-- | The main source code file of LambdaHack the game.
-- Module "TieKnot" is separated to make it usable in tests.
module Main
  ( main
  ) where

import Prelude ()

import Game.LambdaHack.Common.Prelude

import           Control.Concurrent.Async
import qualified Control.Exception as Ex
import qualified GHC.IO.Handle as GHC.IO.Handle
import qualified Options.Applicative as OA
import           System.Exit
import qualified System.IO as SIO

import Game.LambdaHack.Server (serverOptionsPI)
import TieKnot

-- | Parse commandline options, tie the engine, content and clients knot,
-- run the game and handle exit.
main :: IO ()
main = do
  -- For the case when the game is started not on a console.
  isTerminal <- SIO.hIsTerminalDevice SIO.stdout
  unless isTerminal $ do
    fstdout <- SIO.openFile "stdout.txt" SIO.WriteMode
    fstderr <- SIO.openFile "stderr.txt" SIO.WriteMode
    GHC.IO.Handle.hDuplicateTo fstdout SIO.stdout
    GHC.IO.Handle.hDuplicateTo fstderr SIO.stderr
  serverOptions <- OA.execParser serverOptionsPI
  -- Avoid the bound thread that would slow down the communication.
  a <- async $ tieKnot serverOptions
  ex <- waitCatch a
  case ex of
    Right () -> return ()
    Left e -> case Ex.fromException e of
      Just ExitSuccess ->
        exitSuccess  -- we are in the main thread, so here it really exits
      _ -> Ex.throwIO e