{-# LANGUAGE GeneralizedNewtypeDeriving #-}

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

import Graphics.X11.Xlib
import Graphics.X11.Xlib.Extras
import Graphics.X11.Xinerama

import Graphics.Rendering.Cairo

import Control.Monad
import Data.Maybe
import Data.Bits
import Data.Char

import Control.Concurrent
import Control.Concurrent.MVar
import Control.Monad.State
import Control.Monad.Reader
import Control.Monad.Trans

import System.Posix.Types

import Phi.Phi
import qualified Phi.Types as Phi
import qualified Phi.Panel as Panel
import qualified Phi.Widget as Widget
import Phi.X11.Atoms
import qualified Phi.Bindings.Util as Util


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

data PhiState = PhiState { phiRootImage  :: !Surface
                         , phiPanels     :: ![PanelState]
                         , phiRepaint    :: !Bool
                         }

data PanelState = PanelState { panelWindow       :: !Window
                             , panelPixmap       :: !Pixmap
                             , panelArea         :: !Rectangle
                             , panelScreenArea   :: !Rectangle
                             , panelWidgetStates :: ![Widget.WidgetState]
                             }

data PhiConfig = PhiConfig { phiPhi         :: !Phi
                           , phiPanelConfig :: !Panel.PanelConfig
                           , phiXConfig     :: !XConfig
                           , phiAtoms       :: !Atoms
                           }

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

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

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

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

defaultXConfig = XConfig { phiXScreenInfo = getScreenInfo
                         }


runPhi :: XConfig -> Panel.PanelConfig -> [Widget.Widget] -> IO ()
runPhi xconfig config widgets = do
  xSetErrorHandler
  
  phi <- initPhi
  disp <- openDisplay []
  
  atoms <- initAtoms disp
  selectInput disp (defaultRootWindow disp) $ propertyChangeMask.|.structureNotifyMask
  
  bg <- createImageSurface FormatRGB24 1 1
  runPhiX PhiConfig { phiPhi = phi, phiXConfig = xconfig, phiPanelConfig = config, phiAtoms = atoms } PhiState { phiRootImage = bg, phiPanels = [], phiRepaint = True } $ do
    updateRootImage disp
    
    screens <- liftIO $ phiXScreenInfo xconfig disp
    
    panelWindows <- mapM (createPanelWindow disp) screens
                      
    dispmvar <- liftIO $ newMVar disp
    let screenPanels = zip screens panelWindows
        dispvar = Widget.Display dispmvar atoms screenPanels
    widgetStates <- liftIO $ mapM (Widget.createWidgetState phi dispvar) widgets
    
    Widget.withDisplay dispvar $ \disp -> do
      panels <- mapM (\(screen, window) -> createPanel disp window widgetStates screen) screenPanels
      
      forM_ panels $ \panel -> do
        setPanelProperties disp panel
        liftIO $ mapWindow disp (panelWindow panel)
      
      modify $ \state -> state { phiPanels = panels }
      
    liftIO $ forkIO $ receiveEvents phi dispvar

    forever $ do
      available <- messageAvailable phi
      unless available $ do
        repaint <- gets phiRepaint
        when repaint $ do
          updatePanels dispvar
          modify $ \state -> state {phiRepaint = False}
      
      message <- receiveMessage phi
      handleMessage dispvar message
  return ()


handlePanel :: Message -> PanelState -> PanelState
handlePanel message panel@PanelState {panelWidgetStates = widgets} = panel {panelWidgetStates = widgets'}
  where
    widgets' = Widget.handleMessageWidgets message widgets

handleMessage :: Widget.Display -> Message -> PhiX ()
handleMessage dispvar m = do
  modify $ \state@PhiState {phiPanels = panels} -> state {phiPanels = map (handlePanel m) panels}
  
  case (fromMessage m) of
    Just Repaint ->
      modify $ \state -> state {phiRepaint = True}
    _ ->
      case (fromMessage m) of
        Just event@PropertyEvent {} ->
          Widget.withDisplay dispvar $ flip handlePropertyUpdate event
        _ ->
          return ()

