/*
 * Remote Laboratory Protocol Terminal Part
 *
 * 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) 2014 - 2019 Timothy Pearson
 * Raptor Engineering
 * http://www.raptorengineeringinc.com
 */

/* This part illustrates the correct method of transmitting and receiving
 * data in a dedicated thread, using two separate message queues to enable
 * fully non-blocking, event-driven execution.
 *
 * NOTE
 * inboundQueue is filled by the GUI thread with data inbound to the worker thread
 * outboundQueue is filled by the worker thread with data outbound to the GUI thread
 */

#include "define.h"
#include "part.h"

#include <tdeaboutdata.h>   //::createAboutData()
#include <tdeaction.h>
#include <tdelocale.h>
#include <tdemessagebox.h>  //::start()
#include <tdeparts/genericfactory.h>
#include <kstatusbar.h>
#include <kstdaction.h>
#include <tqfile.h>        //encodeName()
#include <tqtimer.h>
#include <tqvbox.h>
#include <tqsocket.h>
#include <tqmutex.h>
#include <tqeventloop.h>
#include <tqapplication.h>
#include <tqpushbutton.h>
#include <klineedit.h>
#include <ktextedit.h>
#include <unistd.h>       //access()
#include <stdint.h>
#include <cmath>

#include "layout.h"

#define NETWORK_COMM_TIMEOUT_MS 15000

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

namespace RemoteLab {

typedef KParts::GenericFactory<RemoteLab::ProtoTerminalPart> Factory;
#define CLIENT_LIBRARY "libremotelab_prototerminal"
K_EXPORT_COMPONENT_FACTORY( libremotelab_prototerminal, RemoteLab::Factory )

ProtoTerminalWorker::ProtoTerminalWorker() : TQObject() {
	m_networkDataMutex = new TQMutex(false);
	m_outboundQueueMutex = new TQMutex(false);
	m_inboundQueueMutex = new TQMutex(false);
	m_newData = false;
}

ProtoTerminalWorker::~ProtoTerminalWorker() {
	delete m_networkDataMutex;
	m_networkDataMutex = NULL;
	delete m_inboundQueueMutex;
	m_inboundQueueMutex = NULL;
	delete m_outboundQueueMutex;
	m_outboundQueueMutex = NULL;
}

void ProtoTerminalWorker::run() {
	TQEventLoop* eventLoop = TQApplication::eventLoop();
	if (!eventLoop) {
		return;
	}

	while (1) {
		m_instrumentMutex->lock();

		// Handle inbound queue
		m_inboundQueueMutex->lock();
		if (m_inboundQueue.count() > 0) {
			TQDataStream ds(m_socket);
			ds.setPrintableData(true);

			ProtoTerminalEventQueue::iterator it;
			for (it = m_inboundQueue.begin(); it != m_inboundQueue.end(); ++it) {
				if ((*it).first == TxRxSyncPoint) {
					break;
				}
				if ((*it).first == ConsoleTextSend) {
					ds << (*it).second.toString();
					m_socket->writeEndOfFrame();
				}
				it = m_inboundQueue.erase(it);
			}
			m_socket->flush();
		}
		m_inboundQueueMutex->unlock();

		// Handle outbound queue
		if (m_newData) {
			bool queue_modified = false;
			m_networkDataMutex->lock();
			m_newData = false;

			// Receive data
			if (m_socket->canReadFrame()) {
				TQDataStream ds(m_socket);
				ds.setPrintableData(true);

				// Get command status
				TQString input;
				while (!ds.atEnd()) {
					ds >> input;
					m_outboundQueueMutex->lock();
					m_outboundQueue.push_back(ProtoTerminalEvent(ConsoleTextReceive, TQVariant(input)));
					m_outboundQueueMutex->unlock();
					queue_modified = true;
				}
				m_socket->clearFrameTail();
			}
			m_networkDataMutex->unlock();

			if (queue_modified) {
				m_inboundQueueMutex->lock();
				ProtoTerminalEventQueue::iterator it = m_inboundQueue.begin();
				if ((it) && (it != m_inboundQueue.end())) {
					// Remove sync point
					if ((*it).first == TxRxSyncPoint) {
						it = m_inboundQueue.erase(it);
					}
				}
				m_inboundQueueMutex->unlock();
				emit(outboundQueueUpdated());
			}
		}

		m_instrumentMutex->unlock();

