{-# LANGUAGE GeneralizedNewtypeDeriving, ExistentialQuantification, TypeFamilies, FlexibleContexts, DeriveDataTypeable #-}

module Phi.X11 ( X11(..)
               , XEvent(..)
               , XMessage(..)
               , XConfig(..)
               , defaultXConfig
               , runPhi
               ) where

import Graphics.XHB hiding (Window)
import qualified  Graphics.XHB.Connection.Open as CO
import Graphics.XHB.Gen.Xinerama
import Graphics.XHB.Gen.Xproto hiding (Window)

import Graphics.Rendering.Cairo

import Control.Monad
import Data.Bits
import Data.Char
import Data.List
import Data.Maybe
import Data.Typeable
import Data.Word

import Control.Arrow ((&&&))
import Control.Concurrent
import Control.Concurrent.MVar
import Control.Monad.State.Strict
import Control.Monad.Reader
import Control.Monad.Trans

import System.Exit
import System.Posix.Signals
import System.Posix.Types

import qualified Phi.Bindings.XCB as XCB

import Phi.Phi
import Phi.X11.Util
import qualified Phi.Types as Phi
import qualified Phi.Panel as Panel
import qualified Phi.Widget as Widget (handleMessage)
import Phi.Widget hiding (handleMessage)
import Phi.X11.Atoms


data X11 = X11 { x11Connection :: !Connection 
               , x11Atoms      :: !Atoms
               , x11Screen     :: !SCREEN
               }

instance Display X11 where
  type Window X11 = WINDOW


newtype XEvent = XEvent SomeEvent deriving Typeable
 
instance Show XEvent where
  show _ = "XEvent (..)"

data XMessage = UpdateScreens [(Rectangle, WINDOW)] deriving (Show, Typeable)


data XConfig = XConfig { phiXScreenInfo :: !(X11 -> IO [Rectangle])
                       }

data PhiState w s c = (Widget w s c X11) => PhiState { phiRootImage    :: !Surface
                                                     , phiPanels       :: ![PanelState w s c]
                                                     , phiRepaint      :: !Bool
                                                     , phiShutdown     :: !Bool
                                                     , phiShutdownHold :: !Int
                                                     , phiWidgetState  :: !s
                                                     }

data PanelState w s c = (Widget w s c X11) => PanelState { panelWindow       :: !WINDOW
                                                         , panelPixmap       :: !PIXMAP
                                                         , panelArea         :: !Rectangle
                                                         , panelScreenArea   :: !Rectangle
                                                         , panelWidgetCache  :: !c
                                                         }

data PhiConfig w s c = PhiConfig { phiPhi          :: !Phi
                                 , phiPanelConfig  :: !Panel.PanelConfig
                                 , phiXConfig      :: !XConfig
                                 , phiX11          :: !X11
                                 , phiXCB          :: !XCB.Connection
                                 , phiWidget       :: !w
                                 }

newtype PhiReader w s c a = PhiReader (ReaderT (PhiConfig w s c) IO a)
                    deriving (Monad, MonadReader (PhiConfig w s c), MonadIO)

runPhiReader :: PhiConfig w s c -> PhiReader w s c a -> IO a
runPhiReader config (PhiReader a) = runReaderT a config

newtype PhiX w s c a = PhiX (StateT (PhiState w s c) (PhiReader w s c) a)
                   deriving (Monad, MonadState (PhiState w s c), MonadReader (PhiConfig w s c), MonadIO)

runPhiX :: PhiConfig w s c -> PhiState w s c -> PhiX w s c a -> IO (a, PhiState w s c)
runPhiX config st (PhiX a) = runPhiReader config $ runStateT a st

defaultXConfig = XConfig { phiXScreenInfo = getScreenInfo
                         }

getScreenInfo :: X11 -> IO [Rectangle]
getScreenInfo x11 = do
  let conn = x11Connection x11
      screen = x11Screen x11
  exs <- queryScreens conn >>= getReply
  case exs of
    Right xs -> return . map screenInfoToRect $ screen_info_QueryScreensReply xs
    Left _ -> getGeometry conn (fromXid . toXid $ root_SCREEN screen) >>= getReply' "getScreenInfo: getGeometry failed" >>=
              return . (\(MkGetGeometryReply _ _ x y w h _) -> [Rectangle (fi x) (fi y) (fi w) (fi h)])
  where
    screenInfoToRect (MkScreenInfo x y w h) = Rectangle (fi x) (fi y) (fi w) (fi h)
    
