/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2012 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

    Carsten Griwodz
    griff@kom.tu-darmstadt.de

    based on linux/SDL_dspaudio.c by Sam Lantinga
*/
#include "SDL_config.h"

/* Allow access to a raw mixing buffer */

#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/mman.h>

#include "SDL_audio.h"
#include "../SDL_audio_c.h"
#include "../SDL_audiodev_c.h"
#include "SDL_umsaudio.h"

/* The tag name used by UMS audio */
#define UMS_DRIVER_NAME         "ums"

#define DEBUG_AUDIO 1

/* Audio driver functions */
static int UMS_OpenAudio(_THIS, SDL_AudioSpec *spec);
static void UMS_PlayAudio(_THIS);
static Uint8 *UMS_GetAudioBuf(_THIS);
static void UMS_CloseAudio(_THIS);

static UMSAudioDevice_ReturnCode UADOpen(_THIS,  string device, string mode, long flags);
static UMSAudioDevice_ReturnCode UADClose(_THIS);
static UMSAudioDevice_ReturnCode UADGetBitsPerSample(_THIS, long* bits);
static UMSAudioDevice_ReturnCode UADSetBitsPerSample(_THIS, long bits);
static UMSAudioDevice_ReturnCode UADSetSampleRate(_THIS, long rate, long* set_rate);
static UMSAudioDevice_ReturnCode UADSetByteOrder(_THIS, string byte_order);
static UMSAudioDevice_ReturnCode UADSetAudioFormatType(_THIS, string fmt);
static UMSAudioDevice_ReturnCode UADSetNumberFormat(_THIS, string fmt);
static UMSAudioDevice_ReturnCode UADInitialize(_THIS);
static UMSAudioDevice_ReturnCode UADStart(_THIS);
static UMSAudioDevice_ReturnCode UADStop(_THIS);
static UMSAudioDevice_ReturnCode UADSetTimeFormat(_THIS,  UMSAudioTypes_TimeFormat fmt );
static UMSAudioDevice_ReturnCode UADWriteBuffSize(_THIS,  long* buff_size );
static UMSAudioDevice_ReturnCode UADWriteBuffRemain(_THIS,  long* buff_size );
static UMSAudioDevice_ReturnCode UADWriteBuffUsed(_THIS,  long* buff_size );
static UMSAudioDevice_ReturnCode UADSetDMABufferSize(_THIS,  long bytes, long* bytes_ret );
static UMSAudioDevice_ReturnCode UADSetVolume(_THIS,  long volume );
static UMSAudioDevice_ReturnCode UADSetBalance(_THIS,  long balance );
static UMSAudioDevice_ReturnCode UADSetChannels(_THIS,  long channels );
static UMSAudioDevice_ReturnCode UADPlayRemainingData(_THIS,  boolean block );
static UMSAudioDevice_ReturnCode UADEnableOutput(_THIS,  string output, long* left_gain, long* right_gain);
static UMSAudioDevice_ReturnCode UADWrite(_THIS,  UMSAudioTypes_Buffer* buff, long samples, long* samples_written);

/* Audio driver bootstrap functions */
static int Audio_Available(void)
{
    return 1;
}

static void Audio_DeleteDevice(_THIS)
{
    if(this->hidden->playbuf._buffer) SDL_free(this->hidden->playbuf._buffer);
    if(this->hidden->fillbuf._buffer) SDL_free(this->hidden->fillbuf._buffer);
    _somFree( this->hidden->umsdev );
    SDL_free(this->hidden);
    SDL_free(this);
}

static SDL_AudioDevice *Audio_CreateDevice(int devindex)
{
    SDL_AudioDevice *this;

    /*
     * Allocate and initialize management storage and private management
     * storage for this SDL-using library.
     */
    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));
#ifdef DEBUG_AUDIO
    fprintf(stderr, "Creating UMS Audio device\n");
#endif

    /*
     * Calls for UMS env initialization and audio object construction.
     */
    this->hidden->ev     = somGetGlobalEnvironment();
    this->hidden->umsdev = UMSAudioDeviceNew();

    /*
     * Set the function pointers.
     */
    this->OpenAudio   = UMS_OpenAudio;
    this->WaitAudio   = NULL;           /* we do blocking output */
    this->PlayAudio   = UMS_PlayAudio;
    this->GetAudioBuf = UMS_GetAudioBuf;
    this->CloseAudio  = UMS_CloseAudio;
    this->free        = Audio_DeleteDevice;

