{-# LANGUAGE PatternGuards #-}
-----------------------------------------------------------------------------
-- |
-- Module      :  XMonad.Util.NamedScratchpad
-- Copyright   :  (c) Konstantin Sobolev <konstantin.sobolev@gmail.com>
-- License     :  BSD-style (see LICENSE)
--
-- Maintainer  :  Konstantin Sobolev <konstantin.sobolev@gmail.com>
-- Stability   :  unstable
-- Portability :  unportable
--
-- Named scratchpads that support several arbitrary applications at the same time.
--
-----------------------------------------------------------------------------

module XMonad.Util.NamedScratchpad (
  -- * Usage
  -- $usage
  NamedScratchpad(..),
  nonFloating,
  defaultFloating,
  customFloating,
  NamedScratchpads,
  namedScratchpadAction,
  spawnHereNamedScratchpadAction,
  customRunNamedScratchpadAction,
  allNamedScratchpadAction,
  namedScratchpadManageHook,
  namedScratchpadFilterOutWorkspace,
  namedScratchpadFilterOutWorkspacePP
  ) where

import XMonad
import XMonad.Hooks.ManageHelpers (doRectFloat)
import XMonad.Actions.DynamicWorkspaces (addHiddenWorkspace)
import XMonad.Hooks.DynamicLog (PP, ppSort)
import XMonad.Actions.SpawnOn (spawnHere)

import qualified Data.List.NonEmpty as NE

import Control.Monad (filterM, unless)
import Data.Maybe (listToMaybe)

import qualified XMonad.StackSet as W


-- $usage
-- Allows to have several floating scratchpads running different applications.
-- Bind a key to 'namedScratchpadSpawnAction'.
-- Pressing it will spawn configured application, or bring it to the current
-- workspace if it already exists.
-- Pressing the key with the application on the current workspace will
-- send it to a hidden workspace called @NSP@.
--
-- If you already have a workspace called @NSP@, it will use that.
-- @NSP@ will also appear in xmobar and dzen status bars. You can tweak your
-- @dynamicLog@ settings to filter it out if you like.
--
-- Create named scratchpads configuration in your xmonad.hs like this:
--
-- > import XMonad.StackSet as W
-- > import XMonad.ManageHook
-- > import XMonad.Util.NamedScratchpad
-- >
-- > scratchpads = [
-- > -- run htop in xterm, find it by title, use default floating window placement
-- >     NS "htop" "xterm -e htop" (title =? "htop") defaultFloating ,
-- >
-- > -- run stardict, find it by class name, place it in the floating window
-- > -- 1/6 of screen width from the left, 1/6 of screen height
-- > -- from the top, 2/3 of screen width by 2/3 of screen height
-- >     NS "stardict" "stardict" (className =? "Stardict")
-- >         (customFloating $ W.RationalRect (1/6) (1/6) (2/3) (2/3)) ,
-- >
-- > -- run gvim, find by role, don't float
-- >     NS "notes" "gvim --role notes ~/notes.txt" (role =? "notes") nonFloating
-- > ] where role = stringProperty "WM_WINDOW_ROLE"
--
-- Add keybindings:
--
-- >  , ((modm .|. controlMask .|. shiftMask, xK_t), namedScratchpadAction scratchpads "htop")
-- >  , ((modm .|. controlMask .|. shiftMask, xK_s), namedScratchpadAction scratchpads "stardict")
-- >  , ((modm .|. controlMask .|. shiftMask, xK_n), namedScratchpadAction scratchpads "notes")
--
-- ... and a manage hook:
--
-- >  , manageHook = namedScratchpadManageHook scratchpads
--
-- For detailed instruction on editing the key binding see
-- "XMonad.Doc.Extending#Editing_key_bindings"
--

-- | Single named scratchpad configuration
data NamedScratchpad = NS { name   :: String      -- ^ Scratchpad name
                          , cmd    :: String      -- ^ Command used to run application
                          , query  :: Query Bool  -- ^ Query to find already running application
                          , hook   :: ManageHook  -- ^ Manage hook called for application window, use it to define the placement. See @nonFloating@, @defaultFloating@ and @customFloating@
                          }

-- | Manage hook that makes the window non-floating
nonFloating :: ManageHook
nonFloating = idHook

-- | Manage hook that makes the window floating with the default placement
defaultFloating :: ManageHook
defaultFloating = doFloat

-- | Manage hook that makes the window floating with custom placement
customFloating :: W.RationalRect -> ManageHook
customFloating = doRectFloat

-- | Named scratchpads configuration
type NamedScratchpads = [NamedScratchpad]

-- | Finds named scratchpad configuration by name
findByName :: NamedScratchpads -> String -> Maybe NamedScratchpad
findByName c s = listToMaybe $ filter ((s ==) . name) c

