{-# LANGUAGE GeneralizedNewtypeDeriving, ExistentialQuantification #-}

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

import Graphics.XHB
import Graphics.XHB.Gen.Xinerama
import Graphics.XHB.Gen.Xproto

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
import Phi.Widget hiding (Display, handleMessage)
import Phi.X11.Atoms


data XConfig = XConfig { phiXScreenInfo :: !(Connection -> IO [RECTANGLE])
                       }

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

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

data PhiConfig w s c = PhiConfig { phiPhi          :: !Phi
                                 , phiPanelConfig  :: !Panel.PanelConfig
                                 , phiXConfig      :: !XConfig
                                 , phiAtoms        :: !Atoms
                                 , 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 :: Connection -> IO [RECTANGLE]
getScreenInfo conn = do
  exs <- queryScreens conn >>= getReply
  case exs of
    Right xs -> return . map screenInfoToRect $ screen_info_QueryScreensReply xs
    Left _ -> getGeometry conn (fromXid . toXid $ getRoot conn) >>= getReply' "getScreenInfo: getGeometry failed" >>=
              return . (\(MkGetGeometryReply _ _ x y w h _) -> [MkRECTANGLE x y w h])
  where
    screenInfoToRect (MkScreenInfo x y w h) = MkRECTANGLE x y w h

runPhi :: (Widget.Widget w s c) => 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
  
  atoms <- initAtoms conn
  changeWindowAttributes conn (getRoot conn) $ toValueParam [(CWEventMask, toMask [EventMaskPropertyChange, EventMaskStructureNotify])]
  
  bg <- createImageSurface FormatRGB24 1 1
  
  screens <- liftIO $ phiXScreenInfo xconfig conn
  panelWindows <- mapM (createPanelWindow conn config) screens
  let dispvar = Widget.Display conn atoms
      widget' = widget <~> separator 0 (if weight widget > 0 then 0 else 1)
      screenPanels = zip screens panelWindows

  initialState <- Widget.initWidget widget' phi dispvar screenPanels

  runPhiX
    PhiConfig { phiPhi = phi
              , phiXConfig = xconfig
              , phiPanelConfig = config
              , phiAtoms = atoms
              , phiWidget = widget'
              }
    PhiState { phiRootImage = bg
             , phiPanels = []
             , phiRepaint = True
             , phiShutdown = False
             , phiShutdownHold = 0
             , phiWidgetState = initialState
             } $ do
    updateRootImage conn xcb
    
    panels <- mapM (\(screen, window) -> createPanel conn window screen) screenPanels
    
    forM_ panels $ \panel -> do
      setPanelProperties conn panel
      liftIO $ mapWindow conn (panelWindow panel)
    
    modify $ \state -> state { phiPanels = panels }
    
    liftIO $ forkIO $ receiveEvents phi conn
    
    forever $ do
      available <- messageAvailable phi
      unless available $ do
        repaint <- gets phiRepaint
        when repaint $ do
          updatePanels conn xcb
          modify $ \state -> state {phiRepaint = False}
      
      message <- receiveMessage phi
      handleMessage conn xcb 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) => Connection -> XCB.Connection -> Message -> PhiX w s c ()
handleMessage conn xcb 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 conn xcb event
        _ ->
          return ()

handleEvent :: (Widget w s c) => Connection -> XCB.Connection -> SomeEvent -> PhiX w s c ()
handleEvent conn xcb event =
  case (fromEvent event) of
    Just e -> handlePropertyNotifyEvent conn xcb e
    Nothing -> case (fromEvent event) of
      Just e -> handleConfigureNotifyEvent conn e
      Nothing -> return ()

handlePropertyNotifyEvent :: (Widget w s c) => Connection -> XCB.Connection -> PropertyNotifyEvent -> PhiX w s c ()
handlePropertyNotifyEvent conn xcb MkPropertyNotifyEvent { atom_PropertyNotifyEvent = atom } = do
  phi <- asks phiPhi
  atoms <- asks phiAtoms
  panels <- gets phiPanels

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

handleConfigureNotifyEvent :: (Widget w s c) => Connection -> ConfigureNotifyEvent -> PhiX w s c ()
handleConfigureNotifyEvent conn MkConfigureNotifyEvent { window_ConfigureNotifyEvent = window } | window == getRoot conn = do  
  phi <- asks phiPhi
  xconfig <- asks phiXConfig
  config <- asks phiPanelConfig
  panels <- gets phiPanels
  let screens = map panelScreenArea panels
  screens' <- liftIO $ phiXScreenInfo xconfig conn
  
