{- This Source Code Form is subject to the terms of the Mozilla Public License,
   v. 2.0. If a copy of the MPL was not distributed with this file, You can
   obtain one at https://mozilla.org/MPL/2.0/. -}

module Language.Elna.Driver
    ( Driver(..)
    , IntermediateStage(..)
    , drive
    , execParser
    ) where

import Data.Maybe (fromMaybe)
import Language.Elna.Driver.CommandLine
    ( CommandLine(..)
    , IntermediateStage(..)
    , commandLine
    )
import Options.Applicative (execParser)
import System.FilePath (replaceExtension, takeFileName)

data Driver = Driver
    { input :: FilePath
    , output :: FilePath
    , intermediateStage :: Maybe IntermediateStage
    } deriving (Eq, Show)

drive :: IO Driver
drive = rewrite <$> execParser commandLine
  where
    rewrite CommandLine{..} =
        let defaultOutputName = replaceExtension (takeFileName input) "o"
            outputName = fromMaybe defaultOutputName output
         in Driver
            { input = input
            , output = outputName
            , intermediateStage = intermediateStage
            }