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

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

   THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
   WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.

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

#if JUCE_PLUGINHOST_VST

//==============================================================================
#undef PRAGMA_ALIGN_SUPPORTED


#if ! JUCE_MSVC
 #define __cdecl
#endif

JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wzero-as-null-pointer-constant")
JUCE_BEGIN_IGNORE_WARNINGS_MSVC (4996)

#define VST_FORCE_DEPRECATED 0
#define JUCE_VSTINTERFACE_H_INCLUDED 1

namespace Vst2
{
struct AEffect;

// If the following files cannot be found then you are probably trying to host
// VST2 plug-ins. To do this you must have a VST2 SDK in your header search
// paths or use the "VST (Legacy) SDK Folder" field in the Projucer. The VST2
// SDK can be obtained from the vstsdk3610_11_06_2018_build_37 (or older) VST3
// SDK or JUCE version 5.3.2.
#include <pluginterfaces/vst2.x/aeffect.h>
#include <pluginterfaces/vst2.x/aeffectx.h>
}

#include "juce_VSTCommon.h"

JUCE_END_IGNORE_WARNINGS_MSVC
JUCE_END_IGNORE_WARNINGS_GCC_LIKE

JUCE_BEGIN_IGNORE_WARNINGS_MSVC (4355)
JUCE_BEGIN_IGNORE_DEPRECATION_WARNINGS

#include "juce_VSTMidiEventList.h"

#if ! JUCE_WINDOWS
 static void _fpreset() {}
 static void _clearfp() {}
#endif

#ifndef JUCE_VST_WRAPPER_LOAD_CUSTOM_MAIN
 #define JUCE_VST_WRAPPER_LOAD_CUSTOM_MAIN
#endif

#ifndef JUCE_VST_WRAPPER_INVOKE_MAIN
#define JUCE_VST_WRAPPER_INVOKE_MAIN  effect = module->moduleMain (audioMaster);
#endif

#ifndef JUCE_VST_FALLBACK_HOST_NAME
 #define JUCE_VST_FALLBACK_HOST_NAME "Juce VST Host"
#endif

//==============================================================================
namespace juce
{

//==============================================================================
namespace
{
    const int fxbVersionNum = 1;

    struct fxProgram
    {
        int32 chunkMagic;    // 'CcnK'
        int32 byteSize;      // of this chunk, excl. magic + byteSize
        int32 fxMagic;       // 'FxCk'
        int32 version;
        int32 fxID;          // fx unique id
        int32 fxVersion;
        int32 numParams;
        char prgName[28];
        float params[1];        // variable no. of parameters
    };

    struct fxSet
    {
        int32 chunkMagic;    // 'CcnK'
        int32 byteSize;      // of this chunk, excl. magic + byteSize
        int32 fxMagic;       // 'FxBk'
        int32 version;
        int32 fxID;          // fx unique id
        int32 fxVersion;
        int32 numPrograms;
        char future[128];
        fxProgram programs[1];  // variable no. of programs
    };

    struct fxChunkSet
    {
        int32 chunkMagic;    // 'CcnK'
        int32 byteSize;      // of this chunk, excl. magic + byteSize
        int32 fxMagic;       // 'FxCh', 'FPCh', or 'FBCh'
        int32 version;
        int32 fxID;          // fx unique id
        int32 fxVersion;
        int32 numPrograms;
        char future[128];
        int32 chunkSize;
        char chunk[8];          // variable
    };

    struct fxProgramSet
    {
        int32 chunkMagic;    // 'CcnK'
        int32 byteSize;      // of this chunk, excl. magic + byteSize
        int32 fxMagic;       // 'FxCh', 'FPCh', or 'FBCh'
        int32 version;
        int32 fxID;          // fx unique id
        int32 fxVersion;
        int32 numPrograms;
        char name[28];
        int32 chunkSize;
        char chunk[8];          // variable
    };

    // Compares a magic value in either endianness.
    static bool compareMagic (int32 magic, const char* name) noexcept
    {
        return magic == (int32) ByteOrder::littleEndianInt (name)
            || magic == (int32) ByteOrder::bigEndianInt (name);
    }

    static int32 fxbName (const char* name) noexcept    { return (int32) ByteOrder::littleEndianInt (name); }
    static int32 fxbSwap (int32 x) noexcept             { return (int32) ByteOrder::swapIfLittleEndian ((uint32) x); }

    static float fxbSwapFloat (const float x) noexcept
    {
       #ifdef JUCE_LITTLE_ENDIAN
        union { uint32 asInt; float asFloat; } n;
        n.asFloat = x;
        n.asInt = ByteOrder::swap (n.asInt);
        return n.asFloat;
       #else
        return x;
       #endif
    }
}

//==============================================================================
namespace
{
    static double getVSTHostTimeNanoseconds() noexcept
    {
       #if JUCE_WINDOWS
        return timeGetTime() * 1000000.0;
       #elif JUCE_LINUX || JUCE_BSD || JUCE_IOS || JUCE_ANDROID
        timeval micro;
        gettimeofday (&micro, nullptr);
        return (double) micro.tv_usec * 1000.0;
       #elif JUCE_MAC
        UnsignedWide micro;
        Microseconds (&micro);
        return micro.lo * 1000.0;
       #endif
    }

    static int shellUIDToCreate = 0;
    static int insideVSTCallback = 0;

    struct IdleCallRecursionPreventer
    {
        IdleCallRecursionPreventer()  : isMessageThread (MessageManager::getInstance()->isThisTheMessageThread())
        {
            if (isMessageThread)
                ++insideVSTCallback;
        }

        ~IdleCallRecursionPreventer()
        {
            if (isMessageThread)
                --insideVSTCallback;
        }

        const bool isMessageThread;
        JUCE_DECLARE_NON_COPYABLE (IdleCallRecursionPreventer)
    };

   #if JUCE_MAC
    static bool makeFSRefFromPath (FSRef* destFSRef, const String& path)
    {
        return FSPathMakeRef (reinterpret_cast<const UInt8*> (path.toRawUTF8()), destFSRef, nullptr) == noErr;
    }
   #endif
}

//==============================================================================
using MainCall = Vst2::AEffect* (VSTCALLBACK*) (Vst2::audioMasterCallback);

//==============================================================================
// Change this to disable logging of various VST activities
#ifndef VST_LOGGING
 #define VST_LOGGING 1
#endif

#if VST_LOGGING
 #define JUCE_VST_LOG(a) Logger::writeToLog(a);
#else
 #define JUCE_VST_LOG(a)
#endif

//==============================================================================
#if JUCE_LINUX || JUCE_BSD

namespace
{
    using EventProcPtr = void (*)(XEvent*);

    Window getChildWindow (Window windowToCheck)
    {
        Window rootWindow, parentWindow;
        Window* childWindows;
        unsigned int numChildren = 0;

        X11Symbols::getInstance()->xQueryTree (XWindowSystem::getInstance()->getDisplay(),
                                               windowToCheck, &rootWindow, &parentWindow, &childWindows, &numChildren);

        if (numChildren > 0)
            return childWindows [0];

        return 0;
    }
}

#endif

//==============================================================================
class VSTXMLInfo
{
public:
    static VSTXMLInfo* createFor (const juce::XmlElement& xml)
    {
        if (xml.hasTagName ("VSTParametersStructure"))
            return new VSTXMLInfo (xml);

        if (const auto* x = xml.getChildByName ("VSTParametersStructure"))
            return new VSTXMLInfo (*x);

        return nullptr;
    }

    struct Group;

    struct Base
    {
        Base() noexcept {}
        virtual ~Base() {}

        Group* parent = nullptr;
    };

    struct Param final : public Base
    {
        int paramID;
        juce::String expr, name, label;
        juce::StringArray shortNames;
        juce::String type;
        int numberOfStates;
        float defaultValue;
    };

    struct Group final : public Base
    {
        juce::String name;
        juce::OwnedArray<Base> paramTree;
    };

    struct Range
    {
        Range() noexcept {}
        Range (const juce::String& s)       { set (s); }

        void set (const juce::String& s)
        {
            inclusiveLow  = s.startsWithChar ('[');
            inclusiveHigh = s.endsWithChar   (']');

            auto str = s.removeCharacters ("[]");

            low  = str.upToFirstOccurrenceOf (",", false, false).getFloatValue();
            high = str.fromLastOccurrenceOf  (",", false, false).getFloatValue();
        }

        bool contains (float f) const noexcept
        {
            return (inclusiveLow  ? (f >= low)  : (f > low))
                && (inclusiveHigh ? (f <= high) : (f < high));
        }

        float low = 0;
        float high = 0;

        bool inclusiveLow = false;
        bool inclusiveHigh = false;
    };

    struct Entry
    {
        juce::String name;
        Range range;
    };

    struct ValueType
    {
        juce::String name, label;
        juce::OwnedArray<Entry> entries;
    };

    struct Template
    {
        juce::String name;
        juce::OwnedArray<Param> params;
    };

    const Param* getParamForID (const int paramID, const Group* const grp) const
    {
        for (auto item : (grp != nullptr ? grp->paramTree : paramTree))
        {
            if (auto param = dynamic_cast<const Param*> (item))
                if (param->paramID == paramID)
                    return param;

            if (auto group = dynamic_cast<const Group*> (item))
                if (auto res = getParamForID (paramID, group))
                    return res;
        }

        return nullptr;
    }

    const ValueType* getValueType (const juce::String& name) const
    {
        for (auto v : valueTypes)
            if (v->name == name)
                return v;

        return nullptr;
    }

    juce::OwnedArray<Base> paramTree;
    juce::OwnedArray<ValueType> valueTypes;
    juce::OwnedArray<Template> templates;

    ValueType switchValueType;

private:
    VSTXMLInfo (const juce::XmlElement& xml)
    {
        switchValueType.entries.add (new Entry ({ TRANS ("Off"), Range ("[0, 0.5[") }));
        switchValueType.entries.add (new Entry ({ TRANS ("On"),  Range ("[0.5, 1]") }));

        for (auto* item : xml.getChildIterator())
        {
            if (item->hasTagName ("Param"))           parseParam (*item, nullptr, nullptr);
            else if (item->hasTagName ("ValueType"))  parseValueType (*item);
            else if (item->hasTagName ("Template"))   parseTemplate (*item);
            else if (item->hasTagName ("Group"))      parseGroup (*item, nullptr);
        }
    }

    void parseParam (const juce::XmlElement& item, Group* group, Template* temp)
    {
        auto param = new Param();

        if (temp != nullptr)
            param->expr = item.getStringAttribute ("id");
        else
            param->paramID = item.getIntAttribute ("id");

        param->name           = item.getStringAttribute ("name");
        param->label          = item.getStringAttribute ("label");
        param->type           = item.getStringAttribute ("type");
        param->numberOfStates = item.getIntAttribute ("numberOfStates");
        param->defaultValue   = (float) item.getDoubleAttribute ("defaultValue");

        param->shortNames.addTokens (item.getStringAttribute ("shortName"), ",", juce::StringRef());
        param->shortNames.trim();
        param->shortNames.removeEmptyStrings();

        if (group != nullptr)
        {
            group->paramTree.add (param);
            param->parent = group;
        }
        else if (temp != nullptr)
        {
            temp->params.add (param);
        }
        else
        {
            paramTree.add (param);
        }
    }

    void parseValueType (const juce::XmlElement& item)
    {
        auto vt = new ValueType();
        valueTypes.add (vt);

        vt->name  = item.getStringAttribute ("name");
        vt->label = item.getStringAttribute ("label");

        int curEntry = 0;
        const int numEntries = item.getNumChildElements();

        for (auto* entryXml : item.getChildWithTagNameIterator ("Entry"))
        {
            auto entry = new Entry();
            entry->name = entryXml->getStringAttribute ("name");

            if (entryXml->hasAttribute ("value"))
            {
                entry->range.set (entryXml->getStringAttribute ("value"));
            }
            else
            {
                entry->range.low  = (float) curEntry / (float) numEntries;
                entry->range.high = (float) (curEntry + 1) / (float) numEntries;

                entry->range.inclusiveLow  = true;
                entry->range.inclusiveHigh = (curEntry == numEntries - 1);
            }

            vt->entries.add (entry);
            ++curEntry;
        }
    }

    void parseTemplate (const juce::XmlElement& item)
    {
        auto temp = new Template();
        templates.add (temp);
        temp->name = item.getStringAttribute ("name");

        for (auto* param : item.getChildIterator())
            parseParam (*param, nullptr, temp);
    }

    void parseGroup (const juce::XmlElement& item, Group* parentGroup)
    {
        auto group = new Group();

        if (parentGroup)
        {
            parentGroup->paramTree.add (group);
            group->parent = parentGroup;
        }
        else
        {
            paramTree.add (group);
        }

        group->name = item.getStringAttribute ("name");

        if (item.hasAttribute ("template"))
        {
            juce::StringArray variables;
            variables.addTokens (item.getStringAttribute ("values"), ";", juce::StringRef());
            variables.trim();

            for (auto temp : templates)
            {
                if (temp->name == item.getStringAttribute ("template"))
                {
                    for (int i = 0; i < temp->params.size(); ++i)
                    {
                        auto param = new Param();
                        group->paramTree.add (param);

                        param->parent         = group;
                        param->paramID        = evaluate (temp->params[i]->expr, variables);
                        param->defaultValue   = temp->params[i]->defaultValue;
                        param->label          = temp->params[i]->label;
                        param->name           = temp->params[i]->name;
                        param->numberOfStates = temp->params[i]->numberOfStates;
                        param->shortNames     = temp->params[i]->shortNames;
                        param->type           = temp->params[i]->type;
                    }
                }
            }
        }
        else
        {
            for (auto* subItem : item.getChildIterator())
            {
                if (subItem->hasTagName ("Param"))       parseParam (*subItem, group, nullptr);
                else if (subItem->hasTagName ("Group"))  parseGroup (*subItem, group);
            }
        }
    }

    int evaluate (juce::String expr, const juce::StringArray& variables) const
    {
        juce::StringArray names;
        juce::Array<int> vals;

        for (auto& v : variables)
        {
            if (v.contains ("="))
            {
                names.add (v.upToFirstOccurrenceOf ("=", false, false));
                vals.add  (v.fromFirstOccurrenceOf ("=", false, false).getIntValue());
            }
        }

        for (int i = 0; i < names.size(); ++i)
        {
            for (;;)
            {
                const int idx = expr.indexOfWholeWord (names[i]);
                if (idx < 0)
                    break;

                expr = expr.replaceSection (idx, names[i].length(), juce::String (vals[i]));
            }
        }

        expr = expr.retainCharacters ("01234567890-+")
                   .replace ("+", " + ")
                   .replace ("-", " - ");

        juce::StringArray tokens;
        tokens.addTokens (expr, " ", juce::StringRef());

        bool add = true;
        int val = 0;

        for (const auto& s : tokens)
        {
            if (s == "+")
            {
                add = true;
            }
            else if (s == "-")
            {
                add = false;
            }
            else
            {
                if (add)
                    val += s.getIntValue();
                else
                    val -= s.getIntValue();
            }
        }

        return val;
    }
};

