/**********************************************************************

  Audacity: A Digital Audio Editor

  PluginManager.cpp

  Leland Lucius

*******************************************************************//*!

\file PluginManager.cpp
\brief

************************************************************************//**
\class PluginManager
\brief PluginManager maintains a list of all plug ins.  That covers modules,
effects, generators, analysis-effects, commands.  It also has functions
for shared and private configs - which need to move out.
*****************************************************************************/


#include "PluginManager.h"



#include <algorithm>

#include <wx/log.h>
#include <wx/tokenzr.h>

#include "BasicUI.h"
#include "PluginProvider.h"

#include "Internat.h" // for macro XO
#include "FileNames.h"
#include "MemoryX.h"
#include "ModuleManager.h"
#include "PlatformCompatibility.h"
#include "Base64.h"
#include "Variant.h"

///////////////////////////////////////////////////////////////////////////////
//
// PluginManager
//
///////////////////////////////////////////////////////////////////////////////

// Registry has the list of plug ins
#define REGVERKEY wxString(wxT("/pluginregistryversion"))
#define REGROOT wxString(wxT("/pluginregistry/"))
#define REGCUSTOMPATHS wxString(wxT("/providercustompaths"))

// Settings has the values of the plug in settings.
#define SETVERKEY wxString(wxT("/pluginsettingsversion"))
#define SETVERCUR wxString(wxT("1.0"))
#define SETROOT wxString(wxT("/pluginsettings/"))

#define KEY_ID                         wxT("ID")
#define KEY_PATH                       wxT("Path")
#define KEY_SYMBOL                     wxT("Symbol")
#define KEY_NAME                       wxT("Name")
#define KEY_VENDOR                     wxT("Vendor")
#define KEY_VERSION                    wxT("Version")
#define KEY_DESCRIPTION                wxT("Description")
#define KEY_LASTUPDATED                wxT("LastUpdated")
#define KEY_ENABLED                    wxT("Enabled")
#define KEY_VALID                      wxT("Valid")
#define KEY_PROVIDERID                 wxT("ProviderID")
#define KEY_EFFECTTYPE                 wxT("EffectType")
#define KEY_EFFECTFAMILY               wxT("EffectFamily")
#define KEY_EFFECTDEFAULT              wxT("EffectDefault")
#define KEY_EFFECTINTERACTIVE          wxT("EffectInteractive")
#define KEY_EFFECTREALTIME             wxT("EffectRealtime")
#define KEY_EFFECTAUTOMATABLE          wxT("EffectAutomatable")
#define KEY_EFFECTTYPE_NONE            wxT("None")
#define KEY_EFFECTTYPE_ANALYZE         wxT("Analyze")
#define KEY_EFFECTTYPE_GENERATE        wxT("Generate")
#define KEY_EFFECTTYPE_PROCESS         wxT("Process")
#define KEY_EFFECTTYPE_TOOL            wxT("Tool")
#define KEY_EFFECTTYPE_HIDDEN          wxT("Hidden")
#define KEY_IMPORTERIDENT              wxT("ImporterIdent")
//#define KEY_IMPORTERFILTER             wxT("ImporterFilter")
#define KEY_IMPORTEREXTENSIONS         wxT("ImporterExtensions")

// ============================================================================
//
// PluginManagerInterface implementation
//
// ============================================================================

const PluginID &PluginManagerInterface::DefaultRegistrationCallback(
   PluginProvider *provider, ComponentInterface *pInterface )
{
   if(auto effectDefinitionInterface = dynamic_cast<EffectDefinitionInterface*>(pInterface))
      return PluginManager::Get().RegisterPlugin(provider, effectDefinitionInterface, PluginTypeEffect);
   return PluginManager::Get().RegisterPlugin(provider, pInterface);
}

const PluginID &PluginManagerInterface::AudacityCommandRegistrationCallback(
   PluginProvider *provider, ComponentInterface *pInterface )
{
   return PluginManager::Get().RegisterPlugin(provider, pInterface);
}

RegistryPath PluginManager::GetPluginEnabledSetting( const PluginID &ID ) const
{
   auto pPlugin = GetPlugin( ID );
   if ( pPlugin )
      return GetPluginEnabledSetting( *pPlugin );
   return {};
}

RegistryPath PluginManager::GetPluginEnabledSetting(
   const PluginDescriptor &desc ) const
{
   switch ( desc.GetPluginType() ) {
      case PluginTypeModule: {
         // Retrieve optional family symbol that was recorded in
         // RegisterPlugin() for the module
         auto family = desc.GetEffectFamily();
         if ( family.empty() ) // as for built-in effect and command modules
            return {};
         else
            return wxT('/') + family + wxT("/Enable");
      }
      case PluginTypeEffect:
         // do NOT use GetEffectFamily() for this descriptor, but instead,
         // delegate to the plugin descriptor of the provider, which may
         // be different (may be empty)
         return GetPluginEnabledSetting( desc.GetProviderID() );
      default:
         return {};
   }
}

bool PluginManager::IsPluginRegistered(
   const PluginPath &path, const TranslatableString *pName)
{
   for (auto &pair : mRegisteredPlugins) {
      if (auto &descriptor = pair.second; descriptor.GetPath() == path) {
         if (pName)
            descriptor.SetSymbol(
               { descriptor.GetSymbol().Internal(), *pName });
         return true;
      }
   }
   return false;
}

bool PluginManager::IsPluginLoaded(const wxString& ID) const
{
   return mLoadedInterfaces.find(ID) != mLoadedInterfaces.end();
}

void PluginManager::RegisterPlugin(PluginDescriptor&& desc)
{
   mRegisteredPlugins[desc.GetID()] = std::move(desc);
}

const PluginID & PluginManager::RegisterPlugin(PluginProvider *provider)
{
   PluginDescriptor & plug =
      CreatePlugin(GetID(provider), provider, PluginTypeModule);
   plug.SetEffectFamily(provider->GetOptionalFamilySymbol().Internal());

   plug.SetEnabled(true);
   plug.SetValid(true);

   return plug.GetID();
}

const PluginID & PluginManager::RegisterPlugin(
   PluginProvider *provider, ComponentInterface *command)
{
   PluginDescriptor & plug = CreatePlugin(GetID(command), command, (PluginType)PluginTypeAudacityCommand);

