///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2016 F4EXB                                                      //
// written by Edouard Griffiths                                                  //
//                                                                               //
// 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 as version 3 of the License, or                  //
//                                                                               //
// 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 V3 for more details.                               //
//                                                                               //
// You should have received a copy of the GNU General Public License             //
// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
///////////////////////////////////////////////////////////////////////////////////

#include <stdio.h>
#include <QDebug>
#include <QThread>

#include "dspdevicesinkengine.h"

#include "dsp/basebandsamplesource.h"
#include "dsp/basebandsamplesink.h"
#include "dsp/devicesamplesink.h"
#include "dsp/dspcommands.h"
#include "samplesourcefifo.h"
#include "threadedbasebandsamplesource.h"

DSPDeviceSinkEngine::DSPDeviceSinkEngine(uint32_t uid, QObject* parent) :
	QThread(parent),
    m_uid(uid),
	m_state(StNotStarted),
	m_deviceSampleSink(0),
	m_sampleSinkSequence(0),
	m_basebandSampleSources(),
	m_spectrumSink(0),
	m_sampleRate(0),
	m_centerFrequency(0),
	m_multipleSourcesDivisionFactor(1)
{
	connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()), Qt::QueuedConnection);
	connect(&m_syncMessenger, SIGNAL(messageSent()), this, SLOT(handleSynchronousMessages()), Qt::QueuedConnection);

	moveToThread(this);
}

DSPDeviceSinkEngine::~DSPDeviceSinkEngine()
{
    stop();
	wait();
}

void DSPDeviceSinkEngine::run()
{
	qDebug() << "DSPDeviceSinkEngine::run";
	m_state = StIdle;
	exec();
}

void DSPDeviceSinkEngine::start()
{
	qDebug() << "DSPDeviceSinkEngine::start";
	QThread::start();
}

void DSPDeviceSinkEngine::stop()
{
	qDebug() << "DSPDeviceSinkEngine::stop";
    gotoIdle();
    m_state = StNotStarted;
    QThread::exit();
//	DSPExit cmd;
//	m_syncMessenger.sendWait(cmd);
}

bool DSPDeviceSinkEngine::initGeneration()
{
	qDebug() << "DSPDeviceSinkEngine::initGeneration";
	DSPGenerationInit cmd;

	return m_syncMessenger.sendWait(cmd) == StReady;
}

bool DSPDeviceSinkEngine::startGeneration()
{
	qDebug() << "DSPDeviceSinkEngine::startGeneration";
	DSPGenerationStart cmd;

	return m_syncMessenger.sendWait(cmd) == StRunning;
}

void DSPDeviceSinkEngine::stopGeneration()
{
	qDebug() << "DSPDeviceSinkEngine::stopGeneration";
	DSPGenerationStop cmd;
	m_syncMessenger.storeMessage(cmd);
	handleSynchronousMessages();
}

void DSPDeviceSinkEngine::setSink(DeviceSampleSink* sink)
{
	qDebug() << "DSPDeviceSinkEngine::setSink";
	DSPSetSink cmd(sink);
	m_syncMessenger.sendWait(cmd);
}

void DSPDeviceSinkEngine::setSinkSequence(int sequence)
{
	qDebug("DSPDeviceSinkEngine::setSinkSequence: seq: %d", sequence);
	m_sampleSinkSequence = sequence;
}

void DSPDeviceSinkEngine::addSource(BasebandSampleSource* source)
{
	qDebug() << "DSPDeviceSinkEngine::addSource: " << source->objectName().toStdString().c_str();
	DSPAddBasebandSampleSource cmd(source);
	m_syncMessenger.sendWait(cmd);
}

void DSPDeviceSinkEngine::removeSource(BasebandSampleSource* source)
{
	qDebug() << "DSPDeviceSinkEngine::removeSource: " << source->objectName().toStdString().c_str();
	DSPRemoveBasebandSampleSource cmd(source);
	m_syncMessenger.sendWait(cmd);
}

void DSPDeviceSinkEngine::addThreadedSource(ThreadedBasebandSampleSource* source)
{
	qDebug() << "DSPDeviceSinkEngine::addThreadedSource: " << source->objectName().toStdString().c_str();
	DSPAddThreadedBasebandSampleSource cmd(source);
	m_syncMessenger.sendWait(cmd);
}

void DSPDeviceSinkEngine::removeThreadedSource(ThreadedBasebandSampleSource* source)
{
	qDebug() << "DSPDeviceSinkEngine::removeThreadedSource: " << source->objectName().toStdString().c_str();
	DSPRemoveThreadedBasebandSampleSource cmd(source);
	m_syncMessenger.sendWait(cmd);
}

