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


#pragma once

#include "CoreMinimal.h"
#include "AssetRegistry/AssetData.h"
#include "Modules/ModuleInterface.h"
#include "ContentBrowserDelegates.h"

class IContentBrowserSingleton;
struct FARFilter;
class FMainMRUFavoritesList;
class FContentBrowserPluginFilter;


/** Extra state generator that adds an icon and a corresponding legend entry on an asset. */
class FAssetViewExtraStateGenerator
{
public:
	FAssetViewExtraStateGenerator(FOnGenerateAssetViewExtraStateIndicators InIconGenerator, FOnGenerateAssetViewExtraStateIndicators InToolTipGenerator)
		: IconGenerator(MoveTemp(InIconGenerator))
		, ToolTipGenerator(MoveTemp(InToolTipGenerator))
		, Handle(FDelegateHandle::GenerateNewHandle)
	{}

	/** Delegate called to generate an extra icon on an asset view. */
	FOnGenerateAssetViewExtraStateIndicators IconGenerator;
	
	/** Delegate called to generate an extra tooltip on an asset view. */
	FOnGenerateAssetViewExtraStateIndicators ToolTipGenerator;

private:
	/** The handle to this extra state generator. */
	FDelegateHandle Handle;

	friend class FContentBrowserModule;
};

/**
 * Content browser module
 */
class FContentBrowserModule : public IModuleInterface
{

public:

	/**  */
	DECLARE_MULTICAST_DELEGATE_TwoParams( FOnFilterChanged, const FARFilter& /*NewFilter*/, bool /*bIsPrimaryBrowser*/ );
	/** */
	DECLARE_MULTICAST_DELEGATE_TwoParams( FOnSearchBoxChanged, const FText& /*InSearchText*/, bool /*bIsPrimaryBrowser*/ );
	/** */
	DECLARE_MULTICAST_DELEGATE_TwoParams( FOnAssetSelectionChanged, const TArray<FAssetData>& /*NewSelectedAssets*/, bool /*bIsPrimaryBrowser*/ );
	/** */
	DECLARE_MULTICAST_DELEGATE_OneParam( FOnSourcesViewChanged, bool /*bExpanded*/ );
	/** */
	DECLARE_MULTICAST_DELEGATE_OneParam( FOnAssetPathChanged, const FString& /*NewPath*/ );
	/** */
	DECLARE_DELEGATE_OneParam( FAddPathViewPluginFilters, TArray<TSharedRef<FContentBrowserPluginFilter>>& /*Filters*/ );
	/** */
	DECLARE_MULTICAST_DELEGATE_OneParam( FOnContentBrowserSettingChanged, FName /*PropertyName*/);
	/** */
	DECLARE_DELEGATE_OneParam( FDefaultSelectedPathsDelegate, TArray<FName>& /*VirtualPaths*/ );
	/** */
	DECLARE_DELEGATE_OneParam( FDefaultPathsToExpandDelegate, TArray<FName>& /*VirtualPaths*/ );

	/**
	 * Called right after the plugin DLL has been loaded and the plugin object has been created
	 */
	virtual void StartupModule();

	/**
	 * Called before the plugin is unloaded, right before the plugin object is destroyed.
	 */
	virtual void ShutdownModule();

	/** Gets the content browser singleton */
	virtual IContentBrowserSingleton& Get() const;

	/**
	 * Add a generator to add extra state functionality to the content browser's assets.
	 * @param Generator the delegates that add functionality. 
	 * @return FDelegateHandle the handle to the extra state generator.
	 */
	virtual FDelegateHandle AddAssetViewExtraStateGenerator(const FAssetViewExtraStateGenerator& Generator);

	/**
	 * Remove an asset view extra state generator.
	 * @param GeneratorHandle the extra state generator's handle.
	 */
	virtual void RemoveAssetViewExtraStateGenerator(const FDelegateHandle& GeneratorHandle);

	/** Delegates to be called to extend the content browser menus */
	virtual TArray<FContentBrowserMenuExtender_SelectedPaths>& GetAllAssetContextMenuExtenders() {return AssetContextMenuExtenders;}
	virtual TArray<FContentBrowserMenuExtender_SelectedPaths>& GetAllPathViewContextMenuExtenders() {return PathViewContextMenuExtenders;}
	virtual TArray<FContentBrowserMenuExtender>& GetAllCollectionListContextMenuExtenders() {return CollectionListContextMenuExtenders;}
	virtual TArray<FContentBrowserMenuExtender>& GetAllCollectionViewContextMenuExtenders() {return CollectionViewContextMenuExtenders;}
	virtual TArray<FContentBrowserMenuExtender_SelectedAssets>& GetAllAssetViewContextMenuExtenders() {return AssetViewContextMenuExtenders;}
	virtual TArray<FContentBrowserMenuExtender>& GetAllAssetViewViewMenuExtenders() {return AssetViewViewMenuExtenders;}

