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

#include "CoreMinimal.h"
#include "Editor.h"
#include "GlobalEditorNotification.h"
#include "ContentStreaming.h"
#include "Widgets/Notifications/SNotificationList.h"

/** Notification class for texture streaming. */
class FTextureStreamingNotificationImpl: public FGlobalEditorNotification
{
protected:
    /** FGlobalEditorNotification interface */
    virtual bool ShouldShowNotification(const bool bIsNotificationAlreadyActive) const override;
    virtual void SetNotificationText(const TSharedPtr<SNotificationItem>& InNotificationItem) const override;

private:
    static int32 GetNumStreamingTextures();
};

/** Global notification object. */
FTextureStreamingNotificationImpl GTextureStreamingNotification;

bool FTextureStreamingNotificationImpl::ShouldShowNotification(const bool bIsNotificationAlreadyActive) const
{
    // We only want to show the notification initially if there's still enough work left to do to warrant it
    // However, if we're already showing the notification, we should continue to do so until all the streaming has finished
    // Never show these notifications during PIE
    const int32 NumStreamingTextures = GetNumStreamingTextures();
    return !GEditor->PlayWorld && ((NumStreamingTextures > 300) || (bIsNotificationAlreadyActive && NumStreamingTextures > 0));
}

void FTextureStreamingNotificationImpl::SetNotificationText(const TSharedPtr<SNotificationItem>& InNotificationItem) const
{
    const int32 NumStreamingTextures = GetNumStreamingTextures();
    if (NumStreamingTextures > 0)
    {
        FFormatNamedArguments Args;
        Args.Add(TEXT("NumTextures"), FText::AsNumber(NumStreamingTextures));
        const FText ProgressMessage = FText::Format(NSLOCTEXT("StreamingTextures", "StreamingTexturesInProgressFormat", "Streaming Textures ({NumTextures})"), Args);

        InNotificationItem->SetText(ProgressMessage);
    }
}

int32 FTextureStreamingNotificationImpl::GetNumStreamingTextures()
{
    FStreamingManagerCollection& StreamingManagerCollection = IStreamingManager::Get();

    if (StreamingManagerCollection.IsTextureStreamingEnabled())
    {
        IRenderAssetStreamingManager& TextureStreamingManager = StreamingManagerCollection.GetTextureStreamingManager();
        return TextureStreamingManager.GetNumWantingResources();
    }

    return 0;
}