//********************************** Banshee Engine (www.banshee3d.com) **************************************************//
//**************** Copyright (c) 2016 Marko Pintera (marko.pintera@gmail.com). All rights reserved. **********************//
#include "BsOAImporter.h"
#include "FileSystem/BsDataStream.h"
#include "FileSystem/BsFileSystem.h"
#include "BsWaveDecoder.h"
#include "BsFLACDecoder.h"
#include "BsOggVorbisDecoder.h"
#include "BsOggVorbisEncoder.h"
#include "Audio/BsAudioClipImportOptions.h"
#include "Audio/BsAudioUtility.h"

namespace bs
{
	OAImporter::OAImporter()
		:SpecificImporter()
	{

	}

	OAImporter::~OAImporter()
	{

	}

	bool OAImporter::isExtensionSupported(const WString& ext) const
	{
		WString lowerCaseExt = ext;
		StringUtil::toLowerCase(lowerCaseExt);

		return lowerCaseExt == L"wav" || lowerCaseExt == L"flac" || lowerCaseExt == L"ogg";
	}

	bool OAImporter::isMagicNumberSupported(const UINT8* magicNumPtr, UINT32 numBytes) const
	{
		// Don't check for magic number, rely on extension
		return true;
	}

	SPtr<ImportOptions> OAImporter::createImportOptions() const
	{
		return bs_shared_ptr_new<AudioClipImportOptions>();
	}

	SPtr<Resource> OAImporter::import(const Path& filePath, SPtr<const ImportOptions> importOptions)
	{
		SPtr<DataStream> stream = FileSystem::openFile(filePath);

		WString extension = filePath.getWExtension();
		StringUtil::toLowerCase(extension);

		UPtr<AudioDecoder> reader(nullptr, nullptr);
		if(extension == L".wav")
			reader = bs_unique_ptr<AudioDecoder>(bs_new<WaveDecoder>());
		else if(extension == L".flac")
			reader = bs_unique_ptr<AudioDecoder>(bs_new<FLACDecoder>());
		else if(extension == L".ogg")
			reader = bs_unique_ptr<AudioDecoder>(bs_new<OggVorbisDecoder>());

		if (reader == nullptr)
			return nullptr;

		AudioDataInfo info;
		if (!reader->isValid(stream))
			return nullptr;

		if (!reader->open(stream, info))
			return nullptr;

		UINT32 bytesPerSample = info.bitDepth / 8;
		UINT32 bufferSize = info.numSamples * bytesPerSample;
		UINT8* sampleBuffer = (UINT8*)bs_alloc(bufferSize);
		reader->read(sampleBuffer, info.numSamples);

		SPtr<const AudioClipImportOptions> clipIO = std::static_pointer_cast<const AudioClipImportOptions>(importOptions);

		// If 3D, convert to mono
		if(clipIO->getIs3D() && info.numChannels > 1)
		{
			UINT32 numSamplesPerChannel = info.numSamples / info.numChannels;

			UINT32 monoBufferSize = numSamplesPerChannel * bytesPerSample;
			UINT8* monoBuffer = (UINT8*)bs_alloc(monoBufferSize);

			AudioUtility::convertToMono(sampleBuffer, monoBuffer, info.bitDepth, numSamplesPerChannel, info.numChannels);

			info.numSamples = numSamplesPerChannel;
			info.numChannels = 1;

			bs_free(sampleBuffer);

			sampleBuffer = monoBuffer;
			bufferSize = monoBufferSize;
		}

		// Convert bit depth if needed
		if(clipIO->getBitDepth() != info.bitDepth)
		{
			UINT32 outBufferSize = info.numSamples * (clipIO->getBitDepth() / 8);
			UINT8* outBuffer = (UINT8*)bs_alloc(outBufferSize);

			AudioUtility::convertBitDepth(sampleBuffer, info.bitDepth, outBuffer, clipIO->getBitDepth(), info.numSamples);

			info.bitDepth = clipIO->getBitDepth();

			bs_free(sampleBuffer);

			sampleBuffer = outBuffer;
			bufferSize = outBufferSize;
		}

		// Encode to Ogg Vorbis if needed
		if(clipIO->getFormat() == AudioFormat::VORBIS)
		{
			// Note: If the original source was in Ogg Vorbis we could just copy it here, but instead we decode to PCM and
			// then re-encode which is redundant. If later we decide to copy be aware that the engine encodes Ogg in a
			// specific quality, and the the import source might have lower or higher bitrate/quality.
			UINT8* encodedSamples = OggVorbisEncoder::PCMToOggVorbis(sampleBuffer, info, bufferSize);

			bs_free(sampleBuffer);
			sampleBuffer = encodedSamples;
		}

		SPtr<MemoryDataStream> sampleStream = bs_shared_ptr_new<MemoryDataStream>(sampleBuffer, bufferSize);

		AUDIO_CLIP_DESC clipDesc;
		clipDesc.bitDepth = info.bitDepth;
		clipDesc.format = clipIO->getFormat();
		clipDesc.frequency = info.sampleRate;
		clipDesc.numChannels = info.numChannels;
		clipDesc.readMode = clipIO->getReadMode();
		clipDesc.is3D = clipIO->getIs3D();

		SPtr<AudioClip> clip = AudioClip::_createPtr(sampleStream, bufferSize, info.numSamples, clipDesc);

		WString fileName = filePath.getWFilename(false);
		clip->setName(fileName);

		return clip;
	}
}