   plug.SetProviderID(PluginManager::GetID(provider));

   plug.SetEnabled(true);
   plug.SetValid(true);

   return plug.GetID();
}

const PluginID & PluginManager::RegisterPlugin(
   PluginProvider *provider, EffectDefinitionInterface *effect, int type)
{
   PluginDescriptor & plug = CreatePlugin(GetID(effect), effect, (PluginType)type);

   plug.SetProviderID(PluginManager::GetID(provider));

   plug.SetEffectType(effect->GetClassification());
   plug.SetEffectFamily(effect->GetFamily().Internal());
   plug.SetEffectInteractive(effect->IsInteractive());
   plug.SetEffectDefault(effect->IsDefault());
   plug.SetRealtimeSupport(effect->RealtimeSupport());
   plug.SetEffectAutomatable(effect->SupportsAutomation());

   plug.SetEnabled(true);
   plug.SetValid(true);

   return plug.GetID();
}

void PluginManager::FindFilesInPathList(const wxString & pattern,
                                        const FilePaths & pathList,
                                        FilePaths & files,
                                        bool directories)
{
   
   wxLogNull nolog;

   // Why bother...
   if (pattern.empty())
   {
      return;
   }

   // TODO:  We REALLY need to figure out the "Audacity" plug-in path(s)

   FilePaths paths;

   // Add the "per-user" plug-ins directory
   {
      const wxFileName &ff = FileNames::PlugInDir();
      paths.push_back(ff.GetFullPath());
   }
 
   // Add the "Audacity" plug-ins directory
   wxFileName ff = PlatformCompatibility::GetExecutablePath();
#if defined(__WXMAC__)
   // Path ends for example in "Audacity.app/Contents/MacOSX"
   //ff.RemoveLastDir();
   //ff.RemoveLastDir();
   // just remove the MacOSX part.
   ff.RemoveLastDir();
#endif
   ff.AppendDir(wxT("plug-ins"));
   paths.push_back(ff.GetPath());

   // Weed out duplicates
   for (const auto &filePath : pathList)
   {
      ff = filePath;
      const wxString path{ ff.GetFullPath() };
      if (paths.Index(path, wxFileName::IsCaseSensitive()) == wxNOT_FOUND)
      {
         paths.push_back(path);
      }
   }

   // Find all matching files in each path
   for (size_t i = 0, cnt = paths.size(); i < cnt; i++)
   {
      ff = paths[i] + wxFILE_SEP_PATH + pattern;
      wxDir::GetAllFiles(ff.GetPath(), &files, ff.GetFullName(), directories ? wxDIR_DEFAULT : wxDIR_FILES);
   }

   return;
}

bool PluginManager::HasConfigGroup(ConfigurationType type, const PluginID & ID,
   const RegistryPath & group)
{
   return HasGroup(Group(type, ID, group));
}

bool PluginManager::GetConfigSubgroups(ConfigurationType type,
   const PluginID & ID, const RegistryPath & group, RegistryPaths & subgroups)
{
   return GetSubgroups(Group(type, ID, group), subgroups);
}

bool PluginManager::HasConfigValue(ConfigurationType type, const PluginID & ID,
      const RegistryPath & group, const RegistryPath & key)
{
   return HasConfigValue(Key(type, ID, group, key));
}

bool PluginManager::GetConfigValue(ConfigurationType type, const PluginID & ID,
   const RegistryPath & group, const RegistryPath & key,
   ConfigReference var, ConfigConstReference defval)
{
   return GetConfigValue(Key(type, ID, group, key), var, defval);
}

bool PluginManager::SetConfigValue(ConfigurationType type, const PluginID & ID,
   const RegistryPath & group, const RegistryPath & key,
   ConfigConstReference value)
{
   return SetConfigValue(Key(type, ID, group, key), value);
}

bool PluginManager::RemoveConfigSubgroup(ConfigurationType type,
   const PluginID & ID, const RegistryPath & group)
{
   bool result = GetSettings()->DeleteGroup(Group(type, ID, group));
   if (result)
   {
      GetSettings()->Flush();
   }

   return result;
}

bool PluginManager::RemoveConfig(ConfigurationType type, const PluginID & ID,
   const RegistryPath & group, const RegistryPath & key)
{
   bool result = GetSettings()->DeleteEntry(Key(type, ID, group, key));
   if (result)
   {
      GetSettings()->Flush();
   }

   return result;
}

// ============================================================================
//
// PluginManager
//
// ============================================================================

// The one and only PluginManager
std::unique_ptr<PluginManager> PluginManager::mInstance{};

// ----------------------------------------------------------------------------
// Creation/Destruction
// ----------------------------------------------------------------------------

PluginManager::PluginManager()
{
   mSettings = NULL;
}

PluginManager::~PluginManager()
{
   // Ensure termination (harmless if already done)
   Terminate();
}

void PluginManager::InitializePlugins()
{
   ModuleManager & moduleManager = ModuleManager::Get();
   //ModuleManager::DiscoverProviders was called earlier, so we
   //can be sure that providers are already loaded

   //Check all known plugins to ensure they are still valid.
   for (auto it = mRegisteredPlugins.begin(); it != mRegisteredPlugins.end();) {
      auto &pluginDesc = it->second;
      const auto pluginType = pluginDesc.GetPluginType();
      if(pluginType == PluginTypeNone || pluginType == PluginTypeModule)
      {
         ++it;
         continue;
      }

      if(!moduleManager.CheckPluginExist(pluginDesc.GetProviderID(), pluginDesc.GetPath()))
         it = mRegisteredPlugins.erase(it);
      else
         ++it;
   }

   Save();
}

// ----------------------------------------------------------------------------
// PluginManager implementation
// ----------------------------------------------------------------------------

static PluginManager::ConfigFactory sFactory;

// ============================================================================
//
// Return reference to singleton
//
// (Thread-safe...no active threading during construction or after destruction)
// ============================================================================

PluginManager & PluginManager::Get()
{
   if (!mInstance)
   {
      mInstance.reset(safenew PluginManager);
   }

   return *mInstance;
}

void PluginManager::Initialize(ConfigFactory factory)
{
   sFactory = move(factory);