void DSPDeviceSinkEngine::addSpectrumSink(BasebandSampleSink* spectrumSink)
{
	qDebug() << "DSPDeviceSinkEngine::addSpectrumSink: " << spectrumSink->objectName().toStdString().c_str();
	DSPAddSpectrumSink cmd(spectrumSink);
	m_syncMessenger.sendWait(cmd);
}

void DSPDeviceSinkEngine::removeSpectrumSink(BasebandSampleSink* spectrumSink)
{
	qDebug() << "DSPDeviceSinkEngine::removeSpectrumSink: " << spectrumSink->objectName().toStdString().c_str();
	DSPRemoveSpectrumSink cmd(spectrumSink);
	m_syncMessenger.sendWait(cmd);
}

QString DSPDeviceSinkEngine::errorMessage()
{
	qDebug() << "DSPDeviceSinkEngine::errorMessage";
	DSPGetErrorMessage cmd;
	m_syncMessenger.sendWait(cmd);
	return cmd.getErrorMessage();
}

QString DSPDeviceSinkEngine::sinkDeviceDescription()
{
	qDebug() << "DSPDeviceSinkEngine::sinkDeviceDescription";
	DSPGetSinkDeviceDescription cmd;
	m_syncMessenger.sendWait(cmd);
	return cmd.getDeviceDescription();
}

void DSPDeviceSinkEngine::work(int nbWriteSamples)
{
	// multiple channel sources handling
	if ((m_threadedBasebandSampleSources.size() + m_basebandSampleSources.size()) > 1)
	{
//	    qDebug("DSPDeviceSinkEngine::work: multiple channel sources handling: %u", m_multipleSourcesDivisionFactor);

	    SampleVector::iterator writeBegin;
	    SampleSourceFifo* sampleFifo = m_deviceSampleSink->getSampleFifo();
	    sampleFifo->getWriteIterator(writeBegin);
	    SampleVector::iterator writeAt = writeBegin;
	    std::vector<SampleVector::iterator> sampleSourceIterators;

	    for (ThreadedBasebandSampleSources::iterator it = m_threadedBasebandSampleSources.begin(); it != m_threadedBasebandSampleSources.end(); ++it)
	    {
	        sampleSourceIterators.push_back(SampleVector::iterator());
	        (*it)->getSampleSourceFifo().readAdvance(sampleSourceIterators.back(), nbWriteSamples);
	        sampleSourceIterators.back() -= nbWriteSamples;
	    }

	    for (BasebandSampleSources::iterator it = m_basebandSampleSources.begin(); it != m_basebandSampleSources.end(); ++it)
	    {
            sampleSourceIterators.push_back(SampleVector::iterator());
            (*it)->getSampleSourceFifo().readAdvance(sampleSourceIterators.back(), nbWriteSamples);
            sampleSourceIterators.back() -= nbWriteSamples;
	    }

	    for (int is = 0; is < nbWriteSamples; is++)
		{
			// pull data from sources FIFOs and merge them in the device sample FIFO
	        for (std::vector<SampleVector::iterator>::iterator it = sampleSourceIterators.begin(); it != sampleSourceIterators.end(); ++it)
	        {
	            Sample s = (**it);
	            s /= m_multipleSourcesDivisionFactor;
	            ++(*it);

	            if (it == sampleSourceIterators.begin()) {
	                (*writeAt) = s;
	            } else {
	                (*writeAt) += s;
	            }
	        }

			sampleFifo->bumpIndex(writeAt);
		}
	}
}

// notStarted -> idle -> init -> running -+
//                ^                       |
//                +-----------------------+

DSPDeviceSinkEngine::State DSPDeviceSinkEngine::gotoIdle()
{
	qDebug() << "DSPDeviceSinkEngine::gotoIdle";

	switch(m_state) {
		case StNotStarted:
			return StNotStarted;

		case StIdle:
		case StError:
			return StIdle;

		case StReady:
		case StRunning:
			break;
	}

	if(m_deviceSampleSink == 0)
	{
		return StIdle;
	}

	// stop everything

	for(BasebandSampleSources::const_iterator it = m_basebandSampleSources.begin(); it != m_basebandSampleSources.end(); it++)
	{
        qDebug() << "DSPDeviceSinkEngine::gotoIdle: stopping " << (*it)->objectName().toStdString().c_str();
		(*it)->stop();
	}

