// Copyright 1998-2015 Epic Games, Inc. All Rights Reserved.

#include "ALAudioDevice.h"
#include "AudioEffect.h"
#include "Engine.h"
#include "IAudioFormat.h"
#include "AudioDecompress.h"
#include "ContentStreaming.h"

/*------------------------------------------------------------------------------------
	FALSoundBuffer.
------------------------------------------------------------------------------------*/
/** 
 * Constructor
 *
 * @param AudioDevice	audio device this sound buffer is going to be attached to.
 */
FALSoundBuffer::FALSoundBuffer( FALAudioDevice* InAudioDevice )
	: FSoundBuffer(InAudioDevice)
{
}

/**
 * Destructor 
 * 
 * Frees wave data and detaches itself from audio device.
 */
FALSoundBuffer::~FALSoundBuffer( void )
{
	// Delete AL buffers.
	alDeleteBuffers(1, &BufferId);
}

/**
 * Static function used to create a buffer.
 *
 * @param InWave		USoundNodeWave to use as template and wave source
 * @param AudioDevice	audio device to attach created buffer to
 * @param	bIsPrecacheRequest	Whether this request is for precaching or not
 * @return	FALSoundBuffer pointer if buffer creation succeeded, NULL otherwise
 */

FALSoundBuffer* FALSoundBuffer::Init(FALAudioDevice* AudioDevice, USoundWave* InWave)
{
	// Can't create a buffer without any source data
	if (InWave == nullptr || InWave->NumChannels == 0)
	{
		return nullptr;
	}

	FAudioDeviceManager* AudioDeviceManager = GEngine->GetAudioDeviceManager();
	check(AudioDeviceManager != nullptr);

	FALSoundBuffer *Buffer = nullptr;

	switch (static_cast<EDecompressionType>(InWave->DecompressionType))
	{
	case DTYPE_Setup:
		// Has circumvented pre-cache mechanism - pre-cache now
		AudioDevice->Precache(InWave, true, false);

		// Recall this function with new decompression type
		return Init(AudioDevice, InWave);

	case DTYPE_Native:
		if (InWave->ResourceID)
		{
			Buffer = static_cast<FALSoundBuffer*>(AudioDeviceManager->WaveBufferMap.FindRef(InWave->ResourceID));
		}

		if (!Buffer)
		{
			Buffer = CreateNativeBuffer(AudioDevice, InWave);
		}
		break;

		// Always create a new buffer for streaming ogg vorbis data
		//Buffer = CreateQueuedBuffer(AudioDevice, InWave);
		//break;

	case DTYPE_Invalid:
	case DTYPE_Preview:
	case DTYPE_Procedural:
	case DTYPE_RealTime:
	default:
		// Invalid will be set if the wave cannot be played
		UE_LOG(LogALAudio, Warning, TEXT("ALSoundBuffer wave '%s' has an invalid decompression type %d."), 
			*InWave->GetName(), static_cast<EDecompressionType>(InWave->DecompressionType));
		break;
	}

	if (Buffer == nullptr)
	{
		UE_LOG(LogALAudio, Warning, TEXT("ALSoundBuffer init failed for wave '%s', decompression type %d."),
			*InWave->GetName(), static_cast<EDecompressionType>(InWave->DecompressionType));
	}

	return Buffer;
}

FALSoundBuffer* FALSoundBuffer::CreateNativeBuffer( FALAudioDevice* AudioDevice, USoundWave* Wave)
{
	SCOPE_CYCLE_COUNTER( STAT_AudioResourceCreationTime );

	// Check to see if thread has finished decompressing on the other thread
	if (Wave->AudioDecompressor)
	{
		Wave->AudioDecompressor->EnsureCompletion();

		// Remove the decompressor
		delete Wave->AudioDecompressor;
		Wave->AudioDecompressor = nullptr;
	}

	// Can't create a buffer without any source data
	if (Wave == nullptr)
	{
		return nullptr;
	}

	if (Wave->NumChannels == 0)
	{
		UE_LOG(LogALAudio, Warning, TEXT("ALSoundBuffer: cannot create buffer for wave '%s' with 0 channels"),
			*Wave->GetName());
		return nullptr;
	}

	Wave->InitAudioResource(AudioDevice->GetRuntimeFormat(Wave));
	FALSoundBuffer* Buffer = nullptr;

	FAudioDeviceManager* AudioDeviceManager = GEngine->GetAudioDeviceManager();
	check(AudioDeviceManager != nullptr);

	// Find the existing buffer if any
	if (Wave->ResourceID)
	{
		Buffer = static_cast<FALSoundBuffer*>(AudioDeviceManager->WaveBufferMap.FindRef(Wave->ResourceID));
	}

	if (Buffer == nullptr)
	{
		// Create new buffer.
		Buffer = new FALSoundBuffer(AudioDevice);

		alGenBuffers(1, &Buffer->BufferId);
		AudioDevice->alError(TEXT("RegisterSound"));

		AudioDeviceManager->TrackResource(Wave, Buffer);

		Buffer->InternalFormat = AudioDevice->GetInternalFormat(Wave->NumChannels);
		Buffer->NumChannels = Wave->NumChannels;
		Buffer->SampleRate = Wave->SampleRate;

		if (Wave->RawPCMData)
		{
			// upload it
			Buffer->BufferSize = Wave->RawPCMDataSize;
			alBufferData(Buffer->BufferId, Buffer->InternalFormat, Wave->RawPCMData, Wave->RawPCMDataSize, Buffer->SampleRate);

			// Free up the data if necessary
			if (Wave->bDynamicResource)
			{
				FMemory::Free( Wave->RawPCMData );
				Wave->RawPCMData = nullptr;
				Wave->bDynamicResource = false;
			}
		}
		else
		{
			// get the raw data
			uint8* SoundData = reinterpret_cast<uint8*>(Wave->RawData.Lock(LOCK_READ_ONLY));
			// it's (possibly) a pointer to a wave file, so skip over the header
			int SoundDataSize = Wave->RawData.GetBulkDataSize();

			// is there a wave header?
			FWaveModInfo WaveInfo;
			if (WaveInfo.ReadWaveInfo(SoundData, SoundDataSize))
			{
				// if so, modify the location and size of the sound data based on header
				SoundData = WaveInfo.SampleDataStart;
				SoundDataSize = WaveInfo.SampleDataSize;
			}
			// let the Buffer know the final size
			Buffer->BufferSize = SoundDataSize;

			// upload it
			alBufferData( Buffer->BufferId, Buffer->InternalFormat, SoundData, Buffer->BufferSize, Buffer->SampleRate );
			// unload it
			Wave->RawData.Unlock();
		}

		if (AudioDevice->alError(TEXT( "RegisterSound (buffer data)")) || (Buffer->BufferSize == 0))
		{
			Buffer->InternalFormat = 0;
		}

		if (Buffer->InternalFormat == 0)
		{
			UE_LOG(LogAudio, Log,TEXT( "Audio: sound format not supported for '%s' (%d)" ), *Wave->GetName(), Wave->NumChannels);
			UE_LOG(LogALAudio, Warning, TEXT("ALSoundBuffer: sound format not supported for wave '%s'"),
				*Wave->GetName());

			delete Buffer;
			Buffer = nullptr;
		}
	}

	return Buffer;
}