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

#pragma once

#include "CoreMinimal.h"
#include "Stats/Stats.h"
#include "UObject/ObjectMacros.h"
#include "Templates/SubclassOf.h"
#include "GameFramework/Actor.h"
#include "AI/Navigation/NavigationTypes.h"
#include "AI/Navigation/NavAgentInterface.h"
#include "NavigationData.h"
#include "Tickable.h"
#include "AI/Navigation/NavPathObserverInterface.h"
#include "NavMesh/RecastNavMesh.h"
#include "NavigationTestingActor.generated.h"

class ANavigationTestingActor;
class UNavigationInvokerComponent;

struct FNavTestTickHelper : FTickableGameObject
{
	TWeakObjectPtr<ANavigationTestingActor> Owner;

	FNavTestTickHelper() : Owner(NULL) {}
	virtual void Tick(float DeltaTime);
	virtual bool IsTickable() const { return Owner.IsValid(); }
	virtual bool IsTickableInEditor() const { return true; }
	virtual TStatId GetStatId() const ;
};

UENUM()
namespace ENavCostDisplay
{
	enum Type
	{
		TotalCost,
		HeuristicOnly,
		RealCostOnly,
	};
}

UCLASS(hidecategories=(Object, Actor, Input, Rendering, Replication, HLOD, Cooking), showcategories=("Input|MouseInput", "Input|TouchInput"), Blueprintable)
class NAVIGATIONSYSTEM_API ANavigationTestingActor : public AActor, public INavAgentInterface, public INavPathObserverInterface
{
	GENERATED_UCLASS_BODY()

private:
	UPROPERTY()
	TObjectPtr<class UCapsuleComponent> CapsuleComponent;

#if WITH_EDITORONLY_DATA
	/** Editor Preview */
	UPROPERTY()
	TObjectPtr<class UNavTestRenderingComponent> EdRenderComp;
#endif // WITH_EDITORONLY_DATA

	UPROPERTY(EditAnywhere, Category = Navigation, meta=(EditCondition="bActAsNavigationInvoker"))
	TObjectPtr<UNavigationInvokerComponent> InvokerComponent;

	UPROPERTY(EditAnywhere, Category = Navigation, meta=(InlineEditConditionToggle))
	uint32 bActAsNavigationInvoker : 1;

public:

	/** @todo document */
	UPROPERTY(EditAnywhere, Category=Agent)
	FNavAgentProperties NavAgentProps;

	UPROPERTY(EditAnywhere, Category=Agent)
	FVector QueryingExtent;

	UPROPERTY(transient)
	TObjectPtr<ANavigationData> MyNavData;

	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category=AgentStatus)
	FVector ProjectedLocation;

	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category=AgentStatus)
	uint32 bProjectedLocationValid : 1;

	/** if set, start the search from this actor, else start the search from the other actor */
	UPROPERTY(EditAnywhere, Category=Pathfinding)
	uint32 bSearchStart : 1;

	/** this multiplier is used to compute a max node cost allowed to the open list
	 *	(cost limit = CostLimitFacotr*InitialHeuristicEstimate) */
	UPROPERTY(EditAnywhere, Category=Pathfinding, meta = (ClampMin = "0", UIMin = "0"))
	float CostLimitFactor;

	/** minimum cost limit clamping value (in cost units)
	 *	used to allow large deviation in short paths */
	UPROPERTY(EditAnywhere, Category = Pathfinding, meta = (ClampMin = "0", UIMin = "0"))
	float MinimumCostLimit;

	/** Instead of regular pathfinding from source to target location do
	 *	a 'backwards' search that searches from the source, but as if the allowed
	 *	movement direction was coming from the target. Meaningful only for paths
	 *	containing one-direction nav links. */
	UPROPERTY(EditAnywhere, Category = Pathfinding)
	uint32 bBacktracking : 1;

	UPROPERTY(EditAnywhere, Category=Pathfinding)
	uint32 bUseHierarchicalPathfinding : 1;

	/** if set, all steps of A* algorithm will be accessible for debugging */
	UPROPERTY(EditAnywhere, Category=Pathfinding)
	uint32 bGatherDetailedInfo : 1;

	UPROPERTY(EditAnywhere, Category=Query)
	uint32 bDrawDistanceToWall : 1;

	/** show polys from open (orange) and closed (yellow) sets */
	UPROPERTY(EditAnywhere, Category=Debug)
	uint32 bShowNodePool : 1;

	/** show current best path */
	UPROPERTY(EditAnywhere, Category=Debug)
	uint32 bShowBestPath : 1;

	/** show which nodes were modified in current A* step */
	UPROPERTY(EditAnywhere, Category=Debug)
	uint32 bShowDiffWithPreviousStep : 1;

	UPROPERTY(EditAnywhere, Category=Debug)
	uint32 bShouldBeVisibleInGame : 1;

