// FileDirectory.h

#ifndef dataset_util__FileDirectory_H
#define dataset_util__FileDirectory_H

// David Adams
// February 2003
//
// Class describing a file system directory.
// Data includes the subdirectories and other files contained
// inside this directory.
// This data reflects the state of the file system at the time
// of construction or the most recent call to update().

#include <vector>
#include <iosfwd>
#include "dataset_util/FileStatus.h"
#include "dataset_util/FileName.h"

class FileDirectory {

public:  // typedefs

  typedef std::string Name;
  typedef std::vector<Name> NameList;
  typedef std::vector<FileStatus> FileList;
  typedef std::vector<FileDirectory> DirectoryList;

private:  // data

  // Specified name for the directory.
  Name m_name;

  // Validity.
  // Set at construction or last update.
  FileStatus m_status;

  // List of files.
  NameList m_file_names;
  FileList m_files;

  // List of subdirectories.
  mutable bool m_subdirs_filled;
  mutable NameList m_subdir_names;
  mutable DirectoryList m_subdirs;

public:  // methods

  // Constructor from file name.
  explicit FileDirectory(Name name ="");

  // Update the contents with the current state of the file system.
  // Returns if the directory is valid.
  bool update();

  // Return the directory name.
  Name name() const { return m_name; }

  // Return if the direectory is valid.
  // Name must be valid and directory must exist.
  // It need not be readable.
  bool is_valid() const;

  // Return the status of the directory.
  const FileStatus& status() const { return m_status; }

  // Return the list of file names relative to the directory.
  // (including subdirectories but not . and ..).
  // Created upon construction and update.
  const NameList& file_names() const { return m_file_names; };

  // Return the list of contained files (including subdirectories
  // but not . and ..).
  // Created upon construction and update.
  const FileList& files() const { return m_files; };

  // Return the subdirectory names relative to the directory.
  // Created on request and cleared during update.
  const NameList& subdir_names() const;

  // Return the subdirectories dirname/subdirname.
  // Created and cleared along with the subdirectory names.
  const DirectoryList& subdirs() const;

  // Return the directory+name for a file inside this directory.
  // E.g. myfile.dat --> mydir/myfile.dat
  // Blank is returned if the input name is blank
  Name prepend(Name fname) const;

  // Find a file in a directory.
  // Returns directory+name for file name if the file exists.
  // Otherwise returns blank.
  Name find(Name fname) const;

};

std::ostream& operator<<(std::ostream& lhs, const FileDirectory& rhs);

#endif