-- | Runs application which should appear in specified scratchpad
runApplication :: NamedScratchpad -> X ()
runApplication = spawn . cmd

-- | Runs application which should appear in a specified scratchpad on the workspace it was launched on
runApplicationHere :: NamedScratchpad -> X ()
runApplicationHere = spawnHere . cmd

-- | Action to pop up specified named scratchpad
namedScratchpadAction :: NamedScratchpads -- ^ Named scratchpads configuration
                      -> String           -- ^ Scratchpad name
                      -> X ()
namedScratchpadAction = customRunNamedScratchpadAction runApplication

-- | Action to pop up specified named scratchpad, initially starting it on the current workspace.
spawnHereNamedScratchpadAction :: NamedScratchpads           -- ^ Named scratchpads configuration
                               -> String                     -- ^ Scratchpad name
                               -> X ()
spawnHereNamedScratchpadAction = customRunNamedScratchpadAction runApplicationHere

-- | Action to pop up specified named scratchpad, given a custom way to initially start the application.
customRunNamedScratchpadAction :: (NamedScratchpad -> X ())  -- ^ Function initially running the application, given the configured @scratchpad@ cmd
                               -> NamedScratchpads           -- ^ Named scratchpads configuration
                               -> String                     -- ^ Scratchpad name
                               -> X ()
customRunNamedScratchpadAction = someNamedScratchpadAction (\f ws -> f $ NE.head ws)

allNamedScratchpadAction :: NamedScratchpads
                         -> String
                         -> X ()
allNamedScratchpadAction = someNamedScratchpadAction mapM_ runApplication

-- | execute some action on a named scratchpad
someNamedScratchpadAction :: ((Window -> X ()) -> NE.NonEmpty Window -> X ())
                          -> (NamedScratchpad -> X ())
                          -> NamedScratchpads
                          -> String
                          -> X ()
someNamedScratchpadAction f runApp scratchpadConfig scratchpadName =
    case findByName scratchpadConfig scratchpadName of
        Just conf -> withWindowSet $ \winSet -> do
            let focusedWspWindows = maybe [] W.integrate (W.stack . W.workspace . W.current $ winSet)
                allWindows        = W.allWindows winSet
            matchingOnCurrent <- filterM (runQuery (query conf)) focusedWspWindows
            matchingOnAll     <- filterM (runQuery (query conf)) allWindows

            case NE.nonEmpty matchingOnCurrent of
                -- no matching window on the current workspace -> scratchpad not running or in background
                Nothing -> case NE.nonEmpty matchingOnAll of
                    Nothing   -> runApp conf
                    Just wins -> f (windows . W.shiftWin (W.currentTag winSet)) wins

                -- matching window running on current workspace -> window should be shifted to scratchpad workspace
                Just wins -> do
                    unless (any (\wsp -> scratchpadWorkspaceTag == W.tag wsp) (W.workspaces winSet))
                        (addHiddenWorkspace scratchpadWorkspaceTag)
                    f (windows . W.shiftWin scratchpadWorkspaceTag) wins

        Nothing -> return ()


-- tag of the scratchpad workspace
scratchpadWorkspaceTag :: String
scratchpadWorkspaceTag = "NSP"

-- | Manage hook to use with named scratchpads
namedScratchpadManageHook :: NamedScratchpads -- ^ Named scratchpads configuration
                          -> ManageHook
namedScratchpadManageHook = composeAll . fmap (\c -> query c --> hook c)

-- | Transforms a workspace list containing the NSP workspace into one that
-- doesn't contain it. Intended for use with logHooks.
namedScratchpadFilterOutWorkspace :: [WindowSpace] -> [WindowSpace]
namedScratchpadFilterOutWorkspace = filter (\(W.Workspace tag _ _) -> tag /= scratchpadWorkspaceTag)

-- | Transforms a pretty-printer into one not displaying the NSP workspace.
--
-- A simple use could be:
--
-- > logHook = dynamicLogWithPP . namedScratchpadFilterOutWorkspace $ def
--
-- Here is another example, when using "XMonad.Layout.IndependentScreens".
-- If you have handles @hLeft@ and @hRight@ for bars on the left and right screens, respectively, and @pp@ is a pretty-printer function that takes a handle, you could write
--
-- > logHook = let log screen handle = dynamicLogWithPP . namedScratchpadFilterOutWorkspacePP . marshallPP screen . pp $ handle
-- >           in log 0 hLeft >> log 1 hRight
namedScratchpadFilterOutWorkspacePP :: PP -> PP
namedScratchpadFilterOutWorkspacePP pp = pp {
  ppSort = fmap (. namedScratchpadFilterOutWorkspace) (ppSort pp)
  }

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