// $Id: AlBuffer.cxx 2333 2010-01-11 18:07:27Z matevz $

// Copyright (C) 1999-2008, Matevz Tadel. All rights reserved.
// This file is part of GLED, released under GNU General Public License version 2.
// For the licensing terms see $GLEDSYS/LICENSE or http://www.gnu.org/.

#include "AlBuffer.h"
#include "AlBuffer.c7"

#include <AL/alut.h>
#include <vorbis/vorbisfile.h>

namespace
{
#ifdef R__BYTESWAP
  static const int slBigEndian = 0;
#else
  static const int slBigEndian = 1;
#endif
}

// AlBuffer

//______________________________________________________________________________
//
//

ClassImp(AlBuffer);

//==============================================================================

void AlBuffer::clear_buffer_props()
{
  mFrequency = mSize = mBits = mChannels = 0;
  mDuration = 0;
}

void AlBuffer::_init()
{
  mAlBuf = 0;
  clear_buffer_props();
}

AlBuffer::AlBuffer(const Text_t* n, const Text_t* t) :
  ZGlass(n, t)
{
  _init();
}

AlBuffer::~AlBuffer()
{
  if (mAlBuf) alDeleteBuffers(1, &mAlBuf);
}

//==============================================================================

void AlBuffer::Load()
{
  static const Exc_t _eh("AlBuffer::Load ");

  if (mAlBuf)
  {
    // !!! Should check use count - the call fails if buffer is still used.
    // !!! But it is not set from AlSource, so think a bit.

    alDeleteBuffers(1, &mAlBuf);
    mAlBuf = 0;
  }

  if (mFile.EndsWith(".wav"))
  {
    mAlBuf = alutCreateBufferFromFile(mFile);
    if (mAlBuf == AL_NONE)
    {
      ISerr(_eh + GForm("Error in alutCreateBufferFromFile: %s\n", alutGetErrorString(alutGetError())));
    }
  }
  else if (mFile.EndsWith(".ogg"))
  {
    OggVorbis_File oggFile;
    int status = ov_fopen((char*)mFile.Data(), &oggFile);
    if (status == 0)
    {
      vorbis_info *info = ov_info(&oggFile, -1);
      ogg_int64_t  len = ov_pcm_total(&oggFile, -1) * info->channels * 2;
      UChar_t     *data = new UChar_t[len];

      int          bs    = -1;
      ogg_int64_t  todo  = len;
      UChar_t     *bufpt = data;

      while (todo)
      {
	long read = ov_read(&oggFile, (char*)bufpt, todo, slBigEndian, 2, 1, &bs);
	todo  -= read;
	bufpt += read;
      }

      alGenBuffers(1, &mAlBuf);
      alBufferData(mAlBuf, (info->channels == 1) ? AL_FORMAT_MONO16 : AL_FORMAT_STEREO16, data, len, info->rate);

      delete [] data;
      ov_clear(&oggFile);
    }
    else
    {
      const char *err;
      switch (status)
      {
	case OV_EREAD:      err = "A read from media returned an error."; break;
	case OV_ENOTVORBIS: err = "Bitstream does not contain any Vorbis data."; break;
	case OV_EVERSION:   err = "Vorbis version mismatch."; break;
	case OV_EBADHEADER: err = "Invalid Vorbis bitstream header."; break;
	case OV_EFAULT:     err = "Internal logic fault; indicates a bug or heap/stack corruption."; break;
	default:            err = "unknown."; break;
      }
      ISerr(_eh + "Error in OGG ov_open: " + err);
    }
  }
  else
  {
    ISerr(_eh + "Unknown file-type.");
  }

  if (mAlBuf != AL_NONE)
  {
    alGetBufferi(mAlBuf, AL_FREQUENCY, &mFrequency);
    alGetBufferi(mAlBuf, AL_SIZE,      &mSize);
    alGetBufferi(mAlBuf, AL_BITS,      &mBits);
    alGetBufferi(mAlBuf, AL_CHANNELS,  &mChannels);
    mDuration = (8.0f * mSize) / (mFrequency * mBits * mChannels);
  }
  else
  {
    clear_buffer_props();
  }

  Stamp(FID());
}