{-# LANGUAGE OverloadedStrings #-}
module Graphics.Layout.CSS.Internal where

import Data.CSS.Syntax.Tokens (Token(..), NumericValue(..))
import qualified Data.Text as Txt
import Data.Scientific (toRealFloat)

type Unitted = (Double, Txt.Text)
auto :: Unitted
auto = (0,"auto")

parseLength :: [Token] -> Maybe Unitted
parseLength [Percentage _ x] = Just (n2f x,"%")
parseLength [Dimension _ x unit]
    | n2f x == 0 && unit == "" = Just (0,"px")
    | unit `elem` units = Just (n2f x,unit)
parseLength [Ident "auto"] = Just (0,"auto")
parseLength [Ident "initial"] = Just (0,"auto")
parseLength _ = Nothing
parseLength' [Ident "min-content"] = Just (0,"min-content")
parseLength' [Ident "max-content"] = Just (0,"max-content")
parseLength' toks = parseLength toks

units = Txt.words "cap ch em ex ic lh rem rlh vh vw vmax vmin vb vi px cm mm Q in pc pt %"

n2f (NVInteger x) = realToFrac x
n2f (NVNumber x) = toRealFloat x