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

#pragma once

#include "CoreMinimal.h"
#include "InputCoreTypes.h"
#include "Components/ActorComponent.h"
#include "HitProxies.h"
#include "ConvexVolume.h"
#include "ComponentVisualizer.generated.h"

class AActor;
class FCanvas;
class FEditorViewportClient;
class FPrimitiveDrawInterface;
class FSceneView;
class FViewport;
class SWidget;
struct FViewportClick;

struct HComponentVisProxy: public HHitProxy
{
    DECLARE_HIT_PROXY(UNREALED_API);

    HComponentVisProxy(const UActorComponent* InComponent, EHitProxyPriority InPriority = HPP_Wireframe)
        : HHitProxy(InPriority), Component(InComponent)
    {}

    virtual EMouseCursor::Type GetMouseCursor() override
    {
        return EMouseCursor::Crosshairs;
    }

    TWeakObjectPtr<const UActorComponent> Component;
};

USTRUCT()
struct FPropertyNameAndIndex
{
public:
    GENERATED_USTRUCT_BODY()

    FPropertyNameAndIndex()
        : Name(NAME_None), Index(INDEX_NONE)
    {}

    explicit FPropertyNameAndIndex(FName InName, int32 InIndex = 0)
        : Name(InName), Index(InIndex)
    {}

    bool IsValid() const { return Name != NAME_None && Index != INDEX_NONE; }

    void Clear()
    {
        Name  = NAME_None;
        Index = INDEX_NONE;
    }

    bool operator==(const FPropertyNameAndIndex& InRHS) const
    {
        return (Name == InRHS.Name && Index == InRHS.Index);
    }

    UPROPERTY()
    FName Name;

    UPROPERTY()
    int32 Index;
};

/**
 * Describes a chain of properties from the parent actor of a given component, to the component itself.
 */
USTRUCT()
struct UNREALED_API FComponentPropertyPath
{
public:
    GENERATED_USTRUCT_BODY()

    FComponentPropertyPath() = default;
    explicit FComponentPropertyPath(const UActorComponent* Component) { Set(Component); }

    /** Resets the property path */
    void Reset()
    {
        ParentOwningActor      = nullptr;
        LastResortComponentPtr = nullptr;
        PropertyChain.Reset();
    }

    /** Gets the parent owning actor for the component, or nullptr if it is not valid */
    AActor* GetParentOwningActor() const { return ParentOwningActor.Get(); }

    /** Gets a pointer to the component, or nullptr if it is not valid */
    UActorComponent* GetComponent() const;

    /** Determines whether the property path is valid or not */
    bool IsValid() const;

    bool operator==(const FComponentPropertyPath& InRHS) const
    {
        return (ParentOwningActor == InRHS.ParentOwningActor && LastResortComponentPtr == InRHS.LastResortComponentPtr && PropertyChain == InRHS.PropertyChain);
    }

    bool operator!=(const FComponentPropertyPath& InRHS) const
    {
        return (ParentOwningActor != InRHS.ParentOwningActor || LastResortComponentPtr != InRHS.LastResortComponentPtr || PropertyChain != InRHS.PropertyChain);
    }

private:
    /** Sets the component referred to by the object */
    void Set(const UActorComponent* Component);

    UPROPERTY()
    TWeakObjectPtr<AActor> ParentOwningActor;

    UPROPERTY()
    TWeakObjectPtr<UActorComponent> LastResortComponentPtr;

    UPROPERTY()
    TArray<FPropertyNameAndIndex> PropertyChain;
};

/** Base class for a component visualizer, that draw editor information for a particular component class */
class UNREALED_API FComponentVisualizer: public TSharedFromThis<FComponentVisualizer>
{
public:
    FComponentVisualizer() {}
    virtual ~FComponentVisualizer() {}

