#include "HelperPluginHost.h"
#include "Constants.h"
#include <juce_audio_basics/juce_audio_basics.h>
#include <pthread.h>
#include <sched.h>

#if JUCE_MAC
#include <objc/objc.h>
#include <objc/message.h>
#endif

// Force helper process to become a proper GUI app on macOS
static void makeGuiProcess()
{
#if JUCE_MAC
    // [NSApp setActivationPolicy:NSApplicationActivationPolicyRegular]
    id nsApp = ((id(*)(id, SEL))objc_msgSend)((id)objc_getClass("NSApplication"),
                                               sel_registerName("sharedApplication"));
    ((void(*)(id, SEL, long))objc_msgSend)(nsApp, sel_registerName("setActivationPolicy:"), 0); // 0 = Regular
    ((void(*)(id, SEL, int))objc_msgSend)(nsApp, sel_registerName("activateIgnoringOtherApps:"), 1);
#endif
}

// Custom window with working close button
class PluginGuiWindow : public juce::DocumentWindow
{
public:
    PluginGuiWindow(const juce::String& name)
        : DocumentWindow(name, juce::Colour(0xff1a1a2e), DocumentWindow::allButtons, true)
    {
        // Use JUCE's own title bar — works regardless of macOS activation policy
        setUsingNativeTitleBar(false);
        setTitleBarHeight(28);
    }

    void closeButtonPressed() override
    {
        setVisible(false);
    }
};

HelperPluginHost::HelperPluginHost()
{
    #if JUCE_PLUGINHOST_VST3
    formatManager.addFormat(new juce::VST3PluginFormat());
    #endif
    #if JUCE_PLUGINHOST_AU
    formatManager.addFormat(new juce::AudioUnitPluginFormat());
    #endif
}

HelperPluginHost::~HelperPluginHost()
{
    stopProcessing();
    hideGui();
    unloadPlugin();
}

bool HelperPluginHost::loadPlugin(const juce::String& path, double sampleRate, int blockSize)
{
    unloadPlugin();

    currentSampleRate = sampleRate;
    currentBlockSize = blockSize;

    juce::File pluginFile(path);
    if (!pluginFile.exists())
        return false;

    juce::OwnedArray<juce::PluginDescription> typesFound;

    for (int i = 0; i < formatManager.getNumFormats(); ++i)
    {
        auto* format = formatManager.getFormat(i);
        bool isVST3 = pluginFile.getFileExtension() == ".vst3";
        bool isAU = pluginFile.getFileExtension() == ".component";

        if (isVST3 && format->getName() != "VST3") continue;
        if (isAU && format->getName() != "AudioUnit") continue;

        format->findAllTypesForFile(typesFound, pluginFile.getFullPathName());
        if (typesFound.size() > 0)
            break;
    }

    if (typesFound.isEmpty())
        return false;

    juce::String errorMessage;
    plugin = formatManager.createPluginInstance(*typesFound[0], sampleRate, blockSize, errorMessage);

    if (plugin == nullptr)
    {
        DBG("HelperPluginHost: Failed to create plugin: " + errorMessage);
        return false;
    }

    plugin->enableAllBuses();

    auto layout = juce::AudioProcessor::BusesLayout();
    layout.inputBuses.add(juce::AudioChannelSet::stereo());
    layout.outputBuses.add(juce::AudioChannelSet::stereo());

    if (plugin->checkBusesLayoutSupported(layout))
        plugin->setBusesLayout(layout);

    plugin->prepareToPlay(sampleRate, blockSize);

    DBG("HelperPluginHost: Loaded " + getPluginName() + " (" + juce::String(getParameterCount()) + " params)");
    return true;
}

void HelperPluginHost::unloadPlugin()
{
    hideGui();
    if (plugin)
    {
        plugin->releaseResources();
        plugin.reset();
    }
}

juce::String HelperPluginHost::getPluginName() const
{
    return plugin ? plugin->getName() : juce::String();
}

int HelperPluginHost::getParameterCount() const
{
    return plugin ? plugin->getParameters().size() : 0;
}

void HelperPluginHost::setSharedAudio(SharedAudioBuffer* shm, SharedSemaphore* inSem, SharedSemaphore* outSem)
{
    sharedAudio = shm;
    inputSem = inSem;
    outputSem = outSem;
}

void HelperPluginHost::startProcessing()
{
    if (processing.load()) return;
    processing.store(true);
    audioThread = std::thread([this]() { audioProcessingLoop(); });
}

void HelperPluginHost::stopProcessing()
{
    processing.store(false);
    if (inputSem) inputSem->signal();
    if (audioThread.joinable())
        audioThread.join();
}

void HelperPluginHost::audioProcessingLoop()
{
    struct sched_param param;
    param.sched_priority = sched_get_priority_max(SCHED_FIFO);
    pthread_setschedparam(pthread_self(), SCHED_FIFO, &param);

    while (processing.load())
    {
        if (!inputSem->wait(100))
            continue;

        if (!processing.load()) break;
        if (!plugin || !sharedAudio) continue;

        auto* header = sharedAudio->getHeader();
        int numChannels = header->numChannels.load();
        int blockSize = header->blockSize.load();

        juce::AudioBuffer<float> buffer(numChannels, blockSize);
        float* channelPtrs[2] = { buffer.getWritePointer(0),
                                   numChannels > 1 ? buffer.getWritePointer(1) : nullptr };
        sharedAudio->readInput(channelPtrs, numChannels, blockSize);

        juce::MidiBuffer midi;
        plugin->processBlock(buffer, midi);

        const float* constPtrs[2] = { buffer.getReadPointer(0),
                                       numChannels > 1 ? buffer.getReadPointer(1) : nullptr };
        sharedAudio->writeOutput(constPtrs, numChannels, blockSize);

        header->state.store(kStateOutputReady);
        outputSem->signal();
    }
}

// --- Parameters ---

std::vector<HelperPluginHost::ParamInfo> HelperPluginHost::searchParams(const juce::String& keyword) const
{
    std::vector<ParamInfo> results;
    if (!plugin) return results;

    auto& params = plugin->getParameters();
    auto keywordLower = keyword.toLowerCase();

    for (int i = 0; i < params.size(); ++i)
    {
        auto* param = params[i];
        auto name = param->getName(128);

        if (name.toLowerCase().contains(keywordLower))
        {
            ParamInfo info;
            info.index = i;
            info.name = name;
            info.value = param->getValue();
            info.displayText = param->getText(param->getValue(), 64);

            if (auto* hosted = dynamic_cast<juce::AudioPluginInstance::HostedParameter*>(param))
                info.id = hosted->getParameterID();
            else
                info.id = juce::String(i);

            results.push_back(info);
            if (results.size() >= PluginBridgeConstants::kMaxParamResults)
                break;
        }
    }

    return results;
}

std::vector<std::pair<int, float>> HelperPluginHost::getParams(const std::vector<int>& ids) const
{
    std::vector<std::pair<int, float>> results;
    if (!plugin) return results;

    auto& params = plugin->getParameters();
    for (int idx : ids)
    {
        if (idx >= 0 && idx < params.size())
            results.push_back({idx, params[idx]->getValue()});
    }
    return results;
}

bool HelperPluginHost::setParams(const std::map<int, float>& values)
{
    if (!plugin) return false;

    auto& params = plugin->getParameters();
    for (auto& [idx, val] : values)
    {
        if (idx >= 0 && idx < params.size())
        {
            auto* param = params[idx];
            param->beginChangeGesture();
            param->setValueNotifyingHost(juce::jlimit(0.0f, 1.0f, val));
            param->endChangeGesture();
        }
    }
    return true;
}

// --- GUI ---

void HelperPluginHost::showGui()
{
    if (!plugin || !plugin->hasEditor()) return;

    juce::MessageManager::callAsync([this]()
    {
        if (!plugin) return;

        // Activate as GUI process (macOS requires this for window interaction)
        makeGuiProcess();

        // If window exists but hidden, just show it
        if (guiWindow)
        {
            guiWindow->setVisible(true);
            guiWindow->toFront(true);
            return;
        }

        auto* editor = plugin->createEditor();
        if (!editor) return;

        guiWindow = std::make_unique<PluginGuiWindow>(plugin->getName());
        guiWindow->setContentOwned(editor, true);
        guiWindow->setResizable(true, true);
        guiWindow->centreWithSize(editor->getWidth(), editor->getHeight() + 28); // +28 for title bar
        guiWindow->setVisible(true);
        guiWindow->toFront(true);
    });
}

void HelperPluginHost::hideGui()
{
    if (guiWindow)
    {
        juce::MessageManager::callAsync([this]()
        {
            guiWindow.reset();
        });
    }
}

// --- State ---

juce::String HelperPluginHost::getStateBase64() const
{
    if (!plugin) return {};

    juce::MemoryBlock stateData;
    plugin->getStateInformation(stateData);
    return stateData.toBase64Encoding();
}

bool HelperPluginHost::setStateBase64(const juce::String& base64State)
{
    if (!plugin) return false;

    juce::MemoryBlock stateData;
    if (!stateData.fromBase64Encoding(base64State))
        return false;

    plugin->setStateInformation(stateData.getData(), (int)stateData.getSize());
    return true;
}

void HelperPluginHost::configure(double sampleRate, int blockSize, int channels)
{
    currentSampleRate = sampleRate;
    currentBlockSize = blockSize;
    currentChannels = channels;

    if (plugin)
    {
        plugin->releaseResources();
        plugin->prepareToPlay(sampleRate, blockSize);
    }
}