{-# LANGUAGE OverloadedStrings #-}

module BNFC.Backend.Common.Makefile where

import BNFC.Prelude

import Data.String (fromString)

import Prettyprinter

-- | Creates a Makefile rule.
--
-- >>> mkRule "main" ["file1","file2"] ["do something"]
-- main : file1 file2
--      do something
-- <BLANKLINE>
--
-- >>> mkRule "main" ["program.exe"] []
-- main : program.exe
-- <BLANKLINE>
--
mkRule :: String   -- ^ The target name.
       -> [String] -- ^ Dependencies.
       -> String   -- ^ Recipe.
       -> Doc ()
mkRule target dependencies recipe =
  if null recipe
  then fromString target <+> colon <+> hsep (fromString <$> dependencies)
  else vsep
    [ fromString target <+> colon <+> hsep (fromString <$> dependencies)
    , "\t" <> fromString recipe
    ]

-- | Variable assignment.
--
-- >>> mkVar "FOO" "bar"
-- FOO=bar
--
mkVar :: String -> String -> Doc ()
mkVar n v = fromString n <> "=" <> fromString v

-- UNUSED:
-- -- | Variable referencing.
-- --
-- -- >>> mkRefVar "FOO"
-- -- ${FOO}
-- --
-- mkRefVar :: String -> Doc
-- mkRefVar m  = case m of
--     "" -> empty
--     _ -> text $ refVar m


-- | Variable referencing.
--
-- >>> refVar "FOO"
-- "${FOO}"
--
refVar :: String -> Doc ()
refVar m = "${" <+> fromString m <+> "}"