module BNFC.Backend.Agda.Options where

import BNFC.Prelude

import Options.Applicative

data AgdaBackendOptions = AgdaOpts
  { nameSpace   :: Maybe String
  , inDir       :: Bool
  , functor     :: Bool
  , generic     :: Bool
  }

agdaOptionsParser :: Parser AgdaBackendOptions
agdaOptionsParser = AgdaOpts
    <$> oNameSpace
    <*> oInDir
    <*> oFunctor
    <*> oGeneric

  where

    -- name-space option
    oNameSpace =
      optional $
      strOption
          ( short 'p'
          <> long "name-space"
          <> help "Prepend NAMESPACE to the package/module name"
          <> metavar "NAMESPACE")

    -- inDir option
    oInDir =
      switch
          ( short 'd'
         <> help "Put Haskell code in modules LANG.* instead of LANG* (recommended)" )

    -- functor option
    oFunctor =
      switch
          ( long "functor"
         <> help "Make the AST a functor and use it to store the position of the nodes" )

    -- generic option
    oGeneric =
      switch
          ( long "generic"
         <> help "Derive Data, Generic, and Typeable instances for AST types" )


printAgdaOptions :: AgdaBackendOptions -> String
printAgdaOptions opts = unwords $ filter (not . null)
  [ nSpace, dir, funct, gen ]

  where

    nSpace = case nameSpace opts of
      Just n  -> "-p " ++ n
      Nothing -> ""

    dir = if inDir opts then "-d" else ""

    funct = if functor opts then "--functor" else ""

    gen = if generic opts then "--generic" else ""