#ifdef DEBUG_AUDIO
    fprintf(stderr, "done\n");
#endif
    return this;
}

AudioBootStrap UMS_bootstrap = {
	UMS_DRIVER_NAME, "AIX UMS audio",
	Audio_Available, Audio_CreateDevice
};

static Uint8 *UMS_GetAudioBuf(_THIS)
{
#ifdef DEBUG_AUDIO
    fprintf(stderr, "enter UMS_GetAudioBuf\n");
#endif
    return this->hidden->fillbuf._buffer;
/*
    long                      bufSize;
    UMSAudioDevice_ReturnCode rc;

    rc = UADSetTimeFormat(this, UMSAudioTypes_Bytes );
    rc = UADWriteBuffSize(this,  bufSize );
*/
}

static void UMS_CloseAudio(_THIS)
{
    UMSAudioDevice_ReturnCode rc;

#ifdef DEBUG_AUDIO
    fprintf(stderr, "enter UMS_CloseAudio\n");
#endif
    rc = UADPlayRemainingData(this, TRUE);
    rc = UADStop(this);
    rc = UADClose(this);
}

static void UMS_PlayAudio(_THIS)
{
    UMSAudioDevice_ReturnCode rc;
    long                      samplesToWrite;
    long                      samplesWritten;
    UMSAudioTypes_Buffer      swpbuf;

#ifdef DEBUG_AUDIO
    fprintf(stderr, "enter UMS_PlayAudio\n");
#endif
    samplesToWrite = this->hidden->playbuf._length/this->hidden->bytesPerSample;
    do
    {
        rc = UADWrite(this,  &this->hidden->playbuf,
		       samplesToWrite,
	               &samplesWritten );
	samplesToWrite -= samplesWritten;

	/* rc values: UMSAudioDevice_Success
	 *            UMSAudioDevice_Failure
	 *            UMSAudioDevice_Preempted
	 *            UMSAudioDevice_Interrupted
	 *            UMSAudioDevice_DeviceError
	 */
	if ( rc == UMSAudioDevice_DeviceError ) {
#ifdef DEBUG_AUDIO
	    fprintf(stderr, "Returning from PlayAudio with devices error\n");
#endif
	    return;
	}
    }
    while(samplesToWrite>0);

    SDL_LockAudio();
    SDL_memcpy( &swpbuf,                &this->hidden->playbuf, sizeof(UMSAudioTypes_Buffer) );
    SDL_memcpy( &this->hidden->playbuf, &this->hidden->fillbuf, sizeof(UMSAudioTypes_Buffer) );
    SDL_memcpy( &this->hidden->fillbuf, &swpbuf,                sizeof(UMSAudioTypes_Buffer) );
    SDL_UnlockAudio();

#ifdef DEBUG_AUDIO
    fprintf(stderr, "Wrote audio data and swapped buffer\n");
#endif
}

#if 0
// 	/* Set the DSP frequency */
// 	value = spec->freq;
// 	if ( ioctl(this->hidden->audio_fd, SOUND_PCM_WRITE_RATE, &value) < 0 ) {
// 		SDL_SetError("Couldn't set audio frequency");
// 		return(-1);
// 	}
// 	spec->freq = value;
#endif

static int UMS_OpenAudio(_THIS, SDL_AudioSpec *spec)
{
    char*  audiodev = "/dev/paud0";
    long   lgain;
    long   rgain;
    long   outRate;
    long   outBufSize;
    long   bitsPerSample;
    long   samplesPerSec;
    long   success;
    Uint16 test_format;
    int    frag_spec;
    UMSAudioDevice_ReturnCode rc;

#ifdef DEBUG_AUDIO
    fprintf(stderr, "enter UMS_OpenAudio\n");
#endif
    rc = UADOpen(this, audiodev,"PLAY", UMSAudioDevice_BlockingIO);
    if ( rc != UMSAudioDevice_Success ) {
	SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno));
	return -1;
    }
 
    rc = UADSetAudioFormatType(this, "PCM"); 

