Source/Plugin/PluginBridgeProcessor.cpp

#include "PluginBridgeProcessor.h"
#include "PluginBridgeEditor.h"
#include "IPCProtocol.h"

#include "json.hpp"
using json = nlohmann::json;

PluginBridgeProcessor::PluginBridgeProcessor()
    : AudioProcessor(BusesProperties()
                         .withInput("Input", juce::AudioChannelSet::stereo(), true)
                         .withOutput("Output", juce::AudioChannelSet::stereo(), true)),
      mcpServer(PluginBridgeConstants::kDefaultMcpPort, helper)
{
    helper.onHelperCrashed = [this]()
    {
        pluginLoaded = false;
        pluginName.clear();
        pluginParamCount = 0;
        DBG("PluginBridgeProcessor: Helper crashed — plugin unloaded");
    };

    mcpServer.start();
}

PluginBridgeProcessor::~PluginBridgeProcessor()
{
    mcpServer.stop();
    helper.killHelper();
}

void PluginBridgeProcessor::prepareToPlay(double sampleRate, int samplesPerBlock)
{
    currentSampleRate = sampleRate;
    currentBlockSize = samplesPerBlock;

    if (helper.isHelperRunning())
    {
        json cmd = {{"cmd", "configure"},
                    {"sampleRate", sampleRate},
                    {"blockSize", samplesPerBlock},
                    {"channels", 2}};
        helper.sendCommand(cmd.dump());

        auto* header = helper.getSharedAudio().getHeader();
        if (header)
        {
            header->sampleRate.store((uint32_t)sampleRate);
            header->blockSize.store((uint32_t)samplesPerBlock);
            header->numChannels.store(2);
        }
    }
}

void PluginBridgeProcessor::releaseResources()
{
}

void PluginBridgeProcessor::processBlock(juce::AudioBuffer<float>& buffer, juce::MidiBuffer&)
{
    juce::ScopedNoDenormals noDenormals;

    auto totalNumInputChannels = getTotalNumInputChannels();
    auto totalNumOutputChannels = getTotalNumOutputChannels();
    for (auto i = totalNumInputChannels; i < totalNumOutputChannels; ++i)
        buffer.clear(i, 0, buffer.getNumSamples());

    if (!pluginLoaded || !helper.isHelperRunning())
        return;

    auto& shm = helper.getSharedAudio();
    if (!shm.isValid()) return;

    int numChannels = buffer.getNumChannels();
    int numSamples = buffer.getNumSamples();

    const float* inputPtrs[2] = {
        buffer.getReadPointer(0),
        numChannels > 1 ? buffer.getReadPointer(1) : buffer.getReadPointer(0)
    };
    shm.writeInput(inputPtrs, numChannels, numSamples);

    auto* header = shm.getHeader();
    header->blockSize.store((uint32_t)numSamples);
    header->numChannels.store((uint32_t)numChannels);
    header->state.store(kStateInputReady);

    helper.getInputSem().signal();

    if (helper.getOutputSem().wait(IPC::kProcessBlockTimeoutMs))
    {
        float* outputPtrs[2] = {
            buffer.getWritePointer(0),
            numChannels > 1 ? buffer.getWritePointer(1) : buffer.getWritePointer(0)
        };
        shm.readOutput(outputPtrs, numChannels, numSamples);
        header->state.store(kStateIdle);
    }
}

juce::AudioProcessorEditor* PluginBridgeProcessor::createEditor()
{
    return new PluginBridgeEditor(*this);
}

void PluginBridgeProcessor::getStateInformation(juce::MemoryBlock& destData)
{
    juce::ValueTree state("PluginBridgeState");
    state.setProperty("pluginPath", pluginPath, nullptr);

    if (pluginLoaded && helper.isHelperRunning())
    {
        auto response = helper.sendCommand("{\"cmd\":\"get_state\"}");
        try {
            auto j = json::parse(response);
            if (j.value("ok", false))
                state.setProperty("pluginState", juce::String(j["state"].get<std::string>()), nullptr);
        } catch (...) {}
    }

