////////////////////////////////////////////////////////////
//
// InputModeRequest.h
//
// Custom input event dispatching system. Uses Unreal's
// built-in input modes (GameOnly / UIOnly) with an
// enhanced input component for GameOnly mode hotkeys.
//
////////////////////////////////////////////////////////////

#pragma once

#include "CoreMinimal.h"
#include "Blueprint/UserWidget.h"
#include "InputModeRequest.generated.h"



////////////////////////////////////////////////////////////
//
// FlxInputModeRequest
//
// Using this struct, a Widget can express a need for a
// particular input mode.  These requests go to the player
// controller, which arbitrates.
//
////////////////////////////////////////////////////////////

USTRUCT(BlueprintType)
struct FlxInputModeRequest
{
	GENERATED_BODY()

	FlxInputModeRequest() = default;

	bool operator == (const FlxInputModeRequest &Other) const;

	// True if this request wants any high-priority resource:
	// keyboard focus, the mouse pointer, or input blocking.
	bool IsHighPrio() const { return Focus != nullptr || ShowPointer || BlockInput; }

	UPROPERTY(BlueprintReadWrite)
	UUserWidget* Widget = nullptr;

	UPROPERTY(BlueprintReadWrite)
	UWidget* Focus = nullptr;

	UPROPERTY(BlueprintReadWrite)
	bool ShowPointer = false;

	UPROPERTY(BlueprintReadWrite)
	bool BlockInput = false;

	UPROPERTY(BlueprintReadWrite)
	bool EnableInputComponent = true;

	UPROPERTY()
	int32 SequenceNumber = 0;

};

USTRUCT()
struct FlxInputModeRequests
{
	GENERATED_BODY()

private:
	UPROPERTY()
	// Sorted by highest priority first, then most recent first.
	TArray<FlxInputModeRequest> Requests;

	UPROPERTY()
	int32 NextSequenceNumber = 0;

public:
	using View = TArrayView<FlxInputModeRequest>;

	// Get the requests array.
	const TArray<FlxInputModeRequest> &GetRequests() const { return Requests; }

	// Sanity check a request to see if it is reasonable.
	static bool SanityCheck(const FlxInputModeRequest &Request);
	
	// Divide Requests into a high-priority slice and a low-priority slice.
	void SplitHighLow(View &High, View &Low); 

	// Apply a request.  Replaces any previous request by the same widget.
	void Request(const FlxInputModeRequest &NewRequest);

	// Find the specified widget, and modify the 'EnableInputComponent'
	// flag.  Adds the widget if it's not already present.
	void SetEnableInputComponent(UUserWidget *Widget, bool EnableInputComponent);

	// Remove all requests by the specified widget.
	void Remove(UUserWidget *Widget);

	// Remove any requests by dead widgets or widgets with no parents.
	void GarbageCollect();
};