{-# LANGUAGE CPP #-}
{-# LANGUAGE TupleSections #-}

------------------------------------------------------------------------------
-- |
-- Module: Xmobar.X11.Draw
-- Copyright: (c) 2018, 2020, 2022 Jose Antonio Ortega Ruiz
-- License: BSD3-style (see LICENSE)
--
-- Maintainer: jao@gnu.org
-- Stability: unstable
-- Portability: portable
-- Created: Sat Nov 24, 2018 18:49
--
--
-- Drawing the xmobar contents
--
------------------------------------------------------------------------------


module Xmobar.X11.Draw (drawInWin) where

import Prelude hiding (lookup)
import Control.Monad.IO.Class
import Control.Monad.Reader
import Control.Arrow ((&&&))
import Data.Map hiding ((\\), foldr, map, filter)
import Data.List ((\\))
import qualified Data.List.NonEmpty as NE

import Graphics.X11.Xlib hiding (textExtents, textWidth, Segment)
import Graphics.X11.Xlib.Extras

import Xmobar.Config.Types
import Xmobar.Run.Parsers hiding (parseString)
import qualified Xmobar.X11.Bitmap as B
import Xmobar.X11.Types
import Xmobar.X11.Text
import Xmobar.X11.ColorCache
import Xmobar.X11.Window (drawBorder)
import Xmobar.System.Utils (safeIndex)

#ifdef XFT
import Xmobar.X11.MinXft
import Graphics.X11.Xrender
#endif

fi :: (Integral a, Num b) => a -> b
fi = fromIntegral

-- | Draws in and updates the window
drawInWin :: Rectangle -> [[Segment]] -> X ()
drawInWin wr@(Rectangle _ _ wid ht) ~[left,center,right] = do
  r <- ask
  let (c,d) = (config &&& display) r
      (w,(fs,vs)) = (window &&& fontListS &&& verticalOffsets) r
      strLn = liftIO . mapM getWidth
      iconW i = maybe 0 B.width (lookup i $ iconS r)
      getWidth (Text s,cl,i,_) =
        textWidth d (safeIndex fs i) s >>= \tw -> return (Text s,cl,i,fi tw)
      getWidth (Icon s,cl,i,_) = return (Icon s,cl,i,fi $ iconW s)
      getWidth (Hspace p,cl,i,_) = return (Hspace p,cl,i,fi p)

  p <- liftIO $ createPixmap d w wid ht
                         (defaultDepthOfScreen (defaultScreenOfDisplay d))
#if XFT
  when (alpha c /= 255) (liftIO $ drawBackground d p (bgColor c) (alpha c) wr)
#else
  _ <- return wr
#endif
  withColors d [bgColor c, borderColor c] $ \[bgcolor, bdcolor] -> do
    gc <- liftIO $ createGC  d w
    liftIO $ setGraphicsExposures d gc False
#if XFT
    when (alpha c == 255) $ do
#else
    do
#endif
      liftIO $ setForeground d gc bgcolor
      liftIO $ fillRectangle d p gc 0 0 wid ht
    -- write to the pixmap the new string
    printStrings p gc fs vs 1 L [] =<< strLn left
    printStrings p gc fs vs 1 R [] =<< strLn right
    printStrings p gc fs vs 1 C [] =<< strLn center
    -- draw border if requested
    liftIO $ drawBorder (border c) (borderWidth c) d p gc bdcolor wid ht
    -- copy the pixmap with the new string to the window
    liftIO $ copyArea d p w gc 0 0 wid ht 0 0
    -- free up everything (we do not want to leak memory!)
    liftIO $ freeGC d gc
    liftIO $ freePixmap d p
    -- resync (discard events, we don't read/process events from this display conn)
    liftIO $ sync d True

verticalOffset :: (Integral b, Integral a, MonadIO m) =>
                  a -> Widget -> XFont -> Int -> Config -> m b
verticalOffset ht (Text t) fontst voffs _
  | voffs > -1 = return $ fi voffs
  | otherwise = do
     (as,ds) <- liftIO $ textExtents fontst t
     let margin = (fi ht - fi ds - fi as) `div` 2
     return $ fi as + margin - 1
verticalOffset ht (Icon _) _ _ conf
  | iconOffset conf > -1 = return $ fi (iconOffset conf)
  | otherwise = return $ fi (ht `div` 2) - 1
verticalOffset _ (Hspace _) _ voffs _ = return $ fi voffs

printString :: Display
            -> Drawable
            -> XFont
            -> GC
            -> String
            -> String
            -> Position
            -> Position
            -> Position
            -> Position
            -> String
            -> Int
            -> IO ()
printString d p (Core fs) gc fc bc x y _ _ s a = do
    setFont d gc $ fontFromFontStruct fs
    withColors d [fc, bc] $ \[fc', bc'] -> do
      setForeground d gc fc'
      when (a == 255) (setBackground d gc bc')
      drawImageString d p gc x y s

printString d p (Utf8 fs) gc fc bc x y _ _ s a =
    withColors d [fc, bc] $ \[fc', bc'] -> do
      setForeground d gc fc'
      when (a == 255) (setBackground d gc bc')
      liftIO $ wcDrawImageString d p fs gc x y s