receiveEvents :: Phi -> Widget.Display -> IO ()
receiveEvents phi dispvar = do
  connection <- Widget.withDisplay dispvar $ return . Fd . connectionNumber
  
  allocaXEvent $ \xevent -> forever $ do
    handled <- Widget.withDisplay dispvar $ \disp -> do
      pend <- pending disp
      if pend /= 0 then
        do
          liftIO $ nextEvent disp xevent
          event <- liftIO $ Util.getEvent disp xevent
          sendMessage phi event

          return True
        else return False
      
    when (not handled) $ threadWaitRead connection

updatePanels :: Widget.Display -> PhiX ()
updatePanels dispvar = do
  rootImage <- gets phiRootImage
  panels <- gets phiPanels
    
  panels' <- forM panels $ \panel -> do
    let pixmap = panelPixmap panel
        area = panelArea panel
    
    let layoutedWidgets = (withDimension area $ Widget.layoutWidgets (panelWidgetStates panel) 0 0) $ panelScreenArea panel
        panel' = panel { panelWidgetStates = layoutedWidgets }
    
    Widget.withDisplay dispvar $ \disp -> do
      let screen = defaultScreen disp
          visual = defaultVisual disp screen
      
      buffer <- liftIO $ withDimension area $ Util.createXlibSurface disp pixmap visual
      
      renderWith buffer $ do
        withPatternForSurface rootImage $ \pattern -> do
          save
          translate (-(fromIntegral $ rect_x area)) (-(fromIntegral $ rect_y area))
          setSource pattern
          paint
          restore
        Widget.renderWidgets layoutedWidgets $ panelScreenArea panel
      
      surfaceFinish buffer
      
      -- copy buffer to window
      liftIO $ do
        setWindowBackgroundPixmap disp (panelWindow panel') pixmap
        (withDimension area $ clearArea disp (panelWindow panel') 0 0) True
        sync disp False
    
    return panel'
  
  modify $ \state -> state { phiPanels = panels' }


handlePropertyUpdate :: Display -> Event -> PhiX ()
handlePropertyUpdate disp PropertyEvent { ev_atom = atom } = do
  phi <- asks phiPhi
  atoms <- asks phiAtoms
  panels <- gets phiPanels

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

updateRootImage :: Display -> PhiX ()
updateRootImage disp = do
  atoms <- asks phiAtoms
  
  let screen = defaultScreen disp
      visual = defaultVisual disp screen
      rootwin = defaultRootWindow disp
  pixmap <- liftM (fromIntegral . fromMaybe 0 . listToMaybe . join . catMaybes) $ forM [atom_XROOTPMAP_ID atoms, atom_XROOTMAP_ID atoms] $
            \atom -> liftIO $ getWindowProperty32 disp atom rootwin
  (_, _, _, rootWidth, rootHeight, _, _) <- liftIO $ getGeometry disp rootwin
  
  -- update surface size
  oldBg <- gets phiRootImage
  imageWidth <- liftM fromIntegral $ imageSurfaceGetWidth oldBg
  imageHeight <- liftM fromIntegral $ imageSurfaceGetHeight oldBg
  when (imageWidth /= rootWidth || imageHeight /= rootHeight) $ do
    surfaceFinish oldBg
    newBg <- liftIO $ createImageSurface FormatRGB24 (fromIntegral rootWidth) (fromIntegral rootHeight)
    modify $ \state -> state { phiRootImage = newBg }
  
  bg <- gets phiRootImage
  rootSurface <- liftIO $ Util.createXlibSurface disp pixmap visual (fromIntegral rootWidth) (fromIntegral rootHeight)
  
  renderWith bg $ withPatternForSurface rootSurface $ \pattern -> do
    setSource pattern
    paint
  
  surfaceFinish rootSurface


createPanel :: Display -> Window -> [Widget.WidgetState] -> Rectangle -> PhiX PanelState
createPanel disp win widgets screenRect = do
  config <- asks phiPanelConfig
  let rect = panelBounds config screenRect
  let screen = defaultScreen disp
      depth = defaultDepth disp screen
    