   // Always load the registry first
   Load();

   // And force load of setting to verify it's accessible
   GetSettings();

   auto &mm = ModuleManager::Get();
   mm.DiscoverProviders();
   for (auto& [id, module] : mm.Providers()) {
      RegisterPlugin(module.get());
      // Allow the module to auto-register children
      module->AutoRegisterPlugins(*this);
   }

   InitializePlugins();
}

void PluginManager::Terminate()
{
   // Get rid of all non-module(effects?) plugins first
   for(auto& p : mRegisteredPlugins)
   {
      auto& desc = p.second;
      if(desc.GetPluginType() == PluginTypeEffect)
         mLoadedInterfaces.erase(desc.GetID());
   }

   // Now get rid of others
   mRegisteredPlugins.clear();
   mLoadedInterfaces.clear();
}

bool PluginManager::DropFile(const wxString &fileName)
{
   using namespace BasicUI;
   auto &mm = ModuleManager::Get();
   const wxFileName src{ fileName };

   for (auto &plug : PluginsOfType(PluginTypeModule)) {
      auto module = static_cast<PluginProvider *>
         (mm.CreateProviderInstance(plug.GetID(), plug.GetPath()));
      if (! module)
         continue;

      const auto &ff = module->InstallPath();
      const auto &extensions = module->GetFileExtensions();
      if ( !ff.empty() &&
          extensions.Index(src.GetExt(), false) != wxNOT_FOUND ) {
         TranslatableString errMsg;
         // Do dry-run test of the file format
         unsigned nPlugIns =
            module->DiscoverPluginsAtPath(fileName, errMsg, {});
         if (nPlugIns) {
            // File contents are good for this module, so check no others.
            // All branches of this block return true, even in case of
            // failure for other reasons, to signal that other drag-and-drop
            // actions should not be tried.

            // Find path to copy it
            wxFileName dst;
            dst.AssignDir( ff );
            dst.SetFullName( src.GetFullName() );
            if ( dst.Exists() ) {
               // Query whether to overwrite
               bool overwrite = (MessageBoxResult::Yes == ShowMessageBox(
                  XO("Overwrite the plug-in file %s?")
                     .Format( dst.GetFullPath() ),
                  MessageBoxOptions{}
                     .Caption(XO("Plug-in already exists"))
                     .ButtonStyle(Button::YesNo)));
               if ( !overwrite )
                  return true;
            }

            // Move the file or subtree
            bool copied = false;
            auto dstPath = dst.GetFullPath();
            if ( src.FileExists() )
               // A simple one-file plug-in
               copied = FileNames::DoCopyFile(
                  src.GetFullPath(), dstPath, true );
            else {
               // A sub-folder
               // such as for some VST packages
               // Recursive copy needed -- to do
               return true;
            }

            if (!copied) {
               ShowMessageBox(
                  XO("Plug-in file is in use. Failed to overwrite") );
               return true;
            }

            // Register for real
            std::vector<PluginID> ids;
            std::vector<wxString> names;
            nPlugIns = module->DiscoverPluginsAtPath(dstPath, errMsg,
               [&](PluginProvider *provider, ComponentInterface *ident)
                                                     -> const PluginID& {
                  // Register as by default, but also collecting the PluginIDs
                  // and names
                  auto &id = PluginManagerInterface::DefaultRegistrationCallback(
                        provider, ident);
                  ids.push_back(id);
                  names.push_back( ident->GetSymbol().Translation() );
                  return id;
               });
            if ( ! nPlugIns ) {
               // Unlikely after the dry run succeeded
               ShowMessageBox(
                  XO("Failed to register:\n%s").Format( errMsg ) );
               return true;
            }

            // Ask whether to enable the plug-ins
            if (auto nIds = ids.size()) {
               auto message = XPC(
               /* i18n-hint A plug-in is an optional added program for a sound
                effect, or generator, or analyzer */
                  "Enable this plug-in?\n",
                  "Enable these plug-ins?\n",
                  0,
                  "plug-ins"
               )( nIds );
               for (const auto &name : names)
                  message.Join( Verbatim( name ), wxT("\n") );
               bool enable = (MessageBoxResult::Yes == ShowMessageBox(
                  message,
                  MessageBoxOptions{}
                     .Caption(XO("Enable new plug-ins"))
                     .ButtonStyle(Button::YesNo)));
               for (const auto &id : ids)
                  mRegisteredPlugins[id].SetEnabled(enable);
               // Make changes to enabled status persist:
               this->Save();
               this->NotifyPluginsChanged();
            }

            return true;
         }
      }
   }
   
   return false;
}

void PluginManager::Load()
{
   // Create/Open the registry
   auto pRegistry = sFactory(FileNames::PluginRegistry());
   auto &registry = *pRegistry;

   // If this group doesn't exist then we have something that's not a registry.
   // We should probably warn the user, but it's pretty unlikely that this will happen.
   if (!registry.HasGroup(REGROOT))
   {
      // Must start over
      // This DeleteAll affects pluginregistry.cfg only, not audacity.cfg
      // That is, the memory of on/off states of effect (and generator,
      // analyzer, and tool) plug-ins
      registry.Clear();
      registry.Flush();
      return;
   }

   // Check for a registry version that we can understand
   // TODO: Should also check for a registry file that is newer than
   // what we can understand.
   mRegver = registry.Read(REGVERKEY);
   if (Regver_lt(mRegver, "1.1")) {
      // Conversion code here, for when registry version changes.