    success = 0;
    test_format = SDL_FirstAudioFormat(spec->format);
    do
    {
#ifdef DEBUG_AUDIO
        fprintf(stderr, "Trying format 0x%4.4x\n", test_format);
#endif
        switch ( test_format )
        {
        case AUDIO_U8:
/* from the mac code: better ? */
/* sample_bits = spec->size / spec->samples / spec->channels * 8; */
	    success       = 1;
            bitsPerSample = 8;
            rc = UADSetSampleRate(this,  spec->freq << 16, &outRate );
            rc = UADSetByteOrder(this, "MSB");       /* irrelevant */
            rc = UADSetNumberFormat(this, "UNSIGNED");
            break;
        case AUDIO_S8:
	    success       = 1;
            bitsPerSample = 8;
            rc = UADSetSampleRate(this,  spec->freq << 16, &outRate );
            rc = UADSetByteOrder(this, "MSB");       /* irrelevant */
            rc = UADSetNumberFormat(this, "SIGNED");
            break;
        case AUDIO_S16LSB:
	    success       = 1;
            bitsPerSample = 16;
            rc = UADSetSampleRate(this,  spec->freq << 16, &outRate );
            rc = UADSetByteOrder(this, "LSB");
            rc = UADSetNumberFormat(this, "SIGNED");
            break;
        case AUDIO_S16MSB:
	    success       = 1;
            bitsPerSample = 16;
            rc = UADSetSampleRate(this,  spec->freq << 16, &outRate );
            rc = UADSetByteOrder(this, "MSB");
            rc = UADSetNumberFormat(this, "SIGNED");
            break;
        case AUDIO_U16LSB:
	    success       = 1;
            bitsPerSample = 16;
            rc = UADSetSampleRate(this,  spec->freq << 16, &outRate );
            rc = UADSetByteOrder(this, "LSB");
            rc = UADSetNumberFormat(this, "UNSIGNED");
            break;
        case AUDIO_U16MSB:
	    success       = 1;
            bitsPerSample = 16;
            rc = UADSetSampleRate(this,  spec->freq << 16, &outRate );
            rc = UADSetByteOrder(this, "MSB");
            rc = UADSetNumberFormat(this, "UNSIGNED");
            break;
        default:
            break;
        }
        if ( ! success ) {
            test_format = SDL_NextAudioFormat();
        }
    }
    while ( ! success && test_format );

    if ( success == 0 ) {
        SDL_SetError("Couldn't find any hardware audio formats");
        return -1;
    }

    spec->format = test_format;

    for ( frag_spec = 0; (0x01<<frag_spec) < spec->size; ++frag_spec );
    if ( (0x01<<frag_spec) != spec->size ) {
        SDL_SetError("Fragment size must be a power of two");
        return -1;
    }
    if ( frag_spec > 2048 ) frag_spec = 2048;

    this->hidden->bytesPerSample   = (bitsPerSample / 8) * spec->channels;
    samplesPerSec                  = this->hidden->bytesPerSample * outRate;

    this->hidden->playbuf._length  = 0;
    this->hidden->playbuf._maximum = spec->size;
    this->hidden->playbuf._buffer  = (unsigned char*)SDL_malloc(spec->size);
    this->hidden->fillbuf._length  = 0;
    this->hidden->fillbuf._maximum = spec->size;
    this->hidden->fillbuf._buffer  = (unsigned char*)SDL_malloc(spec->size);

    rc = UADSetBitsPerSample(this,  bitsPerSample );
    rc = UADSetDMABufferSize(this,  frag_spec, &outBufSize );
    rc = UADSetChannels(this, spec->channels);      /* functions reduces to mono or stereo */

    lgain = 100; /*maximum left input gain*/
    rgain = 100; /*maimum right input gain*/
    rc = UADEnableOutput(this, "LINE_OUT",&lgain,&rgain);
    rc = UADInitialize(this);
    rc = UADStart(this);
    rc = UADSetVolume(this, 100);
    rc = UADSetBalance(this, 0);

    /* We're ready to rock and roll. :-) */
    return 0;
}


static UMSAudioDevice_ReturnCode UADGetBitsPerSample(_THIS, long* bits)
{
    return UMSAudioDevice_get_bits_per_sample( this->hidden->umsdev,
					       this->hidden->ev,
					       bits );
}

static UMSAudioDevice_ReturnCode UADSetBitsPerSample(_THIS, long bits)
{
    return UMSAudioDevice_set_bits_per_sample( this->hidden->umsdev,
					       this->hidden->ev,
					       bits );
}

static UMSAudioDevice_ReturnCode UADSetSampleRate(_THIS, long rate, long* set_rate)
{
    /* from the mac code: sample rate = spec->freq << 16; */
    return UMSAudioDevice_set_sample_rate( this->hidden->umsdev,
					   this->hidden->ev,
					   rate,
					   set_rate );
}

static UMSAudioDevice_ReturnCode UADSetByteOrder(_THIS, string byte_order)
{
    return UMSAudioDevice_set_byte_order( this->hidden->umsdev,
					  this->hidden->ev,
					  byte_order );
}

static UMSAudioDevice_ReturnCode UADSetAudioFormatType(_THIS, string fmt)
{
    /* possible PCM, A_LAW or MU_LAW */
    return UMSAudioDevice_set_audio_format_type( this->hidden->umsdev,
						 this->hidden->ev,
						 fmt );
}

static UMSAudioDevice_ReturnCode UADSetNumberFormat(_THIS, string fmt)
{
    /* possible SIGNED, UNSIGNED, or TWOS_COMPLEMENT */
    return UMSAudioDevice_set_number_format( this->hidden->umsdev,
					     this->hidden->ev,
					     fmt );
}

