///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2017 F4HKW                                                      //
// for F4EXB / SDRAngel                                                          //
//                                                                               //
// 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                  //
// (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 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/>.          //
///////////////////////////////////////////////////////////////////////////////////

#ifndef INCLUDE_ATVDEMOD_H
#define INCLUDE_ATVDEMOD_H

#include <QMutex>
#include <QElapsedTimer>
#include <vector>

#include "dsp/basebandsamplesink.h"
#include "channel/channelsinkapi.h"
#include "dsp/devicesamplesource.h"
#include "dsp/dspcommands.h"
#include "dsp/downchannelizer.h"
#include "dsp/nco.h"
#include "dsp/interpolator.h"
#include "util/movingaverage.h"
#include "dsp/fftfilt.h"
#include "dsp/agc.h"
#include "dsp/phaselock.h"
#include "dsp/recursivefilters.h"
#include "dsp/phasediscri.h"
#include "audio/audiofifo.h"
#include "util/message.h"
#include "gui/tvscreen.h"

class DeviceSourceAPI;
class ThreadedBasebandSampleSink;
class DownChannelizer;

class ATVDemod : public BasebandSampleSink, public ChannelSinkAPI
{
	Q_OBJECT

public:

    enum ATVStd
    {
        ATVStdPAL625,
        ATVStdPAL525,
        ATVStd405,
        ATVStdShortInterleaved,
        ATVStdShort,
        ATVStdHSkip
    };

	enum ATVModulation {
	    ATV_FM1,  //!< Classical frequency modulation with discriminator #1
	    ATV_FM2,  //!< Classical frequency modulation with discriminator #2
	    ATV_FM3,  //!< Classical frequency modulation with phase derivative discriminator
        ATV_AM,   //!< Classical amplitude modulation
        ATV_USB,  //!< AM with vestigial lower side band (main signal is in the upper side)
        ATV_LSB,  //!< AM with vestigial upper side band (main signal is in the lower side)
        ATV_NONE  //!< No modulation just produces zeros
	};

	struct ATVConfig
	{
	    int m_intSampleRate;
	    ATVStd m_enmATVStandard;
	    int m_intNumberOfLines;
	    float m_fltLineDuration;
	    float m_fltTopDuration;
	    float m_fltFramePerS;
	    float m_fltRatioOfRowsToDisplay;
	    float m_fltVoltLevelSynchroTop;
	    float m_fltVoltLevelSynchroBlack;
	    bool m_blnHSync;
	    bool m_blnVSync;
	    bool m_blnInvertVideo;
	    int m_intVideoTabIndex;

	    ATVConfig() :
	        m_intSampleRate(0),
	        m_enmATVStandard(ATVStdPAL625),
	        m_intNumberOfLines(625),
	        m_fltLineDuration(0.0f),
	        m_fltTopDuration(0.0f),
	        m_fltFramePerS(25.0f),
	        m_fltRatioOfRowsToDisplay(0.0f),
	        m_fltVoltLevelSynchroTop(0.0f),
	        m_fltVoltLevelSynchroBlack(1.0f),
	        m_blnHSync(false),
	        m_blnVSync(false),
	        m_blnInvertVideo(false),
			m_intVideoTabIndex(0)
	    {
	    }
	};

    struct ATVRFConfig
    {
	    int64_t       m_intFrequencyOffset;
        ATVModulation m_enmModulation;
        float         m_fltRFBandwidth;
        float         m_fltRFOppBandwidth;
        bool          m_blnFFTFiltering;
        bool          m_blndecimatorEnable;
        float         m_fltBFOFrequency;
        float         m_fmDeviation;

        ATVRFConfig() :
            m_intFrequencyOffset(0),
            m_enmModulation(ATV_FM1),
            m_fltRFBandwidth(0),
            m_fltRFOppBandwidth(0),
            m_blnFFTFiltering(false),
            m_blndecimatorEnable(false),
            m_fltBFOFrequency(0.0f),
            m_fmDeviation(1.0f)
        {
        }
    };

    class MsgConfigureChannelizer : public Message {
        MESSAGE_CLASS_DECLARATION

    public:
        int getCenterFrequency() const { return m_centerFrequency; }

        static MsgConfigureChannelizer* create(int centerFrequency)
        {
            return new MsgConfigureChannelizer(centerFrequency);
        }

    private:
        int m_centerFrequency;

