import Html exposing (Html, text, div, input)
import Html.Events exposing (onInput)
import Html.Attributes exposing (id)
import Tuple exposing (second)
import String exposing (toList, fromList, fromChar)
import List exposing (tail, head, member, map, member)
import Char exposing (isUpper, toUpper, toLower)

type alias Model = (String, String)

model: Model
model = ("", "")

type Msg = Convert String

isVowel : Char -> Bool
isVowel c = member (toUpper c) ['A', 'E', 'I', 'O', 'U']

pigLatinize : String -> String
pigLatinize orig =
   case (map toLower <| toList orig) of
      [] -> ""
      [a] -> (fromChar <| toUpper a) ++ "ay"
      (hd :: snd :: lst) ->
         if isVowel <| hd then
           orig ++ "ay"
         else
           fromList <| [toUpper <| snd] ++ lst ++ [hd] ++ ['a', 'y']

update : Msg -> Model -> Model
update mg mo =
   case mg of
     Convert str -> (str, pigLatinize str)

view : Model -> Html Msg
view model = div[(id "outer-div")][
                   input[(id "input-field"), (onInput Convert)][],
                   text("The piglatinized version is " ++ (second model))]

main : Program Never Model Msg
main = Html.beginnerProgram {
           model = model,
           view = view,
           update = update}