/*

Copyright (C) 2016 Apple Inc. All Rights Reserved.

See LICENSE.txt for this sample’s licensing information

Abstract:

MIDI Processor AU

*/

#include "AUMidiPassThru.h"

static const int kMIDIPacketListSize = 2048;

AUDIOCOMPONENT_ENTRY(AUMIDIEffectFactory, AUMidiPassThru)

#pragma mark AUMidiPassThru

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//  AUMidiPassThru::SetProperty

//

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

AUMidiPassThru::AUMidiPassThru(AudioUnit component) : AUMIDIEffectBase(component), mOutputPacketFIFO(LockFreeFIFO<MIDIPacket>(32))

{

    CreateElements();

    mMIDIOutCB.midiOutputCallback = nullptr;

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//  AUMidiPassThru::SetProperty

//

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

AUMidiPassThru::~AUMidiPassThru()

{

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//  AUMidiPassThru::SetProperty

//

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

OSStatus AUMidiPassThru::GetPropertyInfo(AudioUnitPropertyID inID, AudioUnitScope inScope, AudioUnitElement inElement, UInt32 & outDataSize, Boolean & outWritable)

{

    if (inScope == kAudioUnitScope_Global)

    {

        switch( inID )

        {

            case kAudioUnitProperty_MIDIOutputCallbackInfo:

                outWritable = false;

                outDataSize = sizeof(CFArrayRef);

                return noErr;

            case kAudioUnitProperty_MIDIOutputCallback:

                outWritable = true;

                outDataSize = sizeof(AUMIDIOutputCallbackStruct);

                return noErr;

        }

    }

    return AUMIDIEffectBase::GetPropertyInfo(inID, inScope, inElement, outDataSize, outWritable);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//  AUMidiPassThru::SetProperty

//

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

OSStatus AUMidiPassThru::GetProperty( AudioUnitPropertyID inID, AudioUnitScope inScope, AudioUnitElement inElement, void* outData )

{

    if (inScope == kAudioUnitScope_Global) 

    {

        switch (inID)

        {

            case kAudioUnitProperty_MIDIOutputCallbackInfo:

                CFStringRef string = CFSTR("midiOut");

                CFArrayRef array = CFArrayCreate(kCFAllocatorDefault, (const void**)&string, 1, nullptr);

                CFRelease(string);

                *((CFArrayRef*)outData) = array;

                return noErr;

        }

    }

    return AUMIDIEffectBase::GetProperty(inID, inScope, inElement, outData);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//  AUMidiPassThru::SetProperty

//

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

OSStatus AUMidiPassThru::SetProperty(   AudioUnitPropertyID inID, AudioUnitScope inScope, AudioUnitElement inElement, const void* inData, UInt32 inDataSize)

{

    if (inScope == kAudioUnitScope_Global)

    {

        switch (inID)

        {

            case kAudioUnitProperty_MIDIOutputCallback:

            mMIDIOutCB = *((AUMIDIOutputCallbackStruct*)inData);

            return noErr;

        }

    }

    return AUMIDIEffectBase::SetProperty(inID, inScope, inElement, inData, inDataSize);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//  AUMidiPassThru::HandleMidiEvent

//

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

OSStatus AUMidiPassThru::HandleMidiEvent(UInt8 status, UInt8 channel, UInt8 data1, UInt8 data2, UInt32 inOffsetSampleFrame)

{

    if (!IsInitialized()) return kAudioUnitErr_Uninitialized;

    MIDIPacket* packet = mOutputPacketFIFO.WriteItem();

    mOutputPacketFIFO.AdvanceWritePtr();

    if (packet == NULL)

        return kAudioUnitErr_FailedInitialization;

    memset(packet->data, 0, sizeof(Byte)*256);

    packet->length = 3;

    packet->data[0] = status | channel;

    packet->data[1] = data1;

    packet->data[2] = data2;

    packet->timeStamp = inOffsetSampleFrame;

    return noErr;

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//  AUMidiPassThru::Render

//

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

OSStatus AUMidiPassThru::Render (AudioUnitRenderActionFlags &ioActionFlags, const AudioTimeStamp& inTimeStamp, UInt32 nFrames)

{

    Byte listBuffer[kMIDIPacketListSize];

    MIDIPacketList* packetList = (MIDIPacketList*)listBuffer;

    MIDIPacket* packetListIterator = MIDIPacketListInit(packetList);

    MIDIPacket* packet = mOutputPacketFIFO.ReadItem();

    while (packet != NULL)

    {

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

        // This is where the midi packets get processed

        //

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

        if (packetListIterator == NULL) return noErr;

        packetListIterator = MIDIPacketListAdd(packetList, kMIDIPacketListSize, packetListIterator, packet->timeStamp, packet->length, packet->data);

        mOutputPacketFIFO.AdvanceReadPtr();

        packet = mOutputPacketFIFO.ReadItem();

    }

    if (mMIDIOutCB.midiOutputCallback != NULL && packetList->numPackets > 0)

    {

        mMIDIOutCB.midiOutputCallback(mMIDIOutCB.userData, &inTimeStamp, 0, packetList);

    }

    return noErr;

}