//==============================================================================
struct ModuleHandle final : public ReferenceCountedObject
{
    File file;
    MainCall moduleMain, customMain = {};
    String pluginName;
    std::unique_ptr<XmlElement> vstXml;

    using Ptr = ReferenceCountedObjectPtr<ModuleHandle>;

    static Array<ModuleHandle*>& getActiveModules()
    {
        static Array<ModuleHandle*> activeModules;
        return activeModules;
    }

    //==============================================================================
    static Ptr findOrCreateModule (const File& file)
    {
        for (auto* module : getActiveModules())
            if (module->file == file)
                return module;

        const IdleCallRecursionPreventer icrp;
        shellUIDToCreate = 0;
        _fpreset();

        JUCE_VST_LOG ("Attempting to load VST: " + file.getFullPathName());

        Ptr m = new ModuleHandle (file, nullptr);

        if (m->open())
        {
            _fpreset();
            return m;
        }

        return {};
    }

    //==============================================================================
    ModuleHandle (const File& f, MainCall customMainCall)
        : file (f), moduleMain (customMainCall)
    {
        getActiveModules().add (this);

       #if JUCE_WINDOWS || JUCE_LINUX || JUCE_BSD || JUCE_IOS || JUCE_ANDROID
        fullParentDirectoryPathName = f.getParentDirectory().getFullPathName();
       #elif JUCE_MAC
        FSRef ref;
        makeFSRefFromPath (&ref, f.getParentDirectory().getFullPathName());
        FSGetCatalogInfo (&ref, kFSCatInfoNone, nullptr, nullptr, &parentDirFSSpec, nullptr);
       #endif
    }

    ~ModuleHandle()
    {
        getActiveModules().removeFirstMatchingValue (this);
        close();
    }

    //==============================================================================
   #if ! JUCE_MAC
    String fullParentDirectoryPathName;
   #endif

  #if JUCE_WINDOWS || JUCE_LINUX || JUCE_BSD || JUCE_ANDROID
    DynamicLibrary module;

    bool open()
    {
        if (moduleMain != nullptr)
            return true;

        pluginName = file.getFileNameWithoutExtension();

        module.open (file.getFullPathName());

        moduleMain = (MainCall) module.getFunction ("VSTPluginMain");

        if (moduleMain == nullptr)
            moduleMain = (MainCall) module.getFunction ("main");

        JUCE_VST_WRAPPER_LOAD_CUSTOM_MAIN

        if (moduleMain != nullptr)
        {
            vstXml = parseXML (file.withFileExtension ("vstxml"));

           #if JUCE_WINDOWS
            if (vstXml == nullptr)
                vstXml = parseXML (getDLLResource (file, "VSTXML", 1));
           #endif
        }

        return moduleMain != nullptr;
    }

    void close()
    {
        _fpreset(); // (doesn't do any harm)

        module.close();
    }

    void closeEffect (Vst2::AEffect* eff)
    {
        eff->dispatcher (eff, Vst2::effClose, 0, 0, nullptr, 0);
    }

   #if JUCE_WINDOWS
    static String getDLLResource (const File& dllFile, const String& type, int resID)
    {
        DynamicLibrary dll (dllFile.getFullPathName());
        auto dllModule = (HMODULE) dll.getNativeHandle();

        if (dllModule != INVALID_HANDLE_VALUE)
        {
            if (auto res = FindResource (dllModule, MAKEINTRESOURCE (resID), type.toWideCharPointer()))
            {
                if (auto hGlob = LoadResource (dllModule, res))
                {
                    auto* data = static_cast<const char*> (LockResource (hGlob));
                    return String::fromUTF8 (data, (int) SizeofResource (dllModule, res));
                }
            }
        }

        return {};
    }
   #endif
  #else
    Handle resHandle = {};
    CFUniquePtr<CFBundleRef> bundleRef;

   #if JUCE_MAC
    CFBundleRefNum resFileId = {};
    FSSpec parentDirFSSpec;
   #endif

    bool open()
    {
        if (moduleMain != nullptr)
            return true;

        bool ok = false;

        if (file.hasFileExtension (".vst"))
        {
            auto* utf8 = file.getFullPathName().toRawUTF8();

            if (auto url = CFUniquePtr<CFURLRef> (CFURLCreateFromFileSystemRepresentation (nullptr, (const UInt8*) utf8,
                                                                                           (CFIndex) strlen (utf8), file.isDirectory())))
            {
                bundleRef.reset (CFBundleCreate (kCFAllocatorDefault, url.get()));

                if (bundleRef != nullptr)
                {
                    if (CFBundleLoadExecutable (bundleRef.get()))
                    {
                        moduleMain = (MainCall) CFBundleGetFunctionPointerForName (bundleRef.get(), CFSTR ("main_macho"));

                        if (moduleMain == nullptr)
                            moduleMain = (MainCall) CFBundleGetFunctionPointerForName (bundleRef.get(), CFSTR ("VSTPluginMain"));

                        JUCE_VST_WRAPPER_LOAD_CUSTOM_MAIN

                        if (moduleMain != nullptr)
                        {
                            if (CFTypeRef name = CFBundleGetValueForInfoDictionaryKey (bundleRef.get(), CFSTR ("CFBundleName")))
                            {
                                if (CFGetTypeID (name) == CFStringGetTypeID())
                                {
                                    char buffer[1024];

                                    if (CFStringGetCString ((CFStringRef) name, buffer, sizeof (buffer), CFStringGetSystemEncoding()))
                                        pluginName = buffer;
                                }
                            }

                            if (pluginName.isEmpty())
                                pluginName = file.getFileNameWithoutExtension();

                           #if JUCE_MAC
                            resFileId = CFBundleOpenBundleResourceMap (bundleRef.get());
                           #endif

                            ok = true;

                            auto vstXmlFiles = file
                                                   #if JUCE_MAC
                                                    .getChildFile ("Contents")
                                                    .getChildFile ("Resources")
                                                   #endif
                                                    .findChildFiles (File::findFiles, false, "*.vstxml");

                            if (! vstXmlFiles.isEmpty())
                                vstXml = parseXML (vstXmlFiles.getReference (0));
                        }
                    }

                    if (! ok)
                    {
                        CFBundleUnloadExecutable (bundleRef.get());
                        bundleRef = nullptr;
                    }
                }
            }
        }

        return ok;
    }

    void close()
    {
        if (bundleRef != nullptr)
        {
           #if JUCE_MAC
            CFBundleCloseBundleResourceMap (bundleRef.get(), resFileId);
           #endif

            if (CFGetRetainCount (bundleRef.get()) == 1)
                CFBundleUnloadExecutable (bundleRef.get());

            if (CFGetRetainCount (bundleRef.get()) > 0)
                bundleRef = nullptr;
        }
    }

    void closeEffect (Vst2::AEffect* eff)
    {
        eff->dispatcher (eff, Vst2::effClose, 0, 0, nullptr, 0);
    }

  #endif

private:
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ModuleHandle)
};

static const int defaultVSTSampleRateValue = 44100;
static const int defaultVSTBlockSizeValue = 512;

class TempChannelPointers
{
public:
    template <typename T>
    auto getArrayOfModifiableWritePointers (AudioBuffer<T>& buffer)
    {
        auto& pointers = getPointers (Tag<T>{});

        jassert (buffer.getNumChannels() <= static_cast<int> (pointers.capacity()));
        pointers.resize (jmax (pointers.size(), (size_t) buffer.getNumChannels()));

        std::copy (buffer.getArrayOfWritePointers(),
                   buffer.getArrayOfWritePointers() + buffer.getNumChannels(),
                   pointers.begin());

        return pointers.data();
    }

private:
    template <typename> struct Tag {};

    auto& getPointers (Tag<float>)  { return floatPointers; }
    auto& getPointers (Tag<double>) { return doublePointers; }

    std::vector<float*>  floatPointers  { 128 };
    std::vector<double*> doublePointers { 128 };
};

//==============================================================================
struct VSTPluginInstance final   : public AudioPluginInstance,
                                   private Timer,
                                   private AsyncUpdater
{
    struct VSTParameter final   : public Parameter
    {
        VSTParameter (VSTPluginInstance& parent,
                      const String& paramName,
                      const Array<String>& shortParamNames,
                      float paramDefaultValue,
                      const String& paramLabel,
                      bool paramIsAutomatable,
                      bool paramIsDiscrete,
                      int numParamSteps,
                      bool isBoolSwitch,
                      const StringArray& paramValueStrings,
                      const VSTXMLInfo::ValueType* paramValueType)
            : pluginInstance (parent),
              name (paramName),
              shortNames (shortParamNames),
              defaultValue (paramDefaultValue),
              label (paramLabel),
              automatable (paramIsAutomatable),
              discrete (paramIsDiscrete),
              numSteps (numParamSteps),
              isSwitch (isBoolSwitch),
              vstValueStrings (paramValueStrings),
              valueType (paramValueType)
        {
        }

        float getValue() const override
        {
            if (auto* effect = pluginInstance.vstEffect)
            {
                const ScopedLock sl (pluginInstance.lock);

                return effect->getParameter (effect, getParameterIndex());
            }

            return 0.0f;
        }

        void setValue (float newValue) override
        {
            if (auto* effect = pluginInstance.vstEffect)
            {
                const ScopedLock sl (pluginInstance.lock);

                if (! approximatelyEqual (effect->getParameter (effect, getParameterIndex()), newValue))
                    effect->setParameter (effect, getParameterIndex(), newValue);
            }
        }

        String getText (float value, int maximumStringLength) const override
        {
            if (valueType != nullptr)
            {
                for (auto& v : valueType->entries)
                    if (v->range.contains (value))
                        return v->name;
            }

            return Parameter::getText (value, maximumStringLength);
        }

        float getValueForText (const String& text) const override
        {
            if (valueType != nullptr)
            {
                for (auto& v : valueType->entries)
                    if (v->name == text)
                        return (v->range.high + v->range.low) / 2.0f;
            }

            return Parameter::getValueForText (text);
        }

        String getCurrentValueAsText() const override
        {
            if (valueType != nullptr || ! vstValueStrings.isEmpty())
                return getText (getValue(), 1024);

            return pluginInstance.getTextForOpcode (getParameterIndex(), Vst2::effGetParamDisplay);
        }

        float getDefaultValue() const override
        {
            return defaultValue;
        }

        String getName (int maximumStringLength) const override
        {
            if (name.isEmpty())
                return pluginInstance.getTextForOpcode (getParameterIndex(),
                                                        Vst2::effGetParamName);

            if (name.length() <= maximumStringLength)
                return name;

            if (! shortNames.isEmpty())
            {
                for (auto& n : shortNames)
                    if (n.length() <= maximumStringLength)
                        return n;

                return shortNames.getLast();
            }

            return name;
        }

        String getLabel() const override
        {
            return label.isEmpty() ? pluginInstance.getTextForOpcode (getParameterIndex(),
                                                                      Vst2::effGetParamLabel)
                                   : label;
        }

        bool isAutomatable() const override
        {
            return automatable;
        }

        bool isDiscrete() const override
        {
            return discrete;
        }

        bool isBoolean() const override
        {
            return isSwitch;
        }

        int getNumSteps() const override
        {
            return numSteps;
        }

        StringArray getAllValueStrings() const override
        {
            return vstValueStrings;
        }

        String getParameterID() const override
        {
            return String (getParameterIndex());
        }

        VSTPluginInstance& pluginInstance;

        const String name;
        const Array<String> shortNames;
        const float defaultValue;
        const String label;
        const bool automatable, discrete;
        const int numSteps;
        const bool isSwitch;
        const StringArray vstValueStrings;
        const VSTXMLInfo::ValueType* const valueType;
    };

    VSTPluginInstance (const ModuleHandle::Ptr& mh, const BusesProperties& ioConfig, Vst2::AEffect* effect,
                       double sampleRateToUse, int blockSizeToUse)
        : AudioPluginInstance (ioConfig),
          vstEffect (effect),
          vstModule (mh),
          name (mh->pluginName),
          bypassParam (new VST2BypassParameter (*this))
    {
        jassert (vstEffect != nullptr);

        if (auto* xml = vstModule->vstXml.get())
            xmlInfo.reset (VSTXMLInfo::createFor (*xml));

        refreshParameterList();

        vstSupportsBypass = (pluginCanDo ("bypass") > 0);
        setRateAndBufferSizeDetails (sampleRateToUse, blockSizeToUse);
    }

    void refreshParameterList() override
    {
        AudioProcessorParameterGroup newParameterTree;

        for (int i = 0; i < vstEffect->numParams; ++i)
        {
            String paramName;
            Array<String> shortParamNames;
            float defaultValue = 0;
            String label;
            bool isAutomatable = dispatch (Vst2::effCanBeAutomated, i, 0, nullptr, 0) != 0;
            bool isDiscrete = false;
            int numSteps = AudioProcessor::getDefaultNumParameterSteps();
            bool isBoolSwitch = false;
            StringArray parameterValueStrings;
            const VSTXMLInfo::ValueType* valueType = nullptr;

            if (xmlInfo != nullptr)
            {
                if (auto* param = xmlInfo->getParamForID (i, nullptr))
                {
                    paramName = param->name;

                    for (auto& n : param->shortNames)
                        shortParamNames.add (n);

                    struct LengthComparator
                    {
                        static int compareElements (const juce::String& first, const juce::String& second) noexcept
                        {
                            return first.length() - second.length();
                        }
                    };

                    LengthComparator comp;
                    shortParamNames.sort (comp);

                    defaultValue = param->defaultValue;
                    label = param->label;

                    if (param->type == "switch")
                    {
                        isBoolSwitch = true;
                        numSteps = 2;
                        valueType = &xmlInfo->switchValueType;
                    }
                    else
                    {
                        valueType = xmlInfo->getValueType (param->type);
                    }

                    if (param->numberOfStates >= 2)
                    {
                        numSteps = param->numberOfStates;

                        if (valueType != nullptr)
                        {
                            for (auto* entry : valueType->entries)
                                parameterValueStrings.add (entry->name);

                            parameterValueStrings.removeEmptyStrings();
                        }
                    }

                    isDiscrete = (numSteps != AudioProcessor::getDefaultNumParameterSteps());
                }
            }

            newParameterTree.addChild (std::make_unique<VSTParameter> (*this, paramName, shortParamNames, defaultValue,
                                                                       label, isAutomatable, isDiscrete, numSteps,
                                                                       isBoolSwitch, parameterValueStrings, valueType));
        }

        setHostedParameterTree (std::move (newParameterTree));
    }

    ~VSTPluginInstance() override
    {
        if (vstEffect != nullptr && vstEffect->magic == 0x56737450 /* 'VstP' */)
            callOnMessageThread ([this] { cleanup(); });
    }

    void cleanup()
    {
        if (vstEffect != nullptr && vstEffect->magic == 0x56737450 /* 'VstP' */)
        {
           #if JUCE_MAC
            if (vstModule->resFileId != 0)
                UseResFile (vstModule->resFileId);
           #endif

