// FileDirectory.cxx

#include "dataset_util/FileDirectory.h"
#include <iostream>
#include <algorithm>
#include <sys/types.h>
#include <dirent.h>

using std::string;
using std::ostream;

typedef FileDirectory::Name Name;
typedef FileDirectory::NameList NameList;
typedef FileDirectory::FileList FileList;
typedef FileDirectory::DirectoryList DirectoryList;

//**********************************************************************

// Constructor from string name.

FileDirectory::FileDirectory(Name name)
: m_name(name) {
  update();
}

//**********************************************************************

// Update.

bool FileDirectory::update() {
  m_file_names.erase(m_file_names.begin(), m_file_names.end());
  m_files.erase(m_files.begin(), m_files.end());
  m_subdirs_filled = false;
  m_subdir_names.erase(m_subdir_names.begin(), m_subdir_names.end());
  m_subdirs.erase(m_subdirs.begin(), m_subdirs.end());
  m_status = FileStatus(m_name);
  if ( ! is_valid() ) return false;
  DIR* pdir = opendir(m_name.c_str());
  if ( pdir == 0 ) {
    m_status = FileStatus();
    return false;
  }
  // Read the contents of the directory.
  dirent* pdirent;
  while ( (pdirent = readdir(pdir)) != 0 ) {
    Name name(pdirent->d_name);
    if ( name == "." ) continue;
    if ( name == ".." ) continue;
    m_file_names.push_back(name);
    string fullname = m_name + FileName::string_delimiter() + name;
    FileStatus fstat(fullname);
    m_files.push_back(fstat);
  }
  closedir(pdir);
  return true;
}

//**********************************************************************

// Validity.

bool FileDirectory::is_valid() const {
  return m_status.is_directory();
}

//**********************************************************************

// Return the subdirectory names.
// Created on request and cleared during update.

const NameList& FileDirectory::subdir_names() const {
  if ( is_valid() && ! m_subdirs_filled ) {
    NameList::const_iterator iname = file_names().begin();
    for ( FileList::const_iterator ifile=files().begin();
          ifile!=files().end(); ++ifile ) {
      assert( iname != file_names().end() );
      if ( ifile->is_directory() ) {
	m_subdir_names.push_back(*iname);
	m_subdirs.push_back(FileDirectory(ifile->name()));
      }
      ++iname;
    }
    m_subdirs_filled = true;
  }
  return m_subdir_names;
}

//**********************************************************************

// Return the subdirectories.
// Created on request and cleared during update.

const DirectoryList& FileDirectory::subdirs() const {
  if ( is_valid() && ! m_subdirs_filled ) {
    // Force filling of subdirectory info.
    subdir_names();
  }
  return m_subdirs;
}

//**********************************************************************

// Prepend directory name.

Name FileDirectory::prepend(Name fname) const {
  if ( fname.size() == 0 ) {
    return "";
  }
  return name() + FileName::string_delimiter() + fname;
}

//**********************************************************************

// Find a file.

Name FileDirectory::find(Name fname) const {
  if ( fname.size() == 0 ) {
    return "";
  }
  NameList::const_iterator ifile =
    std::find(file_names().begin(), file_names().end(), fname);
  if ( ifile == file_names().end() ) {
    return "";
  }
  return prepend(fname);
}

//**********************************************************************

// Output stream.

ostream& operator<<(ostream& lhs, const FileDirectory& rhs) {
  if ( rhs.is_valid() ) {
    lhs << rhs.name();
    for ( FileList::const_iterator ifile=rhs.files().begin();
          ifile!=rhs.files().end(); ++ifile ) {
      lhs << "\n  " << *ifile;
    }
    lhs.flush();
  } else {
    lhs << "Invalid directory " << rhs.name();
  }
  return lhs;
}

//**********************************************************************