/**

 * $Id$

 * 

 * The darwin core-audio audio driver

 *

 * Copyright (c) 2008 Nathan Keynes.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 */

#include <stdio.h>

#include <unistd.h>

#include <CoreAudio/CoreAudio.h>

#include "aica/audio.h"

#include "lxdream.h"

#define BUFFER_SIZE (sizeof(float)*2*2205)

static AudioDeviceID output_device;

static volatile audio_buffer_t output_buffer = NULL;

static uint32_t buffer_size;

static OSStatus audio_osx_callback( AudioDeviceID inDevice,

                             const AudioTimeStamp *inNow,

                             const AudioBufferList *inInputData,

                             const AudioTimeStamp *inInputTime,

                             AudioBufferList *outOutputData,

                             const AudioTimeStamp *inOutputTime,

                             void *inClientData)

{

    char *output = outOutputData->mBuffers[0].mData;

    int data_requested = buffer_size;

    while( output_buffer != NULL && data_requested > 0 ) {

        int copysize = output_buffer->length - output_buffer->posn;

        if( copysize > data_requested ) {

            copysize = data_requested;

        }

        memcpy( output, &output_buffer->data[output_buffer->posn], copysize );

        output += copysize;

        data_requested -= copysize;

        output_buffer->posn += copysize;

        if( output_buffer->posn >= output_buffer->length ) {

            output_buffer = audio_next_read_buffer();

        }

    }

    if( data_requested > 0 ) {

        memset( output, 0, data_requested );

    }

    return noErr;

}

static gboolean audio_osx_shutdown()

{

    AudioDeviceStop( output_device, audio_osx_callback );

    AudioDeviceRemoveIOProc( output_device, audio_osx_callback );

    return TRUE;

}

static gboolean audio_osx_init()

{

    UInt32 size = sizeof(output_device);

    AudioStreamBasicDescription outputDesc;

    UInt32 outputDescSize = sizeof(outputDesc);

    if( AudioHardwareGetProperty(kAudioHardwarePropertyDefaultOutputDevice,

            &size, &output_device) != noErr ||

            output_device == kAudioDeviceUnknown ) {

        return FALSE;

    }

    if( AudioDeviceGetProperty( output_device, 1, 0, kAudioDevicePropertyStreamFormat,

            &outputDescSize, &outputDesc ) != noErr ) {

        return FALSE;

    }

    buffer_size = BUFFER_SIZE;

    if( AudioDeviceSetProperty( output_device, 0, 0, 0, kAudioDevicePropertyBufferSize,

            sizeof(buffer_size), &buffer_size ) != noErr ) {

        return FALSE;

    }

    AudioDeviceAddIOProc( output_device, audio_osx_callback, NULL );    

    return TRUE;

}

static gboolean audio_osx_process_buffer( audio_buffer_t buffer )

{

    if( output_buffer == NULL ) {

        output_buffer = buffer;

        output_buffer->posn = 0;

        AudioDeviceStart(output_device, audio_osx_callback);

    }

    return FALSE;

}

static void audio_osx_start()

{

    if( output_buffer != NULL ) {

        AudioDeviceStart(output_device, audio_osx_callback);

    }

}

static void audio_osx_stop()

{

    AudioDeviceStop( output_device, audio_osx_callback );

}

static struct audio_driver audio_osx_driver = { 

        "osx",

        N_("OS X CoreAudio system driver"), 

        1, // Preferred on OS X

        DEFAULT_SAMPLE_RATE,

        AUDIO_FMT_FLOATST,

        audio_osx_init,

        audio_osx_start, 

        audio_osx_process_buffer,

        audio_osx_stop,

        audio_osx_shutdown};

AUDIO_DRIVER( "osx", audio_osx_driver );