// Copyright 1998-2015 Epic Games, Inc. All Rights Reserved.

#include "UnrealEd.h"

#include "BlueprintGraphDefinitions.h"
#include "ClassIconFinder.h"
#include "ComponentAssetBroker.h"
#include "ComponentTypeRegistry.h"
#include "EditorClassUtils.h"
#include "Engine/Selection.h"
#include "IDocumentation.h"
#include "KismetEditorUtilities.h"
#include "SComponentClassCombo.h"
#include "SlateBasics.h"
#include "SListViewSelectorDropdownMenu.h"
#include "SSearchBox.h"

#define LOCTEXT_NAMESPACE "ComponentClassCombo"

FString FComponentClassComboEntry::GetClassName() const
{
	return ComponentClass != nullptr ? ComponentClass->GetDisplayNameText().ToString() : ComponentName;
}

void SComponentClassCombo::Construct(const FArguments& InArgs)
{
	PrevSelectedIndex = INDEX_NONE;
	OnComponentClassSelected = InArgs._OnComponentClassSelected;

	FComponentTypeRegistry::Get().SubscribeToComponentList(ComponentClassList).AddRaw(this, &SComponentClassCombo::UpdateComponentClassList);

	UpdateComponentClassList();

	SAssignNew(ComponentClassListView, SListView<FComponentClassComboEntryPtr>)
		.ListItemsSource(&FilteredComponentClassList)
		.OnSelectionChanged( this, &SComponentClassCombo::OnAddComponentSelectionChanged )
		.OnGenerateRow( this, &SComponentClassCombo::GenerateAddComponentRow )
		.SelectionMode(ESelectionMode::Single);

	SAssignNew(SearchBox, SSearchBox)
		.HintText( LOCTEXT( "BlueprintAddComponentSearchBoxHint", "Search Components" ) )
		.OnTextChanged( this, &SComponentClassCombo::OnSearchBoxTextChanged )
		.OnTextCommitted( this, &SComponentClassCombo::OnSearchBoxTextCommitted );

	// Create the Construct arguments for the parent class (SComboButton)
	SComboButton::FArguments Args;
	Args.ButtonContent()
	[
		SNew(SHorizontalBox)
		+SHorizontalBox::Slot()
		.VAlign(VAlign_Center)
		.AutoWidth()
		.Padding(1.f,1.f)
		[
			SNew(STextBlock)
			.TextStyle(FEditorStyle::Get(), "ContentBrowser.TopBar.Font")
			.Font(FEditorStyle::Get().GetFontStyle("FontAwesome.10"))
			.Text(FText::FromString(FString(TEXT("\xf067"))) /*fa-plus*/)
		]
		+ SHorizontalBox::Slot()
		.VAlign(VAlign_Center)
		.Padding(1.f)
		[
			SNew(STextBlock)
			.Text(LOCTEXT("AddComponentButtonLabel", "Add Component"))
			.TextStyle(FEditorStyle::Get(), "ContentBrowser.TopBar.Font")
			.Visibility(InArgs._IncludeText.Get() ? EVisibility::Visible : EVisibility::Collapsed)
		]
	]
	.MenuContent()
	[

		SNew(SListViewSelectorDropdownMenu<FComponentClassComboEntryPtr>, SearchBox, ComponentClassListView)
		[
			SNew(SBorder)
			.BorderImage(FEditorStyle::GetBrush("Menu.Background"))
			.Padding(2)
			[
				SNew(SBox)
				.WidthOverride(250)
				[				
					SNew(SVerticalBox)
					+SVerticalBox::Slot()
					.Padding(1.f)
					.AutoHeight()
					[
						SearchBox.ToSharedRef()
					]
					+SVerticalBox::Slot()
					.MaxHeight(400)
					[
						ComponentClassListView.ToSharedRef()
					]
				]
			]
		]
	]
	.IsFocusable(true)
	.ContentPadding(FMargin(5, 0))
	.ComboButtonStyle(FEditorStyle::Get(), "ToolbarComboButton")
	.ButtonStyle(FEditorStyle::Get(), "FlatButton.Success")
	.ForegroundColor(FLinearColor::White)
	.OnComboBoxOpened(this, &SComponentClassCombo::ClearSelection);

	SComboButton::Construct(Args);

	ComponentClassListView->EnableToolTipForceField( true );
	// The base class can automatically handle setting focus to a specified control when the combo button is opened
	SetMenuContentWidgetToFocus( SearchBox );
}

SComponentClassCombo::~SComponentClassCombo()
{
	FComponentTypeRegistry::Get().GetOnComponentTypeListChanged().RemoveAll(this);
}

void SComponentClassCombo::ClearSelection()
{
	SearchBox->SetText(FText::GetEmpty());

