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

#pragma once

#include "CoreMinimal.h"
#include "Input/Reply.h"
#include "Widgets/SWidget.h"
#include "Widgets/DeclarativeSyntaxSupport.h"
#include "Widgets/SCompoundWidget.h"
#include "Framework/Docking/TabManager.h"
#include "Toolkits/IToolkit.h"
#include "Toolkits/IToolkitHost.h"
#include "Toolkits/AssetEditorToolkit.h"

class SBorder;

/**
 * Base class for standalone asset editing host tabs
 */
class SStandaloneAssetEditorToolkitHost: public IToolkitHost
    , public SCompoundWidget
{

public:
    SLATE_BEGIN_ARGS(SStandaloneAssetEditorToolkitHost) {}
    SLATE_EVENT(FRequestAssetEditorClose, OnRequestClose)
    SLATE_EVENT(FAssetEditorClosing, OnClose)
    SLATE_END_ARGS()

    /** SCompoundWidget interface */

    /**
     * Constructs this widget
     *
     * @param	InArgs          Declaration from which to construct the widget
     * @param   InTabManager    TabManager to use
     * @param	InitAppName     The app identifier for this standalone toolkit host
     */
    void Construct(const FArguments& InArgs, const TSharedPtr<FTabManager>& InTabManager, const FName InitAppName);

    /**
     * Fills in initial content by loading layout or using the defaults provided.  Must be called after
     * the widget is constructed.
     *
     * @param   DefaultLayout                   The default layout to use if one couldn't be loaded
     * @param   InHostTab                       MajorTab hosting this standalong editor
     * @param   bCreateDefaultStandaloneMenu    True if the asset editor should automatically generate a default "asset" menu, or false if you're going to do this yourself in your derived asset editor's implementation
     */
    void SetupInitialContent(const TSharedRef<FTabManager::FLayout>& DefaultLayout, const TSharedPtr<SDockTab>& InHostTab, const bool bCreateDefaultStandaloneMenu);

    /** Destructor */
    virtual ~SStandaloneAssetEditorToolkitHost();

    /** IToolkitHost interface */
    virtual TSharedRef<class SWidget> GetParentWidget() override;
    virtual void BringToFront() override;
    virtual TSharedRef<class SDockTabStack> GetTabSpot(const EToolkitTabSpot::Type TabSpot) override;
    virtual TSharedPtr<class FTabManager> GetTabManager() const override { return MyTabManager; }
    virtual void OnToolkitHostingStarted(const TSharedRef<class IToolkit>& Toolkit) override;
    virtual void OnToolkitHostingFinished(const TSharedRef<class IToolkit>& Toolkit) override;
    virtual UWorld* GetWorld() const override;
    void CreateDefaultStandaloneMenuBar(UToolMenu* MenuBar);

    /** SWidget overrides */
    virtual bool SupportsKeyboardFocus() const override
    {
        return true;
    }
    virtual FReply OnKeyDown(const FGeometry& MyGeometry, const FKeyEvent& InKeyEvent) override;

    /** Fills in the content by loading the associated layout or using the defaults provided.  Must be called after
     * the widget is constructed.*/
    virtual void RestoreFromLayout(const TSharedRef<FTabManager::FLayout>& NewLayout);

    /** Generates the ui for all menus and toolbars, potentially forcing the menu to be created even if it shouldn't */
    void GenerateMenus(bool bForceCreateMenu);

    /** Gets all extenders that this toolkit host uses */
    TArray<TSharedPtr<FExtender>>& GetMenuExtenders() { return MenuExtenders; }

    /**
     * Set a widget to use in the menu bar overlay
     *
     * @param NewOverlay  The widget to use as the overlay, will appear on the right side of the menu bar.
     */
    void SetMenuOverlay(TSharedRef<SWidget> NewOverlay);

private:
    void OnTabClosed(TSharedRef<SDockTab> TabClosed) const;

    FName GetMenuName() const;

    /** Manages internal tab layout */
    TSharedPtr<FTabManager> MyTabManager;

    /** The widget that will house the default menu widget */
    TSharedPtr<SBorder> MenuWidgetContent;

    /** The widget that will house the overlay widgets (if any) */
    TSharedPtr<SBorder> MenuOverlayWidgetContent;

    /** The default menu widget */
    TSharedPtr<SWidget> DefaultMenuWidget;

    /** The DockTab in which we reside. */
    TWeakPtr<SDockTab> HostTabPtr;

    /** Name ID for this app */
    FName AppName;

    /** List of all of the toolkits we're currently hosting */
    TArray<TSharedPtr<class IToolkit>> HostedToolkits;

    /** The 'owning' asset editor toolkit we're hosting */
    TSharedPtr<class FAssetEditorToolkit> HostedAssetEditorToolkit;

    /** Delegate to be called to determine if we are allowed to close this toolkit host */
    FRequestAssetEditorClose EditorCloseRequest;

    /** Delegate to be called when this toolkit host is closing */
    FAssetEditorClosing EditorClosing;

    /** The menu extenders to populate the main toolkit host menu with */
    TArray<TSharedPtr<FExtender>> MenuExtenders;
};