  pixmap <- liftIO $ (withDimension rect $ createPixmap disp win) depth
  
  return PanelState { panelWindow = win
                    , panelPixmap = pixmap
                    , panelArea = rect
                    , panelScreenArea = screenRect
                    , panelWidgetStates = widgets
                    }

createPanelWindow :: Display -> Rectangle -> PhiX Window
createPanelWindow disp screenRect = do
  config <- asks phiPanelConfig
  let rect = panelBounds config screenRect
      screen = defaultScreen disp
      depth = defaultDepth disp screen
      visual = defaultVisual disp screen
      colormap = defaultColormap disp screen
      rootwin = defaultRootWindow disp
      mask = cWEventMask.|.cWColormap.|.cWBackPixel.|.cWBorderPixel

  liftIO $ allocaSetWindowAttributes $ \attr -> do
    set_colormap attr colormap
    set_background_pixel attr 0
    set_border_pixel attr 0
    set_event_mask attr exposureMask
    withRectangle rect (createWindow disp rootwin) 0 depth inputOutput visual mask attr


setPanelProperties :: Display -> PanelState -> PhiX ()
setPanelProperties disp panel = do
  atoms <- asks phiAtoms
  liftIO $ do
    storeName disp (panelWindow panel) "Phi"
    changeProperty8 disp (panelWindow panel) (atom_NET_WM_NAME atoms) (atomUTF8_STRING atoms) propModeReplace $ map (fromIntegral . ord) "Phi"
    
    changeProperty32 disp (panelWindow panel) (atom_NET_WM_WINDOW_TYPE atoms) aTOM propModeReplace [fromIntegral (atom_NET_WM_WINDOW_TYPE_DOCK atoms)]
    changeProperty32 disp (panelWindow panel) (atom_NET_WM_DESKTOP atoms) cARDINAL propModeReplace [0xFFFFFFFF]
    changeProperty32 disp (panelWindow panel) (atom_NET_WM_STATE atoms) aTOM propModeReplace [ fromIntegral (atom_NET_WM_STATE_SKIP_PAGER atoms)
                                                                                             , fromIntegral (atom_NET_WM_STATE_SKIP_TASKBAR atoms)
                                                                                             , fromIntegral (atom_NET_WM_STATE_STICKY atoms)
                                                                                             , fromIntegral (atom_NET_WM_STATE_BELOW atoms)
                                                                                             ]
    setWMHints disp (panelWindow panel) WMHints { wmh_flags = fromIntegral inputHintBit
                                                , wmh_input = False
                                                , wmh_initial_state = 0
                                                , wmh_icon_pixmap = 0
                                                , wmh_icon_window = 0
                                                , wmh_icon_x = 0
                                                , wmh_icon_y = 0
                                                , wmh_icon_mask = 0
                                                , wmh_window_group = 0
                                                }
    changeProperty32 disp (panelWindow panel) (atom_MOTIF_WM_HINTS atoms) (atom_MOTIF_WM_HINTS atoms) propModeReplace [ 2, 0, 0, 0, 0 ]
    
    Util.setClassHint disp (panelWindow panel) ClassHint { resName = "phi", resClass = "Phi" }
    
  setStruts disp panel


setStruts :: Display -> PanelState -> PhiX ()
setStruts disp panel = do
  atoms <- asks phiAtoms
  config <- asks phiPanelConfig
  let rootwin = defaultRootWindow disp
      position = Panel.panelPosition config
      area = panelArea panel
  (_, _, _, _, rootHeight, _, _) <- liftIO $ getGeometry disp rootwin
  
  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 disp (panelWindow panel) (atom_NET_WM_STRUT atoms) cARDINAL propModeReplace $ take 4 struts
    changeProperty32 disp (panelWindow panel) (atom_NET_WM_STRUT_PARTIAL atoms) cARDINAL propModeReplace struts


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