/**********************************************************************

  Audacity: A Digital Audio Editor

  SoundTouchEffect.h

  Dominic Mazzoni, Vaughan Johnson

  This abstract class contains all of the common code for an
  effect that uses SoundTouch to do its processing (ChangeTempo
  and ChangePitch).

**********************************************************************/



#if USE_SOUNDTOUCH

#ifndef __AUDACITY_EFFECT_SOUNDTOUCH__
#define __AUDACITY_EFFECT_SOUNDTOUCH__

#include "StatefulEffect.h"

// forward declaration of a class defined in SoundTouch.h
// which is not included here
namespace soundtouch { class SoundTouch; }


class TimeWarper;
class LabelTrack;
class NoteTrack;
class WaveChannel;
class WaveTrack;

class EffectSoundTouch /* not final */ : public StatefulEffect
{
public:
   
   // EffectSoundTouch implementation

#ifdef USE_MIDI
   double mSemitones; // pitch change for NoteTracks
   EffectSoundTouch();
#endif
   ~EffectSoundTouch() override;

protected:
   // Effect implementation

   using InitFunction = std::function< void(soundtouch::SoundTouch *soundtouch) >;
   bool ProcessWithTimeWarper(InitFunction initer,
                              const TimeWarper &warper,
                              bool preserveLength);

private:
   bool ProcessLabelTrack(LabelTrack *track, const TimeWarper &warper);
#ifdef USE_MIDI
   bool ProcessNoteTrack(NoteTrack *track, const TimeWarper &warper);
#endif
   bool ProcessOne(soundtouch::SoundTouch *pSoundTouch,
      WaveChannel &orig, WaveTrack &out, sampleCount start, sampleCount end,
      const TimeWarper &warper);
   bool ProcessStereo(soundtouch::SoundTouch *pSoundTouch,
      WaveTrack &orig, WaveTrack &out,
      sampleCount start, sampleCount end,
      const TimeWarper &warper);
   bool ProcessStereoResults(soundtouch::SoundTouch *pSoundTouch,
      const size_t outputCount,
      WaveChannel &outputLeftTrack,
      WaveChannel &outputRightTrack);
   /*!
    @pre `out.NChannels() == orig.NChannels()`
    */
   void Finalize(WaveTrack &orig, WaveTrack &out, const TimeWarper &warper);

   bool   mPreserveLength;

   int    mCurTrackNum;

   double m_maxNewLength;
};

#endif

#endif
