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

  Audacity: A Digital Audio Editor

  VSTEffectsModule.cpp

  Dominic Mazzoni

  Paul Licameli split from VSTEffect.cpp


*//********************************************************************/
#include "VSTEffectsModule.h"

#include "ModuleManager.h"
#include "wxArrayStringEx.h"

#if defined(__WXMSW__)
#include <Windows.h>
#include <shlwapi.h>
#endif

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

// ============================================================================
//
// Module registration entry point
//
// This is the symbol that Audacity looks for when the module is built as a
// dynamic library.
//
// When the module is builtin to Audacity, we use the same function, but it is
// declared static so as not to clash with other builtin modules.
//
// ============================================================================
DECLARE_PROVIDER_ENTRY(AudacityModule)
{
   // Create our effects module and register
   // Trust the module manager not to leak this
   return std::make_unique<VSTEffectsModule>();
}

// ============================================================================
//
// Register this as a builtin module
//
// We also take advantage of the fact that wxModules are initialized before
// the wxApp::OnInit() method is called.  We check to see if Audacity was
// executed to scan a VST effect in a different process.
//
// ============================================================================
DECLARE_BUILTIN_PROVIDER(VSTBuiltin);


///////////////////////////////////////////////////////////////////////////////
///
/// Auto created at program start up, this initialises VST.
///
///////////////////////////////////////////////////////////////////////////////

VSTEffectsModule::VSTEffectsModule()
{
}

VSTEffectsModule::~VSTEffectsModule()
{
}

// ============================================================================
// ComponentInterface implementation
// ============================================================================

PluginPath VSTEffectsModule::GetPath() const
{
   return {};
}

ComponentInterfaceSymbol VSTEffectsModule::GetSymbol() const
{
   return XO("VST Effects");
}

VendorSymbol VSTEffectsModule::GetVendor() const
{
   return XO("The Audacity Team");
}

wxString VSTEffectsModule::GetVersion() const
{
   // This "may" be different if this were to be maintained as a separate DLL
   return AUDACITY_VERSION_STRING;
}

TranslatableString VSTEffectsModule::GetDescription() const
{
   return XO("Adds the ability to use VST effects in Audacity.");
}

// ============================================================================
// PluginProvider implementation
// ============================================================================

bool VSTEffectsModule::Initialize()
{
   // Nothing to do here
   return true;
}

void VSTEffectsModule::Terminate()
{
   // Nothing to do here
   return;
}

bool VSTEffectsModule::SupportsCustomModulePaths() const
{
   return true;
}

EffectFamilySymbol VSTEffectsModule::GetOptionalFamilySymbol()
{
   return VSTPLUGINTYPE;
}

const FileExtensions &VSTEffectsModule::GetFileExtensions()
{
   static FileExtensions result{{ _T("vst") }};
   return result;
}

FilePath VSTEffectsModule::InstallPath()
{
   // Not yet ready for VST drag-and-drop...
   // return FileNames::PlugInDir();

   return {};
}

void VSTEffectsModule::AutoRegisterPlugins(PluginManagerInterface &)
{
}

PluginPaths VSTEffectsModule::FindModulePaths(PluginManagerInterface & pm)
{
   FilePaths pathList;
   FilePaths files;

   // Check for the VST_PATH environment variable
   wxString vstpath = wxString::FromUTF8(getenv("VST_PATH"));
   if (!vstpath.empty())
   {
      wxStringTokenizer tok(vstpath, wxPATH_SEP);
      while (tok.HasMoreTokens())
      {
         pathList.push_back(tok.GetNextToken());
      }
   }
   
   const auto AddCustomPaths = [](PluginManagerInterface& pm, VSTEffectsModule& module, FilePaths& pathList)
   {
      const auto customPaths = pm.ReadCustomPaths(module);
      std::copy(customPaths.begin(), customPaths.end(), std::back_inserter(pathList));
   };

#if defined(__WXMAC__)
#define VSTPATH wxT("/Library/Audio/Plug-Ins/VST")

   // Look in ~/Library/Audio/Plug-Ins/VST and /Library/Audio/Plug-Ins/VST
   pathList.push_back(wxGetHomeDir() + wxFILE_SEP_PATH + VSTPATH);
   pathList.push_back(VSTPATH);
   
   AddCustomPaths(pm, *this, pathList);
   
   // Recursively search all paths for Info.plist files.  This will identify all
   // bundles.
   pm.FindFilesInPathList(wxT("Info.plist"), pathList, files, true);

