// Copyright 1998-2018 Epic Games, Inc. All Rights Reserved.

#pragma once

#include "ImGuiInputHandler.h"

#include <Delegates/Delegate.h>
#include <UObject/Object.h>

// Select right soft class reference header to avoid warning.
#if ENGINE_COMPATIBILITY_LEGACY_STRING_CLASS_REF
#include <StringClassReference.h>
#else
#include <UObject/SoftObjectPath.h>
#endif

#include "ImGuiSettings.generated.h"


/**
 * Struct containing key information that can be used for key binding. Using 'Undetermined' value for modifier keys
 * means that those keys should be ignored when testing for a match.
 */
USTRUCT()
struct FImGuiKeyInfo
{
	GENERATED_BODY()

	UPROPERTY(EditAnywhere)
	FKey Key;

	UPROPERTY(EditAnywhere)
	ECheckBoxState Shift = ECheckBoxState::Undetermined;

	UPROPERTY(EditAnywhere)
	ECheckBoxState Ctrl = ECheckBoxState::Undetermined;

	UPROPERTY(EditAnywhere)
	ECheckBoxState Alt = ECheckBoxState::Undetermined;

	UPROPERTY(EditAnywhere)
	ECheckBoxState Cmd = ECheckBoxState::Undetermined;
};

// Settings for ImGui module.
UCLASS(config=ImGui, defaultconfig)
class UImGuiSettings : public UObject
{
	GENERATED_BODY()

public:

	UImGuiSettings();
	~UImGuiSettings();

	// Path to custom implementation of ImGui Input Handler.
	const FStringClassReference& GetImGuiInputHandlerClass() const { return ImGuiInputHandlerClass; }

	// Get mapping for 'ImGui.SwitchInputMode' command.
	const FImGuiKeyInfo& GetSwitchInputModeKey() const { return SwitchInputModeKey; }

	// Delegate raised when ImGuiInputHandlerClass property has changed.
	FSimpleMulticastDelegate OnImGuiInputHandlerClassChanged;

	virtual void PostInitProperties() override;

protected:

	// Path to own implementation of ImGui Input Handler allowing to customize handling of keyboard and gamepad input.
	// If not set then default handler is used.
	UPROPERTY(EditAnywhere, config, Category = "Extensions", meta = (MetaClass = "ImGuiInputHandler"))
	FStringClassReference ImGuiInputHandlerClass;

	// Define a custom key binding to 'ImGui.SwitchInputMode' command. Binding is only set if key is valid.
	// Note that modifier key properties can be set to one of the three values: undetermined means that state of the given
	// modifier is not tested, checked means that it needs to be pressed and unchecked means that it cannot be pressed.
	//
	// This binding is using Player Input's DebugExecBindings which only works in non-shipment builds.
	UPROPERTY(EditAnywhere, config, Category = "Keyboard Shortcuts")
	FImGuiKeyInfo SwitchInputModeKey;

private:

#if WITH_EDITOR

	void RegisterPropertyChangedDelegate();
	void UnregisterPropertyChangedDelegate();

	void OnPropertyChanged(class UObject* ObjectBeingModified, struct FPropertyChangedEvent& PropertyChangedEvent);

#endif // WITH_EDITOR
};