#pragma once
#include "Pattern/Pattern.h"
#include "Pattern/PatternInstance.h"
#include "Singleton.h"
#include "Pattern/MidiPattern.h"
#include "Pattern/SamplePattern.h"
#include "Midi/Time/TimePos.h"
#include "Midi/Time/TimeSig.h"

DECLARE_MULTICAST_DELEGATE_OneParam(FPatternDelegate, FPattern*)
DECLARE_MULTICAST_DELEGATE_OneParam(FPatternInstanceDelegate, FPatternInstance*)

class FPatternSelector : public TSingleton<FPatternSelector>
{
public:
	void SelectPattern(FPattern* Pattern)
	{
		Range = TRange<AudioFrame>(AudioFrame(), Pattern->GetLength());
		if (SelectedPattern == Pattern)
			return;
		if (SelectedPattern)
			OnPatternDeselected.Broadcast(SelectedPattern);
		SelectedPattern = Pattern;
		OnPatternSelected.Broadcast(SelectedPattern);
	}

	void UnSelectPattern()
	{
		if (SelectedPattern)
			OnPatternDeselected.Broadcast(SelectedPattern);
		SelectedPattern = nullptr;
		Range = TRange<AudioFrame>(AudioFrame(), AudioFrame());
	}

	void SelectPatternInstance(FPatternInstance* PatternInstance)
	{
		FPattern* Pattern = PatternInstance->GetOwner();
		SelectPattern(Pattern);
		Range = PatternInstance->TimeRange;
	}

	FPattern* GetSelectedPattern() const { return SelectedPattern; }
	TRange<AudioFrame> GetRange() const { return Range; }
	
	FPatternDelegate OnPatternSelected;
	FPatternDelegate OnPatternDeselected;
private:
	TRange<AudioFrame> Range;
	FPattern* SelectedPattern = nullptr;
};

class FMidiSequencer : public TSingleton<FMidiSequencer>
{
public: 
	FMidiPattern* NewMidiPattern();
	FSamplePattern* NewSamplePattern(FSampler* InSampler);
	
	void DeletePattern(FPattern* Pattern);
	FPattern* FindPattern(uint32 ID);

	void Process(float SampleRate, uint32 FrameNum);
	
	void UpdateTime();

	const TMap<EPatternType, TArray<FPattern*>>& GetPattern() const { return PatternTypeMap; }
	const TArray<FPattern*>& GetPattern(EPatternType Type) { return PatternTypeMap.FindOrAdd(Type); }
	void ForeachPatternInstance(TFunctionRef<bool(FPatternInstance*)> Func);
	
	FPatternDelegate OnNewPattern;
	FPatternDelegate OnDeletePattern;
	FPatternInstanceDelegate OnCreatePatternInstance;
	FPatternInstanceDelegate OnDeletePatternInstance;
	
	double GetTickPos() const { return FramePos.load().Ticks(); }
	double GetSamplePos() const { return FramePos.load(); }

	void SetTicksPerQuarter(int32 InTicksPerQuarter) { TicksPerQuarter = FMath::Max(48, InTicksPerQuarter); }
	int32 GetTicksPerQuarter() const { return TicksPerQuarter; }
	MidiTick GetBeat() const { return GetTicksPerQuarter() * TimeSig.GetNumerator(); }
	MidiTick GetBar() const { return GetBeat() * TimeSig.GetDenominator(); }
	
	static float FramesPerTick(); // MidiTick转换为Frame的比例

	FTimeSig TimeSig = FTimeSig(4, 4);
	float BPM = 160.f;

	void TogglePlay() { SetPlaying(!Playing); }
	void SetPlaying(bool bPlaying);


	std::atomic<AudioFrame> FramePos;
private:
	void RegisterPattern(FPattern* InPattern);
	
	int32 TicksPerQuarter = 480; // Ticks Per Quarter-Note
	std::atomic_bool Playing = false;

	uint32 IDCounter = 0;
	
	TArray<FPattern*> Patterns;
	TMap<EPatternType, TArray<FPattern*>> PatternTypeMap;
	
};