		// Wait for queue status change or new network activity
		if (!eventLoop->processEvents(TQEventLoop::ExcludeUserInput)) {
			eventLoop->processEvents(TQEventLoop::ExcludeUserInput | TQEventLoop::WaitForMore);
		}
	}

	eventLoop->exit(0);
}

void ProtoTerminalWorker::appendItemToInboundQueue(ProtoTerminalEvent item, bool syncPoint) {
	m_inboundQueueMutex->lock();
	m_inboundQueue.push_back(item);
	if (syncPoint) {
		m_inboundQueue.push_back(ProtoTerminalEvent(TxRxSyncPoint, TQVariant()));
	}
	m_inboundQueueMutex->unlock();
}

bool ProtoTerminalWorker::syncPointActive() {
	bool active = false;

	m_inboundQueueMutex->lock();
	ProtoTerminalEventQueue::iterator it = m_inboundQueue.begin();
	if ((it) && (it != m_inboundQueue.end())) {
		if ((*it).first == TxRxSyncPoint) {
			active = true;
		}
	}
	m_inboundQueueMutex->unlock();

	return active;
}

void ProtoTerminalWorker::wake() {
	// Do nothing -- the main event loop will wake when this is called
}

void ProtoTerminalWorker::dataReceived() {
	m_networkDataMutex->lock();
	m_newData = true;
	m_networkDataMutex->unlock();
}

void ProtoTerminalWorker::lockOutboundQueue() {
	m_outboundQueueMutex->lock();
}

void ProtoTerminalWorker::unlockOutboundQueue() {
	m_outboundQueueMutex->unlock();
}

ProtoTerminalEventQueue* ProtoTerminalWorker::outboundQueue() {
	return &m_outboundQueue;
}

ProtoTerminalPart::ProtoTerminalPart( TQWidget *parentWidget, const char *widgetName, TQObject *parent, const char *name, const TQStringList& )
	: RemoteInstrumentPart( parent, name ), m_commHandlerState(-1), m_commHandlerMode(0), m_commHandlerCommandState(0), m_connectionActiveAndValid(false), m_base(0)
{
	// Initialize important base class variables
	m_clientLibraryName = CLIENT_LIBRARY;

	// Initialize mutex
	m_instrumentMutex = new TQMutex(false);

	// Initialize kpart
	setInstance(Factory::instance());
	setWidget(new TQVBox(parentWidget, widgetName));

	// Set up worker
	m_worker = new ProtoTerminalWorker();
	m_workerThread = new TQEventLoopThread();
	m_worker->moveToThread(m_workerThread);
	TQObject::connect(this, TQT_SIGNAL(wakeWorkerThread()), m_worker, TQT_SLOT(wake()));
	TQObject::connect(m_worker, TQT_SIGNAL(outboundQueueUpdated()), this, TQT_SLOT(processOutboundQueue()));

	// Create timers
	m_updateTimeoutTimer = new TQTimer(this);
	connect(m_updateTimeoutTimer, SIGNAL(timeout()), this, SLOT(networkTimeout()));

	// Create widgets
	m_base = new ProtoTerminalBase(widget());

	// Initialize widgets
	m_base->setMinimumSize(500,350);

	connect(m_base->sendText, SIGNAL(clicked()), this, SLOT(sendTextClicked()));
	connect(m_base->textInput, SIGNAL(returnPressed()), m_base->sendText, SIGNAL(clicked()));

	TQTimer::singleShot(0, this, TQT_SLOT(postInit()));
}

ProtoTerminalPart::~ProtoTerminalPart() {
	if (m_instrumentMutex->locked()) {
		printf("[WARNING] Exiting when data transfer still in progress!\n\r"); fflush(stdout);
	}

	disconnectFromServer();
	delete m_instrumentMutex;

	if (m_workerThread) {
		m_workerThread->terminate();
		m_workerThread->wait();
		delete m_workerThread;
		m_workerThread = NULL;
		delete m_worker;
		m_worker = NULL;
	}
}

void ProtoTerminalPart::postInit() {
	setUsingFixedSize(false);
}

bool ProtoTerminalPart::openURL(const KURL &url) {
	int ret;
	m_connectionActiveAndValid = false;
	ret = connectToServer(url.url());
	processLockouts();
	return (ret != 0);
}

