{-# LANGUAGE OverloadedStrings #-}

module Exercise04 where

import Data.List
import Data.Text

{-WETT-}
xmlLight :: String -> Bool
xmlLight [] = True
xmlLight (x : xs)
  | x == '>' = False
  | x == '<' = "<" `splitOn` pack xs `xmlHelper` []
  | otherwise = xmlLight xs

xmlHelper :: [Text] -> [Text] -> Bool
xmlHelper [] ys = Data.List.null ys
xmlHelper (x : xs) ys = Data.List.length splited == 2 && Data.List.length tag == 1 && if Data.Text.head htag == '/' then ys /= [] && Data.Text.tail htag == Data.List.head ys && xs `xmlHelper` Data.List.tail ys else xmlHelper xs $htag : ys
  where
    splited = splitOn ">" x
    tag = Data.Text.words $ Data.List.head splited
    htag = Data.List.head tag

{-MCCOMMENT: Falls doch noch Tests bzgl. führenden Leerzeichen und / hinzugefügt werden und xmlHelper nicht mehr funktioniert, dann bitte xmlHelper2 verwenden

xmlHelper2 :: [Text] -> [Text] -> Bool
xmlHelper2 [] ys = Data.List.null ys
xmlHelper2 (x : xs) ys = Data.List.length splited == 2 && Data.List.length tag == 1 && htag /= "" && "/" `Data.Text.isInfixOf` Data.Text.tail htag /= True && if Data.Text.head htag == '/' then ys /= [] && Data.Text.tail htag == Data.List.head ys && xs `xmlHelper2` Data.List.tail ys else xmlHelper2 xs $htag : ys
  where
    splited = splitOn ">" x
    tag = splitOn " " $ Data.Text.stripEnd $ Data.List.head splited
    htag = Data.List.head tag

-}

{-TTEW-}