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

  Audacity: A Digital Audio Editor

  ImportFLAC.cpp

  Copyright 2004  Sami Liedes
  Leland Lucius

  Based on ImportPCM.cpp by Dominic Mazzoni
  Licensed under the GNU General Public License v2 or later

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

\class FLACImportFileHandle
\brief An ImportFileHandle for FLAC data

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

\class FLACImportPlugin
\brief An ImportPlugin for FLAC data

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


#include <wx/defs.h>

#include "Import.h"
#include "ImportPlugin.h"
#include "ImportProgressListener.h"

#include "Tags.h"

#define FLAC_HEADER "fLaC"

#define DESC XO("FLAC files")

static const auto exts = {
   wxT("flac"),
   wxT("flc")
};

#include <wx/file.h>
#include <wx/ffile.h>

#include "FLAC++/decoder.h"

#include "WaveTrack.h"
#include "ImportUtils.h"

#ifdef USE_LIBID3TAG
extern "C" {
#include <id3tag.h>
}
#endif

/* FLACPP_API_VERSION_CURRENT is 6 for libFLAC++ from flac-1.1.3 (see <FLAC++/export.h>) */
#if !defined FLACPP_API_VERSION_CURRENT || FLACPP_API_VERSION_CURRENT < 6
#define LEGACY_FLAC
#else
#undef LEGACY_FLAC
#endif


class FLACImportFileHandle;

class MyFLACFile final : public FLAC::Decoder::File
{
 public:
   MyFLACFile(FLACImportFileHandle *handle) : mFile(handle)
   {
      mWasError = false;
      set_metadata_ignore_all();
      set_metadata_respond(FLAC__METADATA_TYPE_VORBIS_COMMENT);
      set_metadata_respond(FLAC__METADATA_TYPE_STREAMINFO);
   }

   bool get_was_error() const
   {
      return mWasError;
   }
   
   ImportProgressListener *mImportProgressListener {nullptr};
   
 private:
   friend class FLACImportFileHandle;
   FLACImportFileHandle *mFile;
   bool                  mWasError;
   wxArrayString         mComments;
 protected:
   FLAC__StreamDecoderWriteStatus write_callback(const FLAC__Frame *frame,
                                                         const FLAC__int32 * const buffer[]) override;
   void metadata_callback(const FLAC__StreamMetadata *metadata) override;
   void error_callback(FLAC__StreamDecoderErrorStatus status) override;
};


class FLACImportPlugin final : public ImportPlugin
{
 public:
   FLACImportPlugin():
   ImportPlugin( FileExtensions( exts.begin(), exts.end() ) )
   {
   }

   ~FLACImportPlugin() { }

   wxString GetPluginStringID() override { return wxT("libflac"); }
   TranslatableString GetPluginFormatDescription() override;
   std::unique_ptr<ImportFileHandle> Open(
      const FilePath &Filename, AudacityProject*)  override;
};


class FLACImportFileHandle final : public ImportFileHandleEx
{
   friend class MyFLACFile;
public:
   FLACImportFileHandle(const FilePath & name);
   ~FLACImportFileHandle();

   bool Init();

   TranslatableString GetFileDescription() override;
   ByteCount GetFileUncompressedBytes() override;
   void Import(ImportProgressListener& progressListener,
               WaveTrackFactory *trackFactory,
               TrackHolders &outTracks,
               Tags *tags) override;

   wxInt32 GetStreamCount() override { return 1; }

   const TranslatableStrings &GetStreamInfo() override
   {
      static TranslatableStrings empty;
      return empty;
   }

   void SetStreamUsage(wxInt32 WXUNUSED(StreamID), bool WXUNUSED(Use)) override
   {}

private:
   sampleFormat          mFormat;
   std::unique_ptr<MyFLACFile> mFile;
   wxFFile               mHandle;
   unsigned long         mSampleRate;
   unsigned long         mNumChannels;
   unsigned long         mBitsPerSample;
   FLAC__uint64          mNumSamples;
   FLAC__uint64          mSamplesDone;
   bool                  mStreamInfoDone;
   TrackListHolder       mTrackList;
};


void MyFLACFile::metadata_callback(const FLAC__StreamMetadata *metadata)
{
   switch (metadata->type)
   {
      case FLAC__METADATA_TYPE_VORBIS_COMMENT:
         for (FLAC__uint32 i = 0; i < metadata->data.vorbis_comment.num_comments; i++) {
            mComments.push_back(UTF8CTOWX((char *)metadata->data.vorbis_comment.comments[i].entry));
         }
      break;

      case FLAC__METADATA_TYPE_STREAMINFO:
         mFile->mSampleRate=metadata->data.stream_info.sample_rate;
         mFile->mNumChannels=metadata->data.stream_info.channels;
         mFile->mBitsPerSample=metadata->data.stream_info.bits_per_sample;
         mFile->mNumSamples=metadata->data.stream_info.total_samples;