        MsgConfigureChannelizer(int centerFrequency) :
            Message(),
            m_centerFrequency(centerFrequency)
        { }
    };

    class MsgReportEffectiveSampleRate : public Message
    {
        MESSAGE_CLASS_DECLARATION

    public:
        int getSampleRate() const { return m_sampleRate; }
        int getNbPointsPerLine() const { return m_nbPointsPerLine; }

        static MsgReportEffectiveSampleRate* create(int sampleRate, int nbPointsPerLine)
        {
            return new MsgReportEffectiveSampleRate(sampleRate, nbPointsPerLine);
        }

    protected:
        int m_sampleRate;
        int m_nbPointsPerLine;

        MsgReportEffectiveSampleRate(int sampleRate, int nbPointsPerLine) :
            Message(),
            m_sampleRate(sampleRate),
            m_nbPointsPerLine(nbPointsPerLine)
        { }
    };

    class MsgReportChannelSampleRateChanged : public Message {
        MESSAGE_CLASS_DECLARATION

    public:
        int getSampleRate() const { return m_sampleRate; }

        static MsgReportChannelSampleRateChanged* create(int sampleRate)
        {
            return new MsgReportChannelSampleRateChanged(sampleRate);
        }

    private:
        int m_sampleRate;

        MsgReportChannelSampleRateChanged(int sampleRate) :
            Message(),
            m_sampleRate(sampleRate)
        { }
    };

    ATVDemod(DeviceSourceAPI *deviceAPI);
	~ATVDemod();
	virtual void destroy() { delete this; }
	void setScopeSink(BasebandSampleSink* scopeSink) { m_scopeSink = scopeSink; }

    void configure(MessageQueue* objMessageQueue,
            float fltLineDurationUs,
            float fltTopDurationUs,
            float fltFramePerS,
            ATVStd enmATVStandard,
            int intNumberOfLines,
            float fltRatioOfRowsToDisplay,
            float fltVoltLevelSynchroTop,
            float fltVoltLevelSynchroBlack,
            bool blnHSync,
            bool blnVSync,
            bool blnInvertVideo,
			int intVideoTabIndex);

    void configureRF(MessageQueue* objMessageQueue,
            int64_t frequencyOffset,
            ATVModulation enmModulation,
            float fltRFBandwidth,
            float fltRFOppBandwidth,
            bool blnFFTFiltering,
            bool blndecimatorEnable,
            float fltBFOFrequency,
            float fmDeviation);

	virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end, bool po);
	virtual void start();
	virtual void stop();
	virtual bool handleMessage(const Message& cmd);

    virtual void getIdentifier(QString& id) { id = objectName(); }
    virtual void getTitle(QString& title) { title = objectName(); }
    virtual qint64 getCenterFrequency() const { return m_rfRunning.m_intFrequencyOffset; }

    virtual QByteArray serialize() const { return QByteArray(); }
    virtual bool deserialize(const QByteArray& data) { (void) data; return false; }

    void setTVScreen(TVScreen *objScreen); //!< set by the GUI
    int getSampleRate();
    int getEffectiveSampleRate();
    double getMagSq() const { return m_objMagSqAverage; } //!< Beware this is scaled to 2^30
    bool getBFOLocked();

    static const QString m_channelIdURI;
    static const QString m_channelId;

private slots:
    void channelSampleRateChanged();

private:
    struct ATVConfigPrivate
    {
        int m_intTVSampleRate;
        int m_intNumberSamplePerLine;