    fi :: (Integral a, Num b) => a -> b
    fi = fromIntegral

runPhi :: (Widget w s c X11) => XConfig -> Panel.PanelConfig -> w -> IO ()
runPhi xconfig config widget = do
  phi <- initPhi
  
  installHandler sigTERM (termHandler phi) Nothing
  installHandler sigINT (termHandler phi) Nothing
  installHandler sigQUIT (termHandler phi) Nothing
  
  conn <- liftM fromJust connect
  xcb <- XCB.connect
  
  let dispname = displayInfo conn
      screen = (roots_Setup . connectionSetup $ conn) !! CO.screen dispname

  atoms <- initAtoms conn
  changeWindowAttributes conn (root_SCREEN screen) $ toValueParam [(CWEventMask, toMask [EventMaskPropertyChange, EventMaskStructureNotify])]
  
  bg <- createImageSurface FormatRGB24 1 1
  
  let x11 = X11 conn atoms screen
  
  screens <- liftIO $ phiXScreenInfo xconfig x11
  panelWindows <- mapM (createPanelWindow conn screen config) screens
  
  let widget' = widget <~> separator 0 (if weight widget > 0 then 0 else 1)
      screenPanels = zip screens panelWindows

  initialState <- initWidget widget' phi x11 screenPanels

  runPhiX
    PhiConfig { phiPhi = phi
              , phiXConfig = xconfig
              , phiPanelConfig = config
              , phiX11 = x11
              , phiXCB = xcb
              , phiWidget = widget'
              }
    PhiState { phiRootImage = bg
             , phiPanels = []
             , phiRepaint = False
             , phiShutdown = False
             , phiShutdownHold = 0
             , phiWidgetState = initialState
             } $ do
    updateRootImage
    
    panels <- mapM (\(screen, window) -> createPanel window screen) screenPanels
    
    forM_ panels setPanelProperties
    
    modify $ \state -> state { phiPanels = panels }
    
    updatePanels
    
    forM_ panels $ liftIO . mapWindow conn . panelWindow
    
    liftIO $ forkIO $ receiveEvents phi conn
    
    forever $ do
      available <- messageAvailable phi
      repaint <- gets phiRepaint
      when (not available && repaint) $ liftIO $ threadDelay 30000
      
      available <- messageAvailable phi
      when (not available && repaint) $ do
        updatePanels
        modify $ \state -> state {phiRepaint = False}
      
      message <- receiveMessage phi
      handleMessage message
      
      
      case (fromMessage message) of
        Just Shutdown ->
          modify $ \state -> state { phiShutdown = True }
        Just HoldShutdown ->
          modify $ \state -> state { phiShutdownHold = phiShutdownHold state + 1 }
        Just ReleaseShutdown ->
          modify $ \state -> state { phiShutdownHold = phiShutdownHold state - 1 }
        _ ->
          return ()
      
      shutdown <- gets phiShutdown
      shutdownHold <- gets phiShutdownHold
      
      when (shutdown && (shutdownHold == 0)) $
        liftIO $ exitSuccess
      
  return ()


termHandler :: Phi -> Handler
termHandler phi = Catch $ sendMessage phi Shutdown


handleMessage :: (Widget w s c X11) => Message -> PhiX w s c ()
handleMessage m = do
  w <- asks phiWidget
  modify $ \state -> state {phiWidgetState = Widget.handleMessage w (phiWidgetState state) m}
  
  case (fromMessage m) of
    Just Repaint ->
      modify $ \state -> state {phiRepaint = True}
    _ ->
      case (fromMessage m) of
        Just (XEvent event) ->
          handleEvent event
        _ ->
          return ()

handleEvent :: (Widget w s c X11) => SomeEvent -> PhiX w s c ()
handleEvent event =
  case (fromEvent event) of
    Just e -> handlePropertyNotifyEvent e
    Nothing -> case (fromEvent event) of
      Just e -> handleConfigureNotifyEvent e
      Nothing -> return ()

handlePropertyNotifyEvent :: (Widget w s c X11) => PropertyNotifyEvent -> PhiX w s c ()
handlePropertyNotifyEvent MkPropertyNotifyEvent { atom_PropertyNotifyEvent = atom } = do
  phi <- asks phiPhi
  atoms <- asks (x11Atoms . phiX11)
  panels <- gets phiPanels

