/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

/* Allow access to a raw mixing buffer */

#include "SDL_timer.h"

#include "SDL_audio.h"

#include "../SDL_audio_c.h"

#include "SDL_dart.h"

// Buffer states:

#define BUFFER_EMPTY       0

#define BUFFER_USED        1

typedef struct _tMixBufferDesc {

  int              iBufferUsage;      // BUFFER_EMPTY or BUFFER_USED

  SDL_AudioDevice *pSDLAudioDevice;

} tMixBufferDesc, *pMixBufferDesc;

//---------------------------------------------------------------------

// DARTEventFunc

//

// This function is called by DART, when an event occures, like end of 

// playback of a buffer, etc...

//---------------------------------------------------------------------

LONG APIENTRY DARTEventFunc(ULONG ulStatus,

			    PMCI_MIX_BUFFER pBuffer,

			    ULONG ulFlags)

{

  if (ulFlags && MIX_WRITE_COMPLETE)

  { // Playback of buffer completed!

    // Get pointer to buffer description

    pMixBufferDesc pBufDesc;

    if (pBuffer)

    {

      pBufDesc = (pMixBufferDesc) (*pBuffer).ulUserParm;

      if (pBufDesc)

      {

        SDL_AudioDevice *pSDLAudioDevice = pBufDesc->pSDLAudioDevice;

        // Set the buffer to be empty

        pBufDesc->iBufferUsage = BUFFER_EMPTY;

        // And notify DART feeder thread that it will have to work a bit.

        if (pSDLAudioDevice)

        DosPostEventSem(pSDLAudioDevice->hidden->hevAudioBufferPlayed);

      }

    }

  }

  return TRUE;

}

int DART_OpenAudio(_THIS, SDL_AudioSpec *spec)

{

  Uint16 test_format = SDL_FirstAudioFormat(spec->format);

  int valid_datatype = 0;

  MCI_AMP_OPEN_PARMS AmpOpenParms;

  MCI_GENERIC_PARMS GenericParms;

  int iDeviceOrd = 0; // Default device to be used

  int bOpenShared = 1; // Try opening it shared

  int iBits = 16; // Default is 16 bits signed

  int iFreq = 44100; // Default is 44KHz

  int iChannels = 2; // Default is 2 channels (Stereo)

  int iNumBufs = 2;  // Number of audio buffers: 2

  int iBufSize;

  int iOpenMode;

  int iSilence;

  int rc;

  // First thing is to try to open a given DART device!

  SDL_memset(&AmpOpenParms, 0, sizeof(MCI_AMP_OPEN_PARMS));

  // pszDeviceType should contain the device type in low word, and device ordinal in high word!

  AmpOpenParms.pszDeviceType = (PSZ) (MCI_DEVTYPE_AUDIO_AMPMIX | (iDeviceOrd << 16));

  iOpenMode = MCI_WAIT | MCI_OPEN_TYPE_ID;

  if (bOpenShared) iOpenMode |= MCI_OPEN_SHAREABLE;

  rc = mciSendCommand( 0, MCI_OPEN,

                       iOpenMode,

		       (PVOID) &AmpOpenParms, 0);

  if (rc!=MCIERR_SUCCESS) // No audio available??

    return (-1);

  // Save the device ID we got from DART!

  // We will use this in the next calls!

  iDeviceOrd = AmpOpenParms.usDeviceID;

  // Determine the audio parameters from the AudioSpec

  if (spec->channels > 2)

    spec->channels = 2;  // !!! FIXME: more than stereo support in OS/2?

  while ((!valid_datatype) && (test_format)) {

    spec->format = test_format;

    valid_datatype = 1;

    switch (test_format) {

      case AUDIO_U8:

        // Unsigned 8 bit audio data

        iSilence = 0x80;

        iBits = 8;

        break;

      case AUDIO_S16LSB:

        // Signed 16 bit audio data

        iSilence = 0x00;

        iBits = 16;

        break;

      default:

        valid_datatype = 0;

        test_format = SDL_NextAudioFormat();

        break;

    }

  }

  if (!valid_datatype) { // shouldn't happen, but just in case...

    // Close DART, and exit with error code!

    mciSendCommand(iDeviceOrd, MCI_CLOSE, MCI_WAIT, &GenericParms, 0);

    SDL_SetError("Unsupported audio format");

    return (-1);

  }

  iFreq = spec->freq;

  iChannels = spec->channels;

  /* Update the fragment size as size in bytes */

  SDL_CalculateAudioSpec(spec);

  iBufSize = spec->size;

  // Now query this device if it supports the given freq/bits/channels!

