module Lang where

import Text.Pandoc.Definition
import Data.Char (toLower)
import qualified Data.Text as Text
import System.IO

data Lang = Lántas deriving (Eq, Show)

type Vars = (?lang :: Maybe Lang)

toLang :: Maybe MetaValue -> IO (Maybe Lang)
toLang (Just (MetaInlines [Str s])) = toLang (Just (MetaString s)) -- ugh
toLang (Just (MetaString (Text.map toLower -> s)))
  | s == "lántas" || s == "laantas" = pure $ Just Lántas
toLang Nothing = pure Nothing
toLang (Just ℓ) = do
  hPutStrLn stderr $ "[WARN] unknown language: " <> show ℓ
  pure Nothing