{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE RankNTypes #-}
module Affection.Subsystems.AffectionWindow where

import Affection.Types
import Affection.Util
import Affection.MessageBus
import Affection.Subsystems.Class

import Control.Concurrent.STM as STM
import Control.Monad.IO.Class (liftIO)

import qualified SDL

data AffectionWindow sd = AffectionWindow
  { windowSubscribers :: forall sd. TVar [(UUID, WindowMessage -> Affection sd ())]
  }

instance Participant (AffectionWindow sd) WindowMessage where
  partSubscribe p funct = do
    uuid <- genUUID
    liftIO $ atomically $ modifyTVar' (windowSubscribers p) ((uuid, funct) :)
    return uuid

  partUnSubscribe p uuid =
    liftIO $ atomically $ modifyTVar' (windowSubscribers p)
      (filter (\(u, _) -> u /= uuid))

  partSubscribers p = do
    subTups <- liftIO $ readTVarIO $ windowSubscribers p
    return $ map snd subTups

instance SDLSubsystem (AffectionWindow sd) WindowMessage where
  consumeSDLEvents aw eps = doConsume eps
    where
      doConsume (e:es) = do
        ts <- getElapsedTime
        case e of
          SDL.WindowShownEvent (SDL.WindowShownEventData window) -> do
            partEmit aw (MsgWindowShow ts window)
            doConsume es
          SDL.WindowHiddenEvent (SDL.WindowHiddenEventData window) -> do
            partEmit aw (MsgWindowHide ts window)
            doConsume es
          SDL.WindowExposedEvent (SDL.WindowExposedEventData window) -> do
            partEmit aw (MsgWindowExpose ts window)
            doConsume es
          SDL.WindowMovedEvent (SDL.WindowMovedEventData window (SDL.P newPos)) -> do
            partEmit aw (MsgWindowMove ts window newPos)
            doConsume es
          SDL.WindowResizedEvent (SDL.WindowResizedEventData window newSize) -> do
            partEmit aw (MsgWindowResize ts window newSize)
            doConsume es
          SDL.WindowSizeChangedEvent (SDL.WindowSizeChangedEventData window) -> do
            partEmit aw (MsgWindowSizeChange ts window)
            doConsume es
          SDL.WindowMinimizedEvent (SDL.WindowMinimizedEventData window) -> do
            partEmit aw (MsgWindowMinimize ts window)
            doConsume es
          SDL.WindowMaximizedEvent (SDL.WindowMaximizedEventData window) -> do
            partEmit aw (MsgWindowMaximize ts window)
            doConsume es
          SDL.WindowRestoredEvent (SDL.WindowRestoredEventData window) -> do
            partEmit aw (MsgWindowRestore ts window)
            doConsume es
          SDL.WindowGainedMouseFocusEvent (SDL.WindowGainedMouseFocusEventData window) -> do
            partEmit aw (MsgWindowGainMouseFocus ts window)
            doConsume es
          SDL.WindowLostMouseFocusEvent (SDL.WindowLostMouseFocusEventData window) -> do
            partEmit aw (MsgWindowLoseMouseFocus ts window)
            doConsume es
          SDL.WindowGainedKeyboardFocusEvent (SDL.WindowGainedKeyboardFocusEventData window) -> do
            partEmit aw (MsgWindowGainKeyboardFocus ts window)
            doConsume es
          SDL.WindowLostKeyboardFocusEvent (SDL.WindowLostKeyboardFocusEventData window) -> do
            partEmit aw (MsgWindowLoseKeyboardFocus ts window)
            doConsume es
          SDL.WindowClosedEvent (SDL.WindowClosedEventData window) -> do
            partEmit aw (MsgWindowClose ts window)
            doConsume es
          _ -> fmap (e :) (doConsume es)