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

enum State {
    Done,
    Start,
    Play,
    Stop
};

class MainContentComponent : public AudioAppComponent,
                             public ChangeListener,
                             public Button::Listener {
public:
    MainContentComponent() : state(Done) {
        
        addAndMakeVisible(&openbtn);
        openbtn.setButtonText("Open");
        openbtn.addListener(this);
        
        addAndMakeVisible(&playbtn);
        playbtn.setButtonText("Play");
        playbtn.addListener(this);
        playbtn.setColour(TextButton::buttonColourId, Colours::green);
        
        playbtn.setEnabled(false);
        addAndMakeVisible (&stopbtn);
        stopbtn.setButtonText("Stop");
        stopbtn.addListener(this);
        stopbtn.setColour(TextButton::buttonColourId, Colours::red);
        stopbtn.setEnabled(false);
        
        formatManager.registerBasicFormats();
        transportSource.addChangeListener(this);
        
        setSize(300, 200);
        
        setAudioChannels(0, 2);
    }

    ~MainContentComponent() {
        shutdownAudio();
    }

    void changeListenerCallback(ChangeBroadcaster* source) override {
        if (source == &transportSource) {
            if (transportSource.isPlaying()) changeState(Play);
            else changeState(Done);
        }
    }
    
    void prepareToPlay(int s, double r) override {
         transportSource.prepareToPlay(s, r);
    }

    void getNextAudioBlock(const AudioSourceChannelInfo& buf) override {
        if (readerSource == nullptr) {
            buf.clearActiveBufferRegion();
            return;
        }
        
        transportSource.getNextAudioBlock(buf);
    }

    void releaseResources() override {
        transportSource.releaseResources();
    }

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

    void resized() override {
        openbtn.setBounds(10, 10, getWidth() - 20, 20);
        playbtn.setBounds(10, 40, getWidth() - 20, 20);
        stopbtn.setBounds (10, 70, getWidth() - 20, 20);
    }


private:
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MainContentComponent)
    TextButton openbtn;
    TextButton playbtn;
    TextButton stopbtn;
    AudioFormatManager formatManager;
    ScopedPointer<AudioFormatReaderSource> readerSource;
    AudioTransportSource transportSource;
    State state;
                                 
    void changeState(State news) {
        if (state == news) return;
        
        state = news;
            
        switch (state) {
            case Done:
                stopbtn.setEnabled(false);
                playbtn.setEnabled(true);
                transportSource.setPosition (0.0);
                break;

            case Start:
                playbtn.setEnabled (false);
                transportSource.start();
                break;

            case Play:
                stopbtn.setEnabled (true);
                break;
                                                 
            case Stop:
                transportSource.stop();
                break;
        }
    }

    void buttonClicked(Button* button) override {
        if (button == &openbtn) openClicked();
        if (button == &playbtn) playClicked();
        if (button == &stopbtn) stopClicked();
    }
                                 
    void openClicked() {
        FileChooser chooser ("Select a file", File::nonexistent, "*.wav");
        if (!chooser.browseForFileToOpen()) return;
        
        File file(chooser.getResult());
        AudioFormatReader* reader = formatManager.createReaderFor(file);
        
        if (reader == nullptr) return;
        
        ScopedPointer<AudioFormatReaderSource> news = new AudioFormatReaderSource(reader, true);
        transportSource.setSource(news, 0, nullptr, reader->sampleRate);
        playbtn.setEnabled(true);
        readerSource = news.release();
    }
                                 
    void playClicked() {
        changeState(Start);
    }
    
    void stopClicked() {
         changeState(Stop);
    }
};

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