        ATVConfigPrivate() :
            m_intTVSampleRate(0),
            m_intNumberSamplePerLine(0)
        {}
    };

    class MsgConfigureATVDemod : public Message
    {
        MESSAGE_CLASS_DECLARATION

        public:
            static MsgConfigureATVDemod* create(
                    float fltLineDurationUs,
                    float fltTopDurationUs,
                    float fltFramePerS,
                    ATVStd enmATVStandard,
                    int intNumberOfLines,
                    float fltRatioOfRowsToDisplay,
                    float fltVoltLevelSynchroTop,
                    float fltVoltLevelSynchroBlack,
                    bool blnHSync,
                    bool blnVSync,
                    bool blnInvertVideo,
					int intVideoTabIndex)
            {
                return new MsgConfigureATVDemod(
                        fltLineDurationUs,
                        fltTopDurationUs,
                        fltFramePerS,
                        enmATVStandard,
                        intNumberOfLines,
                        fltRatioOfRowsToDisplay,
                        fltVoltLevelSynchroTop,
                        fltVoltLevelSynchroBlack,
                        blnHSync,
                        blnVSync,
                        blnInvertVideo,
						intVideoTabIndex);
            }

            ATVConfig m_objMsgConfig;

        private:
            MsgConfigureATVDemod(
                    float fltLineDurationUs,
                    float fltTopDurationUs,
                    float fltFramePerS,
                    ATVStd enmATVStandard,
                    int intNumberOfLines,
                    float flatRatioOfRowsToDisplay,
                    float fltVoltLevelSynchroTop,
                    float fltVoltLevelSynchroBlack,
                    bool blnHSync,
                    bool blnVSync,
                    bool blnInvertVideo,
					int intVideoTabIndex) :
                Message()
            {
                m_objMsgConfig.m_fltVoltLevelSynchroBlack = fltVoltLevelSynchroBlack;
                m_objMsgConfig.m_fltVoltLevelSynchroTop = fltVoltLevelSynchroTop;
                m_objMsgConfig.m_fltFramePerS = fltFramePerS;
                m_objMsgConfig.m_enmATVStandard = enmATVStandard;
                m_objMsgConfig.m_intNumberOfLines = intNumberOfLines;
                m_objMsgConfig.m_fltLineDuration = fltLineDurationUs;
                m_objMsgConfig.m_fltTopDuration = fltTopDurationUs;
                m_objMsgConfig.m_fltRatioOfRowsToDisplay = flatRatioOfRowsToDisplay;
                m_objMsgConfig.m_blnHSync = blnHSync;
                m_objMsgConfig.m_blnVSync = blnVSync;
                m_objMsgConfig.m_blnInvertVideo = blnInvertVideo;
                m_objMsgConfig.m_intVideoTabIndex = intVideoTabIndex;
            }
    };

    class MsgConfigureRFATVDemod : public Message
    {
        MESSAGE_CLASS_DECLARATION

        public:
            static MsgConfigureRFATVDemod* create(
                    int64_t frequencyOffset,
                    ATVModulation enmModulation,
                    float fltRFBandwidth,
                    float fltRFOppBandwidth,
                    bool blnFFTFiltering,
                    bool blndecimatorEnable,
                    int intBFOFrequency,
                    float fmDeviation)
            {
                return new MsgConfigureRFATVDemod(
                        frequencyOffset,
                        enmModulation,
                        fltRFBandwidth,
                        fltRFOppBandwidth,
                        blnFFTFiltering,
                        blndecimatorEnable,
                        intBFOFrequency,
                        fmDeviation);
            }

            ATVRFConfig m_objMsgConfig;

        private:
            MsgConfigureRFATVDemod(
                    int64_t frequencyOffset,
                    ATVModulation enmModulation,
                    float fltRFBandwidth,
                    float fltRFOppBandwidth,
                    bool blnFFTFiltering,
                    bool blndecimatorEnable,
                    float fltBFOFrequency,
                    float fmDeviation) :
                Message()
            {
                m_objMsgConfig.m_intFrequencyOffset = frequencyOffset;
                m_objMsgConfig.m_enmModulation = enmModulation;
                m_objMsgConfig.m_fltRFBandwidth = fltRFBandwidth;
                m_objMsgConfig.m_fltRFOppBandwidth = fltRFOppBandwidth;
                m_objMsgConfig.m_blnFFTFiltering = blnFFTFiltering;
                m_objMsgConfig.m_blndecimatorEnable = blndecimatorEnable;
                m_objMsgConfig.m_fltBFOFrequency = fltBFOFrequency;
                m_objMsgConfig.m_fmDeviation = fmDeviation;
            }
    };

