#include "SSamplePatternInstance.h"

#include "Pattern/SamplePatternInstance.h"
#include "UI/Widget/Thumbnail.h"
#include "UI/Widget/WaveformViewer.h"

FSamplePatternInstanceWaveformHandle::FSamplePatternInstanceWaveformHandle(TSharedRef<SSamplePatternInstance> InPatternInstance):
	PatternInstanceWidget(InPatternInstance)
{
}

TArrayView<const FSamplePeak> FSamplePatternInstanceWaveformHandle::GetWaveform(int32 SizeX)
{
	if (!PatternInstanceWidget.IsValid())
		return TArrayView<const FSamplePeak>();
	const FSamplePatternInstance* Instance = (FSamplePatternInstance*)PatternInstanceWidget.Pin()->GetPatternInstance();
	const FSampler* Sampler = Instance->GetInstanceOwner()->GetSampler();

	if (!RenderData)
	{
		RenderData = new FWaveform(7, 256 * 128);
		RenderData->OnPostUpdatePeak.AddLambda([this]() { OnRequestUpdate.Broadcast(); });
		RenderData->UpdatePeak(Sampler->GetSampleBuffer());
	}
	LastRenderRange = GetRenderRange();
	return RenderData->GetPeakFromRange(0, SizeX, LastRenderRange.GetLowerBoundValue(), LastRenderRange.GetUpperBoundValue());
}

bool FSamplePatternInstanceWaveformHandle::NeedUpdate() const
{
	const TRange<AudioFrame>& RenderRange = GetRenderRange();
	const bool Lower = FMath::IsNearlyEqual(LastRenderRange.GetLowerBoundValue(), RenderRange.GetLowerBoundValue());
	const bool Upper = FMath::IsNearlyEqual(LastRenderRange.GetUpperBoundValue(), RenderRange.GetUpperBoundValue());
	return !(Lower && Upper);
}

TRange<AudioFrame> FSamplePatternInstanceWaveformHandle::GetRenderRange() const
{
	if (!PatternInstanceWidget.IsValid())
		return TRange<AudioFrame>(0, 0);
	const TSharedPtr<SSamplePatternInstance> SamplePatternInstance = PatternInstanceWidget.Pin();
	FSamplePatternInstance* Instance = static_cast<FSamplePatternInstance*>(SamplePatternInstance->GetPatternInstance());
	const TRange<AudioFrame>& TimeRange = Instance->TimeRange;
	TRange<AudioFrame> FrameViewRange = SamplePatternInstance->GetFrameViewRange();

	const AudioFrame InstancePos = Instance->GetMidiPos();
	FrameViewRange = TRange<AudioFrame>(FrameViewRange.GetLowerBoundValue() - InstancePos, FrameViewRange.GetUpperBoundValue() - InstancePos);
	const AudioFrame BeginFrame = FMath::Max(TimeRange.GetLowerBoundValue(), FrameViewRange.GetLowerBoundValue());
	const AudioFrame EndFrame = FMath::Min(TimeRange.GetUpperBoundValue(), FrameViewRange.GetUpperBoundValue());
	
	return TRange<AudioFrame>(BeginFrame, EndFrame);
}

SSamplePatternInstance::SSamplePatternInstance()
{
}

void SSamplePatternInstance::Construct(const FArguments& InArgs)
{
	WaveformHandle = MakeShared<FSamplePatternInstanceWaveformHandle>(SharedThis(this));
	WaveformHandle->OnRequestUpdate.AddLambda([this]()
	{
		Invalidate(EInvalidateWidgetReason::Paint);
	});
	SPatternInstance::Construct(InArgs);
}

TSharedRef<SWidget> SSamplePatternInstance::GetViewWidget()
{
	return SAssignNew(WaveformViewer, SWaveformViewer)
	.WaveformHandle(WaveformHandle);
}

void SSamplePatternInstance::RequestUpdate()
{
	if (WaveformHandle.IsValid() && WaveformHandle->NeedUpdate())
		Invalidate(EInvalidateWidgetReason::Paint);
}

FReply SSamplePatternInstance::OpenPatternMenu()
{
	return FReply::Handled();
}