#pragma region CPL License
/*
Nuclex Native Framework
Copyright (C) 2002-2021 Nuclex Development Labs

This library is free software; you can redistribute it and/or
modify it under the terms of the IBM Common Public License as
published by the IBM Corporation; either version 1.0 of the
License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
IBM Common Public License for more details.

You should have received a copy of the IBM Common Public
License along with this library
*/
#pragma endregion // CPL License

#ifndef NUCLEX_STORAGE_FILESYSTEM_WINDOWS_WINDOWSFILEACCESSAPI_H
#define NUCLEX_STORAGE_FILESYSTEM_WINDOWS_WINDOWSFILEACCESSAPI_H

#include "Nuclex/Storage/Config.h"

#if defined(NUCLEX_STORAGE_WIN32)

#include "../../Helpers/WindowsApi.h"

#include <string> // std::string
#include <cstdint> // std::uint8_t, std::size_t

#include <ShlObj.h> // KNOWNFOLDERID enum

namespace Nuclex { namespace Storage { namespace FileSystem { namespace Windows {

  // ------------------------------------------------------------------------------------------- //

  /// <summary>Wraps file access functions from the Windows file system API</summary>
  /// <remarks>
  ///   <para>
  ///     This is just a small helper class that reduces the amount of boilerplate code
  ///     required when calling the file system API functions from Windows, such as
  ///     checking result codes and transforming paths from UTF-8 to UTF-16 stored in
  ///     wchar_ts of non-standard 2 byte size.
  ///   </para>
  ///   <para>
  ///     It is not intended to hide operating system details or make this API platform
  ///     neutral (the File and Container classes do that), so depending on the amount
  ///     of noise required by the file system APIs, only some methods will be wrapped here.
  ///   </para>
  /// </remarks>
  class WindowsFileAccessApi {

    /// <summary>Opens the specified file for shared reading</summary>
    /// <param name="path">Path of the file that will be opened</param>
    /// <returns>The handle of the opened file</returns>
    public: static HANDLE OpenFileForReading(const std::string &path);

    /// <summary>Creates or opens the specified file for exclusive writing</summary>
    /// <param name="path">Path of the file that will be opened</param>
    /// <returns>The handle of the opened file</returns>
    public: static HANDLE OpenFileForWriting(const std::string &path);

    /// <summary>Moves the file cursor for the specified file</summary>
    /// <param name="fileHandle">File whose file cursor will be moved</param>
    /// <param name="location">Location the file cursor will be moved to</param>
    /// <returns>The actual location the file pointer</returns>
    public: static std::uint64_t SetFilePointer(HANDLE fileHandle, std::uint64_t location);

    /// <summary>Determines the length of the specified file</summary>
    /// <param name="fileHandle">Handle of the file whose length will be determined</param>
    /// <returns>The length of the specified file in bytes</returns>
    public: static std::uint64_t GetFileSize(HANDLE fileHandle);

    /// <summary>Determines the time of last modification for the specified file</summary>
    /// <param name="fileHandle">
    ///   Handle of the file whose time of last modification will be determined
    /// </param>
    /// <returns>The time the specified file was last modified</returns>
    public: static ::FILETIME GetLastModificationTime(HANDLE fileHandle);

    /// <summary>Reads data from the specified file</summary>
    /// <param name="fileHandle">Handle of the file from which data will be read</param>
    /// <param name="buffer">Buffer into which the data will be put</param>
    /// <param name="count">Number of bytes that will be read from the file</param>
    /// <returns>The number of bytes that were actually read</returns>
    public: static std::size_t Read(HANDLE fileHandle, void *buffer, std::size_t count);

    /// <summary>Writes data into the specified file</summary>
    /// <param name="fileHandle">Handle of the file into which data will be written</param>
    /// <param name="buffer">Buffer containing the data that will be written</param>
    /// <param name="count">Number of bytes that will be written into the file</param>
    /// <returns>The number of bytes that were actually written</returns>
    public: static std::size_t Write(HANDLE fileHandle, const void *buffer, std::size_t count);

    /// <summary>Ensures changes to the specified file have been written to disk</summary>
    /// <param name="fileHandle">Handle of the file that will be flushed</param>
    public: static void FlushFileBuffers(HANDLE fileHandle);

    /// <summary>Closes the specified file</summary>
    /// <param name="fileHandle">Handle of the file that will be closed</param>
    /// <param name="throwOnError">
    ///   Whether to throw an exception if the file cannot be closed
    /// </param>
    public: static void CloseFile(HANDLE fileHandle, bool throwOnError = true);

  };

  // ------------------------------------------------------------------------------------------- //

  /// <summary>Closes a file upon destruction</summary>
  class FileScope {

    /// <summary>Initializes the file closer</summary>
    /// <param name="fileHandle">Handle of the file that will be closed</param>
    public: FileScope(HANDLE fileHandle) :
      fileHandle(fileHandle) {}

    /// <summary>Closes the file</summary>
    public: ~FileScope() {
      const bool throwOnError = false;
      WindowsFileAccessApi::CloseFile(this->fileHandle, throwOnError);
    }

    /// <summary>File that will be closed upon destruction</summary>
    private: HANDLE fileHandle;

  };

  // ------------------------------------------------------------------------------------------- //

}}}} // namespace Nuclex::Storage::FileSystem::Windows

#endif // defined(NUCLEX_STORAGE_WIN32)

#endif // NUCLEX_STORAGE_FILESYSTEM_WINDOWS_WINDOWSFILEACCESSAPI_H