#pragma once

#include "AudioBufferQueue.h"

//==============================================================================
template <typename SampleType>
class ScopeComponent : public juce::Component,
    private juce::Timer
{
public:
    using Queue = AudioBufferQueue<SampleType>;

    //==============================================================================
    ScopeComponent(Queue& queueToUse)
        : audioBufferQueue(queueToUse)
    {
        sampleData.fill(SampleType(0));
        setFramesPerSecond(30);
    }

    //==============================================================================
    void setFramesPerSecond(int framesPerSecond)
    {
        jassert(framesPerSecond > 0 && framesPerSecond < 1000);
        startTimerHz(framesPerSecond);
    }

    //==============================================================================
    void paint(juce::Graphics& g) override
    {
        g.fillAll(juce::Colours::black);
        g.setColour(juce::Colours::white);

        auto area = getLocalBounds();
        auto h = (SampleType)area.getHeight();
        auto w = (SampleType)area.getWidth();

        // Oscilloscope
        auto scopeRect = juce::Rectangle<SampleType>{ SampleType(0), SampleType(0), w, h / 2 };
        plot(sampleData.data(), sampleData.size(), g, scopeRect, SampleType(1), h / 4);

        // Spectrum
        auto spectrumRect = juce::Rectangle<SampleType>{ SampleType(0), h / 2, w, h / 2 };
        plot(spectrumData.data(), spectrumData.size() / 4, g, spectrumRect);
    }

    //==============================================================================
    void resized() override {}

private:
    //==============================================================================
    Queue& audioBufferQueue;
    std::array<SampleType, Queue::bufferSize> sampleData;

    juce::dsp::FFT fft{ Queue::order };
    using WindowFun = juce::dsp::WindowingFunction<SampleType>;
    WindowFun windowFun{ (size_t)fft.getSize(), WindowFun::hann };
    std::array<SampleType, 2 * Queue::bufferSize> spectrumData;

    //==============================================================================
    void timerCallback() override
    {
        audioBufferQueue.pop(sampleData.data());
        juce::FloatVectorOperations::copy(spectrumData.data(), sampleData.data(), (int)sampleData.size());

        auto fftSize = (size_t)fft.getSize();

        jassert(spectrumData.size() == 2 * fftSize);
        windowFun.multiplyWithWindowingTable(spectrumData.data(), fftSize);
        fft.performFrequencyOnlyForwardTransform(spectrumData.data());

        static constexpr auto mindB = SampleType(-160);
        static constexpr auto maxdB = SampleType(0);

        for (auto& s : spectrumData)
            s = juce::jmap(juce::jlimit(mindB, maxdB, juce::Decibels::gainToDecibels(s) - juce::Decibels::gainToDecibels(SampleType(fftSize))), mindB, maxdB, SampleType(0), SampleType(1));

        repaint();
    }

    //==============================================================================
    static void plot(const SampleType* data,
        size_t numSamples,
        juce::Graphics& g,
        juce::Rectangle<SampleType> rect,
        SampleType scaler = SampleType(1),
        SampleType offset = SampleType(0))
    {
        auto w = rect.getWidth();
        auto h = rect.getHeight();
        auto right = rect.getRight();

        auto center = rect.getBottom() - offset;
        auto gain = h * scaler;

        for (size_t i = 1; i < numSamples; ++i)
            g.drawLine({ juce::jmap(SampleType(i - 1), SampleType(0), SampleType(numSamples - 1), SampleType(right - w), SampleType(right)),
                          center - gain * data[i - 1],
                          juce::jmap(SampleType(i), SampleType(0), SampleType(numSamples - 1), SampleType(right - w), SampleType(right)),
                          center - gain * data[i] });
    }
};