bool ProtoTerminalPart::closeURL() {
	disconnectFromServer();
	m_url = KURL();
	return true;
}

void ProtoTerminalPart::processLockouts() {
	if (m_connectionActiveAndValid) {
		m_base->setEnabled(true);
	}
	else {
		m_base->setEnabled(false);
	}
}

void ProtoTerminalPart::disconnectFromServerCallback() {
	m_updateTimeoutTimer->stop();
	m_connectionActiveAndValid = false;
}

void ProtoTerminalPart::connectionFinishedCallback() {
	// Finish worker setup
	m_worker->m_socket = m_socket;
	m_worker->m_instrumentMutex = m_instrumentMutex;
	m_socket->moveToThread(m_workerThread);

	connect(m_socket, SIGNAL(readyRead()), m_socket, SLOT(processPendingData()));
	m_socket->processPendingData();
	connect(m_socket, SIGNAL(newDataReceived()), m_worker, SLOT(dataReceived()));
	m_tickerState = 0;
	m_commHandlerState = 0;
	m_commHandlerMode = 0;
	m_socket->setDataTimeout(NETWORK_COMM_TIMEOUT_MS);
	m_updateTimeoutTimer->start(NETWORK_COMM_TIMEOUT_MS, TRUE);

	// Start worker
	m_workerThread->start();
	TQTimer::singleShot(0, m_worker, SLOT(run()));

	processLockouts();
	networkTick();
	return;
}

void ProtoTerminalPart::connectionStatusChangedCallback() {
	processLockouts();
}

void ProtoTerminalPart::setTickerMessage(TQString message) {
	m_connectionActiveAndValid = true;
	TQString tickerChar;
	switch (m_tickerState) {
		case 0:
			tickerChar = "-";
			break;
		case 1:
			tickerChar = "\\";
			break;
		case 2:
			tickerChar = "|";
			break;
		case 3:
			tickerChar = "/";
			break;
	}
	setStatusMessage(message + TQString("... %1").arg(tickerChar));
	m_tickerState++;
	if (m_tickerState > 3) {
		m_tickerState = 0;
	}
}

void ProtoTerminalPart::processOutboundQueue() {
	bool had_events = false;

	m_worker->lockOutboundQueue();

	ProtoTerminalEventQueue* eventQueue = m_worker->outboundQueue();
	ProtoTerminalEventQueue::iterator it;
	for (it = eventQueue->begin(); it != eventQueue->end(); ++it) {
		if ((*it).first == ConsoleTextReceive) {
			TQString input = (*it).second.toString();
			if (input != "") {
				input.replace("\r", "\n");
				m_base->textOutput->append(">>>" + input);
			}
		}
		had_events = true;
	}
	if (had_events) {
		networkTick();
		eventQueue->clear();
	}

	m_worker->unlockOutboundQueue();

	processLockouts();
}

void ProtoTerminalPart::networkTick() {
	m_updateTimeoutTimer->stop();
	setTickerMessage(i18n("Connected"));
	m_connectionActiveAndValid = true;
	processLockouts();
}

void ProtoTerminalPart::networkTimeout() {
	m_updateTimeoutTimer->stop();
	m_socket->clearIncomingData();
	setStatusMessage(i18n("Server ping timeout.  Please verify the status of your network connection."));
	m_connectionActiveAndValid = false;
	processLockouts();
}

void ProtoTerminalPart::sendTextClicked() {
	if (!m_worker->syncPointActive()) {
		m_TextToSend = m_TextToSend + m_base->textInput->text();
		m_base->textInput->setText("");

		m_worker->appendItemToInboundQueue(ProtoTerminalEvent(ConsoleTextSend, TQVariant(m_TextToSend)), true);
		m_base->textOutput->append("<<<" + m_TextToSend);
		m_TextToSend = "";

		emit wakeWorkerThread();
		m_updateTimeoutTimer->start(NETWORK_COMM_TIMEOUT_MS, TRUE);
	}
}

TDEAboutData* ProtoTerminalPart::createAboutData() {
	return new TDEAboutData( APP_NAME, I18N_NOOP( APP_PRETTYNAME ), APP_VERSION );
}

} //namespace RemoteLab

#include "part.moc"