   // Remove the 'Contents/Info.plist' portion of the names
   for (size_t i = 0; i < files.size(); i++)
   {
      files[i] = wxPathOnly(wxPathOnly(files[i]));
      if (!files[i].EndsWith(wxT(".vst")))
      {
         files.erase( files.begin() + i-- );
      }
   }

#elif defined(__WXMSW__)

   TCHAR dpath[MAX_PATH];
   TCHAR tpath[MAX_PATH];
   DWORD len;

   // Try HKEY_CURRENT_USER registry key first
   len = WXSIZEOF(tpath);
   if (SHRegGetUSValue(wxT("Software\\VST"),
                       wxT("VSTPluginsPath"),
                       NULL,
                       tpath,
                       &len,
                       FALSE,
                       NULL,
                       0) == ERROR_SUCCESS)
   {
      tpath[len] = 0;
      dpath[0] = 0;
      ExpandEnvironmentStrings(tpath, dpath, WXSIZEOF(dpath));
      pathList.push_back(dpath);
   }

   // Then try HKEY_LOCAL_MACHINE registry key
   len = WXSIZEOF(tpath);
   if (SHRegGetUSValue(wxT("Software\\VST"),
                       wxT("VSTPluginsPath"),
                       NULL,
                       tpath,
                       &len,
                       TRUE,
                       NULL,
                       0) == ERROR_SUCCESS)
   {
      tpath[len] = 0;
      dpath[0] = 0;
      ExpandEnvironmentStrings(tpath, dpath, WXSIZEOF(dpath));
      pathList.push_back(dpath);
   }

   // Add the default path last
   dpath[0] = 0;
   ExpandEnvironmentStrings(wxT("%ProgramFiles%\\Steinberg\\VSTPlugins"),
                            dpath,
                            WXSIZEOF(dpath));
   pathList.push_back(dpath);

   dpath[0] = 0;
   ExpandEnvironmentStrings(wxT("%COMMONPROGRAMFILES%\\VST2"),
                            dpath,
                            WXSIZEOF(dpath));
   pathList.push_back(dpath);

   AddCustomPaths(pm, *this, pathList);

   // Recursively scan for all DLLs
   pm.FindFilesInPathList(wxT("*.dll"), pathList, files, true);

#else

   // Nothing specified in the VST_PATH environment variable...provide defaults
   if (vstpath.empty())
   {
      // We add this "non-default" one
      pathList.push_back(wxT(LIBDIR) wxT("/vst"));

      // These are the defaults used by other hosts
      pathList.push_back(wxT("/usr/lib/vst"));
      pathList.push_back(wxT("/usr/local/lib/vst"));
      pathList.push_back(wxGetHomeDir() + wxFILE_SEP_PATH + wxT(".vst"));
   }
   
   AddCustomPaths(pm, *this, pathList);

   // Recursively scan for all shared objects
   pm.FindFilesInPathList(wxT("*.so"), pathList, files, true);

#endif

   return { files.begin(), files.end() };
}

unsigned VSTEffectsModule::DiscoverPluginsAtPath(
   const PluginPath & path, TranslatableString &errMsg,
   const RegistrationCallback &callback)
{

   VSTEffectBase effect(path);
   if(effect.InitializePlugin())
   {
      auto effectIDs = effect.GetEffectIDs();
      if(effectIDs.empty())
         //Each VST plugin path in Audacity should have id(index) part in it
         effectIDs.push_back(0);

      for(auto id : effectIDs)
      {
         //Subsequent VSTEffect::Load may seem like overhead, but we need
         //to initialize EffectDefinitionInterface part, which includes
         //properly formatted plugin path
         VSTEffectBase subeffect(wxString::Format("%s;%d", path, id));
         subeffect.Load();
         if(callback)
            callback(this, &subeffect);
      }
      return effectIDs.size();
   }
   errMsg = XO("Could not load the library");
   return 0;
}

std::unique_ptr<ComponentInterface>
VSTEffectsModule::LoadPlugin(const PluginPath & path)
{
   // Acquires a resource for the application.
   // For us, the ID is simply the path to the effect
   auto result = Factory::Call(path);
   if (!result->InitializePlugin())
      result.reset();
   return result;
}

bool VSTEffectsModule::CheckPluginExist(const PluginPath& path) const
{
   const auto modulePath = path.BeforeFirst(wxT(';'));
   return wxFileName::FileExists(modulePath) || wxFileName::DirExists(modulePath);
}