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

   This file is part of the JUCE 7 technical preview.
   Copyright (c) 2022 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For the technical preview this file cannot be licensed commercially.

   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 "UI/MainHostWindow.h"
#include "Plugins/InternalPlugins.h"

#if ! (JUCE_PLUGINHOST_VST || JUCE_PLUGINHOST_VST3 || JUCE_PLUGINHOST_AU)
 #error "If you're building the audio plugin host, you probably want to enable VST and/or AU support"
#endif

class PluginScannerSubprocess : private ChildProcessWorker,
                                private AsyncUpdater
{
public:
    using ChildProcessWorker::initialiseFromCommandLine;

private:
    void handleMessageFromCoordinator (const MemoryBlock& mb) override
    {
        if (mb.isEmpty())
            return;

        if (! doScan (mb))
        {
            {
                const std::lock_guard<std::mutex> lock (mutex);
                pendingBlocks.emplace (mb);
            }

            triggerAsyncUpdate();
        }
    }

    void handleConnectionLost() override
    {
        JUCEApplicationBase::quit();
    }

    void handleAsyncUpdate() override
    {
        for (;;)
        {
            const auto block = [&]() -> MemoryBlock
            {
                const std::lock_guard<std::mutex> lock (mutex);

                if (pendingBlocks.empty())
                    return {};

                auto out = std::move (pendingBlocks.front());
                pendingBlocks.pop();
                return out;
            }();

            if (block.isEmpty())
                return;

            doScan (block);
        }
    }

    bool doScan (const MemoryBlock& block)
    {
        AudioPluginFormatManager formatManager;
        formatManager.addDefaultFormats();

        MemoryInputStream stream { block, false };
        const auto formatName = stream.readString();
        const auto identifier = stream.readString();

        PluginDescription pd;
        pd.fileOrIdentifier = identifier;
        pd.uniqueId = pd.deprecatedUid = 0;

        const auto matchingFormat = [&]() -> AudioPluginFormat*
        {
            for (auto* format : formatManager.getFormats())
                if (format->getName() == formatName)
                    return format;

            return nullptr;
        }();

        if (matchingFormat == nullptr
            || (! MessageManager::getInstance()->isThisTheMessageThread()
                && ! matchingFormat->requiresUnblockedMessageThreadDuringCreation (pd)))
        {
            return false;
        }

        OwnedArray<PluginDescription> results;
        matchingFormat->findAllTypesForFile (results, identifier);
        sendPluginDescriptions (results);
        return true;
    }

    void sendPluginDescriptions (const OwnedArray<PluginDescription>& results)
    {
        XmlElement xml ("LIST");

        for (const auto& desc : results)
            xml.addChildElement (desc->createXml().release());

        const auto str = xml.toString();
        sendMessageToCoordinator ({ str.toRawUTF8(), str.getNumBytesAsUTF8() });
    }

    std::mutex mutex;
    std::queue<MemoryBlock> pendingBlocks;
};

//==============================================================================
class PluginHostApp  : public JUCEApplication,
                       private AsyncUpdater
{
public:
    PluginHostApp() = default;

    void initialise (const String& commandLine) override
    {
        auto scannerSubprocess = std::make_unique<PluginScannerSubprocess>();

        if (scannerSubprocess->initialiseFromCommandLine (commandLine, processUID))
        {
            storedScannerSubprocess = std::move (scannerSubprocess);
            return;
        }

        // initialise our settings file..

        PropertiesFile::Options options;
        options.applicationName     = "Juce Audio Plugin Host";
        options.filenameSuffix      = "settings";
        options.osxLibrarySubFolder = "Preferences";

        appProperties.reset (new ApplicationProperties());
        appProperties->setStorageParameters (options);

        mainWindow.reset (new MainHostWindow());

        commandManager.registerAllCommandsForTarget (this);
        commandManager.registerAllCommandsForTarget (mainWindow.get());

        mainWindow->menuItemsChanged();

        // Important note! We're going to use an async update here so that if we need
        // to re-open a file and instantiate some plugins, it will happen AFTER this
        // initialisation method has returned.
        // On Windows this probably won't make a difference, but on OSX there's a subtle event loop
        // issue that can happen if a plugin runs one of those irritating modal dialogs while it's
        // being loaded. If that happens inside this method, the OSX event loop seems to be in some
        // kind of special "initialisation" mode and things get confused. But if we load the plugin
        // later when the normal event loop is running, everything's fine.
        triggerAsyncUpdate();
    }

    void handleAsyncUpdate() override
    {
        File fileToOpen;

       #if JUCE_ANDROID || JUCE_IOS
        fileToOpen = PluginGraph::getDefaultGraphDocumentOnMobile();
       #else
        for (int i = 0; i < getCommandLineParameterArray().size(); ++i)
        {
            fileToOpen = File::getCurrentWorkingDirectory().getChildFile (getCommandLineParameterArray()[i]);

            if (fileToOpen.existsAsFile())
                break;
        }
       #endif

        if (! fileToOpen.existsAsFile())
        {
            RecentlyOpenedFilesList recentFiles;
            recentFiles.restoreFromString (getAppProperties().getUserSettings()->getValue ("recentFilterGraphFiles"));

            if (recentFiles.getNumFiles() > 0)
                fileToOpen = recentFiles.getFile (0);
        }

        if (fileToOpen.existsAsFile())
            if (auto* graph = mainWindow->graphHolder.get())
                if (auto* ioGraph = graph->graph.get())
                    ioGraph->loadFrom (fileToOpen, true);
    }

    void shutdown() override
    {
        mainWindow = nullptr;
        appProperties = nullptr;
        LookAndFeel::setDefaultLookAndFeel (nullptr);
    }

