/**

 * $Id$

 * 

 * 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 <AudioToolbox/AudioToolbox.h>

#include <AudioUnit/AudioUnitProperties.h>

#include "aica/audio.h"

#include "lxdream.h"

static AudioUnit output_au;

static volatile audio_buffer_t output_buffer = NULL;

static int sample_size;

OSStatus audio_osx_callback( void *inRefCon, AudioUnitRenderActionFlags *ioActionFlags,

                             const AudioTimeStamp *inTimeStamp, UInt32 inBusNumber,

                             UInt32 inNumberFrames, AudioBufferList *ioData )

{

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

    int data_requested = inNumberFrames * sample_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()

{

    AudioUnitUninitialize( output_au );

    CloseComponent( output_au );

    return TRUE;

}

static gboolean audio_osx_init()

{

    AURenderCallbackStruct callbackData;

    AudioStreamBasicDescription outputDesc;

    UInt32 outputDescSize = sizeof(outputDesc);

    ComponentDescription cd;

    Component c;

    cd.componentType = kAudioUnitType_Output;

    cd.componentSubType = kAudioUnitSubType_DefaultOutput;

    cd.componentManufacturer = kAudioUnitManufacturer_Apple;

    cd.componentFlags = 0;

    cd.componentFlagsMask = 0;

    c = FindNextComponent( NULL, &cd );

    if( c == NULL ) {

        return FALSE;

    }

    if( OpenAComponent( c, &output_au ) != noErr ) {

        return FALSE;

    }

    if( AudioUnitGetProperty( output_au, kAudioUnitProperty_StreamFormat,

            kAudioUnitScope_Global, 0, &outputDesc, &outputDescSize ) != noErr ) {

        CloseComponent( output_au );

        return FALSE;

    }

    outputDesc.mSampleRate = DEFAULT_SAMPLE_RATE;

    sample_size = outputDesc.mBytesPerFrame;

    if( AudioUnitSetProperty( output_au, kAudioUnitProperty_StreamFormat,

            kAudioUnitScope_Global, 0, &outputDesc, sizeof(outputDesc) ) != noErr ) {

        CloseComponent( output_au );

        return FALSE;

    }

    if( AudioUnitInitialize( output_au ) != noErr ) {

        CloseComponent( output_au );

        return FALSE;

    }

    callbackData.inputProc = audio_osx_callback;

    callbackData.inputProcRefCon = NULL;

    if( AudioUnitSetProperty( output_au, kAudioUnitProperty_SetRenderCallback,

            kAudioUnitScope_Global, 0, &callbackData, sizeof(callbackData)) != noErr ) {

        audio_osx_shutdown();

        return FALSE;

    }

    return TRUE;

}

static gboolean audio_osx_process_buffer( audio_buffer_t buffer )

{

    if( output_buffer == NULL ) {

        output_buffer = buffer;

        output_buffer->posn = 0;

        AudioOutputUnitStart(output_au);

        return FALSE;

    }

}

void audio_osx_start()

{

}

void audio_osx_stop()

{

}

struct audio_driver audio_osx_driver = { 

        "osx", 

        N_("OS X CoreAudio system driver"), 

        DEFAULT_SAMPLE_RATE,

        AUDIO_FMT_FLOATST,

        audio_osx_init,

        audio_osx_start, 

        audio_osx_process_buffer,

        audio_osx_stop,

        audio_osx_shutdown};