            // Must delete any editors before deleting the plugin instance!
            jassert (getActiveEditor() == nullptr);

            _fpreset(); // some dodgy plug-ins mess around with this

            vstModule->closeEffect (vstEffect);
        }

        vstModule = nullptr;
        vstEffect = nullptr;
    }

    static VSTPluginInstance* create (const ModuleHandle::Ptr& newModule,
                                      double initialSampleRate,
                                      int initialBlockSize)
    {
        if (auto* newEffect = constructEffect (newModule))
        {
            newEffect->resvd2 = 0;

            newEffect->dispatcher (newEffect, Vst2::effIdentify, 0, 0, nullptr, 0);

            auto blockSize = jmax (32, initialBlockSize);

            newEffect->dispatcher (newEffect, Vst2::effSetSampleRate, 0, 0, nullptr, static_cast<float> (initialSampleRate));
            newEffect->dispatcher (newEffect, Vst2::effSetBlockSize,  0, blockSize, nullptr, 0);

            newEffect->dispatcher (newEffect, Vst2::effOpen, 0, 0, nullptr, 0);
            BusesProperties ioConfig = queryBusIO (newEffect);

            return new VSTPluginInstance (newModule, ioConfig, newEffect, initialSampleRate, blockSize);
        }

        return nullptr;
    }

    //==============================================================================
    void fillInPluginDescription (PluginDescription& desc) const override
    {
        desc.name = name;

        {
            char buffer[512] = { 0 };
            dispatch (Vst2::effGetEffectName, 0, 0, buffer, 0);

            desc.descriptiveName = String::createStringFromData (buffer, (int) sizeof (buffer)).trim();

            if (desc.descriptiveName.isEmpty())
                desc.descriptiveName = name;
        }

        desc.fileOrIdentifier = vstModule->file.getFullPathName();
        desc.uniqueId = desc.deprecatedUid = getUID();
        desc.lastFileModTime = vstModule->file.getLastModificationTime();
        desc.lastInfoUpdateTime = Time::getCurrentTime();
        desc.pluginFormatName = "VST";
        desc.category = getCategory();

        {
            char buffer[512] = { 0 };
            dispatch (Vst2::effGetVendorString, 0, 0, buffer, 0);
            desc.manufacturerName = String::createStringFromData (buffer, (int) sizeof (buffer)).trim();
        }

        desc.version = getVersion();
        desc.numInputChannels = getTotalNumInputChannels();
        desc.numOutputChannels = getTotalNumOutputChannels();
        desc.isInstrument = isSynthPlugin();
    }

    bool initialiseEffect (double initialSampleRate, int initialBlockSize)
    {
        if (vstEffect != nullptr)
        {
            vstEffect->resvd2 = (pointer_sized_int) (pointer_sized_int) this;
            initialise (initialSampleRate, initialBlockSize);
            return true;
        }

        return false;
    }

    void initialise (double initialSampleRate, int initialBlockSize)
    {
        if (initialised || vstEffect == nullptr)
            return;

       #if JUCE_WINDOWS
        // On Windows it's highly advisable to create your plugins using the message thread,
        // because many plugins need a chance to create HWNDs that will get their
        // messages delivered by the main message thread, and that's not possible from
        // a background thread.
        JUCE_ASSERT_MESSAGE_THREAD
       #endif

        JUCE_VST_LOG ("Initialising VST: " + vstModule->pluginName + " (" + getVersion() + ")");
        initialised = true;

        setRateAndBufferSizeDetails (initialSampleRate, initialBlockSize);

        dispatch (Vst2::effIdentify, 0, 0, nullptr, 0);

        if (getSampleRate() > 0)
            dispatch (Vst2::effSetSampleRate, 0, 0, nullptr, (float) getSampleRate());

        if (getBlockSize() > 0)
            dispatch (Vst2::effSetBlockSize, 0, jmax (32, getBlockSize()), nullptr, 0);

        dispatch (Vst2::effOpen, 0, 0, nullptr, 0);

        setRateAndBufferSizeDetails (getSampleRate(), getBlockSize());

        if (getNumPrograms() > 1)
            setCurrentProgram (0);
        else
            dispatch (Vst2::effSetProgram, 0, 0, nullptr, 0);

        for (int i = vstEffect->numInputs;  --i >= 0;)  dispatch (Vst2::effConnectInput,  i, 1, nullptr, 0);
        for (int i = vstEffect->numOutputs; --i >= 0;)  dispatch (Vst2::effConnectOutput, i, 1, nullptr, 0);

        if (getVstCategory() != Vst2::kPlugCategShell) // (workaround for Waves 5 plugins which crash during this call)
            updateStoredProgramNames();

        wantsMidiMessages = pluginCanDo ("receiveVstMidiEvent") > 0 || isSynthPlugin();

        setLatencySamples (vstEffect->initialDelay);
    }

    void getExtensions (ExtensionsVisitor& visitor) const override
    {
        struct Extensions final : public ExtensionsVisitor::VSTClient
        {
            explicit Extensions (const VSTPluginInstance* instanceIn) : instance (instanceIn) {}

            AEffect* getAEffectPtr() const noexcept override   { return reinterpret_cast<AEffect*> (instance->vstEffect); }

            const VSTPluginInstance* instance = nullptr;
        };

        visitor.visitVSTClient (Extensions { this });
    }

    void* getPlatformSpecificData() override    { return vstEffect; }

    const String getName() const override
    {
        if (vstEffect != nullptr)
        {
            char buffer[512] = { 0 };

            if (dispatch (Vst2::effGetProductString, 0, 0, buffer, 0) != 0)
            {
                String productName = String::createStringFromData (buffer, (int) sizeof (buffer));

                if (productName.isNotEmpty())
                    return productName;
            }
        }

        return name;
    }

    int getUID() const
    {
        int uid = vstEffect != nullptr ? vstEffect->uniqueID : 0;

        if (uid == 0)
            uid = vstModule->file.hashCode();

        return uid;
    }

    double getTailLengthSeconds() const override
    {
        if (vstEffect == nullptr)
            return 0.0;

        if ((vstEffect->flags & Vst2::effFlagsNoSoundInStop) != 0)
            return 0.0;

        auto tailSize = dispatch (Vst2::effGetTailSize, 0, 0, nullptr, 0);
        auto sampleRate = getSampleRate();

        // remain backward compatible with old JUCE plug-ins: anything larger
        // than INT32_MAX is an invalid tail time but old JUCE 64-bit plug-ins
        // would return INT64_MAX for infinite tail time. So treat anything
        // equal or greater than INT32_MAX as infinite tail time.
        if (tailSize >= std::numeric_limits<int32>::max())
            return std::numeric_limits<double>::infinity();

        if (tailSize >= 0 && sampleRate > 0)
            return static_cast<double> (tailSize) / sampleRate;

        return 0.0;
    }

    bool acceptsMidi() const override    { return wantsMidiMessages; }
    bool producesMidi() const override   { return pluginCanDo ("sendVstMidiEvent") > 0; }
    bool supportsMPE() const override    { return pluginCanDo ("MPE") > 0; }

    Vst2::VstPlugCategory getVstCategory() const noexcept     { return (Vst2::VstPlugCategory) dispatch (Vst2::effGetPlugCategory, 0, 0, nullptr, 0); }

    bool isSynthPlugin() const  { return (vstEffect != nullptr && (vstEffect->flags & Vst2::effFlagsIsSynth) != 0); }

    int pluginCanDo (const char* text) const  { return (int) dispatch (Vst2::effCanDo, 0, 0, (void*) text,  0); }

    std::optional<String> getNameForMidiNoteNumber (int note, int midiChannel) override
    {
        Vst2::MidiKeyName keyName{};

        keyName.thisProgramIndex = getCurrentProgram();
        keyName.thisKeyNumber = note;

        return dispatch (Vst2::effGetMidiKeyName, midiChannel, 0, &keyName, 0.0f) != 0
             ? std::make_optional (String::createStringFromData (keyName.keyName, Vst2::kVstMaxNameLen))
             : std::nullopt;
    }

    //==============================================================================
    void prepareToPlay (double rate, int samplesPerBlockExpected) override
    {
        auto numInputBuses  = getBusCount (true);
        auto numOutputBuses = getBusCount (false);

        setRateAndBufferSizeDetails (rate, samplesPerBlockExpected);

        if (numInputBuses <= 1 && numOutputBuses <= 1)
        {
            SpeakerMappings::VstSpeakerConfigurationHolder inArr  (getChannelLayoutOfBus (true,  0));
            SpeakerMappings::VstSpeakerConfigurationHolder outArr (getChannelLayoutOfBus (false, 0));

            dispatch (Vst2::effSetSpeakerArrangement, 0, (pointer_sized_int) &inArr.get(), (void*) &outArr.get(), 0.0f);
        }

        vstHostTime.tempo = 120.0;
        vstHostTime.timeSigNumerator = 4;
        vstHostTime.timeSigDenominator = 4;
        vstHostTime.sampleRate = rate;
        vstHostTime.samplePos = 0;
        vstHostTime.flags = Vst2::kVstNanosValid
                              | Vst2::kVstAutomationWriting
                              | Vst2::kVstAutomationReading;

        initialise (rate, samplesPerBlockExpected);

        if (initialised)
        {
            wantsMidiMessages = wantsMidiMessages || (pluginCanDo ("receiveVstMidiEvent") > 0) || isSynthPlugin();

            if (wantsMidiMessages)
                midiEventsToSend.ensureSize (256);
            else
                midiEventsToSend.freeEvents();

            incomingMidi.clear();

            dispatch (Vst2::effSetSampleRate, 0, 0, nullptr, (float) rate);
            dispatch (Vst2::effSetBlockSize, 0, jmax (16, samplesPerBlockExpected), nullptr, 0);

            if (supportsDoublePrecisionProcessing())
            {
                int32 vstPrecision = isUsingDoublePrecision() ? Vst2::kVstProcessPrecision64
                                                              : Vst2::kVstProcessPrecision32;

                dispatch (Vst2::effSetProcessPrecision, 0, (pointer_sized_int) vstPrecision, nullptr, 0);
            }

            auto maxChannels = jmax (1, jmax (vstEffect->numInputs, vstEffect->numOutputs));

            tmpBufferFloat .setSize (maxChannels, samplesPerBlockExpected);
            tmpBufferDouble.setSize (maxChannels, samplesPerBlockExpected);

            channelBufferFloat .calloc (static_cast<size_t> (maxChannels));
            channelBufferDouble.calloc (static_cast<size_t> (maxChannels));

            outOfPlaceBuffer.setSize (jmax (1, vstEffect->numOutputs), samplesPerBlockExpected);

            if (! isPowerOn)
                setPower (true);

            // dodgy hack to force some plugins to initialise the sample rate.
            if (! hasEditor())
            {
                if (auto* firstParam = getParameters()[0])
                {
                    auto old = firstParam->getValue();
                    firstParam->setValue ((old < 0.5f) ? 1.0f : 0.0f);
                    firstParam->setValue (old);
                }
            }

            dispatch (Vst2::effStartProcess, 0, 0, nullptr, 0);

            setLatencySamples (vstEffect->initialDelay);
        }
    }

    void releaseResources() override
    {
        if (initialised)
        {
            dispatch (Vst2::effStopProcess, 0, 0, nullptr, 0);
            setPower (false);
        }

        channelBufferFloat.free();
        tmpBufferFloat.setSize (0, 0);

        channelBufferDouble.free();
        tmpBufferDouble.setSize (0, 0);

        outOfPlaceBuffer.setSize (1, 1);
        incomingMidi.clear();

        midiEventsToSend.freeEvents();
    }

    void reset() override
    {
        if (isPowerOn)
        {
            setPower (false);
            setPower (true);
        }
    }

    //==============================================================================
    void processBlock (AudioBuffer<float>& buffer, MidiBuffer& midiMessages) override
    {
        jassert (! isUsingDoublePrecision());
        processAudio (buffer, midiMessages, tmpBufferFloat, channelBufferFloat, false);
    }

    void processBlock (AudioBuffer<double>& buffer, MidiBuffer& midiMessages) override
    {
        jassert (isUsingDoublePrecision());
        processAudio (buffer, midiMessages, tmpBufferDouble, channelBufferDouble, false);
    }

    void processBlockBypassed (AudioBuffer<float>& buffer, MidiBuffer& midiMessages) override
    {
        jassert (! isUsingDoublePrecision());
        processAudio (buffer, midiMessages, tmpBufferFloat, channelBufferFloat, true);
    }

    void processBlockBypassed (AudioBuffer<double>& buffer, MidiBuffer& midiMessages) override
    {
        jassert (isUsingDoublePrecision());
        processAudio (buffer, midiMessages, tmpBufferDouble, channelBufferDouble, true);
    }

    //==============================================================================
    bool supportsDoublePrecisionProcessing() const override
    {
        return ((vstEffect->flags & Vst2::effFlagsCanReplacing) != 0
             && (vstEffect->flags & Vst2::effFlagsCanDoubleReplacing) != 0);
    }

    AudioProcessorParameter* getBypassParameter() const override               { return vstSupportsBypass ? bypassParam.get() : nullptr; }

    //==============================================================================
    bool canAddBus (bool) const override                                       { return false; }
    bool canRemoveBus (bool) const override                                    { return false; }

    bool isBusesLayoutSupported (const BusesLayout& layouts) const override
    {
        auto numInputBuses  = getBusCount (true);
        auto numOutputBuses = getBusCount (false);

        // it's not possible to change layout if there are sidechains/aux buses
        if (numInputBuses > 1 || numOutputBuses > 1)
            return (layouts == getBusesLayout());

        return (layouts.getNumChannels (true,  0) <= vstEffect->numInputs
             && layouts.getNumChannels (false, 0) <= vstEffect->numOutputs);
    }

    //==============================================================================
   #if JUCE_IOS || JUCE_ANDROID
    bool hasEditor() const override                  { return false; }
   #else
    bool hasEditor() const override                  { return vstEffect != nullptr && (vstEffect->flags & Vst2::effFlagsHasEditor) != 0; }
   #endif

    AudioProcessorEditor* createEditor() override;

    //==============================================================================
    const String getInputChannelName (int index) const override
    {
        if (isValidChannel (index, true))
        {
            Vst2::VstPinProperties pinProps;
            if (dispatch (Vst2::effGetInputProperties, index, 0, &pinProps, 0.0f) != 0)
                return String (pinProps.label, sizeof (pinProps.label));
        }

        return {};
    }

    bool isInputChannelStereoPair (int index) const override
    {
        if (! isValidChannel (index, true))
            return false;

