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

#include "Serialization/ArchiveShowReferences.h"
#include "Templates/Casts.h"

/*----------------------------------------------------------------------------
        FArchiveShowReferences.
----------------------------------------------------------------------------*/
/**
 * Constructor
 *
 * @param	inOutputAr		archive to use for logging results
 * @param	LimitOuter		only consider objects that have this object as its Outer
 * @param	inTarget		object to show referencers to
 * @param	inExclude		list of objects that should be ignored if encountered while serializing Target
 */
FArchiveShowReferences::FArchiveShowReferences(FOutputDevice& inOutputAr, UObject* inOuter, UObject* inSource, TArray<UObject*>& inExclude)
    : SourceObject(inSource), SourceOuter(inOuter), OutputAr(inOutputAr), Exclude(inExclude), DidRef(false)
{
    ArIsObjectReferenceCollector = true;

    // there are several types of objects we don't want listed, for different reasons.
    // Prevent them from being logged by adding them to our Found list before we start
    // serialization, so that they won't be listed

    // quick sanity check
    check(SourceObject);
    check(SourceObject->IsValidLowLevel());

    // every object we serialize obviously references our package
    Found.AddUnique(SourceOuter);

    // every object we serialize obviously references its class and its class's parent classes
    for (UClass* ObjectClass = SourceObject->GetClass(); ObjectClass; ObjectClass = ObjectClass->GetSuperClass())
    {
        Found.AddUnique(ObjectClass);
    }

    // similarly, if the object is a class, they all obviously reference their parent classes
    if (UClass* SourceObjectClass = dynamic_cast<UClass*>(SourceObject))
    {
        for (UClass* ParentClass = SourceObjectClass->GetSuperClass(); ParentClass; ParentClass = ParentClass->GetSuperClass())
        {
            Found.AddUnique(ParentClass);
        }
    }

    // OK, now we're all set to go - let's see what Target is referencing.
    SourceObject->Serialize(*this);
}

FArchive& FArchiveShowReferences::operator<<(UObject*& Obj)
{
    if (Obj && Obj->GetOuter() != SourceOuter)
    {
        int32 i;
        for (i = 0; i < Exclude.Num(); i++)
        {
            if (Exclude[i] == Obj->GetOuter())
            {
                break;
            }
        }

        if (i == Exclude.Num())
        {
            if (!DidRef)
            {
                OutputAr.Logf(TEXT("   %s references:"), *Obj->GetFullName());
            }

            OutputAr.Logf(TEXT("      %s"), *Obj->GetFullName());

            DidRef = 1;
        }
    }
    return *this;
}