      // We iterate through the effects, possibly updating their info.
      wxString group = GetPluginTypeString(PluginTypeEffect);
      wxString cfgPath = REGROOT + group + wxCONFIG_PATH_SEPARATOR;
      wxArrayString groupsToDelete;

      auto cfgGroup = registry.BeginGroup(cfgPath);
      for(const auto& groupName : registry.GetChildGroups())
      {
         auto effectGroup = registry.BeginGroup(groupName);
         wxString effectSymbol = registry.Read(KEY_SYMBOL, "");
         wxString effectVersion = registry.Read(KEY_VERSION, "");


         // For 2.3.0 the plugins we distribute have moved around.
         // So we upped the registry version number to 1.1.
         // These particular config edits were originally written to fix Bug 1914.
         if (Regver_le(mRegver, "1.0")) {
            // Nyquist prompt is a built-in that has moved to the tools menu.
            if (effectSymbol == NYQUIST_PROMPT_ID) {
               registry.Write(KEY_EFFECTTYPE, "Tool");
            // Old version of SDE was in Analyze menu.  Now it is in Tools.
            // We don't want both the old and the new.
            } else if ((effectSymbol == "Sample Data Export") && (effectVersion == "n/a")) {
               groupsToDelete.push_back(cfgPath + groupName);
            // Old version of SDI was in Generate menu.  Now it is in Tools.
            } else if ((effectSymbol == "Sample Data Import") && (effectVersion == "n/a")) {
               groupsToDelete.push_back(cfgPath + groupName);
            }
         }
      }
      // Doing the deletion within the search loop risked skipping some items,
      // hence the delayed delete.
      for (unsigned int i = 0; i < groupsToDelete.size(); i++) {
         registry.DeleteGroup(groupsToDelete[i]);
      }
      // Updates done.  Make sure we read the updated data later.
      registry.Flush();
   }

   // Load all provider plugins first
   LoadGroup(&registry, PluginTypeModule);

   // Now the rest
   LoadGroup(&registry, PluginTypeEffect);
   LoadGroup(&registry, PluginTypeAudacityCommand );
   LoadGroup(&registry, PluginTypeExporter);
   LoadGroup(&registry, PluginTypeImporter);

   LoadGroup(&registry, PluginTypeStub);
   return;
}

void PluginManager::LoadGroup(audacity::BasicSettings *pRegistry, PluginType type)
{
#ifdef __WXMAC__
   // Bug 1590: On Mac, we should purge the registry of Nyquist plug-ins
   // bundled with other versions of Audacity, assuming both versions
   // were properly installed in /Applications (or whatever it is called in
   // your locale)

   const auto fullExePath = PlatformCompatibility::GetExecutablePath();

   // Strip rightmost path components up to *.app
   wxFileName exeFn{ fullExePath };
   exeFn.SetEmptyExt();
   exeFn.SetName(wxString{});
   while(exeFn.GetDirCount() && !exeFn.GetDirs().back().EndsWith(".app"))
      exeFn.RemoveLastDir();

   const auto goodPath = exeFn.GetPath();

   if(exeFn.GetDirCount())
      exeFn.RemoveLastDir();
   const auto possiblyBadPath = exeFn.GetPath();

   auto AcceptPath = [&](const wxString &path) {
      if (!path.StartsWith(possiblyBadPath))
         // Assume it's not under /Applications
         return true;
      if (path.StartsWith(goodPath))
         // It's bundled with this executable
         return true;
      return false;
   };
#else
   auto AcceptPath = [](const wxString&){ return true; };
#endif

   wxString strVal;
   bool boolVal;
   wxString cfgPath = REGROOT + GetPluginTypeString(type) + wxCONFIG_PATH_SEPARATOR;

   const auto cfgGroup = pRegistry->BeginGroup(cfgPath);
   for(const auto& group : pRegistry->GetChildGroups())
   {
      PluginDescriptor plug;
      const auto effectGroup = pRegistry->BeginGroup(group);

      auto groupName = ConvertID(group);

      // Bypass group if the ID is already in use
      if (mRegisteredPlugins.count(groupName))
         continue;

      // Set the ID and type
      plug.SetID(groupName);
      plug.SetPluginType(type);

      // Get the provider ID and bypass group if not found
      if (!pRegistry->Read(KEY_PROVIDERID, &strVal, {}))
      {
         // Bypass group if the provider isn't valid
         if (!strVal.empty() && !mRegisteredPlugins.count(strVal))
            continue;
      }
      plug.SetProviderID(PluginID(strVal));

      // Get the path (optional)
      pRegistry->Read(KEY_PATH, &strVal, {});
      if (!AcceptPath(strVal))
         // Ignore the obsolete path in the config file, during session,
         // but don't remove it from the file.  Maybe you really want to
         // switch back to the other version of Audacity and lose nothing.
         continue;
      plug.SetPath(strVal);

      /*
       // PRL: Ignore names  written in configs before 2.3.0!
       // use Internal string only!  Let the present version of Audacity map
       // that to a user-visible string.
      // Get the name and bypass group if not found
      if (!pRegistry->Read(KEY_NAME, &strVal))
      {
         continue;
      }
      plug.SetName(strVal);
       */

      // Get the symbol...Audacity 2.3.0 or later requires it
      // bypass group if not found
      // Note, KEY_SYMBOL started getting written to config files in 2.1.0.
      // KEY_NAME (now ignored) was written before that, but only for VST
      // effects.
      if (!pRegistry->Read(KEY_SYMBOL, &strVal))
         continue;

      // Related to Bug2778: config file only remembered an internal name,
      // so this symbol may not contain the correct TranslatableString.
      // See calls to IsPluginRegistered which can correct that.
      plug.SetSymbol(strVal);

      // Get the version and bypass group if not found
      if (!pRegistry->Read(KEY_VERSION, &strVal))
      {
         continue;
      }
      plug.SetVersion(strVal);

      // Get the vendor and bypass group if not found
      if (!pRegistry->Read(KEY_VENDOR, &strVal))
      {
         continue;
      }
      plug.SetVendor( strVal );

#if 0
      // This was done before version 2.2.2, but the value was not really used
      // But absence of a value will cause early versions to skip the group
      // Therefore we still write a blank to keep pluginregistry.cfg
      // backwards-compatible

      // Get the description and bypass group if not found
      if (!pRegistry->Read(KEY_DESCRIPTION, &strVal))
      {
         continue;
      }
#endif

      // Is it enabled...default to no if not found
      pRegistry->Read(KEY_ENABLED, &boolVal, false);
      plug.SetEnabled(boolVal);