    /**
     * Exponential average using integers and alpha as the inverse of a power of two
     */
    class AvgExpInt
    {
    public:
        AvgExpInt(int log2Alpha) : m_log2Alpha(log2Alpha), m_m1(0), m_start(true) {}
        void reset() { m_start = true; }

        int run(int m0)
        {
            if (m_start)
            {
                m_m1 = m0;
                m_start = false;
                return m0;
            }
            else
            {
                m_m1 = m0 + m_m1 - (m_m1>>m_log2Alpha);
                return m_m1>>m_log2Alpha;
            }
        }

    private:
        int m_log2Alpha;
        int m_m1;
        bool m_start;
    };

    DeviceSourceAPI* m_deviceAPI;
    ThreadedBasebandSampleSink* m_threadedChannelizer;
    DownChannelizer* m_channelizer;

    //*************** SCOPE  ***************

    BasebandSampleSink* m_scopeSink;
    SampleVector m_scopeSampleBuffer;

    //*************** ATV PARAMETERS  ***************
    TVScreen *m_registeredTVScreen;

    //int m_intNumberSamplePerLine;
    int m_intNumberSamplePerTop;
    int m_intNumberOfLines;
    int m_intNumberOfSyncLines;          //!< this is the number of non displayable lines at the start of a frame. First displayable row comes next.
    int m_intNumberOfBlackLines;         //!< this is the total number of lines not part of the image and is used for vertical screen size
    int m_intNumberOfEqLines;            //!< number of equalizing lines both whole and partial
    int m_intNumberSamplePerLineSignals; //!< number of samples in the non image part of the line (signals)
    int m_intNumberSaplesPerHSync;       //!< number of samples per horizontal synchronization pattern (pulse + back porch)
    bool m_interleaved;                  //!< interleaved image

    //*************** PROCESSING  ***************

    int m_intImageIndex;
    int m_intSynchroPoints;

    bool m_blnSynchroDetected;
    bool m_blnVerticalSynchroDetected;

    float m_fltAmpLineAverage;

    float m_fltEffMin;
    float m_fltEffMax;

    float m_fltAmpMin;
    float m_fltAmpMax;
    float m_fltAmpDelta;

    float m_fltBufferI[6];
    float m_fltBufferQ[6];

    int m_intColIndex;
    int m_intSampleIndex;
    int m_intRowIndex;
    int m_intLineIndex;

    AvgExpInt m_objAvgColIndex;
    int m_intAvgColIndex;

    SampleVector m_sampleBuffer;

    //*************** RF  ***************

    MovingAverageUtil<double, double, 32> m_objMagSqAverage;

    NCO m_nco;
    SimplePhaseLock m_bfoPLL;
    SecondOrderRecursiveFilter m_bfoFilter;

    // Interpolator group for decimation and/or double sideband RF filtering
    Interpolator m_interpolator;
    Real m_interpolatorDistance;
    Real m_interpolatorDistanceRemain;

    // Used for vestigial SSB with asymmetrical filtering (needs double sideband scheme)
    fftfilt* m_DSBFilter;
    Complex* m_DSBFilterBuffer;
    int m_DSBFilterBufferIndex;
    static const int m_ssbFftLen;

    // Used for FM
    PhaseDiscriminators m_objPhaseDiscri;

    //QElapsedTimer m_objTimer;

    ATVConfig m_running;
    ATVConfig m_config;

    ATVRFConfig m_rfRunning;
    ATVRFConfig m_rfConfig;

    ATVConfigPrivate m_runningPrivate;
    ATVConfigPrivate m_configPrivate;

    QMutex m_objSettingsMutex;

    void applySettings();
    void applyStandard();
    void demod(Complex& c);
    static float getRFBandwidthDivisor(ATVModulation modulation);

    inline void processHSkip(float& fltVal, int& intVal)
    {
        m_registeredTVScreen->setDataColor(m_intColIndex - m_intNumberSaplesPerHSync + m_intNumberSamplePerTop, intVal, intVal, intVal);