	/** determines which cost will be shown*/
	UPROPERTY(EditAnywhere, Category=Debug)
	TEnumAsByte<ENavCostDisplay::Type> CostDisplayMode;

	/** text canvas offset to apply */
	UPROPERTY(EditAnywhere, Category=Debug)
	FVector2D TextCanvasOffset;

	UPROPERTY(transient, VisibleAnywhere, BlueprintReadOnly, Category=PathfindingStatus)
	uint32 bPathExist : 1;

	UPROPERTY(transient, VisibleAnywhere, BlueprintReadOnly, Category=PathfindingStatus)
	uint32 bPathIsPartial : 1;
	
	UPROPERTY(transient, VisibleAnywhere, BlueprintReadOnly, Category=PathfindingStatus)
	uint32 bPathSearchOutOfNodes : 1;

	/** Time in micro seconds */
	UPROPERTY(transient, VisibleAnywhere, BlueprintReadOnly, Category=PathfindingStatus)
	float PathfindingTime;

	UPROPERTY(transient, VisibleAnywhere, BlueprintReadOnly, Category=PathfindingStatus)
	float PathCost;

	UPROPERTY(transient, VisibleAnywhere, BlueprintReadOnly, Category=PathfindingStatus)
	int32 PathfindingSteps;

	UPROPERTY(EditAnywhere, Category=Pathfinding)
	TObjectPtr<ANavigationTestingActor> OtherActor;

	/** "None" will result in default filter being used */
	UPROPERTY(EditAnywhere, Category=Pathfinding)
	TSubclassOf<class UNavigationQueryFilter> FilterClass;

	UPROPERTY(transient, EditInstanceOnly, Category=Debug, meta=(ClampMin="-1", UIMin="-1"))
	int32 ShowStepIndex;

	UPROPERTY(EditAnywhere, Category=Pathfinding)
	float OffsetFromCornersDistance;

	FVector ClosestWallLocation;

#if WITH_RECAST && WITH_EDITORONLY_DATA
	/** detail data gathered from each step of regular A* algorithm */
	TArray<struct FRecastDebugPathfindingData> DebugSteps;

	FNavTestTickHelper* TickHelper;
#endif

	FNavPathSharedPtr LastPath;
	FNavigationPath::FPathObserverDelegate::FDelegate PathObserver;

	/** Dtor */
	virtual ~ANavigationTestingActor();

	virtual void BeginDestroy() override;

#if WITH_EDITOR
	virtual void PreEditChange(FProperty* PropertyThatWillChange) override;
	virtual void PostEditChangeProperty(FPropertyChangedEvent& PropertyChangedEvent) override;
	virtual void PostEditMove(bool bFinished) override;
	
	virtual void PostLoad() override;
	void TickMe();
#endif // WITH_EDITOR

	//~ Begin INavAgentInterface Interface
	virtual const FNavAgentProperties& GetNavAgentPropertiesRef() const override { return NavAgentProps; }
	virtual FVector GetNavAgentLocation() const override;
	virtual void GetMoveGoalReachTest(const AActor* MovingActor, const FVector& MoveOffset, FVector& GoalOffset, float& GoalRadius, float& GoalHalfHeight) const override {}
	//~ End INavAgentInterface Interface

	//~ Begin INavPathObserverInterface Interface
	virtual void OnPathUpdated(class INavigationPathGenerator* PathGenerator) override {};
	virtual void OnPathInvalid(class INavigationPathGenerator* PathGenerator) override {};
	virtual void OnPathFailed(class INavigationPathGenerator* PathGenerator) override {};
	//~ End INavPathObserverInterface Interface	

	void UpdateNavData();
	void UpdatePathfinding();
	void GatherDetailedData(ANavigationTestingActor* Goal);
	virtual void SearchPathTo(ANavigationTestingActor* Goal);

	/*	Called when given path becomes invalid (via @see PathObserverDelegate)
	 *	NOTE: InvalidatedPath doesn't have to be instance's current Path
	 */
	void OnPathEvent(FNavigationPath* InvalidatedPath, ENavPathEvent::Type Event);

	// Virtual method to override if you want to customize the query being 
	// constructed for the path find (e.g. change the filter or add 
	// constraints/goal evaluators).
	virtual FPathFindingQuery BuildPathFindingQuery(const ANavigationTestingActor* Goal) const;

	/** Returns CapsuleComponent subobject **/
	class UCapsuleComponent* GetCapsuleComponent() const { return CapsuleComponent; }
#if WITH_EDITORONLY_DATA
	/** Returns EdRenderComp subobject **/
	class UNavTestRenderingComponent* GetEdRenderComp() const { return EdRenderComp; }
#endif

protected:
	FVector FindClosestWallLocation() const;
};