module Html
where

import Test.HUnit
import Text.HTML.TagSoup.Entity (lookupEntity)

replace_entities :: String -> String
replace_entities [] = []
replace_entities ('&':xs) =
  let (b, a) = break (== ';') xs in
  case (lookupEntity b, a) of
    (Just c, ';':as) ->  c  : replace_entities as
    _                -> '&' : replace_entities xs
replace_entities (x:xs) = x : replace_entities xs


html_tests :: [Test]
html_tests = [ test_replace_entities ]

test_replace_entities :: Test
test_replace_entities =
    TestCase $ assertEqual description expected_text actual_text
    where
      description = "All entities are replaced correctly."
      actual_text =
        replace_entities $
          ""The moon is gay……" " ++
          "said <insert the current president of the " ++
          "United States of America>. “It’s " ++
          "OK—–he’s not a real doctor.”"
      expected_text =
        "\"The moon is gay……\" said <insert " ++
        "the current president of the United States of America>. " ++
        "“It’s OK—–he’s not a real doctor.”"