    juce::MemoryOutputStream stream(destData, false);
    state.writeToStream(stream);
}

void PluginBridgeProcessor::setStateInformation(const void* data, int sizeInBytes)
{
    auto state = juce::ValueTree::readFromData(data, (size_t)sizeInBytes);
    if (state.isValid())
    {
        auto path = state.getProperty("pluginPath").toString();
        if (path.isNotEmpty())
        {
            loadPlugin(path);

            auto pluginState = state.getProperty("pluginState").toString();
            if (pluginState.isNotEmpty() && helper.isHelperRunning())
            {
                json cmd = {{"cmd", "set_state"}, {"state", pluginState.toStdString()}};
                helper.sendCommand(cmd.dump());
            }
        }
    }
}

bool PluginBridgeProcessor::isMcpServerRunning() const
{
    return mcpServer.isRunning();
}

int PluginBridgeProcessor::getMcpServerPort() const
{
    return mcpServer.getPort();
}

void PluginBridgeProcessor::loadPlugin(const juce::String& path)
{
    if (!helper.isHelperRunning())
    {
        if (!helper.spawnHelper())
        {
            DBG("PluginBridgeProcessor: Failed to spawn helper");
            return;
        }

        json configCmd = {{"cmd", "configure"},
                          {"sampleRate", currentSampleRate},
                          {"blockSize", currentBlockSize},
                          {"channels", 2}};
        helper.sendCommand(configCmd.dump());
    }

    json loadCmd = {{"cmd", "load"},
                    {"path", path.toStdString()},
                    {"sampleRate", currentSampleRate},
                    {"blockSize", currentBlockSize}};

    auto response = helper.sendCommand(loadCmd.dump());

    try
    {
        auto j = json::parse(response);
        if (j.value("ok", false))
        {
            pluginLoaded = true;
            pluginName = juce::String(j["name"].get<std::string>());
            pluginParamCount = j.value("params", 0);
            pluginPath = path;
            DBG("PluginBridgeProcessor: Loaded " + pluginName + " (" + juce::String(pluginParamCount) + " params)");
        }
        else
        {
            pluginLoaded = false;
            DBG("PluginBridgeProcessor: Failed to load: " + juce::String(j.value("error", "unknown")));
        }
    }
    catch (...)
    {
        pluginLoaded = false;
    }
}

void PluginBridgeProcessor::unloadPlugin()
{
    if (helper.isHelperRunning())
        helper.sendCommand("{\"cmd\":\"unload\"}");

    pluginLoaded = false;
    pluginName.clear();
    pluginPath.clear();
    pluginParamCount = 0;
}

void PluginBridgeProcessor::showPluginGui()
{
    if (helper.isHelperRunning())
        helper.sendCommand("{\"cmd\":\"show_gui\"}");
}

void PluginBridgeProcessor::hidePluginGui()
{
    if (helper.isHelperRunning())
        helper.sendCommand("{\"cmd\":\"hide_gui\"}");
}

juce::Array<juce::File> PluginBridgeProcessor::getInstalledPluginFiles() const
{
    juce::Array<juce::File> results;

    juce::Array<juce::File> dirs = {
        juce::File("/Library/Audio/Plug-Ins/VST3"),
        juce::File::getSpecialLocation(juce::File::userHomeDirectory)
            .getChildFile("Library/Audio/Plug-Ins/VST3"),
        juce::File("/Library/Audio/Plug-Ins/Components"),
        juce::File::getSpecialLocation(juce::File::userHomeDirectory)
            .getChildFile("Library/Audio/Plug-Ins/Components")
    };

    for (auto& dir : dirs)
    {
        if (dir.isDirectory())
        {
            auto vst3s = dir.findChildFiles(juce::File::findDirectories, false, "*.vst3");
            auto aus = dir.findChildFiles(juce::File::findDirectories, false, "*.component");
            results.addArray(vst3s);
            results.addArray(aus);
        }
    }

    results.sort();
    return results;
}

juce::AudioProcessor* JUCE_CALLTYPE createPluginFilter()
{
    return new PluginBridgeProcessor();
}