#include "PeakFile.h"

#include "Async.h"
#include "PluginHost/Sampler.h"

#define MID_TO_LOW (16 * 16)

DEFINE_LOG_CATEGORY(LogPeakFile);

TArray<TArray<FSamplePeak>> GenPeakData(const TArray<TArray64<float>>& Data, int32 BlockSize)
{
	TArray<TArray<FSamplePeak>> Out;
	Out.SetNum(Data.Num());
	
	for (int64 Channel = 0; Channel < Data.Num(); ++Channel)
	{
		const uint64 SourceNum = Data[Channel].Num();
		uint64 BlockNum = SourceNum / BlockSize;
		BlockNum += SourceNum % BlockSize ? 1 : 0;
		
		Out[Channel].SetNum(BlockNum);
		uint64 Index = 0;
		for (uint64 j = 0; j < BlockNum; j++)
		{
			float Max = FLT_MIN_EXP;
			float Min = FLT_MAX;
			
			for (uint64 S = 0; S < BlockSize; ++S)
			{
				if (Index >= SourceNum) break;
				const float& Sample = Data[Channel][Index];
				if (Max < Sample) Max = Sample;
				if (Min > Sample) Min = Sample;
				++Index;
			}
			Out[Channel][j].Max = Max;
			Out[Channel][j].Min = Min;
		}
	}
	return Out;
}

void FWaveformRenderData::Generate(const TArray<TArray64<float>>& Data)
{
	Buffer = GenPeakData(Data, BlockSize);
}

FWaveform::FWaveform(int32 LevelNum, int32 MaxBlockSize)
{
	RenderData.SetNum(LevelNum);
	int32 BeginBlock = MaxBlockSize;
	for (int i = 0; i < LevelNum; ++i)
	{
		RenderData[i] = new FWaveformRenderData(BeginBlock);
		BeginBlock /= 4;
	}
}

FWaveform::~FWaveform()
{
	for (int i = 0; i < RenderData.Num(); ++i)
		delete RenderData[i];
}

void FWaveform::UpdatePeak(const TArray<TArray64<float>>& SampleBuffer)
{
	Processing = true;
	Async(EAsyncExecution::TaskGraph, [this, &SampleBuffer]()
	{
		for (int i = 0; i < RenderData.Num(); ++i)
			RenderData[i]->Generate(SampleBuffer);
		
		const float MemSize = GetMemSize();
		UE_LOG(LogPeakFile, Log, TEXT("Waveform MemSize: %f MB"), MemSize / 1024 / 1024);

		// 创建一个主线程TaskGraph任务, 用于通知UI线程更新
		Async(EAsyncExecution::TaskGraphMainThread, [this]()
		{
			OnPostUpdatePeak.Broadcast();
		});
		Processing = false;
	});
}