// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#pragma once

#include <memory>
#include <string>
#include <vector>
#include "common/common_types.h"
#include "core/file_sys/archive_backend.h"
#include "core/hle/kernel/hle_ipc.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/result.h"
#include "core/hle/service/service.h"

namespace FileSys {
class DirectoryBackend;
class FileBackend;
} // namespace FileSys

/// The unique system identifier hash, also known as ID0
static constexpr char SYSTEM_ID[]{"00000000000000000000000000000000"};
/// The scrambled SD card CID, also known as ID1
static constexpr char SDCARD_ID[]{"00000000000000000000000000000000"};

namespace Loader {
class AppLoader;
}

namespace Service::FS {

/// Supported archive types
enum class ArchiveIdCode : u32 {
    SelfNCCH = 0x00000003,
    SaveData = 0x00000004,
    ExtSaveData = 0x00000006,
    SharedExtSaveData = 0x00000007,
    SystemSaveData = 0x00000008,
    SDMC = 0x00000009,
    SDMCWriteOnly = 0x0000000A,
    NCCH = 0x2345678A,
    OtherSaveDataGeneral = 0x567890B2,
    OtherSaveDataPermitted = 0x567890B4,
};

/// Media types for the archives
enum class MediaType : u32 { NAND = 0, SDMC = 1, GameCard = 2 };

typedef u64 ArchiveHandle;

struct FileSessionSlot : public Kernel::SessionRequestHandler::SessionDataBase {
    u32 priority; ///< Priority of the file. TODO(Subv): Find out what this means
    u64 offset;   ///< Offset that this session will start reading from.
    u64 size;     ///< Max size of the file that this session is allowed to access
    bool subfile; ///< Whether this file was opened via OpenSubFile or not.
};

// TODO: File is not a real service, but it can still utilize ServiceFramework::RegisterHandlers.
// Consider splitting ServiceFramework interface.
class File final : public ServiceFramework<File, FileSessionSlot> {
public:
    File(std::unique_ptr<FileSys::FileBackend>&& backend, const FileSys::Path& path);
    ~File() = default;

    std::string GetName() const {
        return "Path: " + path.DebugStr();
    }

    FileSys::Path path;                            ///< Path of the file
    std::unique_ptr<FileSys::FileBackend> backend; ///< File backend interface

    /// Creates a new session to this File and returns the ClientSession part of the connection.
    Kernel::SharedPtr<Kernel::ClientSession> Connect();

private:
    void Read(Kernel::HLERequestContext& ctx);
    void Write(Kernel::HLERequestContext& ctx);
    void GetSize(Kernel::HLERequestContext& ctx);
    void SetSize(Kernel::HLERequestContext& ctx);
    void Close(Kernel::HLERequestContext& ctx);
    void Flush(Kernel::HLERequestContext& ctx);
    void SetPriority(Kernel::HLERequestContext& ctx);
    void GetPriority(Kernel::HLERequestContext& ctx);
    void OpenLinkFile(Kernel::HLERequestContext& ctx);
    void OpenSubFile(Kernel::HLERequestContext& ctx);
};

class Directory final : public ServiceFramework<Directory> {
public:
    Directory(std::unique_ptr<FileSys::DirectoryBackend>&& backend, const FileSys::Path& path);
    ~Directory();

    std::string GetName() const {
        return "Directory: " + path.DebugStr();
    }

    FileSys::Path path;                                 ///< Path of the directory
    std::unique_ptr<FileSys::DirectoryBackend> backend; ///< File backend interface

protected:
    void Read(Kernel::HLERequestContext& ctx);
    void Close(Kernel::HLERequestContext& ctx);
};

/**
 * Opens an archive
 * @param id_code IdCode of the archive to open
 * @param archive_path Path to the archive, used with Binary paths
 * @return Handle to the opened archive
 */
ResultVal<ArchiveHandle> OpenArchive(ArchiveIdCode id_code, FileSys::Path& archive_path);

/**
 * Closes an archive
 * @param handle Handle to the archive to close
 */
ResultCode CloseArchive(ArchiveHandle handle);

/**
 * Registers an Archive type, instances of which can later be opened using its IdCode.
 * @param factory File system backend interface to the archive
 * @param id_code Id code used to access this type of archive
 */
ResultCode RegisterArchiveType(std::unique_ptr<FileSys::ArchiveFactory>&& factory,
                               ArchiveIdCode id_code);

/**
 * Open a File from an Archive
 * @param archive_handle Handle to an open Archive object
 * @param path Path to the File inside of the Archive
 * @param mode Mode under which to open the File
 * @return The opened File object
 */
ResultVal<std::shared_ptr<File>> OpenFileFromArchive(ArchiveHandle archive_handle,
                                                     const FileSys::Path& path,
                                                     const FileSys::Mode mode);

/**
 * Delete a File from an Archive
 * @param archive_handle Handle to an open Archive object
 * @param path Path to the File inside of the Archive
 * @return Whether deletion succeeded
 */
ResultCode DeleteFileFromArchive(ArchiveHandle archive_handle, const FileSys::Path& path);

/**
 * Rename a File between two Archives
 * @param src_archive_handle Handle to the source Archive object
 * @param src_path Path to the File inside of the source Archive
 * @param dest_archive_handle Handle to the destination Archive object
 * @param dest_path Path to the File inside of the destination Archive
 * @return Whether rename succeeded
 */
ResultCode RenameFileBetweenArchives(ArchiveHandle src_archive_handle,
                                     const FileSys::Path& src_path,
                                     ArchiveHandle dest_archive_handle,
                                     const FileSys::Path& dest_path);