	PrevSelectedIndex = INDEX_NONE;
	
	// Clear the selection in such a way as to also clear the keyboard selector
	ComponentClassListView->SetSelection(NULL, ESelectInfo::OnNavigation);

	// Make sure we scroll to the top
	if (ComponentClassList->Num() > 0)
	{
		ComponentClassListView->RequestScrollIntoView((*ComponentClassList)[0]);
	}
}

void SComponentClassCombo::GenerateFilteredComponentList(const FString& InSearchText)
{
	if ( InSearchText.IsEmpty() )
	{
		FilteredComponentClassList = *ComponentClassList;
	}
	else
	{
		FilteredComponentClassList.Empty();

		int32 LastHeadingIndex = INDEX_NONE;
		FComponentClassComboEntryPtr* LastHeadingPtr = nullptr;

		for (int32 ComponentIndex = 0; ComponentIndex < ComponentClassList->Num(); ComponentIndex++)
		{
			FComponentClassComboEntryPtr& CurrentEntry = (*ComponentClassList)[ComponentIndex];

			if (CurrentEntry->IsHeading())
			{
				LastHeadingIndex = FilteredComponentClassList.Num();
				LastHeadingPtr = &CurrentEntry;
			}
			else if (CurrentEntry->IsClass() && CurrentEntry->IsIncludedInFilter())
			{
				FString FriendlyComponentName = GetSanitizedComponentName( CurrentEntry );

				if ( FriendlyComponentName.Contains( InSearchText, ESearchCase::IgnoreCase ) )
				{
					// Add the heading first if it hasn't already been added
					if (LastHeadingIndex != INDEX_NONE)
					{
						FilteredComponentClassList.Insert(*LastHeadingPtr, LastHeadingIndex);
						LastHeadingIndex = INDEX_NONE;
						LastHeadingPtr = nullptr;
					}

					// Add the class
					FilteredComponentClassList.Add( CurrentEntry );
				}
			}
		}

		// Select the first non-category item that passed the filter
		for (FComponentClassComboEntryPtr& TestEntry : FilteredComponentClassList)
		{
			if (TestEntry->IsClass())
			{
				ComponentClassListView->SetSelection(TestEntry, ESelectInfo::OnNavigation);
				break;
			}
		}
	}
}

FText SComponentClassCombo::GetCurrentSearchString() const
{
	return CurrentSearchString;
}

void SComponentClassCombo::OnSearchBoxTextChanged( const FText& InSearchText )
{
	CurrentSearchString = InSearchText;

	// Generate a filtered list
	GenerateFilteredComponentList(CurrentSearchString.ToString());

	// Ask the combo to update its contents on next tick
	ComponentClassListView->RequestListRefresh();
}

void SComponentClassCombo::OnSearchBoxTextCommitted(const FText& NewText, ETextCommit::Type CommitInfo)
{
	if(CommitInfo == ETextCommit::OnEnter)
	{
		auto SelectedItems = ComponentClassListView->GetSelectedItems();
		if(SelectedItems.Num() > 0)
		{
			ComponentClassListView->SetSelection(SelectedItems[0]);
		}
	}
}

// @todo: move this to FKismetEditorUtilities
static UClass* GetAuthoritativeBlueprintClass(UBlueprint const* const Blueprint)
{
	UClass* BpClass = (Blueprint->SkeletonGeneratedClass != nullptr) ? Blueprint->SkeletonGeneratedClass :
		Blueprint->GeneratedClass;

	if (BpClass == nullptr)
	{
		BpClass = Blueprint->ParentClass;
	}

	UClass* AuthoritativeClass = BpClass;
	if (BpClass != nullptr)
	{
		AuthoritativeClass = BpClass->GetAuthoritativeClass();
	}
	return AuthoritativeClass;
}

void SComponentClassCombo::OnAddComponentSelectionChanged( FComponentClassComboEntryPtr InItem, ESelectInfo::Type SelectInfo )
{
	if ( InItem.IsValid() && InItem->IsClass() && SelectInfo != ESelectInfo::OnNavigation)
	{
		// We don't want the item to remain selected
		ClearSelection();

		if ( InItem->IsClass() )
		{
			// Neither do we want the combo dropdown staying open once the user has clicked on a valid option
			SetIsOpen(false, false);

			if( OnComponentClassSelected.IsBound() )
			{
				UClass* ComponentClass = InItem->GetComponentClass();
				if (ComponentClass == nullptr)
				{
					// The class is not loaded yet, so load it:
					const ELoadFlags LoadFlags = LOAD_None;
					UBlueprint* LoadedObject = LoadObject<UBlueprint>(NULL, *InItem->GetComponentPath(), NULL, LoadFlags, NULL);
					ComponentClass = GetAuthoritativeBlueprintClass(LoadedObject);
				}

