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

/*=============================================================================
        AsyncPackage.h: Unreal async loading definitions.
=============================================================================*/

#pragma once

#include "CoreMinimal.h"
#include "UObject/UObjectGlobals.h"
#include "Misc/Guid.h"
#include "Templates/UniquePtr.h"
#include "UObject/LinkerInstancingContext.h"

struct FAsyncPackageDesc
{
    /** Handle for the caller */
    int32 RequestID;
    /** Name of the UPackage to create. */
    FName Name;
    /** Name of the package to load. */
    FName NameToLoad;
    /** GUID of the package to load, or the zeroed invalid GUID for "don't care" */
    FGuid Guid;
    /** Delegate called on completion of loading. This delegate can only be created and consumed on the game thread */
    TUniquePtr<FLoadPackageAsyncDelegate> PackageLoadedDelegate;
    /** The flags that should be applied to the package */
    EPackageFlags PackageFlags;
    /** Package loading priority. Higher number is higher priority. */
    TAsyncLoadPriority Priority;
    /** PIE instance ID this package belongs to, INDEX_NONE otherwise */
    int32 PIEInstanceID;

#if WITH_EDITORONLY_DATA
    /** Instancing context, maps original package to their instanced counterpart, used to remap imports. */
    FLinkerInstancingContext InstancingContext;

    const FLinkerInstancingContext* GetInstancingContext() const { return &InstancingContext; }
    void SetInstancingContext(FLinkerInstancingContext InInstancingContext) { InstancingContext = MoveTemp(InInstancingContext); }
#else
    const FLinkerInstancingContext* GetInstancingContext() const { return nullptr; }
    void SetInstancingContext(FLinkerInstancingContext) {}
#endif

    FAsyncPackageDesc(int32 InRequestID, const FName& InName, FName InPackageToLoadFrom = NAME_None, const FGuid& InGuid = FGuid(), TUniquePtr<FLoadPackageAsyncDelegate>&& InCompletionDelegate = TUniquePtr<FLoadPackageAsyncDelegate>(), EPackageFlags InPackageFlags = PKG_None, int32 InPIEInstanceID = INDEX_NONE, TAsyncLoadPriority InPriority = 0)
        : RequestID(InRequestID), Name(InName), NameToLoad(InPackageToLoadFrom), Guid(InGuid), PackageLoadedDelegate(MoveTemp(InCompletionDelegate)), PackageFlags(InPackageFlags), Priority(InPriority), PIEInstanceID(InPIEInstanceID)
    {
        if (NameToLoad == NAME_None)
        {
            NameToLoad = Name;
        }
    }

    /** This constructor does not modify the package loaded delegate as this is not safe outside the game thread */
    FAsyncPackageDesc(const FAsyncPackageDesc& OldPackage)
        : RequestID(OldPackage.RequestID), Name(OldPackage.Name), NameToLoad(OldPackage.NameToLoad), Guid(OldPackage.Guid), PackageFlags(OldPackage.PackageFlags), Priority(OldPackage.Priority), PIEInstanceID(OldPackage.PIEInstanceID)
#if WITH_EDITORONLY_DATA
          ,
          InstancingContext(OldPackage.InstancingContext)
#endif
    {
    }

    /** This constructor will explicitly copy the package loaded delegate and invalidate the old one */
    FAsyncPackageDesc(const FAsyncPackageDesc& OldPackage, TUniquePtr<FLoadPackageAsyncDelegate>&& InPackageLoadedDelegate)
        : FAsyncPackageDesc(OldPackage)
    {
        PackageLoadedDelegate = MoveTemp(InPackageLoadedDelegate);
    }

#if DO_GUARD_SLOW
    ~FAsyncPackageDesc()
    {
        checkSlow(!PackageLoadedDelegate.IsValid() || IsInGameThread());
    }
#endif
};