{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE TypeSynonymInstances #-}

module IHaskell.Display.Widgets.String.Label (
-- * The Label Widget
LabelWidget, 
             -- * Constructor
             mkLabelWidget) where

-- To keep `cabal repl` happy when running from the ihaskell repo
import           Prelude

import           Data.Aeson
import           Data.IORef (newIORef)

import           IHaskell.Display
import           IHaskell.Eval.Widgets
import           IHaskell.IPython.Message.UUID as U

import           IHaskell.Display.Widgets.Types

-- | A 'LabelWidget' represents a Label widget from IPython.html.widgets.
type LabelWidget = IPythonWidget LabelType

-- | Create a new Label widget
mkLabelWidget :: IO LabelWidget
mkLabelWidget = do
  -- Default properties, with a random uuid
  uuid <- U.random
  let widgetState = WidgetState $ defaultStringWidget "LabelView" "LabelModel"

  stateIO <- newIORef widgetState

  let widget = IPythonWidget uuid stateIO

  -- Open a comm for this widget, and store it in the kernel state
  widgetSendOpen widget $ toJSON widgetState

  -- Return the widget
  return widget

instance IHaskellDisplay LabelWidget where
  display b = do
    widgetSendView b
    return $ Display []

instance IHaskellWidget LabelWidget where
  getCommUUID = uuid