////////////////////////////////////////////////////////////
//
// InputDeviceTracker.h
//
// Tracks the most recently used input device, classifying
// it as keyboard/mouse, Xbox gamepad, or PlayStation
// gamepad. The subsystem registers a Slate input
// preprocessor that watches button-down events; analog
// and mouse-move events are ignored. Read the current
// classification via the static accessor.
//
////////////////////////////////////////////////////////////

#pragma once

#include "CoreMinimal.h"
#include "Subsystems/GameInstanceSubsystem.h"
#include "Framework/Application/IInputProcessor.h"
#include "Common.h"
#include "InputDeviceTracker.generated.h"

////////////////////////////////////////////////////////////
//
// FInputDeviceTrackerProcessor
//
// Slate input preprocessor. Updates the device-class
// static on each button-down event. Never consumes
// events (always returns false).
//
////////////////////////////////////////////////////////////

class FInputDeviceTrackerProcessor : public IInputProcessor
{
public:
	virtual void Tick(const float DeltaTime, FSlateApplication& SlateApp, TSharedRef<ICursor> Cursor) override {}
	virtual bool HandleKeyDownEvent(FSlateApplication& SlateApp, const FKeyEvent& KeyEvent) override;
	virtual bool HandleMouseButtonDownEvent(FSlateApplication& SlateApp, const FPointerEvent& MouseEvent) override;
};

////////////////////////////////////////////////////////////
//
// UlxInputDeviceTracker
//
////////////////////////////////////////////////////////////

UCLASS(MinimalAPI)
class UlxInputDeviceTracker : public UGameInstanceSubsystem
{
	GENERATED_BODY()

public:
	virtual void Initialize(FSubsystemCollectionBase& Collection) override;
	virtual void Deinitialize() override;

	// Returns the classification of the most recently used
	// input device. Defaults to KeyboardMouse until the
	// first gamepad button event is observed.
	//
	UFUNCTION(BlueprintCallable, Category="Luprex|Input")
	static ElxControllerType GetLastControllerType();

private:
	TSharedPtr<FInputDeviceTrackerProcessor> Processor;
};