static UMSAudioDevice_ReturnCode UADInitialize(_THIS)
{
    return UMSAudioDevice_initialize( this->hidden->umsdev,
				      this->hidden->ev );
}

static UMSAudioDevice_ReturnCode UADStart(_THIS)
{
    return UMSAudioDevice_start( this->hidden->umsdev,
				 this->hidden->ev );
}

static UMSAudioDevice_ReturnCode UADSetTimeFormat(_THIS,  UMSAudioTypes_TimeFormat fmt )
{
    /*
     * Switches the time format to the new format, immediately.
     * possible UMSAudioTypes_Msecs, UMSAudioTypes_Bytes or UMSAudioTypes_Samples
     */
    return UMSAudioDevice_set_time_format( this->hidden->umsdev,
					   this->hidden->ev,
					   fmt );
}

static UMSAudioDevice_ReturnCode UADWriteBuffSize(_THIS,  long* buff_size )
{
    /*
     * returns write buffer size in the current time format
     */
    return UMSAudioDevice_write_buff_size( this->hidden->umsdev,
                                           this->hidden->ev,
					   buff_size );
}

static UMSAudioDevice_ReturnCode UADWriteBuffRemain(_THIS,  long* buff_size )
{
    /*
     * returns amount of available space in the write buffer
     * in the current time format
     */
    return UMSAudioDevice_write_buff_remain( this->hidden->umsdev,
                                             this->hidden->ev,
					     buff_size );
}

static UMSAudioDevice_ReturnCode UADWriteBuffUsed(_THIS,  long* buff_size )
{
    /*
     * returns amount of filled space in the write buffer
     * in the current time format
     */
    return UMSAudioDevice_write_buff_used( this->hidden->umsdev,
                                           this->hidden->ev,
					   buff_size );
}

static UMSAudioDevice_ReturnCode UADSetDMABufferSize(_THIS,  long bytes, long* bytes_ret )
{
    /*
     * Request a new DMA buffer size, maximum requested size 2048.
     * Takes effect with next initialize() call.
     * Devices may or may not support DMA.
     */
    return UMSAudioDevice_set_DMA_buffer_size( this->hidden->umsdev,
					       this->hidden->ev,
					       bytes,
					       bytes_ret );
}

static UMSAudioDevice_ReturnCode UADSetVolume(_THIS,  long volume )
{
    /*
     * Set the volume.
     * Takes effect immediately.
     */
    return UMSAudioDevice_set_volume( this->hidden->umsdev,
				      this->hidden->ev,
				      volume );
}

static UMSAudioDevice_ReturnCode UADSetBalance(_THIS,  long balance )
{
    /*
     * Set the balance.
     * Takes effect immediately.
     */
    return UMSAudioDevice_set_balance( this->hidden->umsdev,
				       this->hidden->ev,
				       balance );
}

static UMSAudioDevice_ReturnCode UADSetChannels(_THIS,  long channels )
{
    /*
     * Set mono or stereo.
     * Takes effect with next initialize() call.
     */
    if ( channels != 1 ) channels = 2;
    return UMSAudioDevice_set_number_of_channels( this->hidden->umsdev,
				                  this->hidden->ev,
				                  channels );
}

static UMSAudioDevice_ReturnCode UADOpen(_THIS,  string device, string mode, long flags)
{
    return UMSAudioDevice_open( this->hidden->umsdev,
				this->hidden->ev,
				device,
				mode,
				flags );
}

static UMSAudioDevice_ReturnCode UADWrite(_THIS,  UMSAudioTypes_Buffer* buff,
                                           long samples,
					   long* samples_written)
{
    return UMSAudioDevice_write( this->hidden->umsdev,
				 this->hidden->ev,
				 buff,
				 samples,
				 samples_written );
}

static UMSAudioDevice_ReturnCode UADPlayRemainingData(_THIS,  boolean block )
{
    return UMSAudioDevice_play_remaining_data( this->hidden->umsdev,
					       this->hidden->ev,
					       block);
}

static UMSAudioDevice_ReturnCode UADStop(_THIS)
{
    return UMSAudioDevice_stop( this->hidden->umsdev,
				this->hidden->ev );
}

static UMSAudioDevice_ReturnCode UADClose(_THIS)
{
    return UMSAudioDevice_close( this->hidden->umsdev,
				 this->hidden->ev );
}

static UMSAudioDevice_ReturnCode UADEnableOutput(_THIS,  string output, long* left_gain, long* right_gain)
{
    return UMSAudioDevice_enable_output( this->hidden->umsdev,
					 this->hidden->ev,
					 output,
					 left_gain,
					 right_gain );
}