module Main exposing (main)

import Html exposing (Html, div, h1, text, textarea)
import Html.Attributes exposing (class, readonly, rows, style, value)
import Html.Events exposing (onInput)


-- Fibonacci stuff


fibonacciFy : String -> String -> String
fibonacciFy origIndent input =
 input
  |> String.lines
  |> List.map (fibonacciFyLine origIndent)
  |> String.join "\n"


fibonacciFyLine : String -> String -> String
fibonacciFyLine origIndent input =
 let
  trimed =
    String.trimLeft input

  indentLevel =
    (String.length input - String.length trimed) // String.length origIndent
 in
 String.repeat (cumulativeFib indentLevel) " " ++ trimed


cumulativeFib : Int -> Int
cumulativeFib n =
 List.range 0 n
  |> List.map fibonacci
  |> List.sum


fibonacci : Int -> Int
fibonacci n =
 let
  fib a b n =
    if n <= 0 then
       a
    else
       fib b (a + b) (n - 1)
 in
 fib 0 1 n



--


type Msg
 = SetInput String
 | SetOrigIndent String


update msg model =
 case msg of
  SetInput input ->
    { model | input = input }

  SetOrigIndent ind ->
    { model | origIndent = ind }


view { input, origIndent } =
 div []
  [ div []
    [ text "Original indent:"
    , Html.input [ onInput SetOrigIndent, value origIndent ] []
    ]
  , div []
    [ h1 [] [ text "Original" ]
    , inputTxt [ onInput SetInput ] input
    ]
  , div []
    [ h1 [] [ text "Fibonaccified" ]
    , inputTxt [ readonly True ] (fibonacciFy origIndent input)
    ]
  ]


main =
 Html.beginnerProgram
  { model = { origIndent = "  ", input = sample }
  , update = update
  , view = view
  }



--


inputTxt attrs txt =
 textarea ([ value txt, class "txtInput", rows 17 ] ++ attrs) []


sample =
 """foo {
bar {
 baz {
 quz {
  quux {
  corge {
    grault {
    garply {
       // waldoo
    }
    }
  }
  }
 }
 }
}
}"""