/**
 * Delete a Directory from an Archive
 * @param archive_handle Handle to an open Archive object
 * @param path Path to the Directory inside of the Archive
 * @return Whether deletion succeeded
 */
ResultCode DeleteDirectoryFromArchive(ArchiveHandle archive_handle, const FileSys::Path& path);

/**
 * Delete a Directory and anything under it from an Archive
 * @param archive_handle Handle to an open Archive object
 * @param path Path to the Directory inside of the Archive
 * @return Whether deletion succeeded
 */
ResultCode DeleteDirectoryRecursivelyFromArchive(ArchiveHandle archive_handle,
                                                 const FileSys::Path& path);

/**
 * Create a File in an Archive
 * @param archive_handle Handle to an open Archive object
 * @param path Path to the File inside of the Archive
 * @param file_size The size of the new file, filled with zeroes
 * @return File creation result code
 */
ResultCode CreateFileInArchive(ArchiveHandle archive_handle, const FileSys::Path& path,
                               u64 file_size);

/**
 * Create a Directory from an Archive
 * @param archive_handle Handle to an open Archive object
 * @param path Path to the Directory inside of the Archive
 * @return Whether creation of directory succeeded
 */
ResultCode CreateDirectoryFromArchive(ArchiveHandle archive_handle, const FileSys::Path& path);

/**
 * Rename a Directory between two Archives
 * @param src_archive_handle Handle to the source Archive object
 * @param src_path Path to the Directory inside of the source Archive
 * @param dest_archive_handle Handle to the destination Archive object
 * @param dest_path Path to the Directory inside of the destination Archive
 * @return Whether rename succeeded
 */
ResultCode RenameDirectoryBetweenArchives(ArchiveHandle src_archive_handle,
                                          const FileSys::Path& src_path,
                                          ArchiveHandle dest_archive_handle,
                                          const FileSys::Path& dest_path);

/**
 * Open a Directory from an Archive
 * @param archive_handle Handle to an open Archive object
 * @param path Path to the Directory inside of the Archive
 * @return The opened Directory object
 */
ResultVal<std::shared_ptr<Directory>> OpenDirectoryFromArchive(ArchiveHandle archive_handle,
                                                               const FileSys::Path& path);

/**
 * Get the free space in an Archive
 * @param archive_handle Handle to an open Archive object
 * @return The number of free bytes in the archive
 */
ResultVal<u64> GetFreeBytesInArchive(ArchiveHandle archive_handle);

/**
 * Erases the contents of the physical folder that contains the archive
 * identified by the specified id code and path
 * @param id_code The id of the archive to format
 * @param format_info Format information about the new archive
 * @param path The path to the archive, if relevant.
 * @return ResultCode 0 on success or the corresponding code on error
 */
ResultCode FormatArchive(ArchiveIdCode id_code, const FileSys::ArchiveFormatInfo& format_info,
                         const FileSys::Path& path = FileSys::Path());

/**
 * Retrieves the format info about the archive of the specified type and path.
 * The format info is supplied by the client code when creating archives.
 * @param id_code The id of the archive
 * @param archive_path The path of the archive, if relevant
 * @return The format info of the archive, or the corresponding error code if failed.
 */
ResultVal<FileSys::ArchiveFormatInfo> GetArchiveFormatInfo(ArchiveIdCode id_code,
                                                           FileSys::Path& archive_path);

/**
 * Creates a blank SharedExtSaveData archive for the specified extdata ID
 * @param media_type The media type of the archive to create (NAND / SDMC)
 * @param high The high word of the extdata id to create
 * @param low The low word of the extdata id to create
 * @param smdh_icon the SMDH icon for this ExtSaveData
 * @param format_info Format information about the new archive
 * @return ResultCode 0 on success or the corresponding code on error
 */
ResultCode CreateExtSaveData(MediaType media_type, u32 high, u32 low,
                             const std::vector<u8>& smdh_icon,
                             const FileSys::ArchiveFormatInfo& format_info);

/**
 * Deletes the SharedExtSaveData archive for the specified extdata ID
 * @param media_type The media type of the archive to delete (NAND / SDMC)
 * @param high The high word of the extdata id to delete
 * @param low The low word of the extdata id to delete
 * @return ResultCode 0 on success or the corresponding code on error
 */
ResultCode DeleteExtSaveData(MediaType media_type, u32 high, u32 low);

/**
 * Deletes the SystemSaveData archive folder for the specified save data id
 * @param high The high word of the SystemSaveData archive to delete
 * @param low The low word of the SystemSaveData archive to delete
 * @return ResultCode 0 on success or the corresponding code on error
 */
ResultCode DeleteSystemSaveData(u32 high, u32 low);

/**
 * Creates the SystemSaveData archive folder for the specified save data id
 * @param high The high word of the SystemSaveData archive to create
 * @param low The low word of the SystemSaveData archive to create
 * @return ResultCode 0 on success or the corresponding code on error
 */
ResultCode CreateSystemSaveData(u32 high, u32 low);

/// Initialize archives
void ArchiveInit();

/// Shutdown archives
void ArchiveShutdown();

/// Registers a new NCCH file with the SelfNCCH archive factory
void RegisterSelfNCCH(Loader::AppLoader& app_loader);

/// Register all archive types
void RegisterArchiveTypes();

/// Unregister all archive types
void UnregisterArchiveTypes();

} // namespace Service::FS