      // Is it valid...default to no if not found
      pRegistry->Read(KEY_VALID, &boolVal, false);
      plug.SetValid(boolVal);

      switch (type)
      {
         case PluginTypeModule:
         {
            // Nothing to do here yet
         }
         break;

         case PluginTypeEffect:
         {
            // Get the effect type and bypass group if not found
            if (!pRegistry->Read(KEY_EFFECTTYPE, &strVal))
               continue;

            if (strVal == KEY_EFFECTTYPE_NONE)
               plug.SetEffectType(EffectTypeNone);
            else if (strVal == KEY_EFFECTTYPE_ANALYZE)
               plug.SetEffectType(EffectTypeAnalyze);
            else if (strVal == KEY_EFFECTTYPE_GENERATE)
               plug.SetEffectType(EffectTypeGenerate);
            else if (strVal == KEY_EFFECTTYPE_PROCESS)
               plug.SetEffectType(EffectTypeProcess);
            else if (strVal == KEY_EFFECTTYPE_TOOL)
               plug.SetEffectType(EffectTypeTool);
            else if (strVal == KEY_EFFECTTYPE_HIDDEN)
               plug.SetEffectType(EffectTypeHidden);
            else
               continue;

            // Get the effect family and bypass group if not found
            if (!pRegistry->Read(KEY_EFFECTFAMILY, &strVal))
            {
               continue;
            }
            plug.SetEffectFamily(strVal);

            // Is it a default (above the line) effect and bypass group if not found
            if (!pRegistry->Read(KEY_EFFECTDEFAULT, &boolVal))
            {
               continue;
            }
            plug.SetEffectDefault(boolVal);

            // Is it an interactive effect and bypass group if not found
            if (!pRegistry->Read(KEY_EFFECTINTERACTIVE, &boolVal))
            {
               continue;
            }
            plug.SetEffectInteractive(boolVal);

            // Is it a realtime capable effect and bypass group if not found
            if (!pRegistry->Read(KEY_EFFECTREALTIME, &strVal))
            {
               continue;
            }
            plug.DeserializeRealtimeSupport(strVal);

            // Does the effect support automation...bypass group if not found
            if (!pRegistry->Read(KEY_EFFECTAUTOMATABLE, &boolVal))
            {
               continue;
            }
            plug.SetEffectAutomatable(boolVal);
         }
         break;

         case PluginTypeImporter:
         {
            // Get the importer identifier and bypass group if not found
            if (!pRegistry->Read(KEY_IMPORTERIDENT, &strVal))
            {
               continue;
            }
            plug.SetImporterIdentifier(strVal);

            // Get the importer extensions and bypass group if not found
            if (!pRegistry->Read(KEY_IMPORTEREXTENSIONS, &strVal))
            {
               continue;
            }
            FileExtensions extensions;
            wxStringTokenizer tkr(strVal, wxT(":"));
            while (tkr.HasMoreTokens())
            {
               extensions.push_back(tkr.GetNextToken());
            }
            plug.SetImporterExtensions(extensions);
         }
         break;

         case PluginTypeStub:
         {
            // Nothing additional for stubs
         }
         break;

         // Not used by 2.1.1 or greater and should be removed after a few releases past 2.1.0.
         case PluginTypeNone:
         {
            // Used for stub groups
         }
         break;

         default:
         {
            continue;
         }
      }

      // Everything checked out...accept the plugin
      mRegisteredPlugins[groupName] = std::move(plug);
   }

   return;
}

void PluginManager::Save()
{
   // Create/Open the registry
   auto pRegistry = sFactory(FileNames::PluginRegistry());
   auto &registry = *pRegistry;

   // Clear pluginregistry.cfg (not audacity.cfg)
   registry.Clear();

   // Save the individual groups
   SaveGroup(&registry, PluginTypeEffect);
   SaveGroup(&registry, PluginTypeExporter);
   SaveGroup(&registry, PluginTypeAudacityCommand);
   SaveGroup(&registry, PluginTypeImporter);
   SaveGroup(&registry, PluginTypeStub);

   // Not used by 2.1.1 or greater, but must save to allow users to switch between 2.1.0
   // and 2.1.1+.  This should be removed after a few releases past 2.1.0.
   //SaveGroup(&registry, PluginTypeNone);

   // And now the providers
   SaveGroup(&registry, PluginTypeModule);

   // Write the version string
   registry.Write(REGVERKEY, REGVERCUR);

   // Just to be safe
   registry.Flush();

   mRegver = REGVERCUR;
}

void PluginManager::NotifyPluginsChanged()
{
   Publisher<PluginsChangedMessage>::Publish({});
}

const PluginRegistryVersion &PluginManager::GetRegistryVersion() const
{
   return mRegver;
}


PluginPaths PluginManager::ReadCustomPaths(const PluginProvider& provider)
{
   auto group = mSettings->BeginGroup(REGCUSTOMPATHS);
   const auto key = GetID(&provider);
   const auto paths = mSettings->Read(key, wxString{});
   const auto wxarr = wxSplit(paths, ';');
   return PluginPaths(wxarr.begin(), wxarr.end());
}

void PluginManager::StoreCustomPaths(const PluginProvider& provider, const PluginPaths& paths)
{
   auto group = mSettings->BeginGroup(REGCUSTOMPATHS);
   const auto key = GetID(&provider);
   wxArrayString wxarr;
   std::copy(paths.begin(), paths.end(), std::back_inserter(wxarr));
   mSettings->Write(key, wxJoin(wxarr, ';'));
}

void PluginManager::SaveGroup(audacity::BasicSettings *pRegistry, PluginType type)
{
   wxString group = GetPluginTypeString(type);
   for (auto &pair : mRegisteredPlugins) {
      auto & plug = pair.second;

      if (plug.GetPluginType() != type)
      {
         continue;
      }

      const auto pluginGroup = pRegistry->BeginGroup(REGROOT + group + wxCONFIG_PATH_SEPARATOR + ConvertID(plug.GetID()));

      pRegistry->Write(KEY_PATH, plug.GetPath());

      // See comments with the corresponding load-time call to SetSymbol().
      pRegistry->Write(KEY_SYMBOL, plug.GetSymbol().Internal());