        // Horizontal Synchro detection

        // Floor Detection 0
        if (fltVal < m_running.m_fltVoltLevelSynchroTop)
        {
            m_intSynchroPoints++;
        }
        // Black detection 0.3
        else if (fltVal > m_running.m_fltVoltLevelSynchroBlack)
        {
            m_intSynchroPoints = 0;
        }

        // sync pulse

        m_blnSynchroDetected = (m_intSynchroPoints == m_intNumberSamplePerTop);

        if (m_blnSynchroDetected)
        {
            if (m_intSampleIndex >= (3 * m_runningPrivate.m_intNumberSamplePerLine)/2) // first after skip
            {
                //qDebug("VSync: %d %d %d", m_intColIndex, m_intSampleIndex, m_intLineIndex);
                m_intAvgColIndex = m_intColIndex;
                m_registeredTVScreen->renderImage(0);

                m_intImageIndex++;
                m_intLineIndex = 0;
                m_intRowIndex = 0;
            }

            m_intSampleIndex = 0;
        }
        else
        {
            m_intSampleIndex++;
        }

        if (m_intColIndex < m_runningPrivate.m_intNumberSamplePerLine + m_intNumberSamplePerTop - 1)
        {
            m_intColIndex++;
        }
        else
        {
            if (m_running.m_blnHSync && (m_intLineIndex == 0))
            {
                //qDebug("HCorr: %d", m_intAvgColIndex);
                m_intColIndex = m_intNumberSamplePerTop + (m_runningPrivate.m_intNumberSamplePerLine - m_intAvgColIndex)/2; // amortizing factor 1/2
            }
            else
            {
                m_intColIndex = m_intNumberSamplePerTop;
            }

            if ((m_rfRunning.m_enmModulation == ATV_AM)
                || (m_rfRunning.m_enmModulation == ATV_USB)
                || (m_rfRunning.m_enmModulation == ATV_LSB))
            {
                m_fltAmpMin = m_fltEffMin;
                m_fltAmpMax = m_fltEffMax;
                m_fltAmpDelta = m_fltEffMax-m_fltEffMin;

                if(m_fltAmpDelta<=0.0)
                {
                    m_fltAmpDelta=1.0f;
                }

                //Reset extrema
                m_fltEffMin = 2000000.0f;
                m_fltEffMax = -2000000.0f;
            }

            m_registeredTVScreen->selectRow(m_intRowIndex);
            m_intLineIndex++;
            m_intRowIndex++;
        }
    }

    inline void processClassic(float& fltVal, int& intVal)
    {
        int intSynchroTimeSamples= (3 * m_runningPrivate.m_intNumberSamplePerLine)/4;
        float fltSynchroTrameLevel =  0.5f*((float)intSynchroTimeSamples) * m_running.m_fltVoltLevelSynchroBlack;

        // Horizontal Synchro detection

        // Floor Detection 0
        if (fltVal < m_running.m_fltVoltLevelSynchroTop)
        {
            m_intSynchroPoints++;
        }
        // Black detection 0.3
        else if (fltVal > m_running.m_fltVoltLevelSynchroBlack)
        {
            m_intSynchroPoints = 0;
        }

        m_blnSynchroDetected = (m_intSynchroPoints == m_intNumberSamplePerTop);

        //Horizontal Synchro processing

        bool blnNewLine = false;

        if (m_blnSynchroDetected)
        {
            m_intAvgColIndex = m_intSampleIndex - m_intColIndex - (m_intColIndex < m_runningPrivate.m_intNumberSamplePerLine/2 ? 150 : 0);
            //qDebug("HSync: %d %d %d", m_intSampleIndex, m_intColIndex, m_intAvgColIndex);
            m_intSampleIndex = 0;
        }
        else
        {
            m_intSampleIndex++;
        }

