/* select.c: select from different input when ready*/
#include <stdio.h>
#include <signal.h>
#include <sgtty.h>
#include <termios.h>
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include "tcplib.h"

#define PORT 2527
#define BUFLEN 64

int main(int argc, char *argv[])  {

  int sock;
  char *host;
  int maxfdp1, nfound, nread;
  char buff[BUFSIZ+1];
  int size;
  fd_set readmask;
  char *prompt = "hello-> ";
  int n = strlen(prompt);

  if (argc != 2)  {
    fprintf(stderr,"usage : %s server-name\n", argv[0]);
    exit(1);
  }

  host = argv[1];
  sock = socketClient(host, PORT);
  if (sock <= 0)  {
    fprintf(stderr,"connection failed.\n");
    exit(2);
  }

  for (; ;)  {
    /* initialize the read mask */
    FD_ZERO(&readmask);

    /* we will be checking standard input (file 0) and the 
     * network (file sock) 
    */
    FD_SET(0, &readmask);
    FD_SET(sock, &readmask);
  
    write(1, prompt, n);  /* print the prompt to the screen */

    maxfdp1 = sock + 1;   /* how many file descriptors to check? */

    /* system call 'select' to examine how many inputs are ready */
    nfound = select(maxfdp1, &readmask, (fd_set *)0, (fd_set*)0,
		    (struct timeval *)0);
    if (nfound < 0)    {
      exit(3);
    }
    
    /* check the standard input, keyboard for input */
    if (FD_ISSET(0, &readmask))    {
      nread = read(0, buff, BUFSIZ);
      if (nread < 0) {
	fprintf(stderr, "read error from keyboard\n");
	exit(4);
      }
      else if (nread == 0)
	break;

      if (write(1, buff, nread) != nread) {
	fprintf(stderr, "write error to screen\n");
	exit(5);
      }
    }

    /* 
     * check to see if socket has data, if so read and pass it to the 
     * local screen.
     */
    if (FD_ISSET(sock, &readmask))      {
      write(1, "from server : ", strlen("from server : "));
      nread = read(sock, &size, sizeof(int));
      if (nread <= 0) {
	fprintf(stderr, "read error from socket 1 bytes read = %d\n", nread);
	break;
      }
      nread = read(sock, buff, size);
      if (nread <= 0) {
	fprintf(stderr, "read error from socket 2\n");
	break;
      }
      buff[nread] = 0;
      if (write(1, buff, nread) != nread) {
	fprintf(stderr, "write error in socket\n");
	exit(6);
      }
    }
  }  // for
}