#include "../JuceLibraryCode/JuceHeader.h"

class MainContentComponent : public AudioAppComponent,
                             public Slider::Listener {
public:
    MainContentComponent() : samplerate(0.0),
                             angle(0.0),
                             delta(0.0),
                             current(500.0),
                             target(current) {
        addAndMakeVisible(freqslider);
        freqslider.setRange(50.0, 5000.0);
        freqslider.setSkewFactorFromMidPoint(500.0);
        freqslider.setValue(current, dontSendNotification);
        freqslider.addListener(this);
        
        setSize(800, 600);

        setAudioChannels(0, 1);
    }

    ~MainContentComponent() {
        shutdownAudio();
    }

    void prepareToPlay (int, double sampleRate) override {
        samplerate = sampleRate;
        updateDelta();
    }
    
    void getNextAudioBlock(const AudioSourceChannelInfo& buf) override {
        const float level = 0.125f;
        float* const buffer = buf.buffer->getWritePointer(0, buf.startSample);
        const double lt = target;
        
        if (lt != current) {
            const double i = (lt - current) / buf.numSamples;
            
            for (int s = 0; s < buf.numSamples; ++s) {
                const float c = (float) std::sin (angle);
                current += i;
                updateDelta();
                angle += delta;
                buffer[s] = c * level;
            }
            
            current = lt;
        } else {
            for (int s = 0; s < buf.numSamples; ++s) {
                const float c = (float) std::sin (angle);
                angle += delta;
                buffer[s] = c* level;
            }
        }
    }
    
    void updateDelta() {
        const double c = freqslider.getValue() / samplerate;
        delta = c * 2.0 * double_Pi;
    }
                                 
    void sliderValueChanged(Slider* s) override {
        if (s == &freqslider) target = freqslider.getValue();
    }

    void releaseResources() override {}

    void paint (Graphics& g) override {
        g.fillAll (getLookAndFeel().findColour(ResizableWindow::backgroundColourId));
    }

    void resized() override{
        freqslider.setBounds(10, 10, getWidth() - 10, 20);
    }


private:
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MainContentComponent)
    
    double samplerate, angle, delta;
    double current, target;
    
    Slider freqslider;
};

Component* createMainContentComponent() { return new MainContentComponent(); }