      // PRL:  Writing KEY_NAME which is no longer read, but older Audacity
      // versions expect to find it.
      pRegistry->Write(KEY_NAME, plug.GetSymbol().Msgid().MSGID());

      pRegistry->Write(KEY_VERSION, plug.GetUntranslatedVersion());
      pRegistry->Write(KEY_VENDOR, plug.GetVendor());
      // Write a blank -- see comments in LoadGroup:
      pRegistry->Write(KEY_DESCRIPTION, wxString{});
      pRegistry->Write(KEY_PROVIDERID, plug.GetProviderID());
      pRegistry->Write(KEY_ENABLED, plug.IsEnabled());
      pRegistry->Write(KEY_VALID, plug.IsValid());

      switch (type)
      {
         case PluginTypeModule:
         break;

         case PluginTypeEffect:
         {
            EffectType etype = plug.GetEffectType();
            wxString stype;
            if (etype == EffectTypeNone)
               stype = KEY_EFFECTTYPE_NONE;
            else if (etype == EffectTypeAnalyze)
               stype = KEY_EFFECTTYPE_ANALYZE;
            else if (etype == EffectTypeGenerate)
               stype = KEY_EFFECTTYPE_GENERATE;
            else if (etype == EffectTypeProcess)
               stype = KEY_EFFECTTYPE_PROCESS;
            else if (etype == EffectTypeTool)
               stype = KEY_EFFECTTYPE_TOOL;
            else if (etype == EffectTypeHidden)
               stype = KEY_EFFECTTYPE_HIDDEN;

            pRegistry->Write(KEY_EFFECTTYPE, stype);
            pRegistry->Write(KEY_EFFECTFAMILY, plug.GetEffectFamily());
            pRegistry->Write(KEY_EFFECTDEFAULT, plug.IsEffectDefault());
            pRegistry->Write(KEY_EFFECTINTERACTIVE, plug.IsEffectInteractive());
            pRegistry->Write(KEY_EFFECTREALTIME, plug.SerializeRealtimeSupport());
            pRegistry->Write(KEY_EFFECTAUTOMATABLE, plug.IsEffectAutomatable());
         }
         break;

         case PluginTypeImporter:
         {
            pRegistry->Write(KEY_IMPORTERIDENT, plug.GetImporterIdentifier());
            const auto & extensions = plug.GetImporterExtensions();
            wxString strExt;
            for (size_t i = 0, cnt = extensions.size(); i < cnt; i++)
            {
               strExt += extensions[i] + wxT(":");
            }
            strExt.RemoveLast(1);
            pRegistry->Write(KEY_IMPORTEREXTENSIONS, strExt);
         }
         break;

         default:
         break;
      }
   }

   return;
}

// Here solely for the purpose of Nyquist Workbench until
// a better solution is devised.
const PluginID & PluginManager::RegisterPlugin(
   std::unique_ptr<EffectDefinitionInterface> effect, PluginType type)
{
   PluginDescriptor & plug =
      CreatePlugin(GetID(effect.get()), effect.get(), type);

   plug.SetEffectType(effect->GetType());
   plug.SetEffectFamily(effect->GetFamily().Internal());
   plug.SetEffectInteractive(effect->IsInteractive());
   plug.SetEffectDefault(effect->IsDefault());
   plug.SetRealtimeSupport(effect->RealtimeSupport());
   plug.SetEffectAutomatable(effect->SupportsAutomation());
   
   plug.SetEffectLegacy(true);
   plug.SetEnabled(true);
   plug.SetValid(true);

   mLoadedInterfaces[plug.GetID()] = std::move(effect);

   return plug.GetID();
}

void PluginManager::UnregisterPlugin(const PluginID & ID)
{
   mRegisteredPlugins.erase(ID);
   mLoadedInterfaces.erase(ID);
}

int PluginManager::GetPluginCount(PluginType type)
{
   return count_if(mRegisteredPlugins.begin(), mRegisteredPlugins.end(), [type](auto &pair){
      return pair.second.GetPluginType() == type; });
}

const PluginDescriptor *PluginManager::GetPlugin(const PluginID & ID) const
{
   if (auto iter = mRegisteredPlugins.find(ID); iter != mRegisteredPlugins.end())
      return &iter->second;

   auto iter2 = make_iterator_range(mEffectPluginsCleared)
      .find_if([&ID](const PluginDescriptor& plug) {
         return plug.GetID() == ID;
      });
   if (iter2 != mEffectPluginsCleared.end())
      return &(*iter2);

   return nullptr;
}

void PluginManager::Iterator::Advance(bool incrementing)
{
   const auto end = mPm.mRegisteredPlugins.end();
   if (incrementing && mIterator != end)
      ++mIterator;
   bool all = mPluginType == PluginTypeNone && mEffectType == EffectTypeNone;
   for (; mIterator != end; ++mIterator) {
      auto &plug = mIterator->second;
      if (!all && !(plug.IsValid() && plug.IsEnabled()))
         continue;
      auto plugType = plug.GetPluginType();
      if ((mPluginType == PluginTypeNone || (plugType & mPluginType)) &&
         (mEffectType == EffectTypeNone || plug.GetEffectType() == mEffectType)) {
         if (!all && (plugType & PluginTypeEffect)) {
            // This preference may be written by EffectsPrefs
            auto setting = mPm.GetPluginEnabledSetting( plug );
            if (!(setting.empty() || gPrefs->Read( setting, true )))
               continue;
         }
         // Pause iteration at this match
         break;
      }
   }
}

PluginManager::Iterator::Iterator(PluginManager &manager)
: mPm{ manager }
, mIterator{ manager.mRegisteredPlugins.begin() }
{   
}

PluginManager::Iterator::Iterator(PluginManager &manager, int type)
: mPm{ manager }
, mIterator{ manager.mRegisteredPlugins.begin() }
, mPluginType{ type }
{
   Advance(false);
}

PluginManager::Iterator::Iterator(PluginManager &manager, EffectType type)
: mPm{ manager }
, mIterator{ manager.mRegisteredPlugins.begin() }
, mEffectType{ type }
{
   Advance(false);
}

auto PluginManager::Iterator::operator ++() -> Iterator &
{
   Advance(true);
   return *this;
}

bool PluginManager::IsPluginEnabled(const PluginID & ID)
{
   if (auto iter = mRegisteredPlugins.find(ID); iter == mRegisteredPlugins.end())
      return false;
   else
      return iter->second.IsEnabled();
}

void PluginManager::EnablePlugin(const PluginID & ID, bool enable)
{
   if (auto iter = mRegisteredPlugins.find(ID); iter == mRegisteredPlugins.end())
      return;
   else
      iter->second.SetEnabled(enable);
}

const ComponentInterfaceSymbol & PluginManager::GetSymbol(const PluginID & ID)
{
   if (auto iter = mRegisteredPlugins.find(ID); iter == mRegisteredPlugins.end()) {
      static ComponentInterfaceSymbol empty;
      return empty;
   }
   else
      return iter->second.GetSymbol();
}

