squeezelite-esp32/components/spotify/cspot/bell/main/audio-dsp/include/BellDSP.h

#pragma once

#include <memory>
#include <mutex>
#include <vector>
#include "AudioPipeline.h"
#include "CentralAudioBuffer.h"

namespace bell {
#define MAX_INT16 32767

class BellDSP {
 public:
  BellDSP(std::shared_ptr<CentralAudioBuffer> centralAudioBuffer);
  ~BellDSP() {};

  class AudioEffect {
   public:
    AudioEffect() = default;
    ~AudioEffect() = default;
    size_t duration;
    virtual void apply(float* sampleData, size_t samples, size_t relativePosition) = 0;
  };

  class FadeEffect: public AudioEffect {
  private:
    std::function<void()> onFinish;
    bool isFadeIn;
  public:
    FadeEffect(size_t duration, bool isFadeIn, std::function<void()> onFinish = nullptr);
    ~FadeEffect() {};

    void apply(float* sampleData, size_t samples, size_t relativePosition);
  };

  void applyPipeline(std::shared_ptr<AudioPipeline> pipeline);
  void queryInstantEffect(std::unique_ptr<AudioEffect> instantEffect);

  std::shared_ptr<AudioPipeline> getActivePipeline();

  size_t process(uint8_t* data, size_t bytes, int channels,
                 uint32_t sampleRate, BitWidth bitWidth);

 private:
  std::shared_ptr<AudioPipeline> activePipeline;
  std::shared_ptr<CentralAudioBuffer> buffer;
  std::mutex accessMutex;
  std::vector<float> dataLeft = std::vector<float>(1024);
  std::vector<float> dataRight = std::vector<float>(1024);


  std::unique_ptr<AudioEffect> underflowEffect = nullptr;
  std::unique_ptr<AudioEffect> startEffect = nullptr;
  std::unique_ptr<AudioEffect> instantEffect = nullptr;

  size_t samplesSinceInstantQueued;
};
};  // namespace bell