         // Widen mFormat after examining the file header
         if (mFile->mBitsPerSample<=16) {
            mFile->mFormat=int16Sample;
         } else if (mFile->mBitsPerSample<=24) {
            mFile->mFormat=int24Sample;
         } else {
            mFile->mFormat=floatSample;
         }
         mFile->mStreamInfoDone=true;
      break;
      // handle the other types we do nothing with to avoid a warning
      case FLAC__METADATA_TYPE_PADDING:	// do nothing with padding
      case FLAC__METADATA_TYPE_APPLICATION:	// no idea what to do with this
      case FLAC__METADATA_TYPE_SEEKTABLE:	// don't need a seektable here
      case FLAC__METADATA_TYPE_CUESHEET:	// convert this to labels?
      case FLAC__METADATA_TYPE_PICTURE:		// ignore pictures
      case FLAC__METADATA_TYPE_UNDEFINED:	// do nothing with this either

      // FIXME: not declared when compiling on Ubuntu.
      //case FLAC__MAX_METADATA_TYPE: // quiet compiler warning with this line
      default:
      break;
   }
}

void MyFLACFile::error_callback(FLAC__StreamDecoderErrorStatus WXUNUSED(status))
{
   mWasError = true;

   /*
   switch (status)
   {
   case FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC:
      wxPrintf(wxT("Flac Error: Lost sync\n"));
      break;
   case FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH:
      wxPrintf(wxT("Flac Error: Crc mismatch\n"));
      break;
   case FLAC__STREAM_DECODER_ERROR_STATUS_BAD_HEADER:
      wxPrintf(wxT("Flac Error: Bad Header\n"));
      break;
   default:
      wxPrintf(wxT("Flac Error: Unknown error code\n"));
      break;
   }*/
}

FLAC__StreamDecoderWriteStatus MyFLACFile::write_callback(const FLAC__Frame *frame,
                                                          const FLAC__int32 * const buffer[])
{
   // Don't let C++ exceptions propagate through libflac
   return GuardedCall< FLAC__StreamDecoderWriteStatus > ( [&] {
      auto tmp = ArrayOf< short >{ frame->header.blocksize };

      unsigned chn = 0;
      ImportUtils::ForEachChannel(*mFile->mTrackList, [&](auto& channel)
      {
         if (frame->header.bits_per_sample <= 16) {
            if (frame->header.bits_per_sample == 8) {
               for (unsigned int s = 0; s < frame->header.blocksize; s++) {
                  tmp[s] = buffer[chn][s] << 8;
               }
            } else /* if (frame->header.bits_per_sample == 16) */ {
               for (unsigned int s = 0; s < frame->header.blocksize; s++) {
                  tmp[s] = buffer[chn][s];
               }
            }

            channel.AppendBuffer((samplePtr)tmp.get(),
                     int16Sample,
                     frame->header.blocksize, 1,
                     int16Sample);
         }
         else {
            channel.AppendBuffer((samplePtr)buffer[chn],
                     int24Sample,
                     frame->header.blocksize, 1,
                     int24Sample);
         }
         ++chn;
      });

      mFile->mSamplesDone += frame->header.blocksize;

      if(mFile->mNumSamples > 0)
         mImportProgressListener->OnImportProgress(static_cast<double>(mFile->mSamplesDone) /
                                                   static_cast<double>(mFile->mNumSamples));
      
      if (mFile->IsCancelled() || mFile->IsStopped())
      {
         return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
      }

      return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
   }, MakeSimpleGuard(FLAC__STREAM_DECODER_WRITE_STATUS_ABORT) );
}

TranslatableString FLACImportPlugin::GetPluginFormatDescription()
{
    return DESC;
}


std::unique_ptr<ImportFileHandle> FLACImportPlugin::Open(
   const FilePath &filename, AudacityProject*)
{
   // First check if it really is a FLAC file

   int cnt;
   wxFile binaryFile;
   if (!binaryFile.Open(filename)) {
      return nullptr; // File not found
   }

   // FIXME: TRAP_ERR wxFILE ops in FLAC Import could fail.
   // Seek() return value is not examined, for example.
#ifdef USE_LIBID3TAG
   // Skip any ID3 tags that might be present
   id3_byte_t query[ID3_TAG_QUERYSIZE];
   cnt = binaryFile.Read(query, sizeof(query));
   cnt = id3_tag_query(query, cnt);
   binaryFile.Seek(cnt);
#endif

   char buf[5];
   cnt = binaryFile.Read(buf, 4);
   binaryFile.Close();

   if (cnt == wxInvalidOffset || strncmp(buf, FLAC_HEADER, 4) != 0) {
      // File is not a FLAC file
      return nullptr;
   }

