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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

   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.

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

#include <JuceHeader.h>
#include "InternalPlugins.h"
#include "PluginGraph.h"

//==============================================================================
class InternalPlugin   : public AudioPluginInstance
{
protected:
    InternalPlugin (const PluginDescription& descr,
                    const AudioChannelSet& channelSetToUse = AudioChannelSet::stereo())
        : AudioPluginInstance (getBusProperties (descr.numInputChannels == 0, channelSetToUse)),
          name  (descr.fileOrIdentifier.upToFirstOccurrenceOf (":", false, false)),
          state (descr.fileOrIdentifier.fromFirstOccurrenceOf (":", false, false)),
          isGenerator (descr.numInputChannels == 0),
          hasMidi (descr.isInstrument),
          channelSet (channelSetToUse)
    {
        jassert (channelSetToUse.size() == descr.numOutputChannels);
    }

public:
    //==============================================================================
    const String getName() const override                     { return name; }
    double getTailLengthSeconds() const override              { return 0.0; }
    bool acceptsMidi() const override                         { return hasMidi; }
    bool producesMidi() const override                        { return hasMidi; }
    AudioProcessorEditor* createEditor() override             { return nullptr; }
    bool hasEditor() const override                           { return false; }
    int getNumPrograms() override                             { return 0; }
    int getCurrentProgram() override                          { return 0; }
    void setCurrentProgram (int) override                     {}
    const String getProgramName (int) override                { return {}; }
    void changeProgramName (int, const String&) override      {}
    void getStateInformation (juce::MemoryBlock&) override    {}
    void setStateInformation (const void*, int) override      {}

    //==============================================================================
    bool isBusesLayoutSupported (const BusesLayout& layout) const override
    {
        if (! isGenerator)
            if (layout.getMainOutputChannelSet() != channelSet)
                return false;

        if (layout.getMainInputChannelSet() != channelSet)
            return false;

        return true;
    }

    //==============================================================================
    void fillInPluginDescription (PluginDescription& description) const override
    {
        description = getPluginDescription (name + ":" + state,
                                            isGenerator,
                                            hasMidi,
                                            channelSet);
    }

    static PluginDescription getPluginDescription (const String& identifier,
                                                   bool registerAsGenerator,
                                                   bool acceptsMidi,
                                                   const AudioChannelSet& channelSetToUse
                                                      = AudioChannelSet::stereo())
    {
        PluginDescription descr;
        auto pluginName  = identifier.upToFirstOccurrenceOf (":", false, false);
        auto pluginState = identifier.fromFirstOccurrenceOf (":", false, false);

        descr.name              = pluginName;
        descr.descriptiveName   = pluginName;
        descr.pluginFormatName  = "Internal";
        descr.category          = (registerAsGenerator ? (acceptsMidi ? "Synth" : "Generator") : "Effect");
        descr.manufacturerName  = "JUCE";
        descr.version           = ProjectInfo::versionString;
        descr.fileOrIdentifier  = pluginName + ":" + pluginState;
        descr.uid               = pluginName.hashCode();
        descr.isInstrument      = (acceptsMidi && registerAsGenerator);
        descr.numInputChannels  = (registerAsGenerator ? 0 : channelSetToUse.size());
        descr.numOutputChannels = channelSetToUse.size();

        return descr;
    }
private:
    static BusesProperties getBusProperties (bool registerAsGenerator,
                                             const AudioChannelSet& channelSetToUse)
    {
        return registerAsGenerator ? BusesProperties().withOutput ("Output", channelSetToUse)
                                   : BusesProperties().withInput  ("Input",  channelSetToUse)
                                                      .withOutput ("Output", channelSetToUse);
    }

    //==============================================================================
    String name, state;
    bool isGenerator, hasMidi;
    AudioChannelSet channelSet;

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (InternalPlugin)
};

//==============================================================================
class SineWaveSynth :   public InternalPlugin
{
public:
    SineWaveSynth (const PluginDescription& descr)  : InternalPlugin (descr)
    {
        const int numVoices = 8;

        // Add some voices...
        for (int i = numVoices; --i >= 0;)
            synth.addVoice (new SineWaveVoice());

