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

#pragma once

#include "CoreMinimal.h"
#include "Input/DragAndDrop.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Widgets/SBoxPanel.h"
#include "Widgets/Layout/SBorder.h"
#include "Widgets/Images/SImage.h"
#include "Widgets/Text/STextBlock.h"
#include "EditorStyleSet.h"

#define LOCTEXT_NAMESPACE "DecoratedDragDrop"

class FDecoratedDragDropOp: public FDragDropOperation
{
public:
    DRAG_DROP_OPERATOR_TYPE(FDecoratedDragDropOp, FDragDropOperation)

    /** String to show as hover text */
    FText CurrentHoverText;

    /** Icon to be displayed */
    const FSlateBrush* CurrentIconBrush;

    /** The color of the icon to be displayed. */
    FSlateColor CurrentIconColorAndOpacity;

    FDecoratedDragDropOp()
        : CurrentIconBrush(nullptr), CurrentIconColorAndOpacity(FLinearColor::White), DefaultHoverIcon(nullptr), DefaultHoverIconColorAndOpacity(FLinearColor::White)
    {}

    /** Overridden to provide public access */
    virtual void Construct() override
    {
        FDragDropOperation::Construct();
    }

    /** Set the decorator back to the icon and text defined by the default */
    virtual void ResetToDefaultToolTip()
    {
        CurrentHoverText           = DefaultHoverText;
        CurrentIconBrush           = DefaultHoverIcon;
        CurrentIconColorAndOpacity = DefaultHoverIconColorAndOpacity;
    }

    /** The widget decorator to use */
    virtual TSharedPtr<SWidget> GetDefaultDecorator() const override
    {
        // Create hover widget
        return SNew(SBorder)
            .BorderImage(FEditorStyle::GetBrush("Graph.ConnectorFeedback.Border"))
            .Content()
                [SNew(SHorizontalBox)

                 + SHorizontalBox::Slot()
                       .AutoWidth()
                       .Padding(0.0f, 0.0f, 3.0f, 0.0f)
                       .VAlign(VAlign_Center)
                           [SNew(SImage)
                                .Image(this, &FDecoratedDragDropOp::GetIcon)
                                .ColorAndOpacity(this, &FDecoratedDragDropOp::GetIconColorAndOpacity)]

                 + SHorizontalBox::Slot()
                       .AutoWidth()
                       .VAlign(VAlign_Center)
                           [SNew(STextBlock)
                                .Text(this, &FDecoratedDragDropOp::GetHoverText)]];
    }

    FText GetHoverText() const
    {
        return CurrentHoverText;
    }

    const FSlateBrush* GetIcon() const
    {
        return CurrentIconBrush;
    }

    FSlateColor GetIconColorAndOpacity() const
    {
        return CurrentIconColorAndOpacity;
    }

    /** Set the text and icon for this tooltip */
    void SetToolTip(const FText& Text, const FSlateBrush* Icon)
    {
        CurrentHoverText = Text;
        CurrentIconBrush = Icon;
    }

    /** Setup some default values for the decorator */
    void SetupDefaults()
    {
        DefaultHoverText                = CurrentHoverText;
        DefaultHoverIcon                = CurrentIconBrush;
        DefaultHoverIconColorAndOpacity = CurrentIconColorAndOpacity;
    }

    /** Gets the default hover text for this drag drop op. */
    FText GetDefaultHoverText() const
    {
        return DefaultHoverText;
    }

protected:
    /** Default string to show as hover text */
    FText DefaultHoverText;

    /** Default icon to be displayed */
    const FSlateBrush* DefaultHoverIcon;

    /** Default color and opacity for the default icon to be displayed. */
    FSlateColor DefaultHoverIconColorAndOpacity;
};

#undef LOCTEXT_NAMESPACE