#pragma once
#include "CoreMinimal.h"

class FSampler;

struct FSamplePeak
{
	float Min = 0;
	float Max = 0;

	void operator+=(const FSamplePeak& Other)
	{
		if (Min > Other.Min) Min = Other.Min;
		if (Max < Other.Max) Max = Other.Max;
	}
};

class FPeakBlock
{
public:
	uint16 BlockNum;
	uint16 Size;
	uint16 Res;
	uint16 Resolution;
	TArray<void*> Buffer;
	uint16 MaxLevel;
};

struct FWaveformBuffer
{
	TArray<int16> Buffer;
	void* HiResBuffer;
	TArray<int8> RMSBuffer;
};

class FWaveformRenderData
{
public:
	explicit FWaveformRenderData(int32 BlockSize)
		: BlockSize(BlockSize)
	{
	}

	virtual ~FWaveformRenderData() = default;
	virtual void Generate(const TArray<TArray64<float>>& Data);
	int32 GetMemSize() const
	{
		int32 Size = 0;
		for (const auto& Array : Buffer)
		{
			Size += Array.GetAllocatedSize();
		}
		return Buffer.GetAllocatedSize() + Size;
	}
	const FSamplePeak& GetPeak(const uint16 Channel, const uint64 Frame) const
	{
		const int32 BlockIndex = Frame / BlockSize;
		return Buffer[Channel][BlockIndex];
	}
	
	TArrayView<const FSamplePeak> GetPeakFromRange(const uint16 Channel, uint64 StartFrame, uint64 EndFrame) const
	{
		const int32 StartBlockIndex = StartFrame / BlockSize;
		int32 EndBlockIndex = EndFrame / BlockSize;
		EndBlockIndex = FMath::Min(EndBlockIndex, Buffer[Channel].Num() - 1);

		// TArray<FSamplePeak> Out;
		// Out.SetNum(EndBlockIndex - StartBlockIndex + 1);
		// FMemory::Memcpy(Out.GetData(), Buffer[Channel].GetData() + StartBlockIndex, Out.Num() * sizeof(FSamplePeak));
		return MakeArrayView(&Buffer[Channel][StartBlockIndex], EndBlockIndex - StartBlockIndex + 1);
	}
	TArray<TArray<FSamplePeak>> Buffer;
	const int32 BlockSize; // 每一个块包含多少个Frame
};

class FWaveform
{
public:
	FWaveform(int32 LevelNum, int32 MaxBlockSize = 128 * 128);
	~FWaveform();

	void UpdatePeak(const TArray<TArray64<float>>& SampleBuffer);
	int32 GetMemSize() const
	{
		int32 Size = 0;
		for (int i = 0; i < RenderData.Num(); ++i)
			Size += RenderData[i]->GetMemSize();
		return Size;
	}

	TArrayView<const FSamplePeak> GetPeakFromRange(const uint16 Channel, const int32 Width, const uint64 StartFrame, const uint64 EndFrame) const
	{
		const uint64 FrameCount = EndFrame - StartFrame;
		const int32 BlockSize = FrameCount / Width;
		for (int i = 0; i < RenderData.Num(); ++i)
			if (RenderData[i]->BlockSize <= BlockSize)
				return RenderData[i]->GetPeakFromRange(Channel, StartFrame, EndFrame);
		return RenderData.Last()->GetPeakFromRange(Channel, StartFrame, EndFrame);
	}
	TArray<FWaveformRenderData*> RenderData;
};