  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 $ \(screen, mpanel) ->
      case mpanel of
        Just panel -> do
          let rect = panelBounds config screen
              win = panelWindow panel
          
          liftIO $ configureWindow conn win $ toValueParam [ (ConfigWindowX, fromIntegral $ x_RECTANGLE rect)
                                                           , (ConfigWindowY, fromIntegral $ y_RECTANGLE rect)
                                                           , (ConfigWindowWidth, fromIntegral $ width_RECTANGLE rect)
                                                           , (ConfigWindowHeight, fromIntegral $ height_RECTANGLE rect)
                                                           ]
          
          panel' <- createPanel conn win screen
          setPanelProperties conn panel'
          
          return panel'
        Nothing -> do
          win <- liftIO $ createPanelWindow conn config screen
          panel <- createPanel conn win screen
          setPanelProperties conn panel
          liftIO $ mapWindow conn $ panelWindow panel
          return panel
    
    modify $ \state -> state { phiPanels = panels' }
    
    sendMessage phi $ UpdateScreens $ map (panelScreenArea &&& panelWindow) panels'
    sendMessage phi Repaint

handleConfigureNotifyEvent _ _ = return ()

receiveEvents :: Phi -> Connection -> IO ()
receiveEvents phi conn = do
  forever $ waitForEvent conn >>= sendMessage phi . XEvent

updatePanels :: (Widget w s c) => Connection -> XCB.Connection -> PhiX w s c ()
updatePanels conn xcb = do
  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 $ Widget.render w s 0 0) (panelScreenArea panel)
    
    let screen = head . roots_Setup . connectionSetup $ conn
        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 $ x_RECTANGLE area)) (-(fromIntegral $ y_RECTANGLE 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 :: Connection -> XCB.Connection -> PhiX w s c ()
updateRootImage conn xcb = do
  atoms <- asks phiAtoms
  
  let screen = head . roots_Setup . connectionSetup $ conn
      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) => Connection -> WINDOW -> RECTANGLE -> PhiX w s c (PanelState w s c)
createPanel conn win screenRect = do
  config <- asks phiPanelConfig
  w <- asks phiWidget
  let rect = panelBounds config screenRect
      screen = head . roots_Setup . connectionSetup $ conn
      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 -> Panel.PanelConfig -> RECTANGLE -> IO WINDOW
createPanelWindow conn config screenRect = do
  let rect = panelBounds config screenRect
      screen = head . roots_Setup . connectionSetup $ conn
      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 :: Connection -> PanelState w s c -> PhiX w s c ()
setPanelProperties conn panel = do
  atoms <- asks phiAtoms
  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 conn panel


setStruts :: Connection -> PanelState w s c -> PhiX w s c ()
setStruts conn panel = do
  atoms <- asks phiAtoms
  config <- asks phiPanelConfig
  let rootwin = getRoot conn
      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 $ y_RECTANGLE area) + (fromIntegral $ height_RECTANGLE area)
          makeTopStruts 8 = (fromIntegral $ x_RECTANGLE area)
          makeTopStruts 9 = (fromIntegral $ x_RECTANGLE area) + (fromIntegral $ width_RECTANGLE area) - 1
          makeTopStruts _ = 0
          
          makeBottomStruts 3 = (fromIntegral rootHeight) - (fromIntegral $ y_RECTANGLE area)
          makeBottomStruts 10 = (fromIntegral $ x_RECTANGLE area)
          makeBottomStruts 11 = (fromIntegral $ x_RECTANGLE area) + (fromIntegral $ width_RECTANGLE 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 { height_RECTANGLE = fromIntegral $ Panel.panelSize config }
  Phi.Bottom -> screenBounds { height_RECTANGLE = fromIntegral $ Panel.panelSize config,
                                        y_RECTANGLE = (y_RECTANGLE screenBounds) + (fromIntegral $ height_RECTANGLE screenBounds) - (fromIntegral $ 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 $ x_RECTANGLE r) (fromIntegral $ y_RECTANGLE r)

withDimension :: (Num w, Num h) => RECTANGLE -> (w -> h -> a) -> a
withDimension r f = f (fromIntegral $ width_RECTANGLE r) (fromIntegral $ height_RECTANGLE r)