#include "amuse/EffectDelay.hpp"

#include <cmath>
#include <cstring>

#include "amuse/Common.hpp"
#include "amuse/IBackendVoice.hpp"

namespace amuse {

template <typename T>
EffectDelayImp<T>::EffectDelayImp(uint32_t initDelay, uint32_t initFeedback, uint32_t initOutput, double sampleRate) {
  initDelay = std::clamp(10u, initDelay, 5000u);
  initFeedback = std::clamp(0u, initFeedback, 100u);
  initOutput = std::clamp(0u, initOutput, 100u);

  for (int i = 0; i < 8; ++i) {
    x3c_delay[i] = initDelay;
    x48_feedback[i] = initFeedback;
    x54_output[i] = initOutput;
  }

  _setup(sampleRate);
}

template <typename T>
EffectDelayImp<T>::EffectDelayImp(const EffectDelayInfo& info, double sampleRate) {
  for (int i = 0; i < 8; ++i) {
    x3c_delay[i] = std::clamp(10u, info.delay[i], 5000u);
    x48_feedback[i] = std::clamp(0u, info.feedback[i], 100u);
    x54_output[i] = std::clamp(0u, info.output[i], 100u);
  }

  _setup(sampleRate);
}

template <typename T>
void EffectDelayImp<T>::_setup(double sampleRate) {
  m_sampsPerMs = std::ceil(sampleRate / 1000.0);
  m_blockSamples = m_sampsPerMs * 5;

  _update();
}

template <typename T>
void EffectDelayImp<T>::_update() {
  for (int i = 0; i < 8; ++i) {
    x0_currentSize[i] = ((x3c_delay[i] - 5) * m_sampsPerMs + 159) / 160;
    xc_currentPos[i] = 0;
    x18_currentFeedback[i] = x48_feedback[i] * 128 / 100;
    x24_currentOutput[i] = x54_output[i] * 128 / 100;

    x30_chanLines[i].reset(new T[m_blockSamples * x0_currentSize[i]]);
    memset(x30_chanLines[i].get(), 0, m_blockSamples * x0_currentSize[i] * sizeof(T));
  }

  m_dirty = false;
}

template <typename T>
void EffectDelayImp<T>::applyEffect(T* audio, size_t frameCount, const ChannelMap& chanMap) {
  if (m_dirty)
    _update();

  for (size_t f = 0; f < frameCount;) {
    for (unsigned c = 0; c < chanMap.m_channelCount; ++c) {
      T* chanAud = audio + c;
      for (unsigned i = 0; i < m_blockSamples && f < frameCount; ++i, ++f) {
        T& liveSamp = chanAud[chanMap.m_channelCount * i];
        T& samp = x30_chanLines[c][xc_currentPos[c] * m_blockSamples + i];
        samp = ClampFull<T>(samp * x18_currentFeedback[c] / 128 + liveSamp);
        liveSamp = samp * x24_currentOutput[c] / 128;
      }
      xc_currentPos[c] = (xc_currentPos[c] + 1) % x0_currentSize[c];
    }
    audio += chanMap.m_channelCount * m_blockSamples;
  }
}

template class EffectDelayImp<int16_t>;
template class EffectDelayImp<int32_t>;
template class EffectDelayImp<float>;
} // namespace amuse