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

module IHaskell.Display.Widgets.Float.FloatText (
-- * The FloatText Widget
FloatText, 
           -- * Constructor
           mkFloatText) where

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

import           Control.Monad (when, join, void)
import           Data.Aeson
import qualified Data.HashMap.Strict as HM
import           Data.IORef (newIORef)
import qualified Data.Scientific as Sci
import           Data.Text (Text)
import           Data.Vinyl (Rec(..), (<+>))

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

import           IHaskell.Display.Widgets.Types
import           IHaskell.Display.Widgets.Common

-- | 'FloatText' represents an FloatText widget from IPython.html.widgets.
type FloatText = IPythonWidget FloatTextType

-- | Create a new widget
mkFloatText :: IO FloatText
mkFloatText = do
  -- Default properties, with a random uuid
  uuid <- U.random

  let widgetState = WidgetState $ defaultFloatWidget "FloatTextView"

  stateIO <- newIORef widgetState

  let widget = IPythonWidget uuid stateIO
      initData = object
                   ["model_name" .= str "WidgetModel", "widget_class" .= str "IPython.FloatText"]

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

  -- Return the widget
  return widget

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

instance IHaskellWidget FloatText where
  getCommUUID = uuid
  comm widget (Object dict1) _ = do
    let key1 = "sync_data" :: Text
        key2 = "value" :: Text
        Just (Object dict2) = HM.lookup key1 dict1
        Just (Number value) = HM.lookup key2 dict2
    setField' widget FloatValue (Sci.toRealFloat value)
    triggerChange widget
