#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_FILEMANAGERBACKEND_H
#define NUCLEX_STORAGE_FILESYSTEM_FILEMANAGERBACKEND_H

#include "Nuclex/Storage/Config.h"

#include <memory> // std::weak_ptr
#include <map> // for std::map
#include <string> // for std::string
#include <vector> // for std::vector

namespace Nuclex { namespace Storage { namespace FileSystem {

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

  class Container;
  class File;

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

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

namespace Nuclex { namespace Storage { namespace FileSystem {

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

  /// <summary>Private implementation of the file manager</summary>
  class FileManagerBackend {

    /// <summary>Initializes a new backend for the file manager</summary>
    public: FileManagerBackend() = default;
    /// <summary>Frees all resources owned by the file manager backend</summary>
    public: ~FileManagerBackend() = default;

    /// <summary>Creates a new file instance for the specified path</summary>
    /// <param name="path">Path of the file that will be accessed</param>
    /// <remarks>
    ///   For normal files on the operating system's file system, the path should be
    ///   the shortest absolute path to the same. For files in archives, instead of
    ///   a directory separator an unlikely (but consistent) unicode character may be
    ///   used instead to mark the transition from normal file to archive
    ///   (i.e. /opt/awesome-game/data.zip#textures/logo.png where # is a specific
    ///   unicode character that's unlikely to appear in actual files)
    /// </remarks>
    public: std::shared_ptr<File> RegisterFile(const std::string &path);

    /// <summary>
    ///   Notifies the backend that the file with the specified path is no longer being accessed
    /// </summary>
    /// <param name="path">Path of the file that is no longer accessed</param>
    /// <remarks>
    ///   This method is called from the destructor of the File class and notifies
    ///   the file manager backend that it can remove the file from its map (otherwise
    ///   detached weak_ptrs could accumulate without any limit).
    /// </remarks>
    public: void EliminateFile(const std::string &path) throw();

    /// <summary>
    ///   Notifies the backend that a file has been moved or renamed
    /// </summary>
    /// <param name="originalPath">Original absolute path of the file</parma>
    /// <param name="newPath">New absolute path of the file</param>
    public: void MoveOrRenameFile(const std::string &originalPath, const std::string &newPath);

    /// <summary>A map that allows looking up open files by their absolute paths</summary>
    private: typedef std::map<std::string, std::weak_ptr<File>> PathToFileMap;

    /// <summary>Files that are currently being accessed</summary>
    private: PathToFileMap openFiles;
    /// <summary>Whether all file accesses should be recorded</summary>
    private: bool listPathAccesses;
    /// <summary>List into which all file accesses are written if recording is enabled</summary>
    private: std::vector<std::string> pathAccesses;

  };

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

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

#endif // NUCLEX_STORAGE_FILESYSTEM_FILEMANAGERBACKEND_H