/* server.c */

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

#define BUF_SIZE		1024

void error_exit (char *msg)
{
	perror (msg);
	exit (2);
}

int main(int argc,char *argv[])
{
   int create_socket;
   int bufsize = BUF_SIZE;
   int msglen, n_sent, rcvlen;
   char *buffer = malloc(BUF_SIZE);
   struct sockaddr_in address;
   const struct sockaddr *sendaddr = (struct sockaddr *)&address;
   struct sockaddr fromaddr;
   int fromlen;
   
   /// check for at least 1 argv:
   if (argc < 2) {
	   fprintf (stderr, "usage: server ipv4.dotted.quad.address\n");
	   exit (1);
   }

   printf("\x1B[2J");
   if ((create_socket = socket(AF_INET, SOCK_DGRAM, 0)) > 0)
     printf("socket created\n");
   else error_exit ("socket error");

   address.sin_family = AF_INET;
   address.sin_addr.s_addr = htonl(INADDR_ANY);
   address.sin_port = htons(15000);
   if (inet_pton (AF_INET,argv[1],&address.sin_addr) < 0)
	   error_exit ("inet_pton error");

   if (bind (create_socket, (struct sockaddr *)&address, sizeof(address)) == 0)
     printf("bind socket succeeded\n");
   else error_exit ("bind error");

   for (;;) {
	rcvlen = recvfrom (create_socket, buffer, BUF_SIZE, 0, &fromaddr, &fromlen);
	if (rcvlen < 0)
		error_exit ("recvfrom error");
	buffer [rcvlen] = '\0';
	printf ("Message received: %s\n", buffer);

	printf ("Message to send: ");
	///gets(buffer);
	fgets (buffer, BUF_SIZE, stdin);
	if (strncmp (buffer, "/q", 2) == 0) break; // use /q to quit
	msglen = strlen (buffer);
	///n_sent = sendto (create_socket, buffer, msglen, 0, sendaddr, 10 * sizeof (struct in_addr));
	n_sent = sendto (create_socket, buffer, msglen, 0, (struct sockaddr *)&fromaddr, fromlen);
	if (n_sent < 0)
		error_exit ("sendto error");
	if (n_sent != msglen)
		fprintf (stderr, "sendto: short write (%d / %d)\n",
				n_sent, msglen);
      sleep (1);
   }

   close (create_socket);
}