				UActorComponent* NewActorComponent = OnComponentClassSelected.Execute(ComponentClass, InItem->GetComponentCreateAction(), InItem->GetAssetOverride());
				if(NewActorComponent)
				{
					InItem->GetOnComponentCreated().ExecuteIfBound(NewActorComponent);
				}
			}
		}
	}
	else if ( InItem.IsValid() && SelectInfo != ESelectInfo::OnMouseClick )
	{
		int32 SelectedIdx = INDEX_NONE;
		if (FilteredComponentClassList.Find(InItem, /*out*/ SelectedIdx))
		{
			if (!InItem->IsClass())
			{
				int32 SelectionDirection = SelectedIdx - PrevSelectedIndex;

				// Update the previous selected index
				PrevSelectedIndex = SelectedIdx;

				// Make sure we select past the category header if we started filtering with it selected somehow (avoiding the infinite loop selecting the same item forever)
				if (SelectionDirection == 0)
				{
					SelectionDirection = 1;
				}

				if(SelectedIdx + SelectionDirection >= 0 && SelectedIdx + SelectionDirection < FilteredComponentClassList.Num())
				{
					ComponentClassListView->SetSelection(FilteredComponentClassList[SelectedIdx + SelectionDirection], ESelectInfo::OnNavigation);
				}
			}
			else
			{
				// Update the previous selected index
				PrevSelectedIndex = SelectedIdx;
			}
		}
	}
}

TSharedRef<ITableRow> SComponentClassCombo::GenerateAddComponentRow( FComponentClassComboEntryPtr Entry, const TSharedRef<STableViewBase> &OwnerTable ) const
{
	check( Entry->IsHeading() || Entry->IsSeparator() || Entry->IsClass() );

	if ( Entry->IsHeading() )
	{
		return 
			SNew( STableRow< TSharedPtr<FString> >, OwnerTable )
				.Style(&FEditorStyle::Get().GetWidgetStyle<FTableRowStyle>("TableView.NoHoverTableRow"))
				.ShowSelection(false)
			[
				SNew(SBox)
				.Padding(1.f)
				[
					SNew(STextBlock)
					.Text(FText::FromString(Entry->GetHeadingText()))
					.TextStyle(FEditorStyle::Get(), TEXT("Menu.Heading"))
				]
			];
	}
	else if ( Entry->IsSeparator() )
	{
		return 
			SNew( STableRow< TSharedPtr<FString> >, OwnerTable )
				.Style(&FEditorStyle::Get().GetWidgetStyle<FTableRowStyle>("TableView.NoHoverTableRow"))
				.ShowSelection(false)
			[
				SNew(SBox)
				.Padding(1.f)
				[
					SNew(SBorder)
					.Padding(FEditorStyle::GetMargin(TEXT("Menu.Separator.Padding")))
					.BorderImage(FEditorStyle::GetBrush(TEXT("Menu.Separator")))
				]
			];
	}
	else
	{
		
		return
			SNew( SComboRow< TSharedPtr<FString> >, OwnerTable )
			.ToolTip( GetComponentToolTip(Entry) )
			[
				SNew(SHorizontalBox)
				+SHorizontalBox::Slot()
				.AutoWidth()
				.VAlign(VAlign_Center)
				[
					SNew(SSpacer)
					.Size(FVector2D(8.0f,1.0f))
				]
				+SHorizontalBox::Slot()
				.Padding(1.0f)
				.AutoWidth()
				[
					SNew(SImage)
					.Image( FClassIconFinder::FindIconForClass( Entry->GetIconOverrideBrushName() == NAME_None ? Entry->GetIconClass() : nullptr, Entry->GetIconOverrideBrushName() ) )
				]
				+SHorizontalBox::Slot()
				.AutoWidth()
				.VAlign(VAlign_Center)
				[
					SNew(SSpacer)
					.Size(FVector2D(3.0f,1.0f))
				]
				+SHorizontalBox::Slot()
				.AutoWidth()
				.VAlign(VAlign_Center)
				[
					SNew(STextBlock)
					.HighlightText(this, &SComponentClassCombo::GetCurrentSearchString)
					.Text(this, &SComponentClassCombo::GetFriendlyComponentName, Entry)
				]
			];
	}
}

void SComponentClassCombo::UpdateComponentClassList()
{
	GenerateFilteredComponentList(CurrentSearchString.ToString());
}

