import Lang
import Ebnf
import Spans
import Glosses

import Text.Pandoc.Definition
import Text.Pandoc.JSON
import Text.Pandoc.Walk
import qualified Data.Map as Map


main :: IO ()
main = toJSONFilter filter where
  filter p@(Pandoc (Meta m) _) = do
    lang' <- toLang $ Map.lookup "lang" m
    let ?lang = lang'
    fmap (walk makeEbnf .
          walk (concatMap makeFigures) .
          walk inlineLetterList) $
      walkM spans =<<
      walkM (fmap concat . traverse glosses) p


makeFigures :: Block -> [Block]
makeFigures (Div ("", ["figure"], []) blks) =
  [html "<figure>"] ++ blks ++ [html "</figure>"]
  where html = RawBlock (Format "html")
makeFigures b = [b]


inlineLetterList :: Block -> Block
inlineLetterList (Div a@(_, cs, _) blks)
  | "letter-list" `elem` cs = Div a (walk go blks)
 where
  go (Para xs) = Plain xs
  go b         = b
inlineLetterList b = b