#include "Mixer.hpp"
#include <cstdint>

template <uint32_t NumInputs>
Mixer<NumInputs>::Mixer(float initGain) : normalise_(false) {
  for (uint32_t i = 0; i < NumInputs; ++i) {
    gains_[i] = initGain;
  }
}

template <uint32_t NumInputs>
void Mixer<NumInputs>::process(const float **inputs, float *out,
                               uint32_t frames) {
  mixChannels(inputs, out, frames);
}

template <uint32_t NumInputs>
void Mixer<NumInputs>::processStereo(const float **inputsL,
                                     const float **inputsR, float *outL,
                                     float *outR, uint32_t frames) {
  mixChannels(inputsL, outL, frames);
  mixChannels(inputsR, outR, frames);
}

template <uint32_t NumInputs>
void Mixer<NumInputs>::mixChannels(const float **inputs, float *out,
                                   uint32_t frames) {
  float scale = normalise_ ? (1.0f / NumInputs) : 1.0f;
  for (uint32_t i = 0; i < frames; ++i) {
    float sum = 0.0f;
    for (uint32_t j = 0; j < NumInputs; ++j) {
      sum += inputs[j][i] * (gains_[j] * scale);
    }
    out[i] = sum;
  }
}

template <uint32_t NumInputs>
void Mixer<NumInputs>::setInputGain(uint32_t index, float gain) {
  if (isValidInputIndex(index)) {
    gains_[index] = gain;
  }
}

template <uint32_t NumInputs>
float Mixer<NumInputs>::getInputGain(uint32_t index) const {
  return isValidInputIndex(index) ? gains_[index] : 0;
}

template <uint32_t NumInputs> void Mixer<NumInputs>::setNormalise(bool norm) {
  normalise_ = norm;
}

template <uint32_t NumInputs> bool Mixer<NumInputs>::getNormalise() const {
  return normalise_;
}

template <uint32_t NumInputs>
bool Mixer<NumInputs>::isValidInputIndex(uint32_t index) const {
  return index < NumInputs;
}

template class Mixer<2u>;