   // Open the file for import
   auto handle = std::make_unique<FLACImportFileHandle>(filename);

   bool success = handle->Init();
   if (!success) {
      return nullptr;
   }

   // This std::move is needed to "upcast" the pointer type
   return std::move(handle);
}

static Importer::RegisteredImportPlugin registered{ "FLAC",
   std::make_unique< FLACImportPlugin >()
};

FLACImportFileHandle::FLACImportFileHandle(const FilePath & name)
:  ImportFileHandleEx(name),
   mSamplesDone(0),
   mStreamInfoDone(false)
{
   // Initialize mFormat as narrowest
   mFormat = narrowestSampleFormat;
   mFile = std::make_unique<MyFLACFile>(this);
}

bool FLACImportFileHandle::Init()
{
#ifdef LEGACY_FLAC
   bool success = mFile->set_filename(OSINPUT(mFilename));
   if (!success) {
      return false;
   }
   mFile->set_metadata_respond(FLAC__METADATA_TYPE_STREAMINFO);
   mFile->set_metadata_respond(FLAC__METADATA_TYPE_VORBIS_COMMENT);
   FLAC::Decoder::File::State state = mFile->init();
   if (state != FLAC__FILE_DECODER_OK) {
      return false;
   }
#else
   if (!mHandle.Open(GetFilename(), wxT("rb"))) {
      return false;
   }

   // Even though there is an init() method that takes a filename, use the one that
   // takes a file handle because wxWidgets can open a file with a Unicode name and
   // libflac can't (under Windows).
   //
   // Responsibility for closing the file is passed to libflac.
   // (it happens when mFile->finish() is called)
   bool result = mFile->init(mHandle.fp())?true:false;
   mHandle.Detach();

   if (result != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
      return false;
   }
#endif
   mFile->process_until_end_of_metadata();

#ifdef LEGACY_FLAC
   state = mFile->get_state();
   if (state != FLAC__FILE_DECODER_OK) {
      return false;
   }
#else
   // not necessary to check state, error callback will catch errors, but here's how:
   if (mFile->get_state() > FLAC__STREAM_DECODER_READ_FRAME) {
      return false;
   }
#endif

   if (!mFile->is_valid() || mFile->get_was_error()) {
      // This probably is not a FLAC file at all
      return false;
   }
   return true;
}

TranslatableString FLACImportFileHandle::GetFileDescription()
{
   return DESC;
}


auto FLACImportFileHandle::GetFileUncompressedBytes() -> ByteCount
{
   // TODO: Get Uncompressed byte count.
   return 0;
}


void FLACImportFileHandle::Import(ImportProgressListener& progressListener,
                                  WaveTrackFactory *trackFactory,
                                  TrackHolders &outTracks,
                                  Tags *tags)
{
   BeginImport();
   
   outTracks.clear();

   auto cleanup = finally([&]{ mFile->mImportProgressListener = nullptr; });
   
   wxASSERT(mStreamInfoDone);

   mTrackList = ImportUtils::NewWaveTrack(*trackFactory, mNumChannels, mFormat, mSampleRate);

   mFile->mImportProgressListener = &progressListener;

   // TODO: Vigilant Sentry: Variable res unused after assignment (error code DA1)
   //    Should check the result.
   #ifdef LEGACY_FLAC
      bool res = (mFile->process_until_end_of_file() != 0);
   #else
      bool res = (mFile->process_until_end_of_stream() != 0);
   #endif
   
   if(IsCancelled())
   {
      progressListener.OnImportResult(ImportProgressListener::ImportResult::Cancelled);
      return;
   }

   ImportUtils::FinalizeImport(outTracks, mTrackList);

   wxString comment;
   wxString description;

   size_t cnt = mFile->mComments.size();
   if (cnt > 0) {
      tags->Clear();
      for (size_t c = 0; c < cnt; c++) {
         wxString name = mFile->mComments[c].BeforeFirst(wxT('='));
         wxString value = mFile->mComments[c].AfterFirst(wxT('='));
         wxString upper = name.Upper();
         if (upper == wxT("DATE") && !tags->HasTag(TAG_YEAR)) {
            long val;
            if (value.length() == 4 && value.ToLong(&val)) {
               name = TAG_YEAR;
            }
         }
         else if (upper == wxT("COMMENT") || upper == wxT("COMMENTS")) {
            comment = value;
            continue;
         }
         else if (upper == wxT("DESCRIPTION")) {
            description = value;
            continue;
         }
         tags->SetTag(name, value);
      }

      if (comment.empty()) {
         comment = description;
      }
      if (!comment.empty()) {
         tags->SetTag(TAG_COMMENTS, comment);
      }
   }

   progressListener.OnImportResult(IsStopped()
                                   ? ImportProgressListener::ImportResult::Stopped
                                   : ImportProgressListener::ImportResult::Success);
}

FLACImportFileHandle::~FLACImportFileHandle()
{
   mFile->finish();
}
