{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE LambdaCase #-}
module Main where

import Config
import Parse
import Display
import Export.Queue

import System.FSNotify
import Control.Concurrent
import Control.Monad

import qualified System.FilePath as FP
import qualified System.Directory as D
import qualified System.Environment as A

-- todo [release] [importante] vedi se gli scatti nella animazione c
--      sono dovuti da animascii o da lib. 100% del cpu è troppo!
--      Anzi, sta andando lento il terminale.

main :: IO ()
main = -- imagemagick check
       fmap not isImageMagick >>= \bi ->
       if bi
       then putStrLn "\nThis program needs imagemagick version 6 or later \
                     \to work!\nPlease install it and try again.\n"
       else

       -- args & run
       A.getArgs >>= \as ->
       if null as
         then animascii
         else putStrLn help
    where
          animascii = getConfig >>= \c ->
                      -- render service
                      createQueue       >>= \mvq ->
                      createResultQueue >>= \mrq ->
                      forkIO (startQueue c mvq mrq) >>
                      -- notify service
                      newEmptyMVar  >>= \mvf ->
                      forkIO (notify c mvf mvq) >>= \tid ->
                      -- terminal
                      playAnimation (cFPS c) (cIDir c) mvf mvq mrq

isImageMagick :: IO Bool
isImageMagick = D.findExecutable "convert" >>= \case
                  Nothing -> return False
                  _       -> return True

help :: String
help = unlines $
         ["\nAnimascii - text based ASCII animator, version 0.1.0.0",
         "manual: http://ariis.it/static/articles/animascii/page.html"]


notify :: Config -> MVar FilePath -> MVar [FilePath] -> IO ()
notify c mv mvq =
          withManager $ \mgr -> (wt mgr >> forever (threadDelay 10000000))
    where
          idir = cIDir c

          akt e = putMVar mv (eventPath e) >>
                  addRenderJob (eventPath e) mvq

          wt mgr = watchTree
                    mgr
                    idir
                    ff
                    akt

          -- filter function for Events, ignore removes and dotfiles
          ff :: Event -> Bool
          ff e | Removed {} <- e = False
               | otherwise       = let ep = eventPath e
                                       fn = FP.takeFileName ep
                                       ex = FP.takeExtension ep in
                                   if (head fn /= '.' && ex == ".txt")
                                     then True
                                     else False