-- | This module defines the 'Configuration' type, which is just a
--   wrapper around all of the configuration options we accept on the
--   command line.
--
module Configuration (
  Configuration(..),
  merge_optional )
where

-- System imports.
import System.Console.CmdArgs.Default ( Default(..) )

-- Harbl library imports.
import Network.DNS.RBL.Weight ( Weight )

-- Local imports.
import qualified OptionalConfiguration as OC (
  OptionalConfiguration(..),
  merge_maybe,
  merge_monoid )
import Hosts ( Hosts(..) )
import Lists ( Lists(..) )


-- | The main configuration data type. This will be passed to most of
--   the important functions once it has been created.
--
data Configuration =
  Configuration {
    hosts  :: Hosts,
    lists  :: Lists,
    threshold :: Weight }
    deriving (Show)


-- | A Configuration with all of its fields set to their default
--   values.
--
instance Default Configuration where
  def = Configuration { hosts = def,
                        lists = def,
                        threshold = def }


-- | Merge a 'Configuration' with an 'OptionalConfiguration'. This is
--   more or less the Monoid instance for 'OptionalConfiguration', but
--   since the two types are different, we have to repeat ourselves.
--
merge_optional :: Configuration
               -> OC.OptionalConfiguration
               -> Configuration
merge_optional cfg opt_cfg = Configuration hs ls t
  where
    hs = OC.merge_monoid (hosts cfg) (OC.hosts opt_cfg)
    ls = OC.merge_monoid (lists cfg) (OC.lists opt_cfg)
    t  = OC.merge_maybe (threshold cfg) (OC.threshold opt_cfg)