  SDL_memset(&(_this->hidden->MixSetupParms), 0, sizeof(MCI_MIXSETUP_PARMS));

  _this->hidden->MixSetupParms.ulBitsPerSample = iBits;

  _this->hidden->MixSetupParms.ulFormatTag = MCI_WAVE_FORMAT_PCM;

  _this->hidden->MixSetupParms.ulSamplesPerSec = iFreq;

  _this->hidden->MixSetupParms.ulChannels = iChannels;

  _this->hidden->MixSetupParms.ulFormatMode = MCI_PLAY;

  _this->hidden->MixSetupParms.ulDeviceType = MCI_DEVTYPE_WAVEFORM_AUDIO;

  _this->hidden->MixSetupParms.pmixEvent = DARTEventFunc;

  rc = mciSendCommand (iDeviceOrd, MCI_MIXSETUP,

                       MCI_WAIT | MCI_MIXSETUP_QUERYMODE,

                       &(_this->hidden->MixSetupParms), 0);

  if (rc!=MCIERR_SUCCESS)

  { // The device cannot handle this format!

    // Close DART, and exit with error code!

    mciSendCommand(iDeviceOrd, MCI_CLOSE, MCI_WAIT, &GenericParms, 0);

    SDL_SetError("Audio device doesn't support requested audio format");

    return(-1);

  }

  // The device can handle this format, so initialize!

  rc = mciSendCommand(iDeviceOrd, MCI_MIXSETUP,

                      MCI_WAIT | MCI_MIXSETUP_INIT,

                      &(_this->hidden->MixSetupParms), 0);

  if (rc!=MCIERR_SUCCESS)

  { // The device could not be opened!

    // Close DART, and exit with error code!

    mciSendCommand(iDeviceOrd, MCI_CLOSE, MCI_WAIT, &GenericParms, 0);

    SDL_SetError("Audio device could not be set up");

    return(-1);

  }

  // Ok, the device is initialized.

  // Now we should allocate buffers. For this, we need a place where

  // the buffer descriptors will be:

  _this->hidden->pMixBuffers = (MCI_MIX_BUFFER *) SDL_malloc(sizeof(MCI_MIX_BUFFER)*iNumBufs);

  if (!(_this->hidden->pMixBuffers))

  { // Not enough memory!

    // Close DART, and exit with error code!

    mciSendCommand(iDeviceOrd, MCI_CLOSE, MCI_WAIT, &GenericParms, 0);

    SDL_SetError("Not enough memory for audio buffer descriptors");

    return(-1);

  }

  // Now that we have the place for buffer list, we can ask DART for the

  // buffers!

  _this->hidden->BufferParms.ulNumBuffers = iNumBufs;               // Number of buffers

  _this->hidden->BufferParms.ulBufferSize = iBufSize;               // each with this size

  _this->hidden->BufferParms.pBufList = _this->hidden->pMixBuffers; // getting descriptorts into this list

  // Allocate buffers!

  rc = mciSendCommand(iDeviceOrd, MCI_BUFFER,

                      MCI_WAIT | MCI_ALLOCATE_MEMORY,

                      &(_this->hidden->BufferParms), 0);

  if ((rc!=MCIERR_SUCCESS) || (iNumBufs != _this->hidden->BufferParms.ulNumBuffers) || (_this->hidden->BufferParms.ulBufferSize==0))

  { // Could not allocate memory!

    // Close DART, and exit with error code!

    SDL_free(_this->hidden->pMixBuffers); _this->hidden->pMixBuffers = NULL;

    mciSendCommand(iDeviceOrd, MCI_CLOSE, MCI_WAIT, &GenericParms, 0);

    SDL_SetError("DART could not allocate buffers");

    return(-1);

  }

  // Ok, we have all the buffers allocated, let's mark them!

  {

    int i;

    for (i=0; i<iNumBufs; i++)

    {

      pMixBufferDesc pBufferDesc = (pMixBufferDesc) SDL_malloc(sizeof(tMixBufferDesc));;

      // Check if this buffer was really allocated by DART

      if ((!(_this->hidden->pMixBuffers[i].pBuffer)) || (!pBufferDesc))

      { // Wrong buffer!

        // Close DART, and exit with error code!