	for(ThreadedBasebandSampleSources::const_iterator it = m_threadedBasebandSampleSources.begin(); it != m_threadedBasebandSampleSources.end(); it++)
	{
	    qDebug() << "DSPDeviceSinkEngine::gotoIdle: stopping ThreadedSampleSource(" << (*it)->getSampleSourceObjectName().toStdString().c_str() << ")";
		(*it)->stop();
	}

	if (m_spectrumSink)
	{
        disconnect(m_deviceSampleSink->getSampleFifo(), SIGNAL(dataRead(int)), this, SLOT(handleForwardToSpectrumSink(int)));
        m_spectrumSink->stop();
	}

	m_deviceSampleSink->stop();
	m_deviceDescription.clear();
	m_sampleRate = 0;

	return StIdle;
}

DSPDeviceSinkEngine::State DSPDeviceSinkEngine::gotoInit()
{
	switch(m_state) {
		case StNotStarted:
			return StNotStarted;

		case StRunning: // FIXME: assumes it goes first through idle state. Could we get back to init from running directly?
			return StRunning;

		case StReady:
			return StReady;

		case StIdle:
		case StError:
			break;
	}

	if (m_deviceSampleSink == 0)
	{
		return gotoError("DSPDeviceSinkEngine::gotoInit: No sample source configured");
	}

	// init: pass sample rate and center frequency to all sample rate and/or center frequency dependent sinks and wait for completion

	m_deviceDescription = m_deviceSampleSink->getDeviceDescription();
	m_centerFrequency = m_deviceSampleSink->getCenterFrequency();
	m_sampleRate = m_deviceSampleSink->getSampleRate();

	qDebug() << "DSPDeviceSinkEngine::gotoInit: "
	        << " m_deviceDescription: " << m_deviceDescription.toStdString().c_str()
			<< " sampleRate: " << m_sampleRate
			<< " centerFrequency: " << m_centerFrequency;

	DSPSignalNotification notif(m_sampleRate, m_centerFrequency);

	for (BasebandSampleSources::const_iterator it = m_basebandSampleSources.begin(); it != m_basebandSampleSources.end(); ++it)
	{
		qDebug() << "DSPDeviceSinkEngine::gotoInit: initializing " << (*it)->objectName().toStdString().c_str();
		(*it)->handleMessage(notif);
	}

	for (ThreadedBasebandSampleSources::const_iterator it = m_threadedBasebandSampleSources.begin(); it != m_threadedBasebandSampleSources.end(); ++it)
	{
		qDebug() << "DSPDeviceSinkEngine::gotoInit: initializing ThreadedSampleSource(" << (*it)->getSampleSourceObjectName().toStdString().c_str() << ")";
		(*it)->handleSourceMessage(notif);
	}

	if (m_spectrumSink) {
        m_spectrumSink->handleMessage(notif);
	}

	// pass data to listeners
	if (m_deviceSampleSink->getMessageQueueToGUI())
	{
        DSPSignalNotification* rep = new DSPSignalNotification(notif); // make a copy for the output queue
        m_deviceSampleSink->getMessageQueueToGUI()->push(rep);
	}

	return StReady;
}

DSPDeviceSinkEngine::State DSPDeviceSinkEngine::gotoRunning()
{
	qDebug() << "DSPDeviceSinkEngine::gotoRunning";

	switch(m_state)
    {
		case StNotStarted:
			return StNotStarted;

		case StIdle:
			return StIdle;

		case StRunning:
			return StRunning;

		case StReady:
		case StError:
			break;
	}

	if(m_deviceSampleSink == 0) {
		return gotoError("DSPDeviceSinkEngine::gotoRunning: No sample source configured");
	}

	qDebug() << "DSPDeviceSinkEngine::gotoRunning: " << m_deviceDescription.toStdString().c_str() << " started";

	// Start everything

	if(!m_deviceSampleSink->start())
	{
		return gotoError("DSPDeviceSinkEngine::gotoRunning: Could not start sample source");
	}

	for(BasebandSampleSources::const_iterator it = m_basebandSampleSources.begin(); it != m_basebandSampleSources.end(); it++)
	{
        qDebug() << "DSPDeviceSinkEngine::gotoRunning: starting " << (*it)->objectName().toStdString().c_str();
		(*it)->start();
	}

	for (ThreadedBasebandSampleSources::const_iterator it = m_threadedBasebandSampleSources.begin(); it != m_threadedBasebandSampleSources.end(); ++it)
	{
		qDebug() << "DSPDeviceSinkEngine::gotoRunning: starting ThreadedSampleSource(" << (*it)->getSampleSourceObjectName().toStdString().c_str() << ")";
		(*it)->start();
	}