        // ..and give the synth a sound to play
        synth.addSound (new SineWaveSound());
    }

    static String getIdentifier()
    {
        return "Sine Wave Synth";
    }

    static PluginDescription getPluginDescription()
    {
        return InternalPlugin::getPluginDescription (getIdentifier(), true, true);
    }

    //==============================================================================
    void prepareToPlay (double newSampleRate, int) override
    {
        synth.setCurrentPlaybackSampleRate (newSampleRate);
    }

    void releaseResources() override {}

    //==============================================================================
    void processBlock (AudioBuffer<float>& buffer, MidiBuffer& midiMessages) override
    {
        const int numSamples = buffer.getNumSamples();

        buffer.clear();
        synth.renderNextBlock (buffer, midiMessages, 0, numSamples);
        buffer.applyGain (0.8f);
    }

    using InternalPlugin::processBlock;

private:
    //==============================================================================
    struct SineWaveSound  : public SynthesiserSound
    {
        SineWaveSound() = default;

        bool appliesToNote (int /*midiNoteNumber*/) override    { return true; }
        bool appliesToChannel (int /*midiChannel*/) override    { return true; }
    };

    struct SineWaveVoice  : public SynthesiserVoice
    {
        SineWaveVoice() = default;

        bool canPlaySound (SynthesiserSound* sound) override
        {
            return dynamic_cast<SineWaveSound*> (sound) != nullptr;
        }

        void startNote (int midiNoteNumber, float velocity,
                        SynthesiserSound* /*sound*/,
                        int /*currentPitchWheelPosition*/) override
        {
            currentAngle = 0.0;
            level = velocity * 0.15;
            tailOff = 0.0;

            double cyclesPerSecond = MidiMessage::getMidiNoteInHertz (midiNoteNumber);
            double cyclesPerSample = cyclesPerSecond / getSampleRate();

            angleDelta = cyclesPerSample * 2.0 * double_Pi;
        }

        void stopNote (float /*velocity*/, bool allowTailOff) override
        {
            if (allowTailOff)
            {
                // start a tail-off by setting this flag. The render callback will pick up on
                // this and do a fade out, calling clearCurrentNote() when it's finished.

                if (tailOff == 0.0) // we only need to begin a tail-off if it's not already doing so - the
                    // stopNote method could be called more than once.
                    tailOff = 1.0;
            }
            else
            {
                // we're being told to stop playing immediately, so reset everything..

                clearCurrentNote();
                angleDelta = 0.0;
            }
        }

        void pitchWheelMoved (int /*newValue*/) override
        {
            // not implemented for the purposes of this demo!
        }

        void controllerMoved (int /*controllerNumber*/, int /*newValue*/) override
        {
            // not implemented for the purposes of this demo!
        }

        void renderNextBlock (AudioBuffer<float>& outputBuffer, int startSample, int numSamples) override
        {
            if (angleDelta != 0.0)
            {
                if (tailOff > 0)
                {
                    while (--numSamples >= 0)
                    {
                        const float currentSample = (float) (sin (currentAngle) * level * tailOff);

                        for (int i = outputBuffer.getNumChannels(); --i >= 0;)
                            outputBuffer.addSample (i, startSample, currentSample);

                        currentAngle += angleDelta;
                        ++startSample;

                        tailOff *= 0.99;

                        if (tailOff <= 0.005)
                        {
                            // tells the synth that this voice has stopped
                            clearCurrentNote();

                            angleDelta = 0.0;
                            break;
                        }
                    }
                }
                else
                {
                    while (--numSamples >= 0)
                    {
                        const float currentSample = (float) (sin (currentAngle) * level);

                        for (int i = outputBuffer.getNumChannels(); --i >= 0;)
                            outputBuffer.addSample (i, startSample, currentSample);

                        currentAngle += angleDelta;
                        ++startSample;
                    }
                }
            }
        }

        using SynthesiserVoice::renderNextBlock;

    private:
        double currentAngle = 0, angleDelta = 0, level = 0, tailOff = 0;
    };

    //==============================================================================
    Synthesiser synth;

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (SineWaveSynth)
};

