-- | A newtype around a list of Strings representing blacklists.
--   This is all to avoid an orphan instance of 'Configured' for
--   [String] if we had defined one in e.g. 'OptionalConfiguration'.
--
{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}

module Lists ( Lists(..) )
where

import Data.Configurator () -- Needed for predefined instances.
import Data.Configurator.Types ( Configured(..) )
import Data.Data ( Data )
import Data.Monoid ( Monoid )
import System.Console.CmdArgs.Default ( Default(..) )
import Data.Typeable ( Typeable )

import Configurator ( convert_newtype_list )


-- | A (wrapper around a) list of blacklists.
--
newtype Lists =
  Lists { get_lists :: [String] }
    deriving (Data, Eq, Monoid, Show, Typeable)


-- | The default list of white/blacklists. It's empty.
--
instance Default Lists where def = Lists []

instance Configured Lists where
  -- | This allows us to read a 'Lists' object out of a Configurator
  --   config file: by default Configurator wouldn't know what to do.
  convert = convert_newtype_list Lists