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

#pragma once

#include "CoreMinimal.h"
#include "AssetRegistry/AssetDataTagMapSerializationDetails.h"
#include "Serialization/LargeMemoryWriter.h"
#include "UObject/NameBatchSerialization.h"

struct FAssetData;
struct FAssetRegistrySerializationOptions;

/** @see FAssetRegistryWriter */
class FAssetRegistryReader: public FArchiveProxy
{
public:
    /// @param NumWorkers > 0 for parallel loading
    FAssetRegistryReader(FArchive& Inner, int32 NumWorkers = 0);
    ~FAssetRegistryReader();

    virtual FArchive& operator<<(FName& Value) override;

    void SerializeTagsAndBundles(FAssetData& Out);

    void WaitForTasks();

private:
    TArray<FNameEntryId> Names;
    TRefCountPtr<const FixedTagPrivate::FStore> Tags;
    TFuture<void> Task;

    friend FAssetDataTagMapSharedView LoadTags(FAssetRegistryReader& Reader);
};

#if ALLOW_NAME_BATCH_SAVING

class FAssetRegistryWriterBase
{
protected:
    FLargeMemoryWriter MemWriter;
};

struct FAssetRegistryWriterOptions
{
    FAssetRegistryWriterOptions() = default;
    explicit FAssetRegistryWriterOptions(const FAssetRegistrySerializationOptions& Options);

    FixedTagPrivate::FOptions Tags;
};

/**
 * Indexes FName and tag maps and serializes out deduplicated indices instead.
 *
 * Unlike previous FNameTableArchiveWriter:
 * - Name data stored as name batches, which is faster
 * - Name batch is written as a header instead of footer for faster seek-free loading
 * - Numberless FNames are serialized as a single 32-bit int
 * - Deduplicates all tag values, not just names
 *
 * Use in conjunction with FNameBatchReader.
 *
 * Data is written to inner archive in destructor to achieve seek-free loading.
 */
class FAssetRegistryWriter: public FAssetRegistryWriterBase
    , public FArchiveProxy
{
public:
    FAssetRegistryWriter(const FAssetRegistryWriterOptions& Options, FArchive& Out);
    ~FAssetRegistryWriter();

    virtual FArchive& operator<<(FName& Value) override;

    void SerializeTagsAndBundles(const FAssetData& In);

private:
    TMap<FNameEntryId, uint32> Names;
    FixedTagPrivate::FStoreBuilder Tags;
    FArchive& TargetAr;

    friend void SaveTags(FAssetRegistryWriter& Writer, const FAssetDataTagMapSharedView& Map);
};

#endif