// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once

#include "CoreMinimal.h"
#include "AIController.h"
#include "ShooterAIController.generated.h"

class UStateTreeAIComponent;
class UAIPerceptionComponent;
struct FAIStimulus;

DECLARE_DELEGATE_TwoParams(FShooterPerceptionUpdatedDelegate, AActor*, const FAIStimulus&);
DECLARE_DELEGATE_OneParam(FShooterPerceptionForgottenDelegate, AActor*);

/**
 *  Simple AI Controller for a first person shooter enemy
 */
UCLASS(abstract)
class FIRST_API AShooterAIController : public AAIController
{
	GENERATED_BODY()
	
	/** Runs the behavior StateTree for this NPC */
	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category="Components", meta = (AllowPrivateAccess = "true"))
	UStateTreeAIComponent* StateTreeAI;

	/** Detects other actors through sight, hearing and other senses */
	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category="Components", meta = (AllowPrivateAccess = "true"))
	UAIPerceptionComponent* AIPerception;

protected:

	/** Team tag for pawn friend or foe identification */
	UPROPERTY(EditAnywhere, Category="Shooter")
	FName TeamTag = FName("Enemy");

	/** Enemy currently being targeted */
	TObjectPtr<AActor> TargetEnemy;

public:

	/** Called when an AI perception has been updated. StateTree task delegate hook */
	FShooterPerceptionUpdatedDelegate OnShooterPerceptionUpdated;

	/** Called when an AI perception has been forgotten. StateTree task delegate hook */
	FShooterPerceptionForgottenDelegate OnShooterPerceptionForgotten;

public:

	/** Constructor */
	AShooterAIController();

protected:

	/** Pawn initialization */
	virtual void OnPossess(APawn* InPawn) override;

protected:

	/** Called when the possessed pawn dies */
	UFUNCTION()
	void OnPawnDeath();

public:

	/** Sets the targeted enemy */
	void SetCurrentTarget(AActor* Target);

	/** Clears the targeted enemy */
	void ClearCurrentTarget();

	/** Returns the targeted enemy */
	AActor* GetCurrentTarget() const { return TargetEnemy; };

protected:

	/** Called when the AI perception component updates a perception on a given actor */
	UFUNCTION()
	void OnPerceptionUpdated(AActor* Actor, FAIStimulus Stimulus);

	/** Called when the AI perception component forgets a given actor */
	UFUNCTION()
	void OnPerceptionForgotten(AActor* Actor);
};