	/** Delegates to call to extend the command/keybinds for content browser */
	virtual TArray<FContentBrowserCommandExtender>& GetAllContentBrowserCommandExtenders() { return ContentBrowserCommandExtenders; }

	/** Delegates to be called to add extra state indicators on the asset view */
	virtual const TArray<FAssetViewExtraStateGenerator>& GetAllAssetViewExtraStateGenerators() { return AssetViewExtraStateGenerators; }

	/** Delegates to be called to extend the drag-and-drop support of the asset view */
	virtual TArray<FAssetViewDragAndDropExtender>& GetAssetViewDragAndDropExtenders() { return AssetViewDragAndDropExtenders; }

	/** Delegates to be called to extend list of content browser Plugin Filters*/
	virtual TArray<FAddPathViewPluginFilters>& GetAddPathViewPluginFilters() { return PathViewPluginFilters; }

	/** Delegate accessors */
	FOnFilterChanged& GetOnFilterChanged() { return OnFilterChanged; } 
	FOnSearchBoxChanged& GetOnSearchBoxChanged() { return OnSearchBoxChanged; } 
	FOnAssetSelectionChanged& GetOnAssetSelectionChanged() { return OnAssetSelectionChanged; } 
	FOnSourcesViewChanged& GetOnSourcesViewChanged() { return OnSourcesViewChanged; }
	FOnAssetPathChanged& GetOnAssetPathChanged() { return OnAssetPathChanged; }
	FOnContentBrowserSettingChanged& GetOnContentBrowserSettingChanged() { return OnContentBrowserSettingChanged; }

	/** Override list of paths to select by default */
	FDefaultSelectedPathsDelegate& GetDefaultSelectedPathsDelegate() { return DefaultSelectedPathsDelegate; }

	/** Override list of paths to expand by default */
	FDefaultPathsToExpandDelegate& GetDefaultPathsToExpandDelegate() { return DefaultPathsToExpandDelegate; }

	FMainMRUFavoritesList* GetRecentlyOpenedAssets() const
	{
		return RecentlyOpenedAssets.Get();
	};

	static const FName NumberOfRecentAssetsName;

	void AddDynamicTagAssetClass(const FName& InName) 
	{
		AssetClassesRequiringDynamicTags.AddUnique(InName);
	}


	void RemoveDynamicTagAssetClass(const FName& InName)
	{
		AssetClassesRequiringDynamicTags.Remove(InName);
	}
		
	bool IsDynamicTagAssetClass(const FName& InName)
	{
		return AssetClassesRequiringDynamicTags.Contains(InName);
	}
	
	

private:
	/** Handle changes to content browser settings */
	void ContentBrowserSettingChanged(FName InName);
	
	/** List of asset classes whose tags are dynamic and therefore we should union all asset's tags rather than grabbing the first available. */
	TArray<FName> AssetClassesRequiringDynamicTags;

private:
	IContentBrowserSingleton* ContentBrowserSingleton;
	TSharedPtr<class FContentBrowserSpawner> ContentBrowserSpawner;
	
	/** All extender delegates for the content browser menus */
	TArray<FContentBrowserMenuExtender_SelectedPaths> AssetContextMenuExtenders;
	TArray<FContentBrowserMenuExtender_SelectedPaths> PathViewContextMenuExtenders;
	TArray<FContentBrowserMenuExtender> CollectionListContextMenuExtenders;
	TArray<FContentBrowserMenuExtender> CollectionViewContextMenuExtenders;
	TArray<FContentBrowserMenuExtender_SelectedAssets> AssetViewContextMenuExtenders;
	TArray<FContentBrowserMenuExtender> AssetViewViewMenuExtenders;
	TArray<FContentBrowserCommandExtender> ContentBrowserCommandExtenders;

	/** All delegates generating extra state indicators */
	TArray<FAssetViewExtraStateGenerator> AssetViewExtraStateGenerators;

	/** All extender delegates for the drag-and-drop support of the asset view */
	TArray<FAssetViewDragAndDropExtender> AssetViewDragAndDropExtenders;

	/** All delegates that extend available path view plugin filters */
	TArray<FAddPathViewPluginFilters> PathViewPluginFilters;

	TUniquePtr<FMainMRUFavoritesList> RecentlyOpenedAssets;

	FOnFilterChanged OnFilterChanged;
	FOnSearchBoxChanged OnSearchBoxChanged;
	FOnAssetSelectionChanged OnAssetSelectionChanged;
	FOnSourcesViewChanged OnSourcesViewChanged;
	FOnAssetPathChanged OnAssetPathChanged;
	FOnContentBrowserSettingChanged OnContentBrowserSettingChanged;

	FDefaultSelectedPathsDelegate DefaultSelectedPathsDelegate;
	FDefaultPathsToExpandDelegate DefaultPathsToExpandDelegate;
};