{-# OPTIONS_GHC -fno-warn-orphans #-}
{-|
Module      : Game.GoreAndAsh.SDL.Module
Description : Monad transformer of the module
Copyright   : (c) Anton Gushcha, 2015-2016
License     : BSD3
Maintainer  : ncrashed@gmail.com
Stability   : experimental
Portability : POSIX

The module contains declaration of monad transformer of the core module and
instance for 'GameModule' class.
-}
module Game.GoreAndAsh.SDL.Module(
    SDLT(..)
  ) where

import Control.Monad.Base 
import Control.Monad.Catch
import Control.Monad.Error.Class 
import Control.Monad.Fix 
import Control.Monad.IO.Class 
import Control.Monad.State.Strict
import Control.Monad.Trans.Resource
import Data.Proxy 
import qualified Data.Foldable as F 
import qualified Data.HashMap.Strict as H 
import qualified Data.Sequence as S 
import SDL

import Game.GoreAndAsh
import Game.GoreAndAsh.SDL.State

-- | Monad transformer of SDL core module.
--
-- [@s@] - State of next core module in modules chain;
--
-- [@m@] - Next monad in modules monad stack;
--
-- [@a@] - Type of result value;
--
-- How to embed module:
-- 
-- @
-- type AppStack = ModuleStack [SDLT, ... other modules ... ] IO
--
-- newtype AppMonad a = AppMonad (AppStack a)
--   deriving (Functor, Applicative, Monad, MonadFix, MonadIO, MonadThrow, MonadCatch, MonadSDL)
-- @
--
-- The module is NOT pure within first phase (see 'ModuleStack' docs), therefore currently only 'IO' end monad can handler the module.
newtype SDLT s m a = SDLT { runSDLT :: StateT (SDLState s) m a }
  deriving (Functor, Applicative, Monad, MonadState (SDLState s), MonadFix, MonadTrans, MonadIO, MonadThrow, MonadCatch, MonadMask, MonadError e)

instance MonadBase IO m => MonadBase IO (SDLT s m) where 
  liftBase = SDLT . liftBase

instance MonadResource m => MonadResource (SDLT s m) where 
  liftResourceT = SDLT . liftResourceT
  
instance GameModule m s => GameModule (SDLT s m) (SDLState s) where 
  type ModuleState (SDLT s m) = SDLState s
  runModule (SDLT m) s = do
    s' <- processEvents s 
    clearWindows s'
    ((a, s''), nextState) <- runModule (runStateT m s') (sdlNextState s')
    drawWindows s''
    return (a, flashSDLState $ s'' { 
        sdlNextState = nextState
      })

  newModuleState = emptySDLState <$> newModuleState
  withModule _ io = do
    initializeAll
    liftIO $ putStrLn "SDL initialized"
    withModule (Proxy :: Proxy m) io

  cleanupModule _ = quit

-- | Takes all window and renderers and update them
drawWindows :: MonadIO m => SDLState s -> m ()
drawWindows SDLState{..} = mapM_ go . H.elems $! sdlWindows
  where 
  go WindowInfo{..} = do
    whenJust winfoContext . const . glSwapWindow $! winfoWindow
    present winfoRenderer 

-- | Clear surface of all windows
clearWindows :: MonadIO m => SDLState s -> m ()
clearWindows SDLState{..} = mapM_ go . H.elems $! sdlWindows
  where 
  go WindowInfo{..} = case winfoColor of 
    Nothing -> return ()
    Just c -> do 
      rendererDrawColor winfoRenderer $= c
      clear winfoRenderer

