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

#pragma once

#include "CoreMinimal.h"
#include "Serialization/ArchiveUObject.h"
#include "Serialization/FileRegions.h"
#include "UObject/ObjectResource.h"
#include "UObject/Linker.h"
#include "UObject/UObjectThreadContext.h"
#include "Templates/RefCounting.h"

struct FUntypedBulkData;

/*----------------------------------------------------------------------------
        FLinkerSave.
----------------------------------------------------------------------------*/

/**
 * Handles saving Unreal package files.
 */
class FLinkerSave: public FLinker
    , public FArchiveUObject
{
public:
    FORCEINLINE static ELinkerType::Type StaticType()
    {
        return ELinkerType::Save;
    }

    virtual ~FLinkerSave();

    // Variables.
    /** The archive that actually writes the data to disk. */
    FArchive* Saver;

    FPackageIndex CurrentlySavingExport;
    TArray<FPackageIndex> DepListForErrorChecking;

    /** Index array - location of the resource for a UObject is stored in the ObjectIndices array using the UObject's Index */
    TMap<UObject*, FPackageIndex> ObjectIndicesMap;

    /** List of Searchable Names, by object containing them. This gets turned into package indices later */
    TMap<const UObject*, TArray<FName>> SearchableNamesObjectMap;

    /** Index array - location of the name in the NameMap array for each FName is stored in the NameIndices array using the FName's Index */
    TMap<FNameEntryId, int32> NameIndices;

    /** Save context associated with this linker */
    TRefCountPtr<FUObjectSerializeContext> SaveContext;

    /** List of bulkdata that needs to be stored at the end of the file */
    struct FBulkDataStorageInfo
    {
        /** Offset to the location where the payload offset is stored */
        int64 BulkDataOffsetInFilePos;
        /** Offset to the location where the payload size is stored */
        int64 BulkDataSizeOnDiskPos;
        /** Offset to the location where the bulk data flags are stored */
        int64 BulkDataFlagsPos;
        /** Bulk data flags at the time of serialization */
        uint32 BulkDataFlags;
        /** The file region type to apply to this bulk data */
        EFileRegionType BulkDataFileRegionType;
        /** The bulkdata */
        FUntypedBulkData* BulkData;
    };
    TArray<FBulkDataStorageInfo> BulkDataToAppend;
    TArray<FFileRegion> FileRegions;

    /** A mapping of package name to generated script SHA keys */
    COREUOBJECT_API static TMap<FString, TArray<uint8>> PackagesToScriptSHAMap;

    /** Constructor for file writer */
    FLinkerSave(UPackage* InParent, const TCHAR* InFilename, bool bForceByteSwapping, bool bInSaveUnversioned = false);
    /** Constructor for memory writer */
    FLinkerSave(UPackage* InParent, bool bForceByteSwapping, bool bInSaveUnversioned = false);
    /** Constructor for custom savers. The linker assumes ownership of the custom saver. */
    FLinkerSave(UPackage* InParent, FArchive* InSaver, bool bForceByteSwapping, bool bInSaveUnversioned = false);

    /** Returns the appropriate name index for the source name, or 0 if not found in NameIndices */
    int32 MapName(FNameEntryId Name) const;

    /** Returns the appropriate package index for the source object, or default value if not found in ObjectIndicesMap */
    FPackageIndex MapObject(const UObject* Object) const;

    // FArchive interface.
    using FArchiveUObject::operator<<;  // For visibility of the overloads we don't override
    FArchive& operator<<(FName& InName);
    FArchive& operator<<(UObject*& Obj);
    FArchive& operator<<(FLazyObjectPtr& LazyObjectPtr);
    virtual void SetSerializeContext(FUObjectSerializeContext* InLoadContext) override;
    FUObjectSerializeContext* GetSerializeContext() override;
    virtual void UsingCustomVersion(const struct FGuid& Guid) override;

#if WITH_EDITOR
    // proxy for debugdata
    virtual void PushDebugDataString(const FName& DebugData) override { Saver->PushDebugDataString(DebugData); }
    virtual void PopDebugDataString() override { Saver->PopDebugDataString(); }
#endif

    virtual FString GetArchiveName() const override;

    /**
     * If this archive is a FLinkerLoad or FLinkerSave, returns a pointer to the FLinker portion.
     */
    virtual FLinker* GetLinker() { return this; }

    void Seek(int64 InPos);
    int64 Tell();
    // this fixes the warning : 'FLinkerSave::Serialize' hides overloaded virtual function
    using FLinker::Serialize;
    void Serialize(void* V, int64 Length);

    /**
     * Closes and deletes the Saver (file, memory or custom writer) which will close any associated file handle.
     * Returns false if the owned saver contains errors after closing it, true otherwise.
     */
    bool CloseAndDestroySaver();

    /**
     * Sets a flag indicating that this archive contains data required to be gathered for localization.
     */
    void ThisRequiresLocalizationGather();
};