/*
  ==============================================================================

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{
namespace dsp
{

//==============================================================================
template <typename SampleType, typename InterpolationType>
DelayLine<SampleType, InterpolationType>::DelayLine()
    : DelayLine (0)
{
}

template <typename SampleType, typename InterpolationType>
DelayLine<SampleType, InterpolationType>::DelayLine (int maximumDelayInSamples)
{
    jassert (maximumDelayInSamples >= 0);

    totalSize = jmax (4, maximumDelayInSamples + 1);
    sampleRate = 44100.0;
}

//==============================================================================
template <typename SampleType, typename InterpolationType>
void DelayLine<SampleType, InterpolationType>::setDelay (SampleType newDelayInSamples)
{
    auto upperLimit = (SampleType) (totalSize - 1);
    jassert (isPositiveAndNotGreaterThan (newDelayInSamples, upperLimit));

    delay     = jlimit ((SampleType) 0, upperLimit, newDelayInSamples);
    delayInt  = static_cast<int> (std::floor (delay));
    delayFrac = delay - (SampleType) delayInt;

    updateInternalVariables();
}

template <typename SampleType, typename InterpolationType>
SampleType DelayLine<SampleType, InterpolationType>::getDelay() const
{
    return delay;
}

//==============================================================================
template <typename SampleType, typename InterpolationType>
void DelayLine<SampleType, InterpolationType>::prepare (const ProcessSpec& spec)
{
    jassert (spec.numChannels > 0);

    bufferData.setSize ((int) spec.numChannels, totalSize, false, false, true);

    writePos.resize (spec.numChannels);
    readPos.resize  (spec.numChannels);

    v.resize (spec.numChannels);
    sampleRate = spec.sampleRate;

    reset();
}

template <typename SampleType, typename InterpolationType>
void DelayLine<SampleType, InterpolationType>::reset()
{
    for (auto vec : { &writePos, &readPos })
        std::fill (vec->begin(), vec->end(), 0);

    std::fill (v.begin(), v.end(), static_cast<SampleType> (0));

    bufferData.clear();
}

//==============================================================================
template <typename SampleType, typename InterpolationType>
void DelayLine<SampleType, InterpolationType>::pushSample (int channel, SampleType sample)
{
    bufferData.setSample (channel, writePos[(size_t) channel], sample);
    writePos[(size_t) channel] = (writePos[(size_t) channel] + totalSize - 1) % totalSize;
}

template <typename SampleType, typename InterpolationType>
SampleType DelayLine<SampleType, InterpolationType>::popSample (int channel, SampleType delayInSamples, bool updateReadPointer)
{
    if (delayInSamples >= 0)
        setDelay(delayInSamples);

    auto result = interpolateSample (channel);

    if (updateReadPointer)
        readPos[(size_t) channel] = (readPos[(size_t) channel] + totalSize - 1) % totalSize;

    return result;
}

//==============================================================================
template class DelayLine<float,  DelayLineInterpolationTypes::None>;
template class DelayLine<double, DelayLineInterpolationTypes::None>;
template class DelayLine<float,  DelayLineInterpolationTypes::Linear>;
template class DelayLine<double, DelayLineInterpolationTypes::Linear>;
template class DelayLine<float,  DelayLineInterpolationTypes::Lagrange3rd>;
template class DelayLine<double, DelayLineInterpolationTypes::Lagrange3rd>;
template class DelayLine<float,  DelayLineInterpolationTypes::Thiran>;
template class DelayLine<double, DelayLineInterpolationTypes::Thiran>;

} // namespace dsp
} // namespace juce