        // Free buffer descriptions

        { int j;

          for (j=0; j<i; j++) SDL_free((void *)(_this->hidden->pMixBuffers[j].ulUserParm));

        }

        // and cleanup

        mciSendCommand(iDeviceOrd, MCI_BUFFER, MCI_WAIT | MCI_DEALLOCATE_MEMORY, &(_this->hidden->BufferParms), 0);

        SDL_free(_this->hidden->pMixBuffers); _this->hidden->pMixBuffers = NULL;

        mciSendCommand(iDeviceOrd, MCI_CLOSE, MCI_WAIT, &GenericParms, 0);

        SDL_SetError("Error at internal buffer check");

        return(-1);

      }

      pBufferDesc->iBufferUsage = BUFFER_EMPTY;

      pBufferDesc->pSDLAudioDevice = _this;

      _this->hidden->pMixBuffers[i].ulBufferLength = _this->hidden->BufferParms.ulBufferSize;

      _this->hidden->pMixBuffers[i].ulUserParm = (ULONG) pBufferDesc; // User parameter: Description of buffer

      _this->hidden->pMixBuffers[i].ulFlags = 0; // Some stuff should be flagged here for DART, like end of

                                            // audio data, but as we will continously send

                                            // audio data, there will be no end.:)

      SDL_memset(_this->hidden->pMixBuffers[i].pBuffer, iSilence, iBufSize);

    }

  }

  _this->hidden->iNextFreeBuffer = 0;

  _this->hidden->iLastPlayedBuf = -1;

  // Create event semaphore

  if (DosCreateEventSem(NULL, &(_this->hidden->hevAudioBufferPlayed), 0, FALSE)!=NO_ERROR)

  {

    // Could not create event semaphore!

    {

      int i;

      for (i=0; i<iNumBufs; i++) SDL_free((void *)(_this->hidden->pMixBuffers[i].ulUserParm));

    }

    mciSendCommand(iDeviceOrd, MCI_BUFFER, MCI_WAIT | MCI_DEALLOCATE_MEMORY, &(_this->hidden->BufferParms), 0);

    SDL_free(_this->hidden->pMixBuffers); _this->hidden->pMixBuffers = NULL;

    mciSendCommand(iDeviceOrd, MCI_CLOSE, MCI_WAIT, &GenericParms, 0);

    SDL_SetError("Could not create event semaphore");

    return(-1);

  }

  // Store the new settings in global variables

  _this->hidden->iCurrDeviceOrd = iDeviceOrd;

  _this->hidden->iCurrFreq = iFreq;

  _this->hidden->iCurrBits = iBits;

  _this->hidden->iCurrChannels = iChannels;

  _this->hidden->iCurrNumBufs = iNumBufs;

  _this->hidden->iCurrBufSize = iBufSize;

  return (0);

}

void DART_ThreadInit(_THIS)

{

  return;

}

/* This function waits until it is possible to write a full sound buffer */

void DART_WaitAudio(_THIS)

{

  int i;

  pMixBufferDesc pBufDesc;

  ULONG ulPostCount;

  DosResetEventSem(_this->hidden->hevAudioBufferPlayed, &ulPostCount);

  // If there is already an empty buffer, then return now!

  for (i=0; i<_this->hidden->iCurrNumBufs; i++)

  {

    pBufDesc = (pMixBufferDesc) _this->hidden->pMixBuffers[i].ulUserParm;

    if (pBufDesc->iBufferUsage == BUFFER_EMPTY)

      return;

  }

  // If there is no empty buffer, wait for one to be empty!

  DosWaitEventSem(_this->hidden->hevAudioBufferPlayed, 1000); // Wait max 1 sec!!! Important!

  return;

}

void DART_PlayAudio(_THIS)

{

  int iFreeBuf = _this->hidden->iNextFreeBuffer;

  pMixBufferDesc pBufDesc;

  pBufDesc = (pMixBufferDesc) _this->hidden->pMixBuffers[iFreeBuf].ulUserParm;

  pBufDesc->iBufferUsage = BUFFER_USED;

  // Send it to DART to be queued

  _this->hidden->MixSetupParms.pmixWrite(_this->hidden->MixSetupParms.ulMixHandle,

                                        &(_this->hidden->pMixBuffers[iFreeBuf]), 1);

  _this->hidden->iLastPlayedBuf = iFreeBuf;

  iFreeBuf = (iFreeBuf+1) % _this->hidden->iCurrNumBufs;

  _this->hidden->iNextFreeBuffer = iFreeBuf;

}

Uint8 *DART_GetAudioBuf(_THIS)

{

  int iFreeBuf;

