s.\n", strerror(errno));
		if (close(conn_fd) < 0)
			die("Failed to close connection.");
	}
	close(sock_fd);
	return 1;
}