/***************************************************************************
 *   Copyright (C) 2007 by mati   *
 *   infecto@lcm.pl   *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/


#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <iostream>
#include <cstdlib>

#include <arpa/inet.h>

#include <netdb.h>
#include <netinet/in.h>
#include <unistd.h>
#include <iostream>

#define MAX_MSG 100
#define LINE_ARRAY_SIZE (MAX_MSG+1)

using namespace std;

int main(int argc, char** argv)
{
	int listenSocket, connectSocket, i;
	unsigned short int listenPort;
	socklen_t clientAddressLength;
	struct sockaddr_in clientAddress, serverAddress;
	char line[LINE_ARRAY_SIZE];

	listenPort = atoi(argv[1]); 

  // Create socket for listening for client connection requests.
	listenSocket = socket(AF_INET, SOCK_STREAM, 0);
	if (listenSocket < 0) {
		cerr << "cannot create listen socket";
		exit(1);
	}
  
  // Bind listen socket to listen port.  First set various fields in
  // the serverAddress structure, then call bind().
  // htonl() and htons() convert long integers and short integers
  // (respectively) from host byte order (on x86 this is Least
  // Significant Byte first) to network byte order (Most Significant
  // Byte first).
	serverAddress.sin_family = AF_INET;
	serverAddress.sin_addr.s_addr = htonl(INADDR_ANY);
	serverAddress.sin_port = htons(listenPort);
  
	if (bind(listenSocket,
	    (struct sockaddr *) &serverAddress,
	     sizeof(serverAddress)) < 0) {
		     cerr << "cannot bind socket";
		     exit(1);
	     }

  // Wait for connections from clients.
  // This is a non-blocking call; i.e., it registers this program with
  // the system as expecting connections on this socket, and then
  // this thread of execution continues on.
	     listen(listenSocket, 5);
  
	     while (1) {
		     cout << "Waiting for TCP connection on port " << listenPort << " ...\n";

    // Accept a connection with a client that is requesting one.  The
    // accept() call is a blocking call; i.e., this thread of
    // execution stops until a connection comes in.
    // connectSocket is a new socket that the system provides,
    // separate from listenSocket.  We *could* accept more
    // connections on listenSocket, before connectSocket is closed,
    // but this program doesn't do that.
		     clientAddressLength = sizeof(clientAddress);
		     connectSocket = accept(listenSocket,
					    (struct sockaddr *) &clientAddress,
					     &clientAddressLength);
		     if (connectSocket < 0) {
			     cerr << "cannot accept connection ";
			     exit(1);
		     }
    
    // Show the IP address of the client.
    // inet_ntoa() converts an IP address from binary form to the
    // standard "numbers and dots" notation.
		     cout << "  connected to " << inet_ntoa(clientAddress.sin_addr);

    // Show the client's port number.
    // ntohs() converts a short int from network byte order (which is
    // Most Significant Byte first) to host byte order (which on x86,
    // for example, is Least Significant Byte first).
		     cout << ":" << ntohs(clientAddress.sin_port) << "\n";

    // Read lines from socket, using recv(), storing them in the line
    // array.  If no messages are currently available, recv() blocks
    // until one arrives.
    // First set line to all zeroes, so we'll know where the end of
    // the string is.
		     memset(line, 0x0, LINE_ARRAY_SIZE);
		     while (recv(connectSocket, line, MAX_MSG, 0) > 0) {
			     cout << "  --  " << line << "\n";

      // Convert line to upper case.
			     for (i = 0; line[i] != '\0'; i++)
				     line[i] = toupper(line[i]);

      // Send converted line back to client.
			     if (send(connectSocket, line, strlen(line) + 1, 0) < 0)
				     cerr << "Error: cannot send modified data";

			     memset(line, 0x0, LINE_ARRAY_SIZE);  // set line to all zeroes
		     }
	     }
}