module Main where

import Network

import IO

import System.IO

import Control.Concurrent

import Control.Concurrent.STM

import Control.Exception (finally)

import Control.Monad (forM, forM_, filterM, liftM)

import Data.List

import Miscutils

import HWProto

acceptLoop :: Socket -> TChan ClientInfo -> IO ()

acceptLoop servSock acceptChan = do

	(cHandle, host, port) <- accept servSock

	cChan <- atomically newTChan

	forkIO $ clientLoop cