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

#pragma once

#include "CoreMinimal.h"
#include "Misc/Guid.h"
#include "Serialization/CustomVersion.h"
#include "Misc/EngineVersion.h"
#include "Serialization/StructuredArchive.h"

struct FCompressedChunk;

/*----------------------------------------------------------------------------
        Items stored in Unrealfiles.
----------------------------------------------------------------------------*/

/**
 * Revision data for an Unreal package file.
 */
//@todo: shouldn't need ExportCount/NameCount with the linker free package map; if so, clean this stuff up
struct FGenerationInfo
{
    /**
     * Number of exports in the linker's ExportMap for this generation.
     */
    int32 ExportCount;

    /**
     * Number of names in the linker's NameMap for this generation.
     */
    int32 NameCount;

    /** Constructor */
    FGenerationInfo(int32 InExportCount, int32 InNameCount);

    /** I/O function
     * we use a function instead of operator<< so we can pass in the package file summary for version tests, since archive version hasn't been set yet
     */
    void Serialize(FArchive& Ar, const struct FPackageFileSummary& Summary);
    void Serialize(FStructuredArchive::FSlot Slot, const struct FPackageFileSummary& Summary);
};

/**
 * A "table of contents" for an Unreal package file.  Stored at the top of the file.
 */
struct FPackageFileSummary
{
    /**
     * Magic tag compared against PACKAGE_FILE_TAG to ensure that package is an Unreal package.
     */
    int32 Tag;

private:
    /* UE4 file version */
    int32 FileVersionUE4;
    /* Licensee file version */
    int32 FileVersionLicenseeUE4;
    /* Custom version numbers. Keyed off a unique tag for each custom component. */
    FCustomVersionContainer CustomVersionContainer;

public:
    /**
     * Total size of all information that needs to be read in to create a FLinkerLoad. This includes
     * the package file summary, name table and import & export maps.
     */
    int32 TotalHeaderSize;

    /**
     * The flags for the package
     */
    uint32 PackageFlags;

    /**
     * The Generic Browser folder name that this package lives in
     */
    FString FolderName;

    /**
     * Number of names used in this package
     */
    int32 NameCount;

    /**
     * Location into the file on disk for the name data
     */
    int32 NameOffset;

    /**
     * Localization ID of this package
     * @note This is copy of the version stored in the package meta-data. It exists here so we can query it without having to load the whole package
     */
    FString LocalizationId;

    /**
     * Number of gatherable text data items in this package
     */
    int32 GatherableTextDataCount;

    /**
     * Location into the file on disk for the gatherable text data items
     */
    int32 GatherableTextDataOffset;

    /**
     * Number of exports contained in this package
     */
    int32 ExportCount;

    /**
     * Location into the file on disk for the ExportMap data
     */
    int32 ExportOffset;

    /**
     * Number of imports contained in this package
     */
    int32 ImportCount;

    /**
     * Location into the file on disk for the ImportMap data
     */
    int32 ImportOffset;

    /**
     * Location into the file on disk for the DependsMap data
     */
    int32 DependsOffset;

    /**
     * Number of soft package references contained in this package
     */
    int32 SoftPackageReferencesCount;

    /**
     * Location into the file on disk for the soft package reference list
     */
    int32 SoftPackageReferencesOffset;

    /**
     * Location into the file on disk for the SearchableNamesMap data
     */
    int32 SearchableNamesOffset;

    /**
     * Thumbnail table offset
     */
    int32 ThumbnailTableOffset;

    /**
     * Current id for this package
     */
    UE_DEPRECATED(4.27, "UPackage::Guid has not been used by the engine for a long time and FPackageFileSummary::Guid will be removed.")
    FGuid Guid;

#if WITH_EDITORONLY_DATA
    /**
     * Current persistent id for this package
     */
    FGuid PersistentGuid;
#endif

    /**
     * Data about previous versions of this package
     */
    TArray<FGenerationInfo> Generations;

    /**
     * Engine version this package was saved with. This may differ from CompatibleWithEngineVersion for assets saved with a hotfix release.
     */
    FEngineVersion SavedByEngineVersion;

    /**
     * Engine version this package is compatible with. Assets saved by Hotfix releases and engine versions that maintain binary compatibility will have
     * a CompatibleWithEngineVersion.Patch that matches the original release (as opposed to SavedByEngineVersion which will have a patch version of the new release).
     */
    FEngineVersion CompatibleWithEngineVersion;

    /**
     * Flags used to compress the file on save and uncompress on load.
     */
    uint32 CompressionFlags;

    /**
     * Value that is used to determine if the package was saved by Epic (or licensee) or by a modder, etc
     */
    uint32 PackageSource;

    /**
     * If true, this file will not be saved with version numbers or was saved without version numbers. In this case they are assumed to be the current version.
     * This is only used for full cooks for distribution because it is hard to guarantee correctness
     **/
    bool bUnversioned;

    /**
     * Location into the file on disk for the asset registry tag data
     */
    int32 AssetRegistryDataOffset;

    /** Offset to the location in the file where the bulkdata starts */
    int64 BulkDataStartOffset;
    /**
     * Offset to the location in the file where the FWorldTileInfo data starts
     */
    int32 WorldTileInfoDataOffset;

    /**
     * Streaming install ChunkIDs
     */
    TArray<int32> ChunkIDs;

    int32 PreloadDependencyCount;

    /**
     * Location into the file on disk for the preload dependency data
     */
    int32 PreloadDependencyOffset;

    /** Constructor */
    COREUOBJECT_API FPackageFileSummary();

    // Workaround for clang deprecation warnings for deprecated Guid member in implicit constructors
    PRAGMA_DISABLE_DEPRECATION_WARNINGS
    FPackageFileSummary(FPackageFileSummary&&)                 = default;
    FPackageFileSummary(const FPackageFileSummary&)            = default;
    FPackageFileSummary& operator=(FPackageFileSummary&&)      = default;
    FPackageFileSummary& operator=(const FPackageFileSummary&) = default;
    PRAGMA_ENABLE_DEPRECATION_WARNINGS

    int32 GetFileVersionUE4() const
    {
        return FileVersionUE4;
    }

    int32 GetFileVersionLicenseeUE4() const
    {
        return FileVersionLicenseeUE4;
    }

    const FCustomVersionContainer& GetCustomVersionContainer() const
    {
        return CustomVersionContainer;
    }

    void SetCustomVersionContainer(const FCustomVersionContainer& InContainer);

    void SetFileVersions(const int32 EpicUE4, const int32 LicenseeUE4, const bool bInSaveUnversioned = false)
    {
        FileVersionUE4         = EpicUE4;
        FileVersionLicenseeUE4 = LicenseeUE4;
        bUnversioned           = bInSaveUnversioned;
    }

    /** I/O functions */
    friend COREUOBJECT_API FArchive& operator<<(FArchive& Ar, FPackageFileSummary& Sum);
    friend COREUOBJECT_API void operator<<(FStructuredArchive::FSlot Slot, FPackageFileSummary& Sum);
};