#pragma once
#include "CoreMinimal.h"
#include "Future.h"
#include "Midi/MidiType.h"
#include "Thread/ThreadMessage.h"
#include "Midi/Time/TimePos.h"

class FPatternInstance;
class FPluginHost;

enum class EPatternType
{
	Midi,
	Automation,
	Sample
};

DECLARE_MULTICAST_DELEGATE_ThreeParams(FOnPatternPlay, FPatternInstance* /*Instance*/, AudioFrame /*Pattern Pos*/, uint32 /*Length*/)

class FPattern
{
	FRIEND_THREAD_MESSAGE(CreatePatternInstance)
	FRIEND_THREAD_MESSAGE(DestroyPatternInstance)
public:
	virtual ~FPattern() = default;
	virtual TFuture<FPatternInstance*> RequestCreateInstance(int32 TrackIndex, AudioFrame Pos, AudioFrame PatternBegin, AudioFrame PatternEnd);
	virtual void RequestDestroyInstance(FPatternInstance* Instance);

	TArray<FPatternInstance*> GetInstances() const { return Instances; }
	virtual void Reset() {}

	virtual void Process(AudioFrame PatternPos, uint32 Length) = 0;
	virtual AudioFrame GetLength() = 0;

	void ProcessInstances(AudioFrame SequencePos, uint32 InLength);


	uint32 ID; // 0表示无效
	EPatternType Type;
	FString Name;
	FLinearColor Color;
	TRange<AudioFrame> TimeRange;
	AudioFrame Length;

	FSimpleMulticastDelegate OnChanged;
	FOnPatternPlay OnPlay;
protected:
	FPatternInstance* CreateInstance(int32 TrackIndex, AudioFrame InPos, AudioFrame PatternBegin, AudioFrame PatternEnd);
	void DestroyInstance(FPatternInstance* Instance);

	TArray<FPatternInstance*> Instances;
};