ComponentInterface *PluginManager::Load(const PluginID & ID)
{
   if(auto it = mLoadedInterfaces.find(ID); it != mLoadedInterfaces.end())
      return it->second.get();

   if(auto it = mRegisteredPlugins.find(ID); it != mRegisteredPlugins.end())
   {
      auto& desc = it->second;
      if(desc.GetPluginType() == PluginTypeModule)
         //it's very likely that this code path is not used
         return ModuleManager::Get().CreateProviderInstance(desc.GetID(), desc.GetPath());
      
      if(auto provider = ModuleManager::Get().CreateProviderInstance(desc.GetProviderID(), wxEmptyString))
      {
         auto pluginInterface = provider->LoadPlugin(desc.GetPath());
         auto result = pluginInterface.get();
         mLoadedInterfaces[desc.GetID()] = std::move(pluginInterface);
         return result;
      }
   }
   return nullptr;
}

void PluginManager::ClearEffectPlugins()
{
   mEffectPluginsCleared.clear();

   for ( auto it = mRegisteredPlugins.cbegin(); it != mRegisteredPlugins.cend(); )
   {
      const auto& desc = it->second;
      const auto type = desc.GetPluginType();

      if (type == PluginTypeEffect || type == PluginTypeStub)
      {
         mEffectPluginsCleared.push_back(desc);
         it = mRegisteredPlugins.erase(it);
      }
      else
      {
         ++it;
      }
   }

   // Repeat what usually happens at startup
   // This prevents built-in plugins to appear in the plugin validation list
   for (auto& [_, provider] : ModuleManager::Get().Providers())
      provider->AutoRegisterPlugins(*this);

   // Remove auto registered plugins from "cleared" list
   for ( auto it = mEffectPluginsCleared.begin(); it != mEffectPluginsCleared.end(); )
   {
      if ( mRegisteredPlugins.find(it->GetID()) != mRegisteredPlugins.end() )
         it = mEffectPluginsCleared.erase(it);
      else
         ++it;
   }
}

std::map<wxString, std::vector<wxString>> PluginManager::CheckPluginUpdates()
{
   wxArrayString pathIndex;
   for (auto &pair : mRegisteredPlugins) {
      auto &plug = pair.second;

      // Bypass 2.1.0 placeholders...remove this after a few releases past 2.1.0
      if (plug.GetPluginType() != PluginTypeNone)
         pathIndex.push_back(plug.GetPath().BeforeFirst(wxT(';')));
   }

   // Scan for NEW ones.
   //
   // Because we use the plugins "path" as returned by the providers, we can actually
   // have multiple providers report the same path since, at this point, they only
   // know that the path might possibly be one supported by the provider.
   //
   // When the user enables the plugin, each provider that reported it will be asked
   // to register the plugin.

   auto& moduleManager = ModuleManager::Get();
   std::map<wxString, std::vector<wxString>> newPaths;
   for(auto& [id, provider] : moduleManager.Providers())
   {
      const auto paths = provider->FindModulePaths(*this);
      for(const auto& path : paths)
      {
         const auto modulePath = path.BeforeFirst(';');
         if (!make_iterator_range(pathIndex).contains(modulePath) ||
            make_iterator_range(mEffectPluginsCleared).any_of([&modulePath](const PluginDescriptor& plug) {
               return plug.GetPath().BeforeFirst(wxT(';')) == modulePath;
            })
         )
         {
            newPaths[modulePath].push_back(id);
         }
      }
   }

   return newPaths;
}

PluginID PluginManager::GetID(const PluginProvider *provider)
{
   return ModuleManager::GetID(provider);
}

PluginID PluginManager::GetID(const ComponentInterface *command)
{
   return wxString::Format(wxT("%s_%s_%s_%s_%s"),
                           GetPluginTypeString(PluginTypeAudacityCommand),
                           wxEmptyString,
                           command->GetVendor().Internal(),
                           command->GetSymbol().Internal(),
                           command->GetPath());
}

PluginID PluginManager::OldGetID(const EffectDefinitionInterface* effect)
{
   return wxString::Format(wxT("%s_%s_%s_%s_%s"),
                           GetPluginTypeString(PluginTypeEffect),
                           effect->GetFamily().Internal(),
                           effect->GetVendor().Internal(),
                           effect->GetSymbol().Internal(),
                           effect->GetPath());
}

PluginID PluginManager::GetID(const EffectDefinitionInterface* effect)
{
   return wxJoin(wxArrayStringEx{
      GetPluginTypeString(PluginTypeEffect),
      effect->GetFamily().Internal(),
      effect->GetVendor().Internal(),
      effect->GetSymbol().Internal(),
      effect->GetPath()
   }, '_');
}

Identifier PluginManager::GetEffectNameFromID(const PluginID &ID)
{
   auto strings = wxSplit(ID, '_');
   if (strings.size() == 5)
      return strings[3];
   return {};
}

