/*
 * Remote Laboratory FPGA Server
 *
 * 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 3 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * (c) 2012 Timothy Pearson
 * Raptor Engineering
 * http://www.raptorengineeringinc.com
 */

#include <stdlib.h>

#include <klocale.h>

#include "fpga_conn.h"

/* exception handling */
struct exit_exception {
	int c;
	exit_exception(int c):c(c) { }
};

/*
  The FPGASocket class provides a socket that is connected with a client.
  For every client that connects to the server, the server creates a new
  instance of this class.
*/
FPGASocket::FPGASocket(int sock, TQObject *parent, const char *name) :
	TDEKerberosServerSocket(parent, name), m_criticalSection(0), m_stationID(-1), m_config(static_cast<FPGAServer*>(parent)->m_config), m_database(NULL), m_databaseStationsCursor(NULL) {

	setServiceName("remotefpga");

	line = 0;
	connect(this, SIGNAL(connectionClosed()), SLOT(connectionClosedHandler()));
	setSocket(sock);
}

FPGASocket::~FPGASocket() {
	//
}

void FPGASocket::close() {
	TDEKerberosServerSocket::close();
	connectionClosedHandler();
}

void FPGASocket::connectionClosedHandler() {
	printf("[DEBUG] Connection from %s closed\n\r", m_remoteHost.ascii());

	if (m_criticalSection > 0) {
		throw exit_exception(-1);
	}
}

int FPGASocket::initiateKerberosHandshake() {
	if (setUsingKerberos(true) == 0) {
		TQDataStream ds(this);
		ds << TQString("OK");

		return 0;
	}
	else {
		return -1;
	}
}

void FPGASocket::enterCommandLoop() {
	// RAJA FIXME
}

/*
  The FPGAServer class handles new connections to the server. For every
  client that connects, it creates a new FPGASocket -- that instance is now
  responsible for the communication with that client.
*/
FPGAServer::FPGAServer(TQObject* parent, int port, KSimpleConfig* config) :
	TQServerSocket( port, 1, parent ), m_config(config), m_numberOfConnections(0) {

	if ( !ok() ) {
		printf("[ERROR] Failed to bind to port %d\n\r", port);
		exit(1);
	}

	socketDevice()->setAddressReusable(false);

	printf("[INFO] Server started on port %d\n\r", port); fflush(stdout);
}

FPGAServer::~FPGAServer() {
	//
}

void FPGAServer::newConnection(int socket) {
	FPGASocket *s = new FPGASocket(socket, this);
	s->m_remoteHost = s->peerAddress().toString();
	printf("[DEBUG] New connection from %s\n\r", s->m_remoteHost.ascii());
	if (m_numberOfConnections > 0) {
		printf("[DEBUG] Connection from %s closed due to multiple access attempt\n\r", m_remoteHost.ascii());
		s->close();
		delete s;
		s = NULL;
	}
	if (s->initiateKerberosHandshake() != 0) {
		printf("[DEBUG] Connection from %s closed due to Kerberos failure\n\r", m_remoteHost.ascii());
		s->close();
		delete s;
		s = NULL;
	}
	else {
		m_numberOfConnections++;
		connect(s, SIGNAL(connectionClosed()), s, SLOT(deleteLater()));
		connect(s, SIGNAL(connectionClosed()), this, SLOT(remoteConnectionClosed()));
		emit newConnect(s);
		s->enterCommandLoop();
	}
}

void FPGAServer::remoteConnectionClosed() {
	m_numberOfConnections--;
}