// © 2024 Long Ly. All rights reserved. Any unauthorized use, reproduction, or distribution of this trademark is strictly prohibited and may result in legal action.

#pragma once

#include "CoreMinimal.h"
#include "Components/GameStateComponent.h"
#include "LoadingProcessInterface.h"
#include "OLSExperienceManagerComponent.generated.h"

namespace UE::GameFeatures { struct FResult; }

DECLARE_MULTICAST_DELEGATE_OneParam(FOLSExperienceLoadedNativeDelegate, const class UOLSExperienceDefinitionDataAsset* /*experience*/);

enum class EOLSExperienceLoadState
{
	Unloaded,
	Loading,
	LoadingGameFeatures,
	LoadingChaosTestingDelay,
	ExecutingActions,
	Loaded,
	Deactivating
};

UCLASS()
class OLS_API UOLSExperienceManagerComponent : public UGameStateComponent, public ILoadingProcessInterface 
{
	GENERATED_BODY()

public:

	UOLSExperienceManagerComponent(const FObjectInitializer& objectInitializer);

	//~ Begin UActorComponent interface
	virtual void EndPlay(const EEndPlayReason::Type endPlayReason) override;
	virtual void GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const override;
	//~ End UActorComponent interface

	//~ Begin ILoadingProcessInterface interface
	virtual bool ShouldShowLoadingScreen(FString& outReason) const override;
	//~ End ILoadingProcessInterface

public:

	// This returns the current experience if it is fully loaded, asserting otherwise
	// (i.e., if you called it too soon)
	const UOLSExperienceDefinitionDataAsset* GetCurrentExperienceChecked() const;

	// Tries to set the current experience, either a UI or gameplay one
	void SetCurrentExperience(FPrimaryAssetId experienceId);

	// Returns true if the experience is fully loaded
	bool IsExperienceLoaded() const;

	// Ensures the delegate is called once the experience has been loaded,
	// before others are called.
	// However, if the experience has already loaded, calls the delegate immediately.
	void CallOrRegister_OnExperienceLoaded_HighPriority(FOLSExperienceLoadedNativeDelegate::FDelegate&& delegate);

	// Ensures the delegate is called once the experience has been loaded
	// If the experience has already loaded, calls the delegate immediately
	void CallOrRegister_OnExperienceLoaded(FOLSExperienceLoadedNativeDelegate::FDelegate&& delegate);

	// Ensures the delegate is called once the experience has been loaded
	// If the experience has already loaded, calls the delegate immediately
	void CallOrRegister_OnExperienceLoaded_LowPriority(FOLSExperienceLoadedNativeDelegate::FDelegate&& delegate);

private:

	UFUNCTION()
	void OnRep_CurrentExperience();

private:

	void StartExperienceLoad();
	void OnExperienceLoadComplete();
	void OnGameFeaturePluginLoadComplete(const UE::GameFeatures::FResult& result);
	void OnExperienceFullLoadCompleted();

	void OnActionDeactivationCompleted();
	void OnAllActionsDeactivated();
	
private:

	UPROPERTY(ReplicatedUsing = OnRep_CurrentExperience)
	TObjectPtr<const class UOLSExperienceDefinitionDataAsset> CurrentExperience = nullptr;

private:

	EOLSExperienceLoadState LoadState = EOLSExperienceLoadState::Unloaded;
	
	int32 NumGameFeaturePluginsLoading = 0;
	TArray<FString> GameFeaturePluginURLs;

	int32 NumObservedPausers = 0;
	int32 NumExpectedPausers = 0;

	/**
	 * Delegate called when the experience has finished loading just before others
	 * (e.g., subsystems that set up for regular gameplay)
	 */
	FOLSExperienceLoadedNativeDelegate OnExperienceLoaded_HighPriority;

	/** Delegate called when the experience has finished loading */
	FOLSExperienceLoadedNativeDelegate OnExperienceLoaded;

	/** Delegate called when the experience has finished loading */
	FOLSExperienceLoadedNativeDelegate OnExperienceLoaded_LowPriority;
};