FText SComponentClassCombo::GetFriendlyComponentName(FComponentClassComboEntryPtr Entry) const
{
	// Get a user friendly string from the component name
	FString FriendlyComponentName;

	if( Entry->GetComponentCreateAction() == EComponentCreateAction::CreateNewCPPClass )
	{
		FriendlyComponentName = LOCTEXT("NewCPPComponentFriendlyName", "New C++ Component...").ToString();
	}
	else if (Entry->GetComponentCreateAction() == EComponentCreateAction::CreateNewBlueprintClass )
	{
		FriendlyComponentName = LOCTEXT("NewBlueprintComponentFriendlyName", "New Blueprint Script Component...").ToString();
	}
	else
	{
		FriendlyComponentName = GetSanitizedComponentName(Entry);

		// Don't try to match up assets for USceneComponent it will match lots of things and doesn't have any nice behavior for asset adds 
		if (Entry->GetComponentClass() != USceneComponent::StaticClass() && Entry->GetComponentNameOverride().IsEmpty())
		{
			// Search the selected assets and look for any that can be used as a source asset for this type of component
			// If there is one we append the asset name to the component name, if there are many we append "Multiple Assets"
			FString AssetName;
			UObject* PreviousMatchingAsset = NULL;

			FEditorDelegates::LoadSelectedAssetsIfNeeded.Broadcast();
			USelection* Selection = GEditor->GetSelectedObjects();
			for(FSelectionIterator ObjectIter(*Selection); ObjectIter; ++ObjectIter)
			{
				UObject* Object = *ObjectIter;
				UClass* Class = Object->GetClass();

				TArray<TSubclassOf<UActorComponent> > ComponentClasses = FComponentAssetBrokerage::GetComponentsForAsset(Object);
				for(int32 ComponentIndex = 0; ComponentIndex < ComponentClasses.Num(); ComponentIndex++)
				{
					if(ComponentClasses[ComponentIndex]->IsChildOf(Entry->GetComponentClass()))
					{
						if(AssetName.IsEmpty())
						{
							// If there is no previous asset then we just accept the name
							AssetName = Object->GetName();
							PreviousMatchingAsset = Object;
						}
						else
						{
							// if there is a previous asset then check that we didn't just find multiple appropriate components
							// in a single asset - if the asset differs then we don't display the name, just "Multiple Assets"
							if(PreviousMatchingAsset != Object)
							{
								AssetName = LOCTEXT("MultipleAssetsForComponentAnnotation", "Multiple Assets").ToString();
								PreviousMatchingAsset = Object;
							}
						}
					}
				}
			}

			if(!AssetName.IsEmpty())
			{
				FriendlyComponentName += FString(" (") + AssetName + FString(")");
			}
		}
	}
	return FText::FromString(FriendlyComponentName);
}

FString SComponentClassCombo::GetSanitizedComponentName(FComponentClassComboEntryPtr Entry)
{
	FString DisplayName;
	if (Entry->GetComponentNameOverride() != FString())
	{
		DisplayName = Entry->GetComponentNameOverride();
	}
	else if (UClass* ComponentClass = Entry->GetComponentClass())
	{
		if (ComponentClass->HasMetaData(TEXT("DisplayName")))
		{
			DisplayName = ComponentClass->GetMetaData(TEXT("DisplayName"));
		}
		else
		{
			DisplayName = ComponentClass->GetDisplayNameText().ToString();
			if (!ComponentClass->HasAnyClassFlags(CLASS_CompiledFromBlueprint))
			{
				DisplayName.RemoveFromEnd(TEXT("Component"), ESearchCase::IgnoreCase);
			}
		}
	}
	else
	{
		DisplayName = Entry->GetClassName();
	}
	return FName::NameToDisplayString(DisplayName, false);
}

TSharedRef<SToolTip> SComponentClassCombo::GetComponentToolTip(FComponentClassComboEntryPtr Entry) const
{
	// Special handling for the "New..." options
	if (Entry->GetComponentCreateAction() == EComponentCreateAction::CreateNewCPPClass)
	{
		return SNew(SToolTip)
			.Text(LOCTEXT("NewCPPComponentToolTip", "Create a custom actor component using C++"));
	}
	else if (Entry->GetComponentCreateAction() == EComponentCreateAction::CreateNewBlueprintClass)
	{
		return SNew(SToolTip)
			.Text(LOCTEXT("NewBlueprintComponentToolTip", "Create a custom actor component using Blueprints"));
	}
	
	// Handle components which have a currently loaded class
	if (const UClass* ComponentClass = Entry->GetComponentClass())
	{
		return FEditorClassUtils::GetTooltip(ComponentClass);
	}

	// Fallback for components that don't currently have a loaded class
	return SNew(SToolTip)
		.Text(FText::FromString(Entry->GetClassName()));
}

#undef LOCTEXT_NAMESPACE