  when (atom == atom_XROOTPMAP_ID atoms || atom == atom_XROOTMAP_ID atoms) $ do
    updateRootImage
    sendMessage phi ResetBackground
    sendMessage phi Repaint

handleConfigureNotifyEvent :: (Widget w s c X11) => ConfigureNotifyEvent -> PhiX w s c ()
handleConfigureNotifyEvent MkConfigureNotifyEvent { window_ConfigureNotifyEvent = window } = do
  x11 <- asks phiX11
  let conn = x11Connection x11
      screen = x11Screen x11
      rootWindow = root_SCREEN screen
  when (window == rootWindow) $ do
    phi <- asks phiPhi
    xconfig <- asks phiXConfig
    config <- asks phiPanelConfig
    panels <- gets phiPanels
    let screens = map panelScreenArea panels
    screens' <- liftIO $ phiXScreenInfo xconfig x11
    
    when (screens /= screens') $ do
      liftIO $ do
        mapM_ (freePixmap conn . panelPixmap) panels
        mapM_ (destroyWindow conn . panelWindow) $ drop (length screens') panels
      
      let panelsScreens = zip screens' $ map Just panels ++ repeat Nothing
      
      panels' <- forM panelsScreens $ \(screenarea, mpanel) ->
        case mpanel of
          Just panel -> do
            let rect = panelBounds config screenarea
                win = panelWindow panel
            
            liftIO $ configureWindow conn win $ toValueParam [ (ConfigWindowX, fromIntegral $ rect_x rect)
                                                             , (ConfigWindowY, fromIntegral $ rect_y rect)
                                                             , (ConfigWindowWidth, fromIntegral $ rect_width rect)
                                                             , (ConfigWindowHeight, fromIntegral $ rect_height rect)
                                                             ]
            
            panel' <- createPanel win screenarea
            setPanelProperties panel'
            
            return panel'
          Nothing -> do
            win <- liftIO $ createPanelWindow conn screen config screenarea
            panel <- createPanel win screenarea
            setPanelProperties panel
            liftIO $ mapWindow conn $ panelWindow panel
            return panel
      
      modify $ \state -> state { phiPanels = panels' }
      
      sendMessage phi $ UpdateScreens $ map (panelScreenArea &&& panelWindow) panels'
      sendMessage phi Repaint


maybeReceiveEvents' :: Connection -> IO [XEvent]
maybeReceiveEvents' conn = do
  yield
  mevent <- pollForEvent conn
  case mevent of
    Just event ->
      liftM2 (:) (return . XEvent $ event) (maybeReceiveEvents' conn)
    Nothing ->
      return []
      

receiveEvents' :: Connection -> IO [XEvent]
receiveEvents' conn = do
  liftM2 (:) (liftM XEvent $ waitForEvent conn) (maybeReceiveEvents' conn)


receiveEvents :: Phi -> Connection -> IO ()
receiveEvents phi conn =
  forever $ receiveEvents' conn >>= sendMessages phi

updatePanels :: (Widget w s c X11) => PhiX w s c ()
updatePanels = do
  X11 conn _ screen <- asks phiX11
  xcb <- asks phiXCB
  w <- asks phiWidget
  s <- gets phiWidgetState
  rootImage <- gets phiRootImage
  panels <- gets phiPanels
    
  panels' <- forM panels $ \panel -> do
    let pixmap = panelPixmap panel
        area = panelArea panel
    
    (panelSurfaces, cache') <- liftIO $ flip runStateT (panelWidgetCache panel) $
                               (withDimension area $ render w s 0 0) (panelScreenArea panel)
    
    let visualtype = fromJust $ findVisualtype screen (root_visual_SCREEN screen)
    
    xbuffer <- liftIO $ withDimension area $ XCB.createXCBSurface xcb (fromXid . toXid $ pixmap) visualtype
    
    liftIO $ (withDimension area $ withSimilarSurface xbuffer ContentColor) $ \buffer -> do
      renderWith buffer $ do
        save
        translate (-(fromIntegral $ rect_x area)) (-(fromIntegral $ rect_y area))
        withPatternForSurface rootImage $ \pattern -> do
          patternSetExtend pattern ExtendRepeat
          setSource pattern
        paint
        restore
        
