#!/usr/bin/perl -w
use strict;
$|++;

use CGI::Carp qw(fatalsToBrowser); # DEBUG only

## begin config
my $DIR = "/home/merlyn/Web/Tarserver";
sub VALID {
  local $_ = shift;
  /(\.tgz|\.tar(\.gz)?)\z/ && !/\A\./;
}
## end config

use CGI qw(:all);

(my $path = path_info()) =~ s/\A\///;
my @path = split '/', $path;

my @choices;

if (@path) {                    # first element must be tar.gz
  die "bad tar name: $path[0]" unless VALID($path[0]);
  my $tarchive = "$DIR/$path[0]";
  die "missing tarchive: $tarchive" unless -f $tarchive and -r $tarchive;

  ## must look in contents now
  my @names = do {
    require Cache::FileCache;

    my $cache = Cache::FileCache->new
      ({namespace => 'tarserver',
        username => 'nobody',
        default_expires_in => '10 minutes',
        auto_purge_interval => '1 hour',
       }) or die "Cannot connect to cache";
    if (my $names = $cache->get($tarchive)) {
      @$names;
    } else {
      require Archive::Tar;

      die "Cannot list archive $tarchive"
        unless my @n = Archive::Tar->list_archive($tarchive);
      $cache->set($tarchive, \@n);
      @n;
    }
  };
  
  for my $step (1..$#path) {
    @names = map /\A\/?\Q$path[$step]\E(?:\/(.*))?\z/s, @names;
    die "no such name" unless @names;
    if (grep !defined $_, @names) {
      die "trailing stuff after name" if $step != $#path;
      require Archive::Tar;

      my $at = Archive::Tar->new($tarchive)
        or die "Cannot open archive $tarchive";
      my $file = join "/", @path[1..$#path];
      defined(my $contents = $at->get_content($file))
        or die "Cannot get $file from $tarchive";
  
      require File::MMagic;
      my $mimetype = File::MMagic->new->checktype_contents($contents);
      print header($mimetype), $contents;
      exit 0;
    }
  }
  
  {
    my %choices = ();
    $choices{$_}++ for map /\A([^\/]+\/?)/, @names;

    @choices = sort keys %choices;
  }

} else {                        # choose a top-level item
  opendir D, $DIR;
  @choices = sort grep VALID($_), readdir D;
  closedir D;
}

print header('text/html'), start_html('tar server'), h1('tar server');

## show path
print "from ", a({href => url()}, "Top");
{
  my $link = "";
  for (@path) {
    $link .= "/$_";
    print " / ", a({href => url().$link}, escapeHTML("$_"));
  }
}
print br;

## show sublinks
my $prefix = @path ? join("/", @path, "") : "";
print ul(map {
  li(a({href => url()."/$prefix$_"}, escapeHTML($_)));
} @choices);
  
print end_html;