#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

#define PORT    5000
#define MAXMSG  512

int
    read_from_client (int filedes)
{
    char buffer[MAXMSG];
    int nbytes;
    nbytes = read (filedes, buffer, MAXMSG);
    if (nbytes < 0)
    {
        /* Read error. */
        perror ("read");
        exit (EXIT_FAILURE);
    }
    else if (nbytes == 0)
        /* End-of-file. */
        return -1;
    else
    {
        /* Data read. */
        printf ("Server: got message: `%s'\n", buffer);
        //fprintf (stderr, "Server: got message: `%s'\n", buffer);
        return 0;
    }
}


int main (void)
{
    //extern int make_socket (uint16_t port);
    int sock;
    fd_set active_fd_set, read_fd_set;
    int i;
    struct sockaddr_in clientname;
;
    //size_t size;
    int size;

    /* Create the socket and set it up to accept connections. */
    //sock = make_socket (PORT);
    if((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
    {
        perror("Server-socket() error lol!");
        /*just exit lol!*/
        exit(1);
    }
    printf("Server-socket() is OK...\n");



    /*"address already in use" error message */
    int yes=1;
    if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1)
    {
    perror("Server-setsockopt() error lol!");
    exit(1);
    }
    printf("Server-setsockopt() is OK...\n");


    /* bind */
    clientname.sin_family = AF_INET;
    clientname.sin_addr.s_addr = INADDR_ANY;
    clientname.sin_port = htons(PORT);
    //memset(clientname.sin_zero, '\0', 8);

    if(bind(sock, (struct sockaddr *)&clientname, sizeof(clientname)) == -1)
    {
        perror("Server-bind() error lol!");
        exit(1);
    }
    printf("Server-bind() is OK...\n");


    if (listen (sock, 1) < 0)
    {
        perror ("listen");
        exit (EXIT_FAILURE);
    }

    /* Initialize the set of active sockets. */
    FD_ZERO (&active_fd_set);
    FD_SET (sock, &active_fd_set);

    while (1)
    {
        /* Block until input arrives on one or more active sockets. */
        read_fd_set = active_fd_set;
        if (select (FD_SETSIZE, &read_fd_set, NULL, NULL, NULL) < 0)
        {
            perror ("select");
            exit (EXIT_FAILURE);
        }

        /* Service all the sockets with input pending. */
        for (i = 0; i < FD_SETSIZE; ++i)
            if (FD_ISSET (i, &read_fd_set))
        {
            if (i == sock)
            {
                /* Connection request on original socket. */
                int new;
                size = sizeof (clientname);
                new = accept (sock,  (struct sockaddr *) &clientname, & size);
                if (new < 0)

                {
                    perror ("accept");
                    exit (EXIT_FAILURE);
                }




                FD_SET (new, &active_fd_set);
            }
            else
            {
                /* Data arriving on an already-connected socket. */
                if (read_from_client (i) < 0)
                {
                    //close (i);
                    //FD_CLR (i, &active_fd_set);
                }
            }
        }
    }
}