        forM_ panelSurfaces $ \(updated, SurfaceSlice x surface) -> do
          save
          translate (fromIntegral x) 0
          withPatternForSurface surface setSource
          paint
          restore
      
      renderWith xbuffer $ do
        withPatternForSurface buffer setSource
        paint
    
    surfaceFinish xbuffer
    
    -- update window
    liftIO $ withDimension area $ XCB.clearArea xcb True (panelWindow panel) 0 0
        
    return $ panel { panelWidgetCache = cache' }
  
  modify $ \state -> state { phiPanels = panels' }


updateRootImage :: PhiX w s c ()
updateRootImage = do
  X11 conn atoms screen <- asks phiX11 
  xcb <- asks phiXCB
  
  let visualtype = fromJust $ findVisualtype screen (root_visual_SCREEN screen)
      rootwin = root_SCREEN screen
  
  pixmap <- liftM (fromXid . toXid . fromMaybe 0 . listToMaybe . join . catMaybes) $ forM [atom_XROOTPMAP_ID atoms, atom_XROOTMAP_ID atoms] $
            \atom -> liftIO $ getProperty32 conn rootwin atom
  
  (pixmapWidth, pixmapHeight) <- case (fromXid . toXid $ (pixmap :: PIXMAP) :: Word32) of
    0 -> return (1, 1)
    _ -> liftIO $ getGeometry conn (fromXid . toXid $ pixmap) >>= getReply' "updateRootImage: getGeometry failed" >>= return . (width_GetGeometryReply &&& height_GetGeometryReply)
  
  -- update surface size
  oldBg <- gets phiRootImage
  imageWidth <- liftM fromIntegral $ imageSurfaceGetWidth oldBg
  imageHeight <- liftM fromIntegral $ imageSurfaceGetHeight oldBg
  when (imageWidth /= pixmapWidth || imageHeight /= pixmapHeight) $ do
    surfaceFinish oldBg
    newBg <- liftIO $ createImageSurface FormatRGB24 (fromIntegral pixmapWidth) (fromIntegral pixmapHeight)
    modify $ \state -> state { phiRootImage = newBg }
  
  bg <- gets phiRootImage
  
  case (fromXid . toXid $ pixmap :: Word32) of 
    0 -> do
      renderWith bg $ do
        setSourceRGB 0 0 0
        paint
    _ -> do
      rootSurface <- liftIO $ XCB.createXCBSurface xcb (fromXid . toXid $ pixmap) visualtype (fromIntegral pixmapWidth) (fromIntegral pixmapHeight)
      
      renderWith bg $ withPatternForSurface rootSurface $ \pattern -> do
        setSource pattern
        paint
      
      surfaceFinish rootSurface
  return ()


createPanel :: (Widget w s c X11) => WINDOW -> Rectangle -> PhiX w s c (PanelState w s c)
createPanel win screenRect = do
  (conn, screen) <- asks $ (x11Connection &&& x11Screen) . phiX11
  config <- asks phiPanelConfig
  w <- asks phiWidget
  let rect = panelBounds config screenRect
      depth = root_depth_SCREEN screen
    
  pixmap <- liftIO $ newResource conn
  liftIO $ createPixmap conn $ withDimension rect $ MkCreatePixmap depth pixmap (fromXid . toXid $ win)
  liftIO $ changeWindowAttributes conn win $ toValueParam [(CWBackPixmap, fromXid . toXid $ pixmap)]
  
  return PanelState { panelWindow = win
                    , panelPixmap = pixmap
                    , panelArea = rect
                    , panelScreenArea = screenRect
                    , panelWidgetCache = initCache w
                    }

createPanelWindow :: Connection -> SCREEN -> Panel.PanelConfig -> Rectangle -> IO WINDOW
createPanelWindow conn screen config screenRect = do
  let rect = panelBounds config screenRect
      depth = root_depth_SCREEN screen
      rootwin = root_SCREEN screen
      visual = root_visual_SCREEN screen
  win <- liftIO $ newResource conn
  createWindow conn $ (withRectangle rect $ MkCreateWindow depth win rootwin) 0 WindowClassInputOutput visual $
    toValueParam [(CWEventMask, toMask [EventMaskExposure]), (CWBackPixel, 0), (CWBorderPixel, 0)]
  return win