#ifdef XFT
printString dpy drw fs@(Xft fonts) _ fc bc x y ay ht s al =
  withDrawingColors dpy drw fc bc $ \draw fc' bc' -> do
    when (al == 255) $ do
      (a,d)  <- textExtents fs s
      gi <- xftTxtExtents' dpy fonts s
      if ay < 0
        then drawXftRect draw bc' x (y - a) (1 + xglyphinfo_xOff gi) (a + d + 2)
        else drawXftRect draw bc' x ay (1 + xglyphinfo_xOff gi) ht
    drawXftString' draw fc' fonts (toInteger x) (toInteger y) s
#endif

-- | An easy way to print the stuff we need to print
printStrings :: Drawable
             -> GC
             -> NE.NonEmpty XFont
             -> NE.NonEmpty Int
             -> Position
             -> Align
             -> [((Position, Position), Box)]
             -> [(Widget, TextRenderInfo, Int, Position)] -> X ()
printStrings _ _ _ _ _ _ _ [] = return ()
printStrings dr gc fontlist voffs offs a boxes sl@((s,c,i,l):xs) = do
  r <- ask
  let (conf,d) = (config &&& display) r
      alph = alpha conf
      Rectangle _ _ wid ht = rect r
      totSLen = foldr (\(_,_,_,len) -> (+) len) 0 sl
      remWidth = fi wid - fi totSLen
      fontst = safeIndex fontlist i
      voff = safeIndex voffs i
      offset = case a of
                 C -> (remWidth + offs) `div` 2
                 R -> remWidth
                 L -> offs
      (fc,bc) = colorComponents conf (tColorsString c)
  valign <- verticalOffset ht s fontst voff conf
  let (ht',ay) = case (tBgTopOffset c, tBgBottomOffset c) of
                   (-1,_)  -> (0, -1)
                   (_,-1)  -> (0, -1)
                   (ot,ob) -> (fromIntegral ht - ot - ob, ob)
  case s of
    (Text t) -> liftIO $ printString d dr fontst gc fc bc offset valign ay ht' t alph
    (Icon p) -> liftIO $ maybe (return ())
                           (B.drawBitmap d dr gc fc bc offset valign)
                           (lookup p (iconS r))
    (Hspace _) -> liftIO $ return ()
  let triBoxes = tBoxes c
      dropBoxes = filter (\(_,b) -> b `notElem` triBoxes) boxes
      boxes' = map (\((x1,_),b) -> ((x1, offset + l), b))
                   (filter (\(_,b) -> b `elem` triBoxes) boxes)
            ++ map ((offset, offset + l),) (triBoxes \\ map snd boxes)
  if Prelude.null xs
    then liftIO $ drawBoxes d dr gc (fromIntegral ht) (dropBoxes ++ boxes')
    else liftIO $ drawBoxes d dr gc (fromIntegral ht) dropBoxes
  printStrings dr gc fontlist voffs (offs + l) a boxes' xs

drawBoxes :: Display
          -> Drawable
          -> GC
          -> Position
          -> [((Position, Position), Box)]
          -> IO ()
drawBoxes _ _ _ _ [] = return ()
drawBoxes d dr gc ht (b:bs) = do
  let (xx, Box bb offset lineWidth fc mgs) = b
      lw = fromIntegral lineWidth :: Position
  withColors d [fc] $ \[fc'] -> do
    setForeground d gc fc'
    setLineAttributes d gc lineWidth lineSolid capNotLast joinMiter
    case bb of
      BBVBoth -> do
        drawBoxBorder d dr gc BBTop    offset ht xx lw mgs
        drawBoxBorder d dr gc BBBottom offset ht xx lw mgs
      BBHBoth -> do
        drawBoxBorder d dr gc BBLeft   offset ht xx lw mgs
        drawBoxBorder d dr gc BBRight  offset ht xx lw mgs
      BBFull  -> do
        drawBoxBorder d dr gc BBTop    offset ht xx lw mgs
        drawBoxBorder d dr gc BBBottom offset ht xx lw mgs
        drawBoxBorder d dr gc BBLeft   offset ht xx lw mgs
        drawBoxBorder d dr gc BBRight  offset ht xx lw mgs
      _ -> drawBoxBorder d dr gc bb    offset ht xx lw mgs
  drawBoxes d dr gc ht bs

drawBoxBorder :: Display
              -> Drawable
              -> GC
              -> BoxBorder
              -> BoxOffset
              -> Position
              -> (Position, Position)
              -> Position
              -> BoxMargins
              -> IO ()
drawBoxBorder
  d dr gc pos (BoxOffset alg offset) ht (x1,x2) lw (BoxMargins mt mr mb ml) = do
  let (p1,p2) = case alg of
                 L -> (0,      -offset)
                 C -> (offset, -offset)
                 R -> (offset, 0      )
      lc = lw `div` 2
  case pos of
    BBTop    -> drawLine d dr gc (x1 + p1) (mt + lc) (x2 + p2) (mt + lc)
    BBBottom -> do
      let lc' = max lc 1 + mb
      drawLine d dr gc (x1 + p1) (ht - lc') (x2 + p2) (ht - lc')
    BBLeft   -> drawLine d dr gc (x1 - 1 + ml) p1 (x1 - 1 + ml) (ht + p2)
    BBRight  -> drawLine d dr gc (x2 + lc - 1 - mr) p1 (x2 + lc - 1 - mr) (ht + p2)
    _ -> error "unreachable code"