  Uint8 *pResult;

  pMixBufferDesc pBufDesc;

  if (_this)

  {

    if (_this->hidden)

    {

      iFreeBuf = _this->hidden->iNextFreeBuffer;

      pBufDesc = (pMixBufferDesc) _this->hidden->pMixBuffers[iFreeBuf].ulUserParm;

      if (pBufDesc)

      {

        if (pBufDesc->iBufferUsage == BUFFER_EMPTY)

        {

          pResult = _this->hidden->pMixBuffers[iFreeBuf].pBuffer;

          return pResult; 

        }

      } else

        printf("[DART_GetAudioBuf] : ERROR! pBufDesc = %p\n", pBufDesc);

    } else

      printf("[DART_GetAudioBuf] : ERROR! _this->hidden = %p\n", _this->hidden);

  } else

    printf("[DART_GetAudioBuf] : ERROR! _this = %p\n", _this);

  return NULL;

}

void DART_WaitDone(_THIS)

{

  pMixBufferDesc pBufDesc;

  ULONG ulPostCount;

  APIRET rc;

  pBufDesc = (pMixBufferDesc) _this->hidden->pMixBuffers[_this->hidden->iLastPlayedBuf].ulUserParm;

  rc = NO_ERROR;

  while ((pBufDesc->iBufferUsage != BUFFER_EMPTY) && (rc==NO_ERROR))

  {

    DosResetEventSem(_this->hidden->hevAudioBufferPlayed, &ulPostCount);

    rc = DosWaitEventSem(_this->hidden->hevAudioBufferPlayed, 1000); // 1 sec timeout! Important!

  }

}

void DART_CloseAudio(_THIS)

{

  MCI_GENERIC_PARMS GenericParms;

  int rc;

  // Stop DART playback

  rc = mciSendCommand(_this->hidden->iCurrDeviceOrd, MCI_STOP, MCI_WAIT, &GenericParms, 0);

  if (rc!=MCIERR_SUCCESS)

  {

#ifdef SFX_DEBUG_BUILD

    printf("Could not stop DART playback!\n");

    fflush(stdout);

#endif

  }

  // Close event semaphore

  DosCloseEventSem(_this->hidden->hevAudioBufferPlayed);

  // Free memory of buffer descriptions

  {

    int i;

    for (i=0; i<_this->hidden->iCurrNumBufs; i++) SDL_free((void *)(_this->hidden->pMixBuffers[i].ulUserParm));

  }

  // Deallocate buffers

  rc = mciSendCommand(_this->hidden->iCurrDeviceOrd, MCI_BUFFER, MCI_WAIT | MCI_DEALLOCATE_MEMORY, &(_this->hidden->BufferParms), 0);

  // Free bufferlist

  SDL_free(_this->hidden->pMixBuffers); _this->hidden->pMixBuffers = NULL;

  // Close dart

  rc = mciSendCommand(_this->hidden->iCurrDeviceOrd, MCI_CLOSE, MCI_WAIT, &(GenericParms), 0);

}

/* Audio driver bootstrap functions */

int Audio_Available(void)

{

  return(1);

}

void Audio_DeleteDevice(SDL_AudioDevice *device)

{

  SDL_free(device->hidden);

  SDL_free(device);

}

SDL_AudioDevice *Audio_CreateDevice(int devindex)

{

  SDL_AudioDevice *this;

  /* Initialize all variables that we clean on shutdown */

  this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));

  if ( this )

  {

    SDL_memset(this, 0, (sizeof *this));

    this->hidden = (struct SDL_PrivateAudioData *)

      SDL_malloc((sizeof *this->hidden));

  }

  if ( (this == NULL) || (this->hidden == NULL) )

  {

    SDL_OutOfMemory();

    if ( this )

      SDL_free(this);

    return(0);

  }

  SDL_memset(this->hidden, 0, (sizeof *this->hidden));

  /* Set the function pointers */

  this->OpenAudio = DART_OpenAudio;

  this->ThreadInit = DART_ThreadInit;

  this->WaitAudio = DART_WaitAudio;

  this->PlayAudio = DART_PlayAudio;

  this->GetAudioBuf = DART_GetAudioBuf;

  this->WaitDone = DART_WaitDone;

  this->CloseAudio = DART_CloseAudio;

  this->free = Audio_DeleteDevice;

  return this;

}

AudioBootStrap DART_bootstrap = {

	"dart", "OS/2 Direct Audio RouTines (DART)",

	Audio_Available, Audio_CreateDevice

};