// Copyright 1998-2019 Epic Games, Inc. All Rights Reserved.

#pragma once

#include "CoreMinimal.h"
#include "Misc/Crc.h"
#include "GeometryCollection/ManagedArray.h"
#include "GeometryCollection/GeometryCollectionSimulationTypes.h"
#include "GeometryCollectionObject.generated.h"

class UMaterialInterface;
class UGeometryCollectionCache;
class FGeometryCollection;
class FManagedArrayCollection;
struct FGeometryCollectionSection;
struct FSharedSimulationParameters;

USTRUCT()
struct GEOMETRYCOLLECTIONENGINE_API FGeometryCollectionSizeSpecificData
{
	GENERATED_BODY()

	FGeometryCollectionSizeSpecificData();

	/** The max size these settings apply to*/
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	float MaxSize;

	/*
	*  CollisionType defines how to initialize the rigid collision structures.
	*/
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	ECollisionTypeEnum CollisionType;

	/*
	*  CollisionType defines how to initialize the rigid collision structures.
	*/
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	EImplicitTypeEnum ImplicitType;

	/*
	*  Resolution on the smallest axes for the level set. (def: 5)
	*/
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	int32 MinLevelSetResolution;

	/*
	*  Resolution on the smallest axes for the level set. (def: 10)
	*/
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	int32 MaxLevelSetResolution;

	/*
	*  Resolution on the smallest axes for the level set. (def: 5)
	*/
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	int32 MinClusterLevelSetResolution;

	/*
	*  Resolution on the smallest axes for the level set. (def: 10)
	*/
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	int32 MaxClusterLevelSetResolution;

	/*
	*  Resolution on the smallest axes for the level set. (def: 10)
	*/
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	int32 CollisionObjectReductionPercentage;

	/**
	 * Number of particles on the triangulated surface to use for collisions.
	 */
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	float CollisionParticlesFraction;

	/**
	 * Max number of particles.
	 */
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	int32 MaximumCollisionParticles;

};

/**
* UGeometryCollectionObject (UObject)
*
* UObject wrapper for the FGeometryCollection
*
*/
UCLASS(customconstructor)
class GEOMETRYCOLLECTIONENGINE_API UGeometryCollection : public UObject
{
	GENERATED_UCLASS_BODY()

public:

	UGeometryCollection(const FObjectInitializer& ObjectInitializer = FObjectInitializer::Get());

	/** UObject Interface */
	virtual void PostLoad() override;
#if WITH_EDITOR
	virtual void PostEditChangeProperty(struct FPropertyChangedEvent& PropertyChangedEvent) override;
#endif
	virtual bool Modify(bool bAlwaysMarkDirty = true) override;
	/** End UObject Interface */

	void Serialize(FArchive& Ar);

#if WITH_EDITOR
	void EnsureDataIsCooked();
#endif

	/** Accessors for internal geometry collection */
	void SetGeometryCollection(TSharedPtr<FGeometryCollection, ESPMode::ThreadSafe> GeometryCollectionIn) { GeometryCollection = GeometryCollectionIn; }
	TSharedPtr<FGeometryCollection, ESPMode::ThreadSafe>       GetGeometryCollection() { return GeometryCollection; }
	const TSharedPtr<FGeometryCollection, ESPMode::ThreadSafe> GetGeometryCollection() const { return GeometryCollection; }

	int32 AppendGeometry(const UGeometryCollection & Element, bool ReindexAllMaterials = false, const FTransform& TransformRoot = FTransform::Identity);
	int32 NumElements(const FName & Group) const;
	void RemoveElements(const FName & Group, const TArray<int32>& SortedDeletionList);

	/** ReindexMaterialSections */
	void ReindexMaterialSections();

	/** appends the standard materials to this uobject */
	void InitializeMaterials();

	/** Returns true if there is anything to render */
	bool HasVisibleGeometry() const;

	/** Invalidates this collection signaling a structural change and renders any previously recorded caches unable to play with this collection */
	void InvalidateCollection();