        Vst2::VstPinProperties pinProps;
        if (dispatch (Vst2::effGetInputProperties, index, 0, &pinProps, 0.0f) != 0)
            return (pinProps.flags & Vst2::kVstPinIsStereo) != 0;

        return true;
    }

    const String getOutputChannelName (int index) const override
    {
        if (isValidChannel (index, false))
        {
            Vst2::VstPinProperties pinProps;
            if (dispatch (Vst2::effGetOutputProperties, index, 0, &pinProps, 0.0f) != 0)
                return String (pinProps.label, sizeof (pinProps.label));
        }

        return {};
    }

    bool isOutputChannelStereoPair (int index) const override
    {
        if (! isValidChannel (index, false))
            return false;

        Vst2::VstPinProperties pinProps;
        if (dispatch (Vst2::effGetOutputProperties, index, 0, &pinProps, 0.0f) != 0)
            return (pinProps.flags & Vst2::kVstPinIsStereo) != 0;

        return true;
    }

    bool isValidChannel (int index, bool isInput) const noexcept
    {
        return isPositiveAndBelow (index, isInput ? getTotalNumInputChannels()
                                                  : getTotalNumOutputChannels());
    }

    //==============================================================================
    int getNumPrograms() override          { return vstEffect != nullptr ? jmax (0, vstEffect->numPrograms) : 0; }

    // NB: some plugs return negative numbers from this function.
    int getCurrentProgram() override       { return (int) dispatch (Vst2::effGetProgram, 0, 0, nullptr, 0); }

    void setCurrentProgram (int newIndex) override
    {
        if (getNumPrograms() > 0 && newIndex != getCurrentProgram())
            dispatch (Vst2::effSetProgram, 0, jlimit (0, getNumPrograms() - 1, newIndex), nullptr, 0);
    }

    const String getProgramName (int index) override
    {
        if (index >= 0)
        {
            if (index == getCurrentProgram())
                return getCurrentProgramName();

            if (vstEffect != nullptr)
            {
                char nm[264] = { 0 };

                if (dispatch (Vst2::effGetProgramNameIndexed, jlimit (0, getNumPrograms() - 1, index), -1, nm, 0) != 0)
                    return String::fromUTF8 (nm).trim();
            }
        }

        return {};
    }

    void changeProgramName (int index, const String& newName) override
    {
        if (index >= 0 && index == getCurrentProgram())
        {
            if (getNumPrograms() > 0 && newName != getCurrentProgramName())
                dispatch (Vst2::effSetProgramName, 0, 0, (void*) newName.substring (0, 24).toRawUTF8(), 0.0f);
        }
        else
        {
            jassertfalse; // xxx not implemented!
        }
    }

    //==============================================================================
    void getStateInformation (MemoryBlock& mb) override                  { saveToFXBFile (mb, true); }
    void getCurrentProgramStateInformation (MemoryBlock& mb) override    { saveToFXBFile (mb, false); }

    void setStateInformation (const void* data, int size) override               { loadFromFXBFile (data, (size_t) size); }
    void setCurrentProgramStateInformation (const void* data, int size) override { loadFromFXBFile (data, (size_t) size); }

    //==============================================================================
    void timerCallback() override
    {
        if (dispatch (Vst2::effIdle, 0, 0, nullptr, 0) == 0)
            stopTimer();
    }

    void handleAsyncUpdate() override
    {
        updateHostDisplay (AudioProcessorListener::ChangeDetails().withProgramChanged (true)
                                                                  .withParameterInfoChanged (true));
    }

    pointer_sized_int handleCallback (int32 opcode, int32 index, pointer_sized_int value, void* ptr, float opt)
    {
        switch (opcode)
        {
            case Vst2::audioMasterAutomate:
                if (auto* param = getParameters()[index])
                    param->sendValueChangedMessageToListeners (opt);
                else
                    jassertfalse; // Invalid parameter index!

                break;

            case Vst2::audioMasterProcessEvents:            handleMidiFromPlugin ((const Vst2::VstEvents*) ptr); break;
            case Vst2::audioMasterGetTime:                  return getVSTTime();
            case Vst2::audioMasterIdle:                     handleIdle(); break;
            case Vst2::audioMasterSizeWindow:               setWindowSize (index, (int) value); return 1;
            case Vst2::audioMasterUpdateDisplay:            triggerAsyncUpdate(); break;
            case Vst2::audioMasterIOChanged:                setLatencySamples (vstEffect->initialDelay); break;
            case Vst2::audioMasterNeedIdle:                 startTimer (50); break;

            case Vst2::audioMasterGetSampleRate:            return (pointer_sized_int) (getSampleRate() > 0 ? getSampleRate() : defaultVSTSampleRateValue);
            case Vst2::audioMasterGetBlockSize:             return (pointer_sized_int) (getBlockSize() > 0  ? getBlockSize()  : defaultVSTBlockSizeValue);
            case Vst2::audioMasterWantMidi:                 wantsMidiMessages = true; break;
            case Vst2::audioMasterGetDirectory:             return getVstDirectory();

            case Vst2::audioMasterTempoAt:                  return (pointer_sized_int) (extraFunctions != nullptr ? extraFunctions->getTempoAt ((int64) value) : 0);
            case Vst2::audioMasterGetAutomationState:       return (pointer_sized_int) (extraFunctions != nullptr ? extraFunctions->getAutomationState() : 0);

            case Vst2::audioMasterBeginEdit:
                if (auto* param = getParameters()[index])
                    param->beginChangeGesture();
                else
                    jassertfalse; // Invalid parameter index!

                break;

            case Vst2::audioMasterEndEdit:
                if (auto* param = getParameters()[index])
                    param->endChangeGesture();
                else
                    jassertfalse; // Invalid parameter index!

                break;

            case Vst2::audioMasterPinConnected:             return isValidChannel (index, value == 0) ? 0 : 1; // (yes, 0 = true)
            case Vst2::audioMasterGetCurrentProcessLevel:   return isNonRealtime() ? 4 : 0;

            // none of these are handled (yet)...
            case Vst2::audioMasterSetTime:
            case Vst2::audioMasterGetParameterQuantization:
            case Vst2::audioMasterGetInputLatency:
            case Vst2::audioMasterGetOutputLatency:
            case Vst2::audioMasterGetPreviousPlug:
            case Vst2::audioMasterGetNextPlug:
            case Vst2::audioMasterWillReplaceOrAccumulate:
            case Vst2::audioMasterOfflineStart:
            case Vst2::audioMasterOfflineRead:
            case Vst2::audioMasterOfflineWrite:
            case Vst2::audioMasterOfflineGetCurrentPass:
            case Vst2::audioMasterOfflineGetCurrentMetaPass:
            case Vst2::audioMasterGetOutputSpeakerArrangement:
            case Vst2::audioMasterVendorSpecific:
            case Vst2::audioMasterSetIcon:
            case Vst2::audioMasterGetLanguage:
            case Vst2::audioMasterOpenWindow:
            case Vst2::audioMasterCloseWindow:
                break;

            default:
                return handleGeneralCallback (opcode, index, value, ptr, opt);
        }

        return 0;
    }

    // handles non plugin-specific callbacks.
    static pointer_sized_int handleGeneralCallback (int32 opcode, int32 /*index*/, pointer_sized_int /*value*/, void* ptr, float /*opt*/)
    {
        switch (opcode)
        {
            case Vst2::audioMasterCanDo:                        return handleCanDo ((const char*) ptr);
            case Vst2::audioMasterVersion:                      return 2400;
            case Vst2::audioMasterCurrentId:                    return shellUIDToCreate;
            case Vst2::audioMasterGetNumAutomatableParameters:  return 0;
            case Vst2::audioMasterGetAutomationState:           return 1;
            case Vst2::audioMasterGetVendorVersion:             return 0x0101;

            case Vst2::audioMasterGetVendorString:
            case Vst2::audioMasterGetProductString:             return getHostName ((char*) ptr);

            case Vst2::audioMasterGetSampleRate:                return (pointer_sized_int) defaultVSTSampleRateValue;
            case Vst2::audioMasterGetBlockSize:                 return (pointer_sized_int) defaultVSTBlockSizeValue;
            case Vst2::audioMasterSetOutputSampleRate:          return 0;

            default:
                DBG ("*** Unhandled VST Callback: " + String ((int) opcode));
                break;
        }

        return 0;
    }

    //==============================================================================
    pointer_sized_int dispatch (int opcode, int index, pointer_sized_int value, void* const ptr, float opt) const
    {
        pointer_sized_int result = 0;

        if (vstEffect != nullptr)
        {
            const ScopedLock sl (lock);
            const IdleCallRecursionPreventer icrp;

            try
            {
               #if JUCE_MAC
                auto oldResFile = CurResFile();

                if (vstModule->resFileId != 0)
                    UseResFile (vstModule->resFileId);
               #endif

                result = vstEffect->dispatcher (vstEffect, opcode, index, value, ptr, opt);

               #if JUCE_MAC
                auto newResFile = CurResFile();

                if (newResFile != oldResFile)  // avoid confusing the parent app's resource file with the plug-in's
                {
                    vstModule->resFileId = newResFile;
                    UseResFile (oldResFile);
                }
               #endif
            }
            catch (...)
            {}
        }

        return result;
    }

    bool loadFromFXBFile (const void* const data, const size_t dataSize)
    {
        if (dataSize < 28)
            return false;

        auto set = (const fxSet*) data;

        if ((! compareMagic (set->chunkMagic, "CcnK")) || fxbSwap (set->version) > fxbVersionNum)
            return false;

        if (compareMagic (set->fxMagic, "FxBk"))
        {
            // bank of programs
            if (fxbSwap (set->numPrograms) >= 0)
            {
                auto oldProg = getCurrentProgram();
                auto numParams = fxbSwap (((const fxProgram*) (set->programs))->numParams);
                auto progLen = (int) sizeof (fxProgram) + (numParams - 1) * (int) sizeof (float);

                for (int i = 0; i < fxbSwap (set->numPrograms); ++i)
                {
                    if (i != oldProg)
                    {
                        auto prog = addBytesToPointer (set->programs, i * progLen);

                        if (getAddressDifference (prog, set) >= (int) dataSize)
                            return false;

                        if (fxbSwap (set->numPrograms) > 0)
                            setCurrentProgram (i);

                        if (! restoreProgramSettings (prog))
                            return false;
                    }
                }

                if (fxbSwap (set->numPrograms) > 0)
                    setCurrentProgram (oldProg);

                auto prog = addBytesToPointer (set->programs, oldProg * progLen);

                if (getAddressDifference (prog, set) >= (int) dataSize)
                    return false;

                if (! restoreProgramSettings (prog))
                    return false;
            }
        }
        else if (compareMagic (set->fxMagic, "FxCk"))
        {
            // single program
            auto prog = (const fxProgram*) data;

            if (! compareMagic (prog->chunkMagic, "CcnK"))
                return false;

            changeProgramName (getCurrentProgram(), prog->prgName);

            for (int i = 0; i < fxbSwap (prog->numParams); ++i)
                if (auto* param = getParameters()[i])
                    param->setValue (fxbSwapFloat (prog->params[i]));
        }
        else if (compareMagic (set->fxMagic, "FBCh"))
        {
            // non-preset chunk
            auto cset = (const fxChunkSet*) data;

            if ((size_t) fxbSwap (cset->chunkSize) + sizeof (fxChunkSet) - 8 > (size_t) dataSize)
                return false;

            setChunkData (cset->chunk, fxbSwap (cset->chunkSize), false);
        }
        else if (compareMagic (set->fxMagic, "FPCh"))
        {
            // preset chunk
            auto cset = (const fxProgramSet*) data;

            if ((size_t) fxbSwap (cset->chunkSize) + sizeof (fxProgramSet) - 8 > (size_t) dataSize)
                return false;

            setChunkData (cset->chunk, fxbSwap (cset->chunkSize), true);

            changeProgramName (getCurrentProgram(), cset->name);
        }
        else
        {
            return false;
        }

        return true;
    }

    bool saveToFXBFile (MemoryBlock& dest, bool isFXB, int maxSizeMB = 128)
    {
        auto numPrograms = getNumPrograms();
        auto numParams = getParameters().size();

        if (usesChunks())
        {
            MemoryBlock chunk;
            getChunkData (chunk, ! isFXB, maxSizeMB);

            if (isFXB)
            {
                auto totalLen = sizeof (fxChunkSet) + chunk.getSize() - 8;
                dest.setSize (totalLen, true);

                auto set = (fxChunkSet*) dest.getData();
                set->chunkMagic = fxbName ("CcnK");
                set->byteSize = 0;
                set->fxMagic = fxbName ("FBCh");
                set->version = fxbSwap (fxbVersionNum);
                set->fxID = fxbSwap (getUID());
                set->fxVersion = fxbSwap (getVersionNumber());
                set->numPrograms = fxbSwap (numPrograms);
                set->chunkSize = fxbSwap ((int32) chunk.getSize());

                chunk.copyTo (set->chunk, 0, chunk.getSize());
            }
            else
            {
                auto totalLen = sizeof (fxProgramSet) + chunk.getSize() - 8;
                dest.setSize (totalLen, true);

                auto set = (fxProgramSet*) dest.getData();
                set->chunkMagic = fxbName ("CcnK");
                set->byteSize = 0;
                set->fxMagic = fxbName ("FPCh");
                set->version = fxbSwap (fxbVersionNum);
                set->fxID = fxbSwap (getUID());
                set->fxVersion = fxbSwap (getVersionNumber());
                set->numPrograms = fxbSwap (numPrograms);
                set->chunkSize = fxbSwap ((int32) chunk.getSize());

                getCurrentProgramName().copyToUTF8 (set->name, sizeof (set->name) - 1);
                chunk.copyTo (set->chunk, 0, chunk.getSize());
            }
        }
        else
        {
            if (isFXB)
            {
                auto progLen = (int) sizeof (fxProgram) + (numParams - 1) * (int) sizeof (float);
                auto len = (size_t) (progLen * jmax (1, numPrograms)) + (sizeof (fxSet) - sizeof (fxProgram));
                dest.setSize (len, true);

                auto set = (fxSet*) dest.getData();
                set->chunkMagic = fxbName ("CcnK");
                set->byteSize = 0;
                set->fxMagic = fxbName ("FxBk");
                set->version = fxbSwap (fxbVersionNum);
                set->fxID = fxbSwap (getUID());
                set->fxVersion = fxbSwap (getVersionNumber());
                set->numPrograms = fxbSwap (numPrograms);