-- | Catch all SDL events
processEvents :: MonadIO m => SDLState s -> m (SDLState s)
processEvents sdlState = do 
  es <- pollEvents
  return $! F.foldl' process sdlState (eventPayload <$> es)
  where 
  process s e = case e of 
    WindowShownEvent d -> s { sdlWindowShownEvents = sdlWindowShownEvents s S.|> d }
    WindowHiddenEvent d -> s { sdlWindowHiddenEvents = sdlWindowHiddenEvents s S.|> d }
    WindowExposedEvent d -> s { sdlWindowExposedEvents = sdlWindowExposedEvents s S.|> d }
    WindowMovedEvent d -> s { sdlWindowMovedEvents = sdlWindowMovedEvents s S.|> d }
    WindowResizedEvent d -> s { sdlWindowResizedEvents = sdlWindowResizedEvents s S.|> d }
    WindowSizeChangedEvent d -> s { sdlWindowSizeChangedEvents = sdlWindowSizeChangedEvents s S.|> d }
    WindowMinimizedEvent d -> s { sdlWindowMinimizedEvents = sdlWindowMinimizedEvents s S.|> d }
    WindowMaximizedEvent d -> s { sdlWindowMaximizedEvents = sdlWindowMaximizedEvents s S.|> d }
    WindowRestoredEvent d -> s { sdlWindowRestoredEvents = sdlWindowRestoredEvents s S.|> d }
    WindowGainedMouseFocusEvent d -> s { sdlWindowGainedMouseFocusEvents = sdlWindowGainedMouseFocusEvents s S.|> d }
    WindowLostMouseFocusEvent d -> s { sdlWindowLostMouseFocusEvents = sdlWindowLostMouseFocusEvents s S.|> d }
    WindowGainedKeyboardFocusEvent d -> s { sdlWindowGainedKeyboardFocusEvents = sdlWindowGainedKeyboardFocusEvents s S.|> d }
    WindowLostKeyboardFocusEvent d -> s { sdlWindowLostKeyboardFocusEvents = sdlWindowLostKeyboardFocusEvents s S.|> d }
    WindowClosedEvent d -> s { sdlWindowClosedEvents = sdlWindowClosedEvents s S.|> d }
    KeyboardEvent d -> s { sdlKeyboardEvents = sdlKeyboardEvents s S.|> d }
    TextEditingEvent d -> s { sdlTextEditingEvents = sdlTextEditingEvents s S.|> d }
    TextInputEvent d -> s { sdlTextInputEvents = sdlTextInputEvents s S.|> d }
    MouseMotionEvent d -> s { sdlMouseMotionEvents = sdlMouseMotionEvents s S.|> d }
    MouseButtonEvent d -> s { sdlMouseButtonEvents = sdlMouseButtonEvents s S.|> d }
    MouseWheelEvent d -> s { sdlMouseWheelEvents = sdlMouseWheelEvents s S.|> d }
    JoyAxisEvent d -> s { sdlJoyAxisEvents = sdlJoyAxisEvents s S.|> d }
    JoyBallEvent d -> s { sdlJoyBallEvents = sdlJoyBallEvents s S.|> d }
    JoyHatEvent d -> s { sdlJoyHatEvents = sdlJoyHatEvents s S.|> d }
    JoyButtonEvent d -> s { sdlJoyButtonEvents = sdlJoyButtonEvents s S.|> d }
    JoyDeviceEvent d -> s { sdlJoyDeviceEvents = sdlJoyDeviceEvents s S.|> d }
    ControllerAxisEvent d -> s { sdlControllerAxisEvents = sdlControllerAxisEvents s S.|> d }
    ControllerButtonEvent d -> s { sdlControllerButtonEvents = sdlControllerButtonEvents s S.|> d }
    ControllerDeviceEvent d -> s { sdlControllerDeviceEvents = sdlControllerDeviceEvents s S.|> d }
    QuitEvent -> s { sdlQuitEvent = True }
    UserEvent d -> s { sdlUserEvents = sdlUserEvents s S.|> d }
    SysWMEvent d -> s { sdlSysWMEvents = sdlSysWMEvents s S.|> d }
    TouchFingerEvent d -> s { sdlTouchFingerEvents = sdlTouchFingerEvents s S.|> d }
    MultiGestureEvent d -> s { sdlMultiGestureEvents = sdlMultiGestureEvents s S.|> d }
    DollarGestureEvent d -> s { sdlDollarGestureEvents = sdlDollarGestureEvents s S.|> d }
    DropEvent d -> s { sdlDropEvents = sdlDropEvents s S.|> d }
    ClipboardUpdateEvent d -> s { sdlClipboardUpdateEvents = sdlClipboardUpdateEvents s S.|> d }
    _ -> s