module Watcher where

-- Venzone level REPLer, requested by sm

import Paths
import Venzone

import Terminal.Game hiding ( Event )
import System.FSNotify

import qualified Control.Concurrent as CC
import qualified Control.Monad      as CM
import qualified Data.Function      as F
import qualified System.FilePath    as FP


watchMode :: FilePath -> IO ()
watchMode fp =
      -- kill/launch venzone instance part
      CC.newChan                       >>= \chan ->
      CC.forkIO (levelSpawner fp chan) >>

      -- file watcher
      watcher fp chan

-- watch file `fp` and sends events to chan `chan`
watcher :: FilePath -> CC.Chan Event -> IO ()
watcher fp chan = withManagerConf conf repJob
    where
          -- debounces to 5/100 of a second, again to counter vim frenzy
          conf :: WatchConfig
          conf = defaultConfig { confDebounce = Debounce ( 5 / 100 ) }

          -- repeated IO action
          repJob :: WatchManager -> IO a
          repJob mgr = let oneSec = 10 ^ (6 :: Int) in
                       watchChan mgr                >>
                       CM.forever (CC.threadDelay oneSec)

          watchChan :: WatchManager -> IO ()
          watchChan mgr = () <$ watchDirChan mgr dir ff chan

          -- dir to watch
          dir :: FilePath
          dir = FP.dropFileName fp

          -- only match our specific file (and not vim crap)
          -- and only add/mod events
          ff :: Event -> Bool
          ff e = let ep = eventPath e
                 in isAddMod e &&
                    F.on (==) FP.takeFileName ep fp

          isAddMod :: Event -> Bool
          isAddMod Modified {} = True
          isAddMod Added {}    = True
          isAddMod _           = False

levelSpawner :: FilePath -> CC.Chan Event -> IO ()
levelSpawner fp chan =
            instanceVenzone >>= \ti ->
            loop ti
    where
          instanceVenzone :: IO CC.ThreadId
          instanceVenzone = CC.forkIO (levelMode fp)

          loop :: CC.ThreadId -> IO ()
          loop ti = CC.readChan chan   >>
                      -- blocks until. We don't care about the specific
                      -- event since it is filtered above
                    CC.killThread ti   >>
                    -- to counter vim
                    CC.threadDelay 1000 >>
                    instanceVenzone >>= \ti2 ->
                    loop ti2

-- todo [refactor] [refactor] astrai con normalMode
levelMode :: FilePath -> IO ()
levelMode fp = errorPress $
    (bundleStories . (:[]) <$> findSingleStory fp) >>= \gv ->
    -- todo [refactor] astrarre questa keypress?
    let gv' = setupGame gv [KeyPress 'd'] in
    playGame gv' >>
    return ()