                MemoryBlock oldSettings;
                createTempParameterStore (oldSettings);

                auto oldProgram = getCurrentProgram();

                if (oldProgram >= 0)
                    setParamsInProgramBlock (addBytesToPointer (set->programs, oldProgram * progLen));

                for (int i = 0; i < numPrograms; ++i)
                {
                    if (i != oldProgram)
                    {
                        setCurrentProgram (i);
                        setParamsInProgramBlock (addBytesToPointer (set->programs, i * progLen));
                    }
                }

                if (oldProgram >= 0)
                    setCurrentProgram (oldProgram);

                restoreFromTempParameterStore (oldSettings);
            }
            else
            {
                dest.setSize ((size_t) ((numParams - 1) * (int) sizeof (float)) + sizeof (fxProgram), true);
                setParamsInProgramBlock ((fxProgram*) dest.getData());
            }
        }

        return true;
    }

    bool usesChunks() const noexcept        { return vstEffect != nullptr && (vstEffect->flags & Vst2::effFlagsProgramChunks) != 0; }

    bool getChunkData (MemoryBlock& mb, bool isPreset, int maxSizeMB) const
    {
        if (usesChunks())
        {
            void* data = nullptr;
            auto bytes = (size_t) dispatch (Vst2::effGetChunk, isPreset ? 1 : 0, 0, &data, 0.0f);

            if (data != nullptr && bytes <= (size_t) maxSizeMB * 1024 * 1024)
            {
                mb.setSize (bytes);
                mb.copyFrom (data, 0, bytes);

                return true;
            }
        }

        return false;
    }

    bool setChunkData (const void* data, const int size, bool isPreset)
    {
        if (size > 0 && usesChunks())
        {
            dispatch (Vst2::effSetChunk, isPreset ? 1 : 0, size, (void*) data, 0.0f);

            if (! isPreset)
                updateStoredProgramNames();

            return true;
        }

        return false;
    }

    bool updateSizeFromEditor (int w, int h);

    Vst2::AEffect* vstEffect;
    ModuleHandle::Ptr vstModule;

    std::unique_ptr<VSTPluginFormat::ExtraFunctions> extraFunctions;

private:
    //==============================================================================
    struct VST2BypassParameter final : public Parameter
    {
        VST2BypassParameter (VSTPluginInstance& effectToUse)
            : parent (effectToUse),
              vstOnStrings (TRANS ("on"), TRANS ("yes"), TRANS ("true")),
              vstOffStrings (TRANS ("off"), TRANS ("no"), TRANS ("false")),
              values (TRANS ("Off"), TRANS ("On"))
        {
        }

        void setValue (float newValue) override
        {
            currentValue = (! approximatelyEqual (newValue, 0.0f));

            if (parent.vstSupportsBypass)
                parent.dispatch (Vst2::effSetBypass, 0, currentValue ? 1 : 0, nullptr, 0.0f);
        }

        float getValueForText (const String& text) const override
        {
            String lowercaseText (text.toLowerCase());

            for (auto& testText : vstOnStrings)
                if (lowercaseText == testText)
                    return 1.0f;

            for (auto& testText : vstOffStrings)
                if (lowercaseText == testText)
                    return 0.0f;

            return text.getIntValue() != 0 ? 1.0f : 0.0f;
        }

        float getValue() const override                                     { return currentValue; }
        float getDefaultValue() const override                              { return 0.0f; }
        String getName (int /*maximumStringLength*/) const override         { return "Bypass"; }
        String getText (float value, int) const override                    { return (! approximatelyEqual (value, 0.0f) ? TRANS ("On") : TRANS ("Off")); }
        bool isAutomatable() const override                                 { return true; }
        bool isDiscrete() const override                                    { return true; }
        bool isBoolean() const override                                     { return true; }
        int getNumSteps() const override                                    { return 2; }
        StringArray getAllValueStrings() const override                     { return values; }
        String getLabel() const override                                    { return {}; }
        String getParameterID() const override                              { return {}; }

        VSTPluginInstance& parent;
        bool currentValue = false;
        StringArray vstOnStrings, vstOffStrings, values;
    };

    //==============================================================================
    String name;
    CriticalSection lock;
    std::atomic<bool> wantsMidiMessages { false };
    bool initialised = false;
    std::atomic<bool> isPowerOn { false };
    bool lastProcessBlockCallWasBypass = false, vstSupportsBypass = false;
    mutable StringArray programNames;
    AudioBuffer<float> outOfPlaceBuffer;
    TempChannelPointers tempChannelPointers[2];

    CriticalSection midiInLock;
    MidiBuffer incomingMidi;
    VSTMidiEventList midiEventsToSend;
    Vst2::VstTimeInfo vstHostTime;

    AudioBuffer<float> tmpBufferFloat;
    HeapBlock<float*> channelBufferFloat;

    AudioBuffer<double> tmpBufferDouble;
    HeapBlock<double*> channelBufferDouble;
    std::unique_ptr<VST2BypassParameter> bypassParam;

    std::unique_ptr<VSTXMLInfo> xmlInfo;

    static pointer_sized_int handleCanDo (const char* name)
    {
        static const char* canDos[] = { "supplyIdle",
                                        "sendVstEvents",
                                        "sendVstMidiEvent",
                                        "sendVstTimeInfo",
                                        "receiveVstEvents",
                                        "receiveVstMidiEvent",
                                        "supportShell",
                                        "sizeWindow",
                                        "shellCategory" };

        for (int i = 0; i < numElementsInArray (canDos); ++i)
            if (strcmp (canDos[i], name) == 0)
                return 1;

        return 0;
    }

    static pointer_sized_int getHostName (char* name)
    {
        String hostName (JUCE_VST_FALLBACK_HOST_NAME);

        if (auto* app = JUCEApplicationBase::getInstance())
            hostName = app->getApplicationName();

        hostName.copyToUTF8 (name, (size_t) jmin (Vst2::kVstMaxVendorStrLen, Vst2::kVstMaxProductStrLen) - 1);
        return 1;
    }

    pointer_sized_int getVSTTime() noexcept
    {
        JUCE_BEGIN_IGNORE_WARNINGS_MSVC (4311)

        return (pointer_sized_int) &vstHostTime;

        JUCE_END_IGNORE_WARNINGS_MSVC
    }

    void handleIdle()
    {
        if (insideVSTCallback == 0 && MessageManager::getInstance()->isThisTheMessageThread())
        {
            const IdleCallRecursionPreventer icrp;

           #if JUCE_MAC
            if (getActiveEditor() != nullptr)
                dispatch (Vst2::effEditIdle, 0, 0, nullptr, 0);
           #endif

            Timer::callPendingTimersSynchronously();
            handleUpdateNowIfNeeded();

            for (int i = ComponentPeer::getNumPeers(); --i >= 0;)
                if (auto* p = ComponentPeer::getPeer (i))
                    p->performAnyPendingRepaintsNow();
        }
    }

    void setWindowSize (int width, int height)
    {
       #if JUCE_LINUX || JUCE_BSD
        const MessageManagerLock mmLock;
       #endif

        updateSizeFromEditor (width, height);
    }

    //==============================================================================
    static Vst2::AEffect* constructEffect (const ModuleHandle::Ptr& module)
    {
        Vst2::AEffect* effect = nullptr;
        try
        {
            const IdleCallRecursionPreventer icrp;
            _fpreset();

            JUCE_VST_LOG ("Creating VST instance: " + module->pluginName);

           #if JUCE_MAC
            if (module->resFileId != 0)
                UseResFile (module->resFileId);
           #endif

            constexpr Vst2::audioMasterCallback audioMaster = [] (Vst2::AEffect* eff,
                                                                  Vst2::VstInt32 opcode,
                                                                  Vst2::VstInt32 index,
                                                                  Vst2::VstIntPtr value,
                                                                  void* ptr,
                                                                  float opt) -> Vst2::VstIntPtr
            {
                if (eff != nullptr)
                    if (auto* instance = (VSTPluginInstance*) (eff->resvd2))
                        return instance->handleCallback (opcode, index, value, ptr, opt);

                return VSTPluginInstance::handleGeneralCallback (opcode, index, value, ptr, opt);
            };

            {
                JUCE_VST_WRAPPER_INVOKE_MAIN
            }

            if (effect != nullptr && effect->magic == 0x56737450 /* 'VstP' */)
            {
                jassert (effect->resvd2 == 0);
                jassert (effect->object != nullptr);

                _fpreset(); // some dodgy plugs mess around with this
            }
            else
            {
                effect = nullptr;
            }
        }
        catch (...)
        {}

        return effect;
    }

    static BusesProperties queryBusIO (Vst2::AEffect* effect)
    {
        BusesProperties returnValue;

        if (effect->numInputs == 0 && effect->numOutputs == 0)
            return returnValue;

        // Workaround for old broken JUCE plug-ins which would return an invalid
        // speaker arrangement if the host didn't ask for a specific arrangement
        // beforehand.
        // Check if the plug-in reports any default layouts. If it doesn't, then
        // try setting a default layout compatible with the number of pins this
        // plug-in is reporting.
        if (! pluginHasDefaultChannelLayouts (effect))
        {
            SpeakerMappings::VstSpeakerConfigurationHolder canonicalIn  (AudioChannelSet::canonicalChannelSet (effect->numInputs));
            SpeakerMappings::VstSpeakerConfigurationHolder canonicalOut (AudioChannelSet::canonicalChannelSet (effect->numOutputs));

            effect->dispatcher (effect, Vst2::effSetSpeakerArrangement, 0,
                                      (pointer_sized_int) &canonicalIn.get(), (void*) &canonicalOut.get(), 0.0f);
        }

        const auto arrangement = getSpeakerArrangementWrapper (effect);

        for (int dir = 0; dir < 2; ++dir)
        {
            const bool isInput = (dir == 0);
            const int opcode = (isInput ? Vst2::effGetInputProperties : Vst2::effGetOutputProperties);
            const int maxChannels = (isInput ? effect->numInputs : effect->numOutputs);
            const auto* arr = (isInput ? arrangement.in : arrangement.out);
            bool busAdded = false;

            Vst2::VstPinProperties pinProps;
            AudioChannelSet layout;

            for (int ch = 0; ch < maxChannels; ch += layout.size())
            {
                if (effect->dispatcher (effect, opcode, ch, 0, &pinProps, 0.0f) == 0)
                    break;

                if ((pinProps.flags & Vst2::kVstPinUseSpeaker) != 0)
                {
                    layout = SpeakerMappings::vstArrangementTypeToChannelSet (pinProps.arrangementType, 0);

                    if (layout.isDisabled())
                        break;
                }
                else if (arr == nullptr)
                {
                    layout = ((pinProps.flags & Vst2::kVstPinIsStereo) != 0 ? AudioChannelSet::stereo() : AudioChannelSet::mono());
                }
                else
                    break;

                busAdded = true;
                returnValue.addBus (isInput, pinProps.label, layout, true);
            }

            // no buses?
            if (! busAdded && maxChannels > 0)
            {
                String busName = (isInput ? "Input" : "Output");

                if (effect->dispatcher (effect, opcode, 0, 0, &pinProps, 0.0f) != 0)
                    busName = pinProps.label;

                if (arr != nullptr)
                    layout = SpeakerMappings::vstArrangementTypeToChannelSet (*arr);
                else
                    layout = AudioChannelSet::canonicalChannelSet (maxChannels);

                returnValue.addBus (isInput, busName, layout, true);
            }
        }

        return returnValue;
    }

    static bool pluginHasDefaultChannelLayouts (Vst2::AEffect* effect)
    {
        if (getSpeakerArrangementWrapper (effect).isValid())
            return true;

        for (int dir = 0; dir < 2; ++dir)
        {
            const bool isInput = (dir == 0);
            const int opcode = (isInput ? Vst2::effGetInputProperties : Vst2::effGetOutputProperties);
            const int maxChannels = (isInput ? effect->numInputs : effect->numOutputs);

            int channels = 1;

            for (int ch = 0; ch < maxChannels; ch += channels)
            {
                Vst2::VstPinProperties pinProps;

                if (effect->dispatcher (effect, opcode, ch, 0, &pinProps, 0.0f) == 0)
                    return false;

                if ((pinProps.flags & Vst2::kVstPinUseSpeaker) != 0)
                    return true;

                channels = (pinProps.flags & Vst2::kVstPinIsStereo) != 0 ? 2 : 1;
            }
        }

        return false;
    }

    struct SpeakerArrangements
    {
        const Vst2::VstSpeakerArrangement* in;
        const Vst2::VstSpeakerArrangement* out;

        bool isValid() const noexcept { return in != nullptr && out != nullptr; }
    };

    static SpeakerArrangements getSpeakerArrangementWrapper (Vst2::AEffect* effect)
    {
        // Workaround: unfortunately old JUCE VST-2 plug-ins had a bug and would crash if
        // you try to get the speaker arrangement when there are no input channels present.
        // Hopefully, one day (when there are no more old JUCE plug-ins around), we can
        // comment out the next two lines.
        if (effect->numInputs == 0)
            return { nullptr, nullptr };

        SpeakerArrangements result { nullptr, nullptr };
        const auto dispatchResult = effect->dispatcher (effect,
                                                        Vst2::effGetSpeakerArrangement,
                                                        0,
                                                        reinterpret_cast<pointer_sized_int> (&result.in),
                                                        &result.out,
                                                        0.0f);

        if (dispatchResult != 0)
            return result;

        return { nullptr, nullptr };
    }

    template <typename Member, typename Value>
    void setFromOptional (Member& target, Optional<Value> opt, int32_t flag)
    {
        if (opt.hasValue())
        {
            target = static_cast<Member> (*opt);
            vstHostTime.flags |= flag;
        }
        else
        {
            vstHostTime.flags &= ~flag;
        }
    }

    //==============================================================================
    template <typename FloatType>
    void processAudio (AudioBuffer<FloatType>& buffer, MidiBuffer& midiMessages,
                       AudioBuffer<FloatType>& tmpBuffer,
                       HeapBlock<FloatType*>& channelBuffer,
                       bool processBlockBypassedCalled)
    {
        if (vstSupportsBypass)
        {
            updateBypass (processBlockBypassedCalled);
        }
        else if (processBlockBypassedCalled)
        {
            // if this vst does not support bypass then we will have to do this ourselves
            AudioProcessor::processBlockBypassed (buffer, midiMessages);
            return;
        }