setPanelProperties :: PanelState w s c -> PhiX w s c ()
setPanelProperties panel = do
  (conn, atoms) <- asks $ (x11Connection &&& x11Atoms) .  phiX11
  liftIO $ do
    let name = map (fromIntegral . ord) "Phi"
    changeProperty8 conn PropModeReplace (panelWindow panel) (atomWM_NAME atoms) (atomSTRING atoms) name
    changeProperty8 conn PropModeReplace (panelWindow panel) (atom_NET_WM_NAME atoms) (atomUTF8_STRING atoms) name
    
    changeProperty32 conn PropModeReplace (panelWindow panel) (atom_NET_WM_WINDOW_TYPE atoms) (atomATOM atoms) [fromXid . toXid $ atom_NET_WM_WINDOW_TYPE_DOCK atoms]
    changeProperty32 conn PropModeReplace (panelWindow panel) (atom_NET_WM_DESKTOP atoms) (atomCARDINAL atoms) [0xFFFFFFFF]
    changeProperty32 conn PropModeReplace (panelWindow panel) (atom_NET_WM_STATE atoms) (atomATOM atoms) $
      map (fromXid . toXid) [ atom_NET_WM_STATE_SKIP_PAGER atoms
                            , atom_NET_WM_STATE_SKIP_TASKBAR atoms
                            , atom_NET_WM_STATE_STICKY atoms
                            , atom_NET_WM_STATE_BELOW atoms
                            ]
    
    changeProperty32 conn PropModeReplace (panelWindow panel) (atom_MOTIF_WM_HINTS atoms) (atom_MOTIF_WM_HINTS atoms) [ 2, 0, 0, 0, 0 ]
    
    changeProperty8 conn PropModeReplace (panelWindow panel) (atomWM_CLASS atoms) (atomSTRING atoms) $ map (fromIntegral . ord) "phi\0Phi"
  
  setStruts panel


setStruts :: PanelState w s c -> PhiX w s c ()
setStruts panel = do
  X11 conn atoms screen <- asks phiX11
  config <- asks phiPanelConfig
  let rootwin = root_SCREEN screen
      position = Panel.panelPosition config
      area = panelArea panel
  rootHeight <- liftIO $ getGeometry conn (fromXid . toXid $ rootwin) >>= getReply' "setStruts: getGeometry failed" >>= return . height_GetGeometryReply
  
  let struts = [makeStruts i | i <- [0..11]]
        where
          makeTopStruts 2 = (fromIntegral $ rect_y area) + (fromIntegral $ rect_height area)
          makeTopStruts 8 = (fromIntegral $ rect_x area)
          makeTopStruts 9 = (fromIntegral $ rect_x area) + (fromIntegral $ rect_width area) - 1
          makeTopStruts _ = 0
          
          makeBottomStruts 3 = (fromIntegral rootHeight) - (fromIntegral $ rect_y area)
          makeBottomStruts 10 = (fromIntegral $ rect_x area)
          makeBottomStruts 11 = (fromIntegral $ rect_x area) + (fromIntegral $ rect_width area) - 1
          makeBottomStruts _ = 0
          
          makeStruts = case position of
            Phi.Top -> makeTopStruts
            Phi.Bottom -> makeBottomStruts
  
  liftIO $ do
    changeProperty32 conn PropModeReplace (panelWindow panel) (atom_NET_WM_STRUT atoms) (atomCARDINAL atoms) $ take 4 struts
    changeProperty32 conn PropModeReplace (panelWindow panel) (atom_NET_WM_STRUT_PARTIAL atoms) (atomCARDINAL atoms) struts


panelBounds :: Panel.PanelConfig -> Rectangle -> Rectangle
panelBounds config screenBounds = case Panel.panelPosition config of
  Phi.Top -> screenBounds { rect_height = Panel.panelSize config }
  Phi.Bottom -> screenBounds { rect_height = Panel.panelSize config,
                               rect_y = rect_y screenBounds + rect_height screenBounds - Panel.panelSize config }

withRectangle :: (Num x, Num y, Num w, Num h) => Rectangle -> (x -> y -> w -> h -> a) -> a
withRectangle r = withDimension r . withPosition r

withPosition :: (Num x, Num y) => Rectangle -> (x -> y -> a) -> a
withPosition r f = f (fromIntegral $ rect_x r) (fromIntegral $ rect_y r)

withDimension :: (Num w, Num h) => Rectangle -> (w -> h -> a) -> a
withDimension r f = f (fromIntegral $ rect_width r) (fromIntegral $ rect_height r)