define cgit::filter (
  String $filtername = $name,
  Optional[String] $source = undef,
  Optional[String] $content = undef,
  Hash $file_props = {},
  Enum['lua', 'exec'] $type = stdlib::extname($source) ? {
    '.lua'  => 'lua',
    default => 'exec',
  }
) {

  $valid_filters = [
    'about',
    'auth',
    'commit',
    'email',
    'owner',
    'source',
  ]

  if ! member($valid_filters, $filtername) {
    crit("${filtername} not a valid cgit filter")
  }

  $dest = "${cgit::filterpath}/${filtername}-filter"

  file { $dest:
    ensure  => file,
    mode    => $type ? {
      'lua'  => '0444',
      'exec' => '0555',
    },
    source  => $source,
    content => $content,
    *       => $file_props,
  }

  concat::fragment { "cgit config filter ${filtername}":
    target  => $::cgit::cgitrc,
    content => "${filter_name}-filter=${type}:${dest}\n",
  }
}