/***************************************************************************/
/*                                                                         */
/* Server program which wait for the client to connect and reads the data  */
/*     using non-blocking socket.                                          */
/* The reading of non-blocking sockets is done in a loop until data        */
/*     arrives to the sockfd.                                              */
/*                                                                         */
/* based on Beej's program - look in the simple TCP server for further doc.*/
/*                                                                         */
/*                                                                         */
/***************************************************************************/

    
    #include <stdio.h> 
    #include <stdlib.h> 
    #include <errno.h> 
    #include <string.h> 
    #include <sys/types.h> 
    #include <netinet/in.h> 
    #include <sys/socket.h> 
    #include <sys/wait.h> 
    #include <fcntl.h> /* Added for the nonblocking socket */

    #define MYPORT 3456    /* the port users will be connecting to */
    #define BACKLOG 10     /* how many pending connections queue will hold */

    main()
    {
        int 			sockfd, new_fd;  /* listen on sock_fd, new connection on new_fd */
        struct 	sockaddr_in 	my_addr;    /* my address information */
        struct 	sockaddr_in 	their_addr; /* connector's address information */
        int 			sin_size;
	char			string_read[255];
	int 			n,i;
	int			last_fd;	/* Thelast sockfd that is connected	*/

        if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
            perror("socket");
            exit(1);
        }
	
	last_fd = sockfd;

        my_addr.sin_family = AF_INET;         /* host byte order */
        my_addr.sin_port = htons(MYPORT);     /* short, network byte order */
        my_addr.sin_addr.s_addr = INADDR_ANY; /* auto-fill with my IP */
        bzero(&(my_addr.sin_zero), 8);        /* zero the rest of the struct */

        if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) \
                                                                      == -1) {
            perror("bind");
            exit(1);
        }

        if (listen(sockfd, BACKLOG) == -1) {
            perror("listen");
            exit(1);
        }

      	if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr, \
       			&sin_size)) == -1) {
       		perror("accept");
        			}
        fcntl(last_fd, F_SETFL, O_NONBLOCK); /* Change the socket into non-blocking state	*/
        fcntl(new_fd, F_SETFL, O_NONBLOCK); /* Change the socket into non-blocking state	*/

	while(1){
		for (i=sockfd;i<=last_fd;i++){
			printf("Round number %d\n",i);
       			if (i = sockfd){
		 		sin_size = sizeof(struct sockaddr_in);
        			if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr, \
        					&sin_size)) == -1) {
        				perror("accept");
        			}
         			printf("server: got connection from %s\n", \
					 inet_ntoa(their_addr.sin_addr)); 
    	    			fcntl(new_fd, F_SETFL, O_NONBLOCK);
				last_fd = new_fd;
			}
			else{
	    			n=recv(new_fd,string_read,sizeof(string_read),0);
				if (n < 1){ 
					perror("recv - non blocking \n");
	    				printf("Round %d, and the data read size is: n=%d \n",i,n);
				}
				else{
			        	string_read[n] = '\0';
	    				printf("The string is: %s \n",string_read);
            				if (send(new_fd, "Hello, world!\n", 14, 0) == -1)
                				perror("send");
				}
	    		}
		}
	}

        
    }