package Tie::Filesystem;

use warnings;
use strict;

our $DIR_SEP = '/';

sub TIEHASH {
  my $class = shift;
  my $root  = shift || '/';
  
  bless {root => $root}, $class;
}

sub FETCH {
  my $self = shift;
  my $leaf = shift;
  
  my $pathname = $self->{'root'} . $DIR_SEP . $leaf;
  
  return undef unless -e $pathname;
  
  if (-d $pathname) {
    my %dir;
    tie %dir, 'Tie::Filesystem', $pathname;
    return \%dir;
  }
  
  return $pathname; #in the future, possibly return something useful
}

sub EXISTS {
  my $self = shift;
  my $leaf = shift;
  
  return -e ($self-{'root'} .  $DIR_SEP . $leaf);
}

sub FIRSTKEY {
  my $self = shift;
  
  opendir DIR, $self->{'root'} or return undef;
  $self->{'dir_handle'} = \*DIR; #This magic allows NEXTKEY to work almost sanely;
  
  return readdir DIR;
}

sub NEXTKEY {
  my $self = shift;
  my $dir = $self->{'dir_handle'};
  return undef unless $dir;
  
  my $entry = readdir $$dir;
  closedir $$dir unless $entry;
  
  return $entry;
}

1;