//==============================================================================
class ReverbPlugin    : public InternalPlugin
{
public:
    ReverbPlugin (const PluginDescription& descr) :   InternalPlugin (descr)
    {}

    static String getIdentifier()
    {
        return "Reverb";
    }

    static PluginDescription getPluginDescription()
    {
        return InternalPlugin::getPluginDescription (getIdentifier(), false, false);
    }

    void prepareToPlay (double newSampleRate, int) override
    {
        reverb.setSampleRate (newSampleRate);
    }

    void reset() override
    {
        reverb.reset();
    }

    void releaseResources() override {}

    void processBlock (AudioBuffer<float>& buffer, MidiBuffer&) override
    {
        auto numChannels = buffer.getNumChannels();

        if (numChannels == 1)
            reverb.processMono (buffer.getWritePointer (0), buffer.getNumSamples());
        else
            reverb.processStereo (buffer.getWritePointer (0),
                                  buffer.getWritePointer (1),
                                  buffer.getNumSamples());

        for (int ch = 2; ch < numChannels; ++ch)
            buffer.clear (ch, 0, buffer.getNumSamples());
    }

    using InternalPlugin::processBlock;

private:
    Reverb reverb;
};

//==============================================================================
InternalPluginFormat::InternalPluginFormat()
{
    {
        AudioProcessorGraph::AudioGraphIOProcessor p (AudioProcessorGraph::AudioGraphIOProcessor::audioOutputNode);
        p.fillInPluginDescription (audioOutDesc);
    }

    {
        AudioProcessorGraph::AudioGraphIOProcessor p (AudioProcessorGraph::AudioGraphIOProcessor::audioInputNode);
        p.fillInPluginDescription (audioInDesc);
    }

    {
        AudioProcessorGraph::AudioGraphIOProcessor p (AudioProcessorGraph::AudioGraphIOProcessor::midiInputNode);
        p.fillInPluginDescription (midiInDesc);
    }

    {
        AudioProcessorGraph::AudioGraphIOProcessor p (AudioProcessorGraph::AudioGraphIOProcessor::midiOutputNode);
        p.fillInPluginDescription (midiOutDesc);
    }
}

std::unique_ptr<AudioPluginInstance> InternalPluginFormat::createInstance (const String& name)
{
    if (name == audioOutDesc.name) return std::make_unique<AudioProcessorGraph::AudioGraphIOProcessor> (AudioProcessorGraph::AudioGraphIOProcessor::audioOutputNode);
    if (name == audioInDesc.name)  return std::make_unique<AudioProcessorGraph::AudioGraphIOProcessor> (AudioProcessorGraph::AudioGraphIOProcessor::audioInputNode);
    if (name == midiInDesc.name)   return std::make_unique<AudioProcessorGraph::AudioGraphIOProcessor> (AudioProcessorGraph::AudioGraphIOProcessor::midiInputNode);
    if (name == midiOutDesc.name)  return std::make_unique<AudioProcessorGraph::AudioGraphIOProcessor> (AudioProcessorGraph::AudioGraphIOProcessor::midiOutputNode);

    if (name == SineWaveSynth::getIdentifier()) return std::make_unique<SineWaveSynth> (SineWaveSynth::getPluginDescription());
    if (name == ReverbPlugin::getIdentifier())  return std::make_unique<ReverbPlugin>  (ReverbPlugin::getPluginDescription());

    return {};
}

void InternalPluginFormat::createPluginInstance (const PluginDescription& desc,
                                                 double /*initialSampleRate*/, int /*initialBufferSize*/,
                                                 PluginCreationCallback callback)
{
    if (auto p = createInstance (desc.name))
        callback (std::move (p), {});
    else
        callback (nullptr, NEEDS_TRANS ("Invalid internal plugin name"));
}

bool InternalPluginFormat::requiresUnblockedMessageThreadDuringCreation (const PluginDescription&) const
{
    return false;
}

void InternalPluginFormat::getAllTypes (Array<PluginDescription>& results)
{
    results.add (audioInDesc, audioOutDesc, midiInDesc, midiOutDesc,
                 SineWaveSynth::getPluginDescription(), ReverbPlugin::getPluginDescription());
}