#if WITH_EDITOR
	/** Create the simulation data that can be shared among all instances (mass, volume, etc...)*/
	void CreateSimulationData();
#endif

	/** Fills params struct with parameters used for precomputing content. */
	void GetSharedSimulationParams(FSharedSimulationParameters& OutParams) const;
	void FixupRemoveOnFractureMaterials(FSharedSimulationParameters& SharedParms) const;

	/** Accessors for the two guids used to identify this collection */
	FGuid GetIdGuid() const;
	FGuid GetStateGuid() const;

	/** The editable mesh representation of this geometry collection */
	class UObject* EditableMesh;
	
	UPROPERTY(EditAnywhere, Category = "Materials")
	TArray<UMaterialInterface*> Materials;

	/*
	*  CollisionType defines how to initialize the rigid collision structures.
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	ECollisionTypeEnum CollisionType;

	/*
	*  CollisionType defines how to initialize the rigid collision structures.
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	EImplicitTypeEnum ImplicitType;

	/*
	*  Resolution on the smallest axes for the level set. (def: 5)
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	int32 MinLevelSetResolution;

	/*
	*  Resolution on the smallest axes for the level set. (def: 10)
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	int32 MaxLevelSetResolution;

	/*
	*  Resolution on the smallest axes for the level set. (def: 5)
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	int32 MinClusterLevelSetResolution;

	/*
	*  Resolution on the smallest axes for the level set. (def: 10)
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	int32 MaxClusterLevelSetResolution;

	/*
	*  Resolution on the smallest axes for the level set. (def: 10)
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	float CollisionObjectReductionPercentage;

	/**
	* Mass As Density, units are in kg/m^3
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	bool bMassAsDensity;

	/**
	* Total Mass of Collection. If density, units are in kg/m^3
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	float Mass;

	/**
	* Smallest allowable mass (def:0.1)
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	float MinimumMassClamp;

	/**
	 * Number of particles on the triangulated surface to use for collisions.
	 */
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	float CollisionParticlesFraction;

	/**
	 * Max number of particles.
	 */
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Collisions")
	int32 MaximumCollisionParticles;

	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Collisions")
	TArray<FGeometryCollectionSizeSpecificData> SizeSpecificData;
	
	/**
	* Enable remove pieces on fracture
	*/
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "ChaosPhysics|Fracture")
	bool EnableRemovePiecesOnFracture;

	/**
	* Materials relating to remove on fracture
	*/
	UPROPERTY(EditAnywhere, Category = "ChaosPhysics|Fracture")
	TArray<UMaterialInterface*> RemoveOnFractureMaterials;

	FORCEINLINE const int GetBoneSelectedMaterialIndex() const { return BoneSelectedMaterialIndex; }

#if WITH_EDITORONLY_DATA
	/** Information for thumbnail rendering */
	UPROPERTY(VisibleAnywhere, Instanced, AdvancedDisplay, Category = GeometryCollection)
	class UThumbnailInfo* ThumbnailInfo;
#endif // WITH_EDITORONLY_DATA


private:
#if WITH_EDITOR
	void CreateSimulationDataImp(bool bCopyFromDDC, const TCHAR* OverrideVersion = nullptr);
#endif

private:

	/** Guid created on construction of this collection. It should be used to uniquely identify this collection */
	UPROPERTY()
	FGuid PersistentGuid;

	/** 
	 * Guid that can be invalidated on demand - essentially a 'version' that should be changed when a structural change is made to
	 * the geometry collection. This signals to any caches that attempt to link to a geometry collection whether the collection
	 * is still valid (hasn't structurally changed post-recording)
	 */
	UPROPERTY()
	FGuid StateGuid;

#if WITH_EDITOR
	//Used to determine whether we need to cook content
	FGuid LastBuiltGuid;
#endif

	// #todo(dmp): rename to be consistent BoneSelectedMaterialID?
	UPROPERTY()
	int32 BoneSelectedMaterialIndex;

	TSharedPtr<FGeometryCollection, ESPMode::ThreadSafe> GeometryCollection;
};