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

        if (initialised)
        {
            if (auto* currentPlayHead = getPlayHead())
            {
                if (const auto position = currentPlayHead->getPosition())
                {
                    if (const auto samplePos = position->getTimeInSamples())
                        vstHostTime.samplePos = (double) *samplePos;
                    else
                        jassertfalse; // VST hosts *must* call setTimeInSamples on the audio playhead

                    if (auto sig = position->getTimeSignature())
                    {
                        vstHostTime.flags |= Vst2::kVstTimeSigValid;
                        vstHostTime.timeSigNumerator   = sig->numerator;
                        vstHostTime.timeSigDenominator = sig->denominator;
                    }
                    else
                    {
                        vstHostTime.flags &= ~Vst2::kVstTimeSigValid;
                    }

                    setFromOptional (vstHostTime.ppqPos,      position->getPpqPosition(),               Vst2::kVstPpqPosValid);
                    setFromOptional (vstHostTime.barStartPos, position->getPpqPositionOfLastBarStart(), Vst2::kVstBarsValid);
                    setFromOptional (vstHostTime.nanoSeconds, position->getHostTimeNs(),                Vst2::kVstNanosValid);
                    setFromOptional (vstHostTime.tempo,       position->getBpm(),                       Vst2::kVstTempoValid);

                    int32 newTransportFlags = 0;
                    if (position->getIsPlaying())     newTransportFlags |= Vst2::kVstTransportPlaying;
                    if (position->getIsRecording())   newTransportFlags |= Vst2::kVstTransportRecording;

                    if (newTransportFlags != (vstHostTime.flags & (Vst2::kVstTransportPlaying
                                                                   | Vst2::kVstTransportRecording)))
                        vstHostTime.flags = (vstHostTime.flags & ~(Vst2::kVstTransportPlaying | Vst2::kVstTransportRecording)) | newTransportFlags | Vst2::kVstTransportChanged;
                    else
                        vstHostTime.flags &= ~Vst2::kVstTransportChanged;

                    const auto optionalFrameRate = [fr = position->getFrameRate()]() -> Optional<Vst2::VstInt32>
                    {
                        if (! fr.hasValue())
                            return {};

                        switch (fr->getBaseRate())
                        {
                            case 24:        return fr->isPullDown() ? Vst2::kVstSmpte239fps : Vst2::kVstSmpte24fps;
                            case 25:        return fr->isPullDown() ? Vst2::kVstSmpte249fps : Vst2::kVstSmpte25fps;
                            case 30:        return fr->isPullDown() ? (fr->isDrop() ? Vst2::kVstSmpte2997dfps : Vst2::kVstSmpte2997fps)
                                                                    : (fr->isDrop() ? Vst2::kVstSmpte30dfps   : Vst2::kVstSmpte30fps);
                            case 60:        return fr->isPullDown() ? Vst2::kVstSmpte599fps : Vst2::kVstSmpte60fps;
                        }

                        return {};
                    }();

                    vstHostTime.flags |= optionalFrameRate ? Vst2::kVstSmpteValid : 0;
                    vstHostTime.smpteFrameRate = optionalFrameRate.orFallback (Vst2::VstSmpteFrameRate{});
                    const auto effectiveRate = position->getFrameRate().hasValue() ? position->getFrameRate()->getEffectiveRate() : 0.0;
                    vstHostTime.smpteOffset = (int32) (position->getTimeInSeconds().orFallback (0.0) * 80.0 * effectiveRate + 0.5);

                    if (const auto loop = position->getLoopPoints())
                    {
                        vstHostTime.flags |= Vst2::kVstCyclePosValid;
                        vstHostTime.cycleStartPos = loop->ppqStart;
                        vstHostTime.cycleEndPos   = loop->ppqEnd;
                    }
                    else
                    {
                        vstHostTime.flags &= ~Vst2::kVstCyclePosValid;
                    }

                    if (position->getIsLooping())
                        vstHostTime.flags |= Vst2::kVstTransportCycleActive;
                    else
                        vstHostTime.flags &= ~Vst2::kVstTransportCycleActive;
                }
            }

            vstHostTime.nanoSeconds = getVSTHostTimeNanoseconds();

            if (wantsMidiMessages)
            {
                midiEventsToSend.clear();
                midiEventsToSend.ensureSize (1);

                for (const auto metadata : midiMessages)
                    midiEventsToSend.addEvent (metadata.data, metadata.numBytes,
                                               jlimit (0, numSamples - 1, metadata.samplePosition));

                vstEffect->dispatcher (vstEffect, Vst2::effProcessEvents, 0, 0, midiEventsToSend.events, 0);
            }

            _clearfp();

            // always ensure that the buffer is at least as large as the maximum number of channels
            auto maxChannels = jmax (vstEffect->numInputs, vstEffect->numOutputs);
            auto channels = channelBuffer.get();

            if (numChannels < maxChannels)
            {
                if (numSamples > tmpBuffer.getNumSamples())
                    tmpBuffer.setSize (tmpBuffer.getNumChannels(), numSamples);

                tmpBuffer.clear();
            }

            for (int ch = 0; ch < maxChannels; ++ch)
                channels[ch] = (ch < numChannels ? buffer.getWritePointer (ch) : tmpBuffer.getWritePointer (ch));

            {
                AudioBuffer<FloatType> processBuffer (channels, maxChannels, numSamples);

                invokeProcessFunction (processBuffer, numSamples);
            }
        }
        else
        {
            // Not initialised, so just bypass.
            for (int i = getTotalNumOutputChannels(); --i >= 0;)
                buffer.clear (i, 0, buffer.getNumSamples());
        }

        {
            // copy any incoming midi.
            const ScopedLock sl (midiInLock);

            midiMessages.swapWith (incomingMidi);
            incomingMidi.clear();
        }
    }

    //==============================================================================
    inline void invokeProcessFunction (AudioBuffer<float>& buffer, int32 sampleFrames)
    {
        if ((vstEffect->flags & Vst2::effFlagsCanReplacing) != 0)
        {
            vstEffect->processReplacing (vstEffect, tempChannelPointers[0].getArrayOfModifiableWritePointers (buffer),
                                                    tempChannelPointers[1].getArrayOfModifiableWritePointers (buffer), sampleFrames);
        }
        else
        {
            outOfPlaceBuffer.setSize (vstEffect->numOutputs, sampleFrames);
            outOfPlaceBuffer.clear();

            vstEffect->process (vstEffect, tempChannelPointers[0].getArrayOfModifiableWritePointers (buffer),
                                           tempChannelPointers[1].getArrayOfModifiableWritePointers (outOfPlaceBuffer), sampleFrames);

            for (int i = vstEffect->numOutputs; --i >= 0;)
                buffer.copyFrom (i, 0, outOfPlaceBuffer.getReadPointer (i), sampleFrames);
        }
    }

    inline void invokeProcessFunction (AudioBuffer<double>& buffer, int32 sampleFrames)
    {
        vstEffect->processDoubleReplacing (vstEffect, tempChannelPointers[0].getArrayOfModifiableWritePointers (buffer),
                                                      tempChannelPointers[1].getArrayOfModifiableWritePointers (buffer), sampleFrames);
    }

    //==============================================================================
    bool restoreProgramSettings (const fxProgram* const prog)
    {
        if (compareMagic (prog->chunkMagic, "CcnK")
             && compareMagic (prog->fxMagic, "FxCk"))
        {
            changeProgramName (getCurrentProgram(), prog->prgName);

            for (int i = 0; i < fxbSwap (prog->numParams); ++i)
                if (auto* param = getParameters()[i])
                    param->setValue (fxbSwapFloat (prog->params[i]));

            return true;
        }

        return false;
    }

    String getTextForOpcode (const int index, const int opcode) const
    {
        if (vstEffect == nullptr)
            return {};

        jassert (index >= 0 && index < vstEffect->numParams);
        char nm[256] = { 0 };
        dispatch (opcode, index, 0, nm, 0);
        return String::createStringFromData (nm, (int) sizeof (nm)).trim();
    }

    String getCurrentProgramName()
    {
        String progName;

        if (vstEffect != nullptr)
        {
            {
                char nm[256] = { 0 };
                dispatch (Vst2::effGetProgramName, 0, 0, nm, 0);
                progName = String::createStringFromData (nm, (int) sizeof (nm)).trim();
            }

            const int index = getCurrentProgram();

            if (index >= 0 && programNames[index].isEmpty())
            {
                while (programNames.size() < index)
                    programNames.add (String());

                programNames.set (index, progName);
            }
        }

        return progName;
    }

    void setParamsInProgramBlock (fxProgram* prog)
    {
        auto numParams = getParameters().size();

        prog->chunkMagic = fxbName ("CcnK");
        prog->byteSize = 0;
        prog->fxMagic = fxbName ("FxCk");
        prog->version = fxbSwap (fxbVersionNum);
        prog->fxID = fxbSwap (getUID());
        prog->fxVersion = fxbSwap (getVersionNumber());
        prog->numParams = fxbSwap (numParams);

        getCurrentProgramName().copyToUTF8 (prog->prgName, sizeof (prog->prgName) - 1);

        for (int i = 0; i < numParams; ++i)
            if (auto* param = getParameters()[i])
                prog->params[i] = fxbSwapFloat (param->getValue());
    }

    void updateStoredProgramNames()
    {
        if (vstEffect != nullptr && getNumPrograms() > 0)
        {
            char nm[256] = { 0 };

            // only do this if the plugin can't use indexed names.
            if (dispatch (Vst2::effGetProgramNameIndexed, 0, -1, nm, 0) == 0)
            {
                auto oldProgram = getCurrentProgram();
                MemoryBlock oldSettings;
                createTempParameterStore (oldSettings);

                for (int i = 0; i < getNumPrograms(); ++i)
                {
                    setCurrentProgram (i);
                    getCurrentProgramName();  // (this updates the list)
                }

                setCurrentProgram (oldProgram);
                restoreFromTempParameterStore (oldSettings);
            }
        }
    }

    void handleMidiFromPlugin (const Vst2::VstEvents* events)
    {
        if (events != nullptr)
        {
            const ScopedLock sl (midiInLock);
            VSTMidiEventList::addEventsToMidiBuffer (events, incomingMidi);
        }
    }

    //==============================================================================
    void createTempParameterStore (MemoryBlock& dest)
    {
        auto numParameters = getParameters().size();
        dest.setSize (64 + 4 * (size_t) numParameters);
        dest.fillWith (0);

        getCurrentProgramName().copyToUTF8 ((char*) dest.getData(), 63);

        auto p = unalignedPointerCast<float*> (((char*) dest.getData()) + 64);

        for (int i = 0; i < numParameters; ++i)
            if (auto* param = getParameters()[i])
                p[i] = param->getValue();
    }

    void restoreFromTempParameterStore (const MemoryBlock& m)
    {
        changeProgramName (getCurrentProgram(), (const char*) m.getData());

        auto p = unalignedPointerCast<float*> (((char*) m.getData()) + 64);
        auto numParameters = getParameters().size();

        for (int i = 0; i < numParameters; ++i)
            if (auto* param = getParameters()[i])
                param->setValue (p[i]);
    }

    pointer_sized_int getVstDirectory() const
    {
       #if JUCE_MAC
        return (pointer_sized_int) (void*) &vstModule->parentDirFSSpec;
       #else
        return (pointer_sized_int) (pointer_sized_uint) vstModule->fullParentDirectoryPathName.toRawUTF8();
       #endif
    }

    //==============================================================================
    int getVersionNumber() const noexcept   { return vstEffect != nullptr ? vstEffect->version : 0; }

    String getVersion() const
    {
        auto v = (unsigned int) dispatch (Vst2::effGetVendorVersion, 0, 0, nullptr, 0);

        String s;

        if (v == 0 || (int) v == -1)
            v = (unsigned int) getVersionNumber();

        if (v != 0)
        {
            // See yfede's post for the rational on this encoding
            // https://forum.juce.com/t/issues-with-version-integer-reported-by-vst2/23867/6

            unsigned int major = 0, minor = 0, bugfix = 0, build = 0;

            if (v < 10)            // Encoding A
            {
                major = v;
            }
            else if (v < 10000)    // Encoding B
            {
                major  = (v / 1000);
                minor  = (v % 1000) / 100;
                bugfix = (v % 100)  / 10;
                build  = (v % 10);
            }
            else if (v < 0x10000)  // Encoding C
            {
                major  = (v / 10000);
                minor  = (v % 10000) / 1000;
                bugfix = (v % 1000)  / 100;
                build  = (v % 100)   / 10;
            }
            else if (v < 0x650000) // Encoding D
            {
                major  = (v >> 16) & 0xff;
                minor  = (v >> 8)  & 0xff;
                bugfix = (v >> 0)  & 0xff;
            }
            else                  // Encoding E
            {
                major  = (v / 10000000);
                minor  = (v % 10000000) / 100000;
                bugfix = (v % 100000)   / 1000;
                build  = (v % 1000);
            }

            s << (int) major << '.' << (int) minor << '.' << (int) bugfix << '.' << (int) build;
        }

        return s;
    }

    const char* getCategory() const
    {
        switch (getVstCategory())
        {
            case Vst2::kPlugCategEffect:          return "Effect";
            case Vst2::kPlugCategSynth:           return "Synth";
            case Vst2::kPlugCategAnalysis:        return "Analysis";
            case Vst2::kPlugCategMastering:       return "Mastering";
            case Vst2::kPlugCategSpacializer:     return "Spacial";
            case Vst2::kPlugCategRoomFx:          return "Reverb";
            case Vst2::kPlugSurroundFx:           return "Surround";
            case Vst2::kPlugCategRestoration:     return "Restoration";
            case Vst2::kPlugCategGenerator:       return "Tone generation";
            case Vst2::kPlugCategOfflineProcess:  return "Offline Process";
            case Vst2::kPlugCategShell:           return "Shell";
            case Vst2::kPlugCategUnknown:         return "Unknown";
            case Vst2::kPlugCategMaxCount:
            default:                              break;
        }

        return nullptr;
    }

    void setPower (const bool on)
    {
        dispatch (Vst2::effMainsChanged, 0, on ? 1 : 0, nullptr, 0);
        isPowerOn = on;
    }

    //==============================================================================
    void updateBypass (bool processBlockBypassedCalled)
    {
        if (processBlockBypassedCalled)
        {
            if (approximatelyEqual (bypassParam->getValue(), 0.0f) || ! lastProcessBlockCallWasBypass)
                bypassParam->setValue (1.0f);
        }
        else
        {
            if (lastProcessBlockCallWasBypass)
                bypassParam->setValue (0.0f);
        }

        lastProcessBlockCallWasBypass = processBlockBypassedCalled;
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (VSTPluginInstance)
};

//==============================================================================
#if ! (JUCE_IOS || JUCE_ANDROID)
struct VSTPluginWindow;
static Array<VSTPluginWindow*> activeVSTWindows;

//==============================================================================
struct VSTPluginWindow final : public AudioProcessorEditor,
                              #if ! JUCE_MAC
                               private ComponentMovementWatcher,
                              #endif
                               private Timer
{
public:
    VSTPluginWindow (VSTPluginInstance& plug)
        : AudioProcessorEditor (&plug),
         #if ! JUCE_MAC
          ComponentMovementWatcher (this),
         #endif
          plugin (plug)
    {
       #if JUCE_LINUX || JUCE_BSD
        pluginWindow = None;
        ignoreUnused (pluginRefusesToResize, alreadyInside);
       #elif JUCE_MAC
        ignoreUnused (recursiveResize, pluginRefusesToResize, alreadyInside);

        cocoaWrapper.reset (new NSViewComponentWithParent (plugin));
        addAndMakeVisible (cocoaWrapper.get());
       #endif

        activeVSTWindows.add (this);