// This string persists in configuration files
// So config compatibility will break if it is changed across Audacity versions
wxString PluginManager::GetPluginTypeString(PluginType type)
{
   wxString str;

   switch (type)
   {
   default:
   case PluginTypeNone:
      str = wxT("Placeholder");
      break;
   case PluginTypeStub:
      str = wxT("Stub");
      break;
   case PluginTypeEffect:
      str = wxT("Effect");
      break;
   case PluginTypeAudacityCommand:
      str = wxT("Generic");
      break;
   case PluginTypeExporter:
      str = wxT("Exporter");
      break;
   case PluginTypeImporter:
      str = wxT("Importer");
      break;
   case PluginTypeModule:
      str = ModuleManager::GetPluginTypeString();
      break;
   }

   return str;
}

bool PluginManager::IsPluginAvailable(const PluginDescriptor& plug)
{
   const auto& providerID = plug.GetProviderID();
   auto provider = ModuleManager::Get().CreateProviderInstance(providerID, wxEmptyString);

   if (provider == nullptr)
   {
      wxLogWarning("Unable to find a provider for '%s'", providerID);
      return false;
   }

   if (provider->CheckPluginExist(plug.GetPath()) == false)
   {
      wxLogWarning("Plugin '%s' does not exist", plug.GetID());
      return false;
   }

   return true;
}

PluginDescriptor & PluginManager::CreatePlugin(const PluginID & id,
                                               ComponentInterface *ident,
                                               PluginType type)
{
   // This will either create a NEW entry or replace an existing entry
   PluginDescriptor & plug = mRegisteredPlugins[id];

   plug.SetPluginType(type);

   plug.SetID(id);
   plug.SetPath(ident->GetPath());
   plug.SetSymbol(ident->GetSymbol());
   plug.SetVendor(ident->GetVendor().Internal());
   plug.SetVersion(ident->GetVersion());

   return plug;
}

audacity::BasicSettings *PluginManager::GetSettings()
{
   if (!mSettings)
   {
      mSettings = sFactory(FileNames::PluginSettings());

      // Check for a settings version that we can understand
      if (mSettings->HasEntry(SETVERKEY))
      {
         wxString setver = mSettings->Read(SETVERKEY, SETVERKEY);
         if (setver < SETVERCUR )
         {
            // This is where we'd put in conversion code when the
            // settings version changes.
            //
            // Should also check for a settings file that is newer than
            // what we can understand.
         }
      }
      else
      {
         // Make sure is has a version string
         mSettings->Write(SETVERKEY, SETVERCUR);
         mSettings->Flush();
      }
   }

   return mSettings.get();
}

bool PluginManager::HasGroup(const RegistryPath & groupName)
{
   auto settings = GetSettings();

   if(!settings->HasGroup(groupName))
      return false;
   
   auto group = settings->BeginGroup(groupName);
   return !settings->GetChildGroups().empty() || !settings->GetChildKeys().empty();
}

bool PluginManager::GetSubgroups(const RegistryPath & groupName, RegistryPaths & subgroups)
{
   if (groupName.empty() || !HasGroup(groupName))
   {
      return false;
   }

   auto group = GetSettings()->BeginGroup(groupName);
   for(const auto& name : GetSettings()->GetChildGroups())
      subgroups.push_back(name);

   return true;
}

bool PluginManager::HasConfigValue(const RegistryPath & key)
{
   return GetSettings()->Exists(key);
}

template<typename T> class TD;

bool PluginManager::GetConfigValue(
   const RegistryPath & key, ConfigReference var, ConfigConstReference defval)
{
   using namespace Variant;
   if (key.empty())
      return false;
   const auto visitor = [&](const auto var){
      const auto pVar = &var.get();
      // precondition is that defval wraps same type as var
      using Type = typename decltype(var)::type;
      const auto pDefval =
         std::get_if<std::reference_wrapper<const Type>>(&defval);
      //TD<decltype(pDefval)> defType;
      //return true;
      return GetSettings()->Read(key, pVar, pDefval->get());
   };
   return Visit(visitor, var);
}

bool PluginManager::SetConfigValue(
   const RegistryPath & key, ConfigConstReference value)
{
   using namespace Variant;
   if (key.empty())
      return false;
   const auto visitor = [&](const auto value){
      return GetSettings()->Write(key, value.get()) && GetSettings()->Flush();
   };
   return Visit(visitor, value);
}

/* Return value is a key for lookup in a config file */
RegistryPath PluginManager::SettingsPath(
   ConfigurationType type, const PluginID & ID)
{
   bool shared = (type == ConfigurationType::Shared);

   // All the strings reported by PluginDescriptor and used in this function
   // persist in the plugin settings configuration file, so they should not
   // be changed across Audacity versions, or else compatibility of the
   // configuration files will break.

   if (auto iter = mRegisteredPlugins.find(ID); iter == mRegisteredPlugins.end())
      return {};
   else {
      const PluginDescriptor & plug = iter->second;
      
      wxString id = GetPluginTypeString(plug.GetPluginType()) +
                    wxT("_") +
                    plug.GetEffectFamily() + // is empty for non-Effects
                    wxT("_") +
                    plug.GetVendor() +
                    wxT("_") +
                    (shared ? wxString{} : plug.GetSymbol().Internal());

      return SETROOT +
             ConvertID(id) +
             wxCONFIG_PATH_SEPARATOR +
             (shared ? wxT("shared") : wxT("private")) +
             wxCONFIG_PATH_SEPARATOR;
   }
}

/* Return value is a key for lookup in a config file */
RegistryPath PluginManager::Group( ConfigurationType type,
   const PluginID & ID, const RegistryPath & group) 
{
   auto path = SettingsPath(type, ID);

   wxFileName ff(group);
   if (!ff.GetName().empty())
   {
      path += ff.GetFullPath(wxPATH_UNIX) + wxCONFIG_PATH_SEPARATOR;
   }

   return path;
}

/* Return value is a key for lookup in a config file */
RegistryPath PluginManager::Key(ConfigurationType type, const PluginID & ID,
   const RegistryPath & group, const RegistryPath & key)
{
   auto path = Group(type, ID, group);
   if (path.empty())
   {
      return path;
   }

   return path + key;
}

// Sanitize the ID...not the best solution, but will suffice until this
// is converted to XML.  We use base64 encoding to preserve case.
wxString PluginManager::ConvertID(const PluginID & ID)
{
   if (ID.StartsWith(wxT("base64:")))
   {
      wxString id = ID.Mid(7);
      ArrayOf<char> buf{ id.length() / 4 * 3 };
      id =  wxString::FromUTF8(buf.get(), Base64::Decode(id, buf.get()));
      return id;
   }

   const wxCharBuffer & buf = ID.ToUTF8();
   return wxT("base64:") + Base64::Encode(buf, strlen(buf));
}

// This is defined out-of-line here, to keep ComponentInterface free of other
// #include directives.
TranslatableString ComponentInterface::GetName() const
{
   return GetSymbol().Msgid();
}
