module Update.UpdateEdition
  ( updateEdition
  , EditionAction(..)
  ) where

import Char (..)

import Model.Edition.Edition (..)

import Utils.List (..)

type EditionAction =
  DeleteLast
  | AddChar KeyCode

updateEdition : EditionAction -> Edition -> Edition
updateEdition action edition =
  case action of
    DeleteLast ->
      case maybeTail edition.chars of
        Just tailChars ->
          { edition | chars <- tailChars }
        Nothing ->
          edition
    AddChar keyCode ->
      case keyCodeToChar edition.kind keyCode of
        Just char ->
          { edition | chars <- char :: edition.chars }
        Nothing ->
          edition