        Vst2::ERect* rect = nullptr;
        dispatch (Vst2::effEditGetRect, 0, 0, &rect, 0);

        if (rect != nullptr)
            updateSizeFromEditor (rect->right - rect->left, rect->bottom - rect->top);
        else
            updateSizeFromEditor (1, 1);

        setOpaque (true);
        setVisible (true);

       #if JUCE_WINDOWS
        addAndMakeVisible (embeddedComponent);
       #endif
    }

    ~VSTPluginWindow() override
    {
        activeVSTWindows.removeFirstMatchingValue (this);

        closePluginWindow();

       #if JUCE_MAC
        cocoaWrapper.reset();
       #endif

        plugin.editorBeingDeleted (this);
    }

    //==============================================================================
    /*  Convert from the hosted VST's coordinate system to the component's coordinate system. */
    Rectangle<int> vstToComponentRect (Component& editor, const Rectangle<int>& vr) const
    {
        return editor.getLocalArea (nullptr, vr / (nativeScaleFactor * getDesktopScaleFactor()));
    }

    Rectangle<int> componentToVstRect (Component& editor, const Rectangle<int>& vr) const
    {
        if (auto* tl = editor.getTopLevelComponent())
            return tl->getLocalArea (&editor, vr) * nativeScaleFactor * tl->getDesktopScaleFactor();

        return {};
    }

    bool updateSizeFromEditor (int w, int h)
    {
        const auto correctedBounds = vstToComponentRect (*this, { w, h });
        setSize (correctedBounds.getWidth(), correctedBounds.getHeight());

      #if JUCE_MAC
        if (cocoaWrapper != nullptr)
            cocoaWrapper->setSize (correctedBounds.getWidth(), correctedBounds.getHeight());
      #endif

        return true;
    }

   #if JUCE_MAC
    void paint (Graphics& g) override
    {
        g.fillAll (Colours::black);
    }

    void visibilityChanged() override
    {
        if (isShowing())
            openPluginWindow ((NSView*) cocoaWrapper->getView());
        else
            closePluginWindow();
    }

    void childBoundsChanged (Component*) override
    {
        auto w = cocoaWrapper->getWidth();
        auto h = cocoaWrapper->getHeight();

        if (w != getWidth() || h != getHeight())
            setSize (w, h);
    }

    void parentHierarchyChanged() override { visibilityChanged(); }
   #else
    float getEffectiveScale() const
    {
        return nativeScaleFactor * userScaleFactor;
    }

    void paint (Graphics& g) override
    {
       #if JUCE_LINUX || JUCE_BSD
        if (isOpen)
        {
            if (pluginWindow != 0)
            {
                auto clip = componentToVstRect (*this, g.getClipBounds().toNearestInt());

                X11Symbols::getInstance()->xClearArea (display, pluginWindow, clip.getX(), clip.getY(),
                                                       static_cast<unsigned int> (clip.getWidth()),
                                                       static_cast<unsigned int> (clip.getHeight()), True);
            }
        }
        else
       #endif
        {
            g.fillAll (Colours::black);
        }
    }

    void componentMovedOrResized (bool /*wasMoved*/, bool /*wasResized*/) override
    {
        if (recursiveResize)
            return;

        if (getPeer() != nullptr)
        {
            const ScopedValueSetter<bool> recursiveResizeSetter (recursiveResize, true);

           #if JUCE_WINDOWS
            embeddedComponent.setBounds (getLocalBounds());
           #elif JUCE_LINUX || JUCE_BSD
            const auto pos = componentToVstRect (*this, getLocalBounds());

            if (pluginWindow != 0)
            {
                auto* symbols = X11Symbols::getInstance();
                symbols->xMoveResizeWindow (display,
                                            pluginWindow,
                                            pos.getX(),
                                            pos.getY(),
                                            (unsigned int) pos.getWidth(),
                                            (unsigned int) pos.getHeight());
                symbols->xMapRaised (display, pluginWindow);
                symbols->xFlush (display);
            }
           #endif
        }
    }

    using ComponentMovementWatcher::componentMovedOrResized;

    void componentVisibilityChanged() override
    {
        if (isShowing())
            openPluginWindow();
        else if (! shouldAvoidDeletingWindow())
            closePluginWindow();

        setContentScaleFactor();

       #if JUCE_LINUX || JUCE_BSD
        MessageManager::callAsync ([safeThis = SafePointer<VSTPluginWindow> { this }]
        {
            if (safeThis != nullptr)
                safeThis->componentMovedOrResized (true, true);
        });
       #else
        componentMovedOrResized (true, true);
       #endif
    }

    using ComponentMovementWatcher::componentVisibilityChanged;

    void componentPeerChanged() override
    {
        closePluginWindow();

        if (getPeer() != nullptr)
        {
            openPluginWindow();
            componentMovedOrResized (true, true);
        }
    }

    void setContentScaleFactor()
    {
        if (pluginRespondsToDPIChanges)
            dispatch (Vst2::effVendorSpecific,
                      (int) ByteOrder::bigEndianInt ("PreS"),
                      (int) ByteOrder::bigEndianInt ("AeCs"),
                      nullptr, getEffectiveScale());
    }
   #endif

    void setScaleFactor (float scale) override
    {
        userScaleFactor = scale;

       #if ! JUCE_MAC
        setContentScaleFactor();
       #endif

       #if JUCE_WINDOWS
        resizeToFit();
       #endif
    }

    //==============================================================================
    bool keyStateChanged (bool) override                 { return pluginWantsKeys; }
    bool keyPressed (const juce::KeyPress&) override     { return pluginWantsKeys; }

    //==============================================================================
    void timerCallback() override
    {
        if (isShowing())
        {
           #if JUCE_WINDOWS
            if (--sizeCheckCount <= 0)
            {
                sizeCheckCount = 10;
                checkPluginWindowSize();
            }
           #endif

            static bool reentrantGuard = false;

            if (! reentrantGuard)
            {
                reentrantGuard = true;

               #if JUCE_WINDOWS
                // Some plugins may draw/resize inside their idle callback, so ensure that
                // DPI awareness is set correctly inside this call.
                ScopedThreadDPIAwarenessSetter scope (getPluginHWND());
               #endif
                plugin.dispatch (Vst2::effEditIdle, 0, 0, nullptr, 0);

                reentrantGuard = false;
            }

           #if JUCE_LINUX || JUCE_BSD
            if (pluginWindow == 0)
            {
                updatePluginWindowHandle();

                if (pluginWindow != 0)
                    componentMovedOrResized (true, true);
            }
           #endif
        }
    }

    //==============================================================================
    void mouseDown ([[maybe_unused]] const MouseEvent& e) override
    {
       #if JUCE_WINDOWS || JUCE_LINUX || JUCE_BSD
        toFront (true);
       #endif
    }

    void broughtToFront() override
    {
        if (activeVSTWindows.removeFirstMatchingValue (this) != -1)
            activeVSTWindows.add (this);

       #if JUCE_MAC
        dispatch (Vst2::effEditTop, 0, 0, nullptr, 0);
       #endif
    }

private:
    //==============================================================================
    // This is a workaround for old Mackie plugins that crash if their
    // window is deleted more than once.
    bool shouldAvoidDeletingWindow() const
    {
        return plugin.getPluginDescription()
                .manufacturerName.containsIgnoreCase ("Loud Technologies");
    }

    // This is an old workaround for some plugins that need a repaint when their
    // windows are first created, but it breaks some Izotope plugins.
    bool shouldRepaintCarbonWindowWhenCreated()
    {
        return ! plugin.getName().containsIgnoreCase ("izotope");
    }

    //==============================================================================
   #if JUCE_MAC
    void openPluginWindow (void* parentWindow)
    {
        if (isOpen || parentWindow == nullptr)
            return;

        isOpen = true;

        Vst2::ERect* rect = nullptr;
        dispatch (Vst2::effEditGetRect, 0, 0, &rect, 0);
        dispatch (Vst2::effEditOpen, 0, 0, parentWindow, 0);

        // do this before and after like in the steinberg example
        dispatch (Vst2::effEditGetRect, 0, 0, &rect, 0);
        dispatch (Vst2::effGetProgram, 0, 0, nullptr, 0); // also in steinberg code

        // Install keyboard hooks
        pluginWantsKeys = (dispatch (Vst2::effKeysRequired, 0, 0, nullptr, 0) == 0);

        // double-check it's not too tiny
        int w = 250, h = 150;

        if (rect != nullptr)
        {
            w = rect->right - rect->left;
            h = rect->bottom - rect->top;

            if (w == 0 || h == 0)
            {
                w = 250;
                h = 150;
            }
        }

        w = jmax (w, 32);
        h = jmax (h, 32);

        updateSizeFromEditor (w, h);

        startTimer (18 + juce::Random::getSystemRandom().nextInt (5));
        repaint();
    }
   #else
    void openPluginWindow()
    {
        if (isOpen)
            return;

        JUCE_VST_LOG ("Opening VST UI: " + plugin.getName());
        isOpen = true;

        pluginRespondsToDPIChanges = plugin.pluginCanDo ("supportsViewDpiScaling") > 0;

        setContentScaleFactor();

        Vst2::ERect* rect = nullptr;

        dispatch (Vst2::effEditGetRect, 0, 0, &rect, 0);

       #if JUCE_WINDOWS
        auto* handle = embeddedComponent.getHWND();
       #else
        auto* handle = getWindowHandle();
       #endif
        dispatch (Vst2::effEditOpen, 0, 0, handle, 0);
        dispatch (Vst2::effEditGetRect, 0, 0, &rect, 0);  // do this before and after like in the steinberg example
        dispatch (Vst2::effGetProgram, 0, 0, nullptr, 0); // also in steinberg code

        pluginWantsKeys = (dispatch (Vst2::effKeysRequired, 0, 0, nullptr, 0) == 0);

       #if JUCE_WINDOWS
        originalWndProc = nullptr;
        auto* pluginHWND = getPluginHWND();

        if (pluginHWND == nullptr)
        {
            isOpen = false;
            setSize (300, 150);
            return;
        }

        JUCE_BEGIN_IGNORE_WARNINGS_MSVC (4244)

        if (! pluginWantsKeys)
        {
            originalWndProc = (void*) GetWindowLongPtr (pluginHWND, GWLP_WNDPROC);
            SetWindowLongPtr (pluginHWND, GWLP_WNDPROC, (LONG_PTR) vstHookWndProc);
        }

        JUCE_END_IGNORE_WARNINGS_MSVC

        RECT r;

        {
            ScopedThreadDPIAwarenessSetter threadDpiAwarenessSetter { pluginHWND };
            GetWindowRect (pluginHWND, &r);
        }

        auto w = (int) (r.right - r.left);
        auto h = (int) (r.bottom - r.top);

        if (rect != nullptr)
        {
            auto rw = rect->right - rect->left;
            auto rh = rect->bottom - rect->top;

            if ((rw > 50 && rh > 50 && rw < 2000 && rh < 2000 && (! isWithin (w, rw, 2) || ! isWithin (h, rh, 2)))
                || ((w == 0 && rw > 0) || (h == 0 && rh > 0)))
            {
                // very dodgy logic to decide which size is right.
                if (std::abs (rw - w) > 350 || std::abs (rh - h) > 350)
                {
                    ScopedThreadDPIAwarenessSetter threadDpiAwarenessSetter { pluginHWND };

                    SetWindowPos (pluginHWND, nullptr,
                                  0, 0, rw, rh,
                                  SWP_NOMOVE | SWP_NOACTIVATE | SWP_NOOWNERZORDER | SWP_NOZORDER);

                    GetWindowRect (pluginHWND, &r);

                    w = r.right - r.left;
                    h = r.bottom - r.top;

                    pluginRefusesToResize = (w != rw) || (h != rh);

                    w = rw;
                    h = rh;
                }
            }
        }
       #elif JUCE_LINUX || JUCE_BSD
        updatePluginWindowHandle();

        int w = 250, h = 150;

        if (rect != nullptr)
        {
            w = rect->right - rect->left;
            h = rect->bottom - rect->top;

            if (w == 0 || h == 0)
            {
                w = 250;
                h = 150;
            }
        }

        if (pluginWindow != 0)
            X11Symbols::getInstance()->xMapRaised (display, pluginWindow);
       #endif

        // double-check it's not too tiny
        w = jmax (w, 32);
        h = jmax (h, 32);

        updateSizeFromEditor (w, h);

       #if JUCE_WINDOWS
        checkPluginWindowSize();
       #endif

        startTimer (18 + juce::Random::getSystemRandom().nextInt (5));
        repaint();
    }
   #endif

    //==============================================================================
    void closePluginWindow()
    {
        if (isOpen)
        {
            // You shouldn't end up hitting this assertion unless the host is trying to do GUI
            // cleanup on a non-GUI thread. If it does that, bad things could happen in here.
            JUCE_ASSERT_MESSAGE_MANAGER_IS_LOCKED

            JUCE_VST_LOG ("Closing VST UI: " + plugin.getName());
            isOpen = false;
            dispatch (Vst2::effEditClose, 0, 0, nullptr, 0);
            stopTimer();

           #if JUCE_WINDOWS
            JUCE_BEGIN_IGNORE_WARNINGS_MSVC (4244)
            auto* pluginHWND = getPluginHWND();

            if (originalWndProc != nullptr && pluginHWND != nullptr && IsWindow (pluginHWND))
                SetWindowLongPtr (pluginHWND, GWLP_WNDPROC, (LONG_PTR) originalWndProc);
            JUCE_END_IGNORE_WARNINGS_MSVC

            originalWndProc = nullptr;
           #elif JUCE_LINUX || JUCE_BSD
            pluginWindow = 0;
           #endif
        }
    }

    //==============================================================================
    pointer_sized_int dispatch (const int opcode, const int index, const int value, void* const ptr, float opt)
    {
        return plugin.dispatch (opcode, index, value, ptr, opt);
    }

    //==============================================================================
   #if JUCE_WINDOWS
    bool isWindowSizeCorrectForPlugin (int w, int h)
    {
        if (pluginRefusesToResize)
            return true;

        const auto converted = vstToComponentRect (*this, { w, h });
        return (isWithin (converted.getWidth(), getWidth(), 5) && isWithin (converted.getHeight(), getHeight(), 5));
    }

    void resizeToFit()
    {
        Vst2::ERect* rect = nullptr;
        dispatch (Vst2::effEditGetRect, 0, 0, &rect, 0);

        auto w = rect->right - rect->left;
        auto h = rect->bottom - rect->top;

        if (! isWindowSizeCorrectForPlugin (w, h))
        {
            updateSizeFromEditor (w, h);
            embeddedComponent.updateHWNDBounds();
            sizeCheckCount = 0;
        }
    }

    void checkPluginWindowSize()
    {
        if (! pluginRespondsToDPIChanges)
            resizeToFit();
    }