    /** */
    virtual void OnRegister() {}
    /** Draw visualization for the supplied component */
    virtual void DrawVisualization(const UActorComponent* Component, const FSceneView* View, FPrimitiveDrawInterface* PDI) {}
    /** Draw HUD on viewport for the supplied component */
    virtual void DrawVisualizationHUD(const UActorComponent* Component, const FViewport* Viewport, const FSceneView* View, FCanvas* Canvas) {}
    /** */
    virtual bool VisProxyHandleClick(FEditorViewportClient* InViewportClient, HComponentVisProxy* VisProxy, const FViewportClick& Click) { return false; }
    /** */
    virtual void EndEditing() {}
    /** */
    virtual bool GetWidgetLocation(const FEditorViewportClient* ViewportClient, FVector& OutLocation) const { return false; }
    /** */
    virtual bool GetCustomInputCoordinateSystem(const FEditorViewportClient* ViewportClient, FMatrix& OutMatrix) const { return false; }
    /** */
    virtual bool HandleInputDelta(FEditorViewportClient* ViewportClient, FViewport* Viewport, FVector& DeltaTranslate, FRotator& DeltalRotate, FVector& DeltaScale) { return false; }
    /** */
    virtual bool HandleInputKey(FEditorViewportClient* ViewportClient, FViewport* Viewport, FKey Key, EInputEvent Event) { return false; }
    /** Handle click modified by Alt, Ctrl and/or Shift. The input HitProxy may not be on this component. */
    virtual bool HandleModifiedClick(FEditorViewportClient* InViewportClient, HHitProxy* HitProxy, const FViewportClick& Click) { return false; }
    /** Handle box select input */
    virtual bool HandleBoxSelect(const FBox& InBox, FEditorViewportClient* InViewportClient, FViewport* InViewport) { return false; }
    /** Handle frustum select input */
    virtual bool HandleFrustumSelect(const FConvexVolume& InFrustum, FEditorViewportClient* InViewportClient, FViewport* InViewport) { return false; }
    /** Return whether focus on selection should focus on bounding box defined by active visualizer */
    virtual bool HasFocusOnSelectionBoundingBox(FBox& OutBoundingBox) { return false; }
    /** Pass snap input to active visualizer */
    virtual bool HandleSnapTo(const bool bInAlign, const bool bInUseLineTrace, const bool bInUseBounds, const bool bInUsePivot, AActor* InDestination) { return false; }
    /** Get currently edited component, this is needed to reset the active visualizer after undo/redo */
    virtual UActorComponent* GetEditedComponent() const { return nullptr; }

    /** */
    virtual TSharedPtr<SWidget> GenerateContextMenu() const { return TSharedPtr<SWidget>(); }
    /** */
    virtual bool IsVisualizingArchetype() const { return false; }

    // So deprecated code expecting this as an inner class still works
    using FPropertyNameAndIndex = ::FPropertyNameAndIndex;

    /** Find the name of the property that points to this component */
    UE_DEPRECATED(4.24, "Please use the FComponentPropertyPath class to build property name paths for components.")
    static FPropertyNameAndIndex GetComponentPropertyName(const UActorComponent* Component);

    /** Get a component pointer from the property name */
    UE_DEPRECATED(4.24, "Please use the FComponentPropertyPath::GetComponent() to retrieve a component pointer from a property name path.")
    static UActorComponent* GetComponentFromPropertyName(const AActor* CompOwner, const FPropertyNameAndIndex& Property);

    /** Notify that a component property has been modified */
    static void NotifyPropertyModified(UActorComponent* Component, FProperty* Property, EPropertyChangeType::Type PropertyChangeType = EPropertyChangeType::Unspecified);

    /** Notify that many component properties have been modified */
    static void NotifyPropertiesModified(UActorComponent* Component, const TArray<FProperty*>& Properties, EPropertyChangeType::Type PropertyChangeType = EPropertyChangeType::Unspecified);
};

struct FCachedComponentVisualizer
{
    FComponentPropertyPath ComponentPropertyPath;
    TSharedPtr<FComponentVisualizer> Visualizer;

    FCachedComponentVisualizer(UActorComponent* InComponent, TSharedPtr<FComponentVisualizer>& InVisualizer)
        : ComponentPropertyPath(InComponent), Visualizer(InVisualizer)
    {}
};