	if (m_spectrumSink)
	{
        connect(m_deviceSampleSink->getSampleFifo(), SIGNAL(dataRead(int)), this, SLOT(handleForwardToSpectrumSink(int)));
        m_spectrumSink->start();
	}

	qDebug() << "DSPDeviceSinkEngine::gotoRunning: input message queue pending: " << m_inputMessageQueue.size();

	return StRunning;
}

DSPDeviceSinkEngine::State DSPDeviceSinkEngine::gotoError(const QString& errorMessage)
{
	qDebug() << "DSPDeviceSinkEngine::gotoError";

	m_errorMessage = errorMessage;
	m_deviceDescription.clear();
	m_state = StError;
	return StError;
}

void DSPDeviceSinkEngine::handleSetSink(DeviceSampleSink* sink)
{
	gotoIdle();

	m_deviceSampleSink = sink;

	if(m_deviceSampleSink != 0)
	{
		qDebug("DSPDeviceSinkEngine::handleSetSink: set %s", qPrintable(sink->getDeviceDescription()));
	}
	else
	{
		qDebug("DSPDeviceSinkEngine::handleSetSource: set none");
	}
}

void DSPDeviceSinkEngine::handleData(int nbSamples)
{
	if(m_state == StRunning)
	{
		work(nbSamples);
	}
}

void DSPDeviceSinkEngine::handleSynchronousMessages()
{
    Message *message = m_syncMessenger.getMessage();
	qDebug() << "DSPDeviceSinkEngine::handleSynchronousMessages: " << message->getIdentifier();

	if (DSPGenerationInit::match(*message))
	{
		m_state = gotoIdle();

		if(m_state == StIdle) {
			m_state = gotoInit(); // State goes ready if init is performed
		}
	}
	else if (DSPGenerationStart::match(*message))
	{
		if(m_state == StReady) {
			m_state = gotoRunning();
		}
	}
	else if (DSPGenerationStop::match(*message))
	{
		m_state = gotoIdle();
	}
	else if (DSPGetSinkDeviceDescription::match(*message))
	{
		((DSPGetSinkDeviceDescription*) message)->setDeviceDescription(m_deviceDescription);
	}
	else if (DSPGetErrorMessage::match(*message))
	{
		((DSPGetErrorMessage*) message)->setErrorMessage(m_errorMessage);
	}
	else if (DSPSetSink::match(*message)) {
		handleSetSink(((DSPSetSink*) message)->getSampleSink());
	}
	else if (DSPAddSpectrumSink::match(*message))
	{
		m_spectrumSink = ((DSPAddSpectrumSink*) message)->getSampleSink();
	}
	else if (DSPRemoveSpectrumSink::match(*message))
	{
		BasebandSampleSink* spectrumSink = ((DSPRemoveSpectrumSink*) message)->getSampleSink();

		if(m_state == StRunning) {
			spectrumSink->stop();
		}

		m_spectrumSink = 0;
	}
	else if (DSPAddBasebandSampleSource::match(*message))
	{
		BasebandSampleSource* source = ((DSPAddBasebandSampleSource*) message)->getSampleSource();
		m_basebandSampleSources.push_back(source);
        DSPSignalNotification notif(m_sampleRate, m_centerFrequency);
        source->handleMessage(notif);
		checkNumberOfBasebandSources();

        if (m_state == StRunning)
        {
            source->start();
        }
	}
	else if (DSPRemoveBasebandSampleSource::match(*message))
	{
		BasebandSampleSource* source = ((DSPRemoveBasebandSampleSource*) message)->getSampleSource();

		if(m_state == StRunning) {
			source->stop();
		}

		m_basebandSampleSources.remove(source);
		checkNumberOfBasebandSources();
	}
	else if (DSPAddThreadedBasebandSampleSource::match(*message))
	{
		ThreadedBasebandSampleSource *threadedSource = ((DSPAddThreadedBasebandSampleSource*) message)->getThreadedSampleSource();
		m_threadedBasebandSampleSources.push_back(threadedSource);
        DSPSignalNotification notif(m_sampleRate, m_centerFrequency);
        threadedSource->handleSourceMessage(notif);
		checkNumberOfBasebandSources();

        if (m_state == StRunning)
        {
            threadedSource->start();
        }
	}
	else if (DSPRemoveThreadedBasebandSampleSource::match(*message))
	{
		ThreadedBasebandSampleSource* threadedSource = ((DSPRemoveThreadedBasebandSampleSource*) message)->getThreadedSampleSource();
		if (m_state == StRunning) {
		    threadedSource->stop();
		}

		m_threadedBasebandSampleSources.remove(threadedSource);
		checkNumberOfBasebandSources();
	}

	m_syncMessenger.done(m_state);
}

void DSPDeviceSinkEngine::handleInputMessages()
{
	qDebug() << "DSPDeviceSinkEngine::handleInputMessages";

	Message* message;

	while ((message = m_inputMessageQueue.pop()) != 0)
	{
		qDebug("DSPDeviceSinkEngine::handleInputMessages: message: %s", message->getIdentifier());

		if (DSPSignalNotification::match(*message))
		{
			DSPSignalNotification *notif = (DSPSignalNotification *) message;

			// update DSP values

			m_sampleRate = notif->getSampleRate();
			m_centerFrequency = notif->getCenterFrequency();

			qDebug() << "DSPDeviceSinkEngine::handleInputMessages: DSPSignalNotification(" << m_sampleRate << "," << m_centerFrequency << ")";

            // forward source changes to sources with immediate execution

			for(BasebandSampleSources::const_iterator it = m_basebandSampleSources.begin(); it != m_basebandSampleSources.end(); it++)
			{
				qDebug() << "DSPDeviceSinkEngine::handleInputMessages: forward message to " << (*it)->objectName().toStdString().c_str();
				(*it)->handleMessage(*message);
			}

			for (ThreadedBasebandSampleSources::const_iterator it = m_threadedBasebandSampleSources.begin(); it != m_threadedBasebandSampleSources.end(); ++it)
			{
				qDebug() << "DSPDeviceSinkEngine::handleSourceMessages: forward message to ThreadedSampleSource(" << (*it)->getSampleSourceObjectName().toStdString().c_str() << ")";
				(*it)->handleSourceMessage(*message);
			}

			// forward changes to listeners on DSP output queue
			if (m_deviceSampleSink->getMessageQueueToGUI())
			{
                DSPSignalNotification* rep = new DSPSignalNotification(*notif); // make a copy for the output queue
                m_deviceSampleSink->getMessageQueueToGUI()->push(rep);
			}

			delete message;
		}
	}
}

void DSPDeviceSinkEngine::handleForwardToSpectrumSink(int nbSamples)
{
	if (m_spectrumSink)
	{
		SampleSourceFifo* sampleFifo = m_deviceSampleSink->getSampleFifo();
		SampleVector::iterator readUntil;
		sampleFifo->getReadIterator(readUntil);
		m_spectrumSink->feed(readUntil - nbSamples, readUntil, false);
	}
}

void DSPDeviceSinkEngine::checkNumberOfBasebandSources()
{
    SampleSourceFifo* sampleFifo = m_deviceSampleSink->getSampleFifo();

    // single channel source handling
    if ((m_threadedBasebandSampleSources.size() + m_basebandSampleSources.size()) == 1)
    {
        qDebug("DSPDeviceSinkEngine::checkNumberOfBasebandSources: single channel mode");
        disconnect(sampleFifo, SIGNAL(dataWrite(int)), this, SLOT(handleData(int)));

        if (m_threadedBasebandSampleSources.size() == 1) {
            m_threadedBasebandSampleSources.back()->setDeviceSampleSourceFifo(sampleFifo);
        } else if (m_basebandSampleSources.size() == 1) {
            m_threadedBasebandSampleSources.back()->setDeviceSampleSourceFifo(sampleFifo);
        }

        m_multipleSourcesDivisionFactor = 1; // for consistency but it is not used in this case
    }
    // null or multiple channel sources handling
    else
    {
        int nbSources = 0;

        for (ThreadedBasebandSampleSources::iterator it = m_threadedBasebandSampleSources.begin(); it != m_threadedBasebandSampleSources.end(); ++it)
        {
            (*it)->setDeviceSampleSourceFifo(0);
            nbSources++;
        }

        for (BasebandSampleSources::iterator it = m_basebandSampleSources.begin(); it != m_basebandSampleSources.end(); ++it)
        {
            (*it)->setDeviceSampleSourceFifo(0);
            nbSources++;
        }

        if (nbSources == 0) {
            m_multipleSourcesDivisionFactor = 1;
        } else if (nbSources < 3) {
            m_multipleSourcesDivisionFactor = nbSources;
        } else {
            m_multipleSourcesDivisionFactor = 1<<nbSources;
        }

        if (nbSources > 1) {
            connect(sampleFifo, SIGNAL(dataWrite(int)), this, SLOT(handleData(int)), Qt::QueuedConnection);
        }

        qDebug("DSPDeviceSinkEngine::checkNumberOfBasebandSources: handle %d channel(s)", nbSources);
    }
}