    // hooks to get keyboard events from VST windows.
    static LRESULT CALLBACK vstHookWndProc (HWND hW, UINT message, WPARAM wParam, LPARAM lParam)
    {
        for (int i = activeVSTWindows.size(); --i >= 0;)
        {
            Component::SafePointer<VSTPluginWindow> w (activeVSTWindows[i]);

            auto* pluginHWND = w->getPluginHWND();

            if (w != nullptr && pluginHWND == hW)
            {
                if (message == WM_CHAR
                    || message == WM_KEYDOWN
                    || message == WM_SYSKEYDOWN
                    || message == WM_KEYUP
                    || message == WM_SYSKEYUP
                    || message == WM_APPCOMMAND)
                {
                    SendMessage ((HWND) w->getTopLevelComponent()->getWindowHandle(),
                                 message, wParam, lParam);
                }

                if (w != nullptr) // (may have been deleted in SendMessage callback)
                    return CallWindowProc ((WNDPROC) w->originalWndProc,
                                           (HWND) pluginHWND,
                                           message, wParam, lParam);
            }
        }

        return DefWindowProc (hW, message, wParam, lParam);
    }
   #endif

   #if JUCE_LINUX || JUCE_BSD
    void updatePluginWindowHandle()
    {
        pluginWindow = getChildWindow ((Window) getWindowHandle());
    }
   #endif

    //==============================================================================
    #if JUCE_MAC
      std::unique_ptr<NSViewComponentWithParent> cocoaWrapper;

      void resized() override
      {
      }
    #endif

    //==============================================================================
    VSTPluginInstance& plugin;
    float userScaleFactor = 1.0f;
    bool isOpen = false, recursiveResize = false;
    bool pluginWantsKeys = false, pluginRefusesToResize = false, alreadyInside = false;

   #if ! JUCE_MAC
    bool pluginRespondsToDPIChanges = false;

    float nativeScaleFactor = 1.0f;

    struct ScaleNotifierCallback
    {
        VSTPluginWindow& window;

        void operator() (float platformScale) const
        {
            MessageManager::callAsync ([ref = Component::SafePointer<VSTPluginWindow> (&window), platformScale]
            {
                if (auto* r = ref.getComponent())
                {
                    r->nativeScaleFactor = platformScale;
                    r->setContentScaleFactor();

                   #if JUCE_WINDOWS
                    r->resizeToFit();
                    r->embeddedComponent.updateHWNDBounds();
                   #endif
                    r->componentMovedOrResized (true, true);
                }
            });
        }
    };

    NativeScaleFactorNotifier scaleNotifier { this, ScaleNotifierCallback { *this } };

    #if JUCE_WINDOWS
     struct ViewComponent final : public HWNDComponent
     {
         ViewComponent()
         {
             setOpaque (true);
             inner.addToDesktop (0);

             if (auto* peer = inner.getPeer())
                 setHWND (peer->getNativeHandle());
         }

         void paint (Graphics& g) override { g.fillAll (Colours::black); }

     private:
         struct Inner final : public Component
         {
             Inner() { setOpaque (true); }
             void paint (Graphics& g) override { g.fillAll (Colours::black); }
         };

         Inner inner;
     };

     HWND getPluginHWND() const
     {
         return GetWindow ((HWND) embeddedComponent.getHWND(), GW_CHILD);
     }

     ViewComponent embeddedComponent;
     void* originalWndProc = {};
     int sizeCheckCount = 0;
    #elif JUCE_LINUX || JUCE_BSD
     ::Display* display = XWindowSystem::getInstance()->getDisplay();
     Window pluginWindow = 0;
    #endif
   #else
     static constexpr auto nativeScaleFactor = 1.0f;
   #endif

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (VSTPluginWindow)
};
#endif

//==============================================================================
AudioProcessorEditor* VSTPluginInstance::createEditor()
{
   #if JUCE_IOS || JUCE_ANDROID
    return nullptr;
   #else
    return hasEditor() ? new VSTPluginWindow (*this)
                       : nullptr;
   #endif
}

bool VSTPluginInstance::updateSizeFromEditor ([[maybe_unused]] int w, [[maybe_unused]] int h)
{
   #if ! JUCE_IOS && ! JUCE_ANDROID
    if (auto* editor = dynamic_cast<VSTPluginWindow*> (getActiveEditor()))
        return editor->updateSizeFromEditor (w, h);
   #endif

    return false;
}

//==============================================================================
// entry point for all callbacks from the plugin
//==============================================================================
VSTPluginFormat::VSTPluginFormat() {}
VSTPluginFormat::~VSTPluginFormat() {}

static std::unique_ptr<VSTPluginInstance> createAndUpdateDesc (VSTPluginFormat& format, PluginDescription& desc)
{
    if (auto p = format.createInstanceFromDescription (desc, 44100.0, 512))
    {
        if (auto instance = dynamic_cast<VSTPluginInstance*> (p.release()))
        {
           #if JUCE_MAC
            if (instance->vstModule->resFileId != 0)
                UseResFile (instance->vstModule->resFileId);
           #endif

            instance->fillInPluginDescription (desc);
            return std::unique_ptr<VSTPluginInstance> (instance);
        }

        jassertfalse;
    }

    return {};
}

void VSTPluginFormat::findAllTypesForFile (OwnedArray<PluginDescription>& results,
                                           const String& fileOrIdentifier)
{
    if (! fileMightContainThisPluginType (fileOrIdentifier))
        return;

    PluginDescription desc;
    desc.fileOrIdentifier = fileOrIdentifier;
    desc.uniqueId = desc.deprecatedUid = 0;

    auto instance = createAndUpdateDesc (*this, desc);

    if (instance == nullptr)
        return;

    if (instance->getVstCategory() != Vst2::kPlugCategShell)
    {
        // Normal plugin...
        results.add (new PluginDescription (desc));

        instance->dispatch (Vst2::effOpen, 0, 0, nullptr, 0);
    }
    else
    {
        // It's a shell plugin, so iterate all the subtypes...
        for (;;)
        {
            char shellEffectName [256] = { 0 };
            auto uid = (int) instance->dispatch (Vst2::effShellGetNextPlugin, 0, 0, shellEffectName, 0);

            if (uid == 0)
                break;

            desc.uniqueId = desc.deprecatedUid = uid;
            desc.name = shellEffectName;

            aboutToScanVSTShellPlugin (desc);

            std::unique_ptr<VSTPluginInstance> shellInstance (createAndUpdateDesc (*this, desc));

            if (shellInstance != nullptr)
            {
                jassert (desc.deprecatedUid == uid);
                jassert (desc.uniqueId == uid);
                desc.hasSharedContainer = true;
                desc.name = shellEffectName;

                if (! arrayContainsPlugin (results, desc))
                    results.add (new PluginDescription (desc));
            }
        }
    }
}

void VSTPluginFormat::createPluginInstance (const PluginDescription& desc,
                                            double sampleRate, int blockSize,
                                            PluginCreationCallback callback)
{
    std::unique_ptr<VSTPluginInstance> result;

    if (fileMightContainThisPluginType (desc.fileOrIdentifier))
    {
        File file (desc.fileOrIdentifier);

        auto previousWorkingDirectory = File::getCurrentWorkingDirectory();
        file.getParentDirectory().setAsCurrentWorkingDirectory();

        if (auto module = ModuleHandle::findOrCreateModule (file))
        {
            shellUIDToCreate = desc.uniqueId != 0 ? desc.uniqueId : desc.deprecatedUid;

            result.reset (VSTPluginInstance::create (module, sampleRate, blockSize));

            if (result != nullptr && ! result->initialiseEffect (sampleRate, blockSize))
                result.reset();
        }

        previousWorkingDirectory.setAsCurrentWorkingDirectory();
    }

    String errorMsg;

    if (result == nullptr)
        errorMsg = TRANS ("Unable to load XXX plug-in file").replace ("XXX", "VST-2");

    callback (std::move (result), errorMsg);
}

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

bool VSTPluginFormat::fileMightContainThisPluginType (const String& fileOrIdentifier)
{
    auto f = File::createFileWithoutCheckingPath (fileOrIdentifier);

  #if JUCE_MAC || JUCE_IOS
    return f.isDirectory() && f.hasFileExtension (".vst");
  #elif JUCE_WINDOWS
    return f.existsAsFile() && f.hasFileExtension (".dll");
  #elif JUCE_LINUX || JUCE_BSD || JUCE_ANDROID
    return f.existsAsFile() && f.hasFileExtension (".so");
  #endif
}

String VSTPluginFormat::getNameOfPluginFromIdentifier (const String& fileOrIdentifier)
{
    return fileOrIdentifier;
}

bool VSTPluginFormat::pluginNeedsRescanning (const PluginDescription& desc)
{
    return File (desc.fileOrIdentifier).getLastModificationTime() != desc.lastFileModTime;
}

bool VSTPluginFormat::doesPluginStillExist (const PluginDescription& desc)
{
    return File (desc.fileOrIdentifier).exists();
}

StringArray VSTPluginFormat::searchPathsForPlugins (const FileSearchPath& directoriesToSearch, const bool recursive, bool)
{
    StringArray results;

    for (int j = 0; j < directoriesToSearch.getNumPaths(); ++j)
        recursiveFileSearch (results, directoriesToSearch [j], recursive);

    return results;
}

void VSTPluginFormat::recursiveFileSearch (StringArray& results, const File& dir, const bool recursive)
{
    // avoid allowing the dir iterator to be recursive, because we want to avoid letting it delve inside
    // .component or .vst directories.
    for (const auto& iter : RangedDirectoryIterator (dir, false, "*", File::findFilesAndDirectories))
    {
        auto f = iter.getFile();
        bool isPlugin = false;

        if (fileMightContainThisPluginType (f.getFullPathName()))
        {
            isPlugin = true;
            results.add (f.getFullPathName());
        }

        if (recursive && (! isPlugin) && f.isDirectory())
            recursiveFileSearch (results, f, true);
    }
}

FileSearchPath VSTPluginFormat::getDefaultLocationsToSearch()
{
   #if JUCE_MAC
    return FileSearchPath ("~/Library/Audio/Plug-Ins/VST;/Library/Audio/Plug-Ins/VST");
   #elif JUCE_LINUX || JUCE_BSD || JUCE_ANDROID
    return FileSearchPath (SystemStats::getEnvironmentVariable ("VST_PATH",
                                                                "/usr/lib/vst;/usr/local/lib/vst;~/.vst")
                             .replace (":", ";"));
   #elif JUCE_WINDOWS
    auto programFiles = File::getSpecialLocation (File::globalApplicationsDirectory).getFullPathName();

    FileSearchPath paths;
    paths.add (WindowsRegistry::getValue ("HKEY_LOCAL_MACHINE\\Software\\VST\\VSTPluginsPath"));
    paths.addIfNotAlreadyThere (programFiles + "\\Steinberg\\VstPlugins");
    paths.addIfNotAlreadyThere (programFiles + "\\VstPlugins");
    paths.removeRedundantPaths();
    return paths;
   #elif JUCE_IOS
    // on iOS you can only load plug-ins inside the hosts bundle folder
    CFUniquePtr<CFURLRef> relativePluginDir (CFBundleCopyBuiltInPlugInsURL (CFBundleGetMainBundle()));
    CFUniquePtr<CFURLRef> pluginDir (CFURLCopyAbsoluteURL (relativePluginDir.get()));

    CFUniquePtr<CFStringRef> path (CFURLCopyFileSystemPath (pluginDir.get(), kCFURLPOSIXPathStyle));
    FileSearchPath retval (String (CFStringGetCStringPtr (path.get(), kCFStringEncodingUTF8)));
    return retval;
   #endif
}

const XmlElement* VSTPluginFormat::getVSTXML (AudioPluginInstance* plugin)
{
    if (auto* vst = dynamic_cast<VSTPluginInstance*> (plugin))
        if (vst->vstModule != nullptr)
            return vst->vstModule->vstXml.get();

    return nullptr;
}

bool VSTPluginFormat::loadFromFXBFile (AudioPluginInstance* plugin, const void* data, size_t dataSize)
{
    if (auto* vst = dynamic_cast<VSTPluginInstance*> (plugin))
        return vst->loadFromFXBFile (data, dataSize);

    return false;
}

bool VSTPluginFormat::saveToFXBFile (AudioPluginInstance* plugin, MemoryBlock& dest, bool asFXB)
{
    if (auto* vst = dynamic_cast<VSTPluginInstance*> (plugin))
        return vst->saveToFXBFile (dest, asFXB);

    return false;
}

bool VSTPluginFormat::getChunkData (AudioPluginInstance* plugin, MemoryBlock& result, bool isPreset)
{
    if (auto* vst = dynamic_cast<VSTPluginInstance*> (plugin))
        return vst->getChunkData (result, isPreset, 128);

    return false;
}

bool VSTPluginFormat::setChunkData (AudioPluginInstance* plugin, const void* data, int size, bool isPreset)
{
    if (auto* vst = dynamic_cast<VSTPluginInstance*> (plugin))
        return vst->setChunkData (data, size, isPreset);

    return false;
}

AudioPluginInstance* VSTPluginFormat::createCustomVSTFromMainCall (void* entryPointFunction,
                                                                   double initialSampleRate, int initialBufferSize)
{
    ModuleHandle::Ptr module = new ModuleHandle (File(), (MainCall) entryPointFunction);

    if (module->open())
    {
        std::unique_ptr<VSTPluginInstance> result (VSTPluginInstance::create (module, initialSampleRate, initialBufferSize));

        if (result != nullptr)
            if (result->initialiseEffect (initialSampleRate, initialBufferSize))
                return result.release();
    }

    return nullptr;
}

void VSTPluginFormat::setExtraFunctions (AudioPluginInstance* plugin, ExtraFunctions* functions)
{
    std::unique_ptr<ExtraFunctions> f (functions);

    if (auto* vst = dynamic_cast<VSTPluginInstance*> (plugin))
        std::swap (vst->extraFunctions, f);
}

AudioPluginInstance* VSTPluginFormat::getPluginInstanceFromVstEffectInterface (void* aEffect)
{
    if (auto* vstAEffect = reinterpret_cast<Vst2::AEffect*> (aEffect))
        if (auto* instanceVST = reinterpret_cast<VSTPluginInstance*> (vstAEffect->resvd2))
            return dynamic_cast<AudioPluginInstance*> (instanceVST);

    return nullptr;
}

pointer_sized_int JUCE_CALLTYPE VSTPluginFormat::dispatcher (AudioPluginInstance* plugin, int32 opcode, int32 index, pointer_sized_int value, void* ptr, float opt)
{
    if (auto* vst = dynamic_cast<VSTPluginInstance*> (plugin))
        return vst->dispatch (opcode, index, value, ptr, opt);

    return {};
}

void VSTPluginFormat::aboutToScanVSTShellPlugin (const PluginDescription&) {}

} // namespace juce

JUCE_END_IGNORE_DEPRECATION_WARNINGS
JUCE_END_IGNORE_WARNINGS_MSVC

#endif
