///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2019-2020, 2022-2023 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
//                                                                               //
// 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_WFMDEMODSINK_H
#define INCLUDE_WFMDEMODSINK_H

#include <QVector>

#include "dsp/channelsamplesink.h"
#include "dsp/nco.h"
#include "dsp/interpolator.h"
#include "util/movingaverage.h"
#include "dsp/fftfilt.h"
#include "dsp/phasediscri.h"
#include "audio/audiofifo.h"

#include "wfmdemodsettings.h"

class ChannelAPI;

class WFMDemodSink : public ChannelSampleSink {
public:
    WFMDemodSink();
	~WFMDemodSink();

    virtual void feed(const SampleVector::const_iterator& begin, const SampleVector::const_iterator& end);

    double getMagSq() const { return m_movingAverage.asDouble(); }
    bool getSquelchOpen() const { return m_squelchOpen; }
    int getSquelchState() const { return m_squelchState; }

    void getMagSqLevels(double& avg, double& peak, int& nbSamples)
    {
        if (m_magsqCount > 0)
        {
            m_magsq = m_magsqSum / m_magsqCount;
            m_magSqLevelStore.m_magsq = m_magsq;
            m_magSqLevelStore.m_magsqPeak = m_magsqPeak;
        }

        avg = m_magSqLevelStore.m_magsq;
        peak = m_magSqLevelStore.m_magsqPeak;
        nbSamples = m_magsqCount == 0 ? 1 : m_magsqCount;

        m_magsqSum = 0.0f;
        m_magsqPeak = 0.0f;
        m_magsqCount = 0;
    }

    void applyChannelSettings(int channelSampleRate, int channelFrequencyOffset, bool force = false);
    void applySettings(const QStringList& settingsKeys, const WFMDemodSettings& settings, bool force = false);

    AudioFifo *getAudioFifo() { return &m_audioFifo; }
    void setAudioFifoLabel(const QString& label) { m_audioFifo.setLabel(label); }
    void applyAudioSampleRate(int sampleRate);
    int getAudioSampleRate() const { return m_audioSampleRate; }
    void setChannel(ChannelAPI *channel) { m_channel = channel; }

private:
    struct MagSqLevelsStore
    {
        MagSqLevelsStore() :
            m_magsq(1e-12),
            m_magsqPeak(1e-12)
        {}
        double m_magsq;
        double m_magsqPeak;
    };

	enum RateState {
		RSInitialFill,
		RSRunning
	};

    int m_channelSampleRate;
    int m_channelFrequencyOffset;
    WFMDemodSettings m_settings;
    ChannelAPI *m_channel;

    int m_audioSampleRate;

	NCO m_nco;
	Interpolator m_interpolator; //!< Interpolator between sample rate sent from DSP engine and requested RF bandwidth (rational)
	Real m_interpolatorDistance;
	Real m_interpolatorDistanceRemain;
	fftfilt* m_rfFilter;

	Real m_squelchLevel;
	int m_squelchState;
    bool m_squelchOpen;
    double m_magsq; //!< displayed averaged value
    double m_magsqSum;
    double m_magsqPeak;
    int  m_magsqCount;
    MagSqLevelsStore m_magSqLevelStore;

	MovingAverageUtil<Real, double, 16> m_movingAverage;
	Real m_fmExcursion;

	AudioVector m_audioBuffer;
	std::size_t m_audioBufferFill;

	AudioFifo m_audioFifo;
	PhaseDiscriminators m_phaseDiscri;

    QVector<qint16> m_demodBuffer;
    int m_demodBufferFill;

    static const unsigned int m_rfFilterFftLength;
};

#endif // INCLUDE_WFMDEMODSINK_H
