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

#pragma once

#include "CoreMinimal.h"
#include "Serialization/ArchiveUObject.h"
#include "Serialization/MemoryWriter.h"
#include "Containers/Queue.h"

/*----------------------------------------------------------------------------
FArchiveObjectCrc32
----------------------------------------------------------------------------*/

/**
 * Calculates a checksum on an object's serialized data stream.
 */
class COREUOBJECT_API FArchiveObjectCrc32: public FArchiveUObject
{
public:
    /**
     * Default constructor.
     */
    FArchiveObjectCrc32();

    //~ Begin FArchive Interface
    virtual void Serialize(void* Data, int64 Length);
    virtual FArchive& operator<<(class FName& Name);
    virtual FArchive& operator<<(class UObject*& Object);
    virtual FString GetArchiveName() const { return TEXT("FArchiveObjectCrc32"); }
    //~ End FArchive Interface

    /**
     * Serialize the given object, calculate and return its checksum.
     */
    uint32 Crc32(UObject* Object, uint32 CRC = 0);

protected:
    /** Return if object was already serialized */
    virtual bool CustomSerialize(class UObject* Object) { return false; }

    /** Internal byte array used for serialization */
    TArray<uint8> SerializedObjectData;
    /** Internal archive used for serialization */
    FMemoryWriter MemoryWriter;
    /** Internal queue of object references awaiting serialization */
    TQueue<UObject*> ObjectsToSerialize;
    /** Internal currently serialized object */
    const UObject* ObjectBeingSerialized;
    /** Internal root object */
    const UObject* RootObject;
};