        if (!m_running.m_blnHSync && (m_intColIndex >= m_runningPrivate.m_intNumberSamplePerLine)) // H Sync not active
        {
            m_intColIndex = 0;
            blnNewLine = true;
        }
        else if (m_intColIndex >= m_runningPrivate.m_intNumberSamplePerLine + m_intNumberSamplePerTop) // No valid H sync
        {
            if (m_running.m_blnHSync && (m_intLineIndex == 0))
            {
                //qDebug("HSync: %d %d", m_intColIndex, m_intAvgColIndex);
                m_intColIndex = m_intNumberSamplePerTop + m_intAvgColIndex/4; // amortizing 1/4
            }
            else
            {
                m_intColIndex = m_intNumberSamplePerTop;
            }

            blnNewLine = true;
        }

        if (blnNewLine)
        {
            if ((m_rfRunning.m_enmModulation == ATV_AM)
                || (m_rfRunning.m_enmModulation == ATV_USB)
                || (m_rfRunning.m_enmModulation == ATV_LSB))
            {
                m_fltAmpMin = m_fltEffMin;
                m_fltAmpMax = m_fltEffMax;
                m_fltAmpDelta = m_fltEffMax-m_fltEffMin;

                if(m_fltAmpDelta<=0.0)
                {
                    m_fltAmpDelta=1.0f;
                }

                //Reset extrema
                m_fltEffMin = 2000000.0f;
                m_fltEffMax = -2000000.0f;
            }

            m_fltAmpLineAverage=0.0f;

            //New line + Interleaving
            m_intRowIndex += m_interleaved ? 2 : 1;

            if (m_intRowIndex < m_intNumberOfLines)
            {
                m_registeredTVScreen->selectRow(m_intRowIndex - m_intNumberOfSyncLines);
            }

            m_intLineIndex++;
        }

        // Filling pixels

        // +4 is to compensate shift due to hsync amortizing factor of 1/4
        m_registeredTVScreen->setDataColor(m_intColIndex - m_intNumberSaplesPerHSync + m_intNumberSamplePerTop + 4, intVal, intVal, intVal);
        m_intColIndex++;

        // Vertical sync and image rendering

        if ((m_running.m_blnVSync) && (m_intLineIndex < m_intNumberOfLines)) // VSync activated and lines in range
        {
            if (m_intColIndex >= intSynchroTimeSamples)
            {
                if (m_fltAmpLineAverage <= fltSynchroTrameLevel)
                {
                    m_fltAmpLineAverage = 0.0f;

                    if (!m_blnVerticalSynchroDetected) // not yet
                    {
                        m_blnVerticalSynchroDetected = true; // prevent repetition

                        if ((m_intLineIndex % 2 == 0) || !m_interleaved) // even => odd image
                        {
                            m_registeredTVScreen->renderImage(0);
                            m_intRowIndex = 1;
                        }
                        else
                        {
                            m_intRowIndex = 0;
                        }

                        m_registeredTVScreen->selectRow(m_intRowIndex - m_intNumberOfSyncLines);
                        m_intLineIndex = 0;
                        m_intImageIndex++;
                    }
                }
                else
                {
                    m_blnVerticalSynchroDetected = false; // reset
                }
            }
        }
        else // no VSync or lines out of range => arbitrary
        {
            if (m_intLineIndex >= m_intNumberOfLines/2)
            {
                if (m_intImageIndex % 2 == 1) // odd image
                {
                    m_registeredTVScreen->renderImage(0);

                    if (m_rfRunning.m_enmModulation == ATV_AM)
                    {
                        m_fltAmpMin = m_fltEffMin;
                        m_fltAmpMax = m_fltEffMax;
                        m_fltAmpDelta = m_fltEffMax-m_fltEffMin;

                        if(m_fltAmpDelta<=0.0)
                        {
                            m_fltAmpDelta=1.0f;
                        }

                        //Reset extrema
                        m_fltEffMin = 2000000.0f;
                        m_fltEffMax = -2000000.0f;
                    }

                    m_intRowIndex = 1;
                }
                else
                {
                    m_intRowIndex = 0;
                }

                m_registeredTVScreen->selectRow(m_intRowIndex - m_intNumberOfSyncLines);
                m_intLineIndex = 0;
                m_intImageIndex++;
            }
        }
    }
};

#endif // INCLUDE_ATVDEMOD_H