    void suspended() override
    {
       #if JUCE_ANDROID || JUCE_IOS
        if (auto graph = mainWindow->graphHolder.get())
            if (auto ioGraph = graph->graph.get())
                ioGraph->saveDocument (PluginGraph::getDefaultGraphDocumentOnMobile());
       #endif
    }

    void systemRequestedQuit() override
    {
        if (mainWindow != nullptr)
            mainWindow->tryToQuitApplication();
        else
            JUCEApplicationBase::quit();
    }

    bool backButtonPressed() override
    {
        if (mainWindow->graphHolder != nullptr)
            mainWindow->graphHolder->hideLastSidePanel();

        return true;
    }

    const String getApplicationName() override       { return "Juce Plug-In Host"; }
    const String getApplicationVersion() override    { return ProjectInfo::versionString; }
    bool moreThanOneInstanceAllowed() override       { return true; }

    ApplicationCommandManager commandManager;
    std::unique_ptr<ApplicationProperties> appProperties;

private:
    std::unique_ptr<MainHostWindow> mainWindow;
    std::unique_ptr<PluginScannerSubprocess> storedScannerSubprocess;
};

static PluginHostApp& getApp()                    { return *dynamic_cast<PluginHostApp*>(JUCEApplication::getInstance()); }

ApplicationProperties& getAppProperties()         { return *getApp().appProperties; }
ApplicationCommandManager& getCommandManager()    { return getApp().commandManager; }

bool isOnTouchDevice()
{
    static bool isTouch = Desktop::getInstance().getMainMouseSource().isTouch();
    return isTouch;
}

//==============================================================================
static AutoScale autoScaleFromString (StringRef str)
{
    if (str.isEmpty())                     return AutoScale::useDefault;
    if (str == CharPointer_ASCII { "0" })  return AutoScale::scaled;
    if (str == CharPointer_ASCII { "1" })  return AutoScale::unscaled;

    jassertfalse;
    return AutoScale::useDefault;
}

static const char* autoScaleToString (AutoScale autoScale)
{
    if (autoScale == AutoScale::scaled)    return "0";
    if (autoScale == AutoScale::unscaled)  return "1";

    return {};
}

AutoScale getAutoScaleValueForPlugin (const String& identifier)
{
    if (identifier.isNotEmpty())
    {
        auto plugins = StringArray::fromLines (getAppProperties().getUserSettings()->getValue ("autoScalePlugins"));
        plugins.removeEmptyStrings();

        for (auto& plugin : plugins)
        {
            auto fromIdentifier = plugin.fromFirstOccurrenceOf (identifier, false, false);

            if (fromIdentifier.isNotEmpty())
                return autoScaleFromString (fromIdentifier.fromFirstOccurrenceOf (":", false, false));
        }
    }

    return AutoScale::useDefault;
}

void setAutoScaleValueForPlugin (const String& identifier, AutoScale s)
{
    auto plugins = StringArray::fromLines (getAppProperties().getUserSettings()->getValue ("autoScalePlugins"));
    plugins.removeEmptyStrings();

    auto index = [identifier, plugins]
    {
        auto it = std::find_if (plugins.begin(), plugins.end(),
                                [&] (const String& str) { return str.startsWith (identifier); });

        return (int) std::distance (plugins.begin(), it);
    }();

    if (s == AutoScale::useDefault && index != plugins.size())
    {
        plugins.remove (index);
    }
    else
    {
        auto str = identifier + ":" + autoScaleToString (s);

        if (index != plugins.size())
            plugins.getReference (index) = str;
        else
            plugins.add (str);
    }

    getAppProperties().getUserSettings()->setValue ("autoScalePlugins", plugins.joinIntoString ("\n"));
}

static bool isAutoScaleAvailableForPlugin (const PluginDescription& description)
{
    return autoScaleOptionAvailable
          && description.pluginFormatName.containsIgnoreCase ("VST");
}

bool shouldAutoScalePlugin (const PluginDescription& description)
{
    if (! isAutoScaleAvailableForPlugin (description))
        return false;

    const auto scaleValue = getAutoScaleValueForPlugin (description.fileOrIdentifier);

    return (scaleValue == AutoScale::scaled
              || (scaleValue == AutoScale::useDefault
                    && getAppProperties().getUserSettings()->getBoolValue ("autoScalePluginWindows")));
}

void addPluginAutoScaleOptionsSubMenu (AudioPluginInstance* pluginInstance,
                                       PopupMenu& menu)
{
    if (pluginInstance == nullptr)
        return;

    auto description = pluginInstance->getPluginDescription();

    if (! isAutoScaleAvailableForPlugin (description))
        return;

    auto identifier = description.fileOrIdentifier;

    PopupMenu autoScaleMenu;

    autoScaleMenu.addItem ("Default",
                           true,
                           getAutoScaleValueForPlugin (identifier) == AutoScale::useDefault,
                           [identifier] { setAutoScaleValueForPlugin (identifier, AutoScale::useDefault); });

    autoScaleMenu.addItem ("Enabled",
                           true,
                           getAutoScaleValueForPlugin (identifier) == AutoScale::scaled,
                           [identifier] { setAutoScaleValueForPlugin (identifier, AutoScale::scaled); });

    autoScaleMenu.addItem ("Disabled",
                           true,
                           getAutoScaleValueForPlugin (identifier) == AutoScale::unscaled,
                           [identifier] { setAutoScaleValueForPlugin (identifier, AutoScale::unscaled); });

    menu.addSubMenu ("Auto-scale window", autoScaleMenu);
}

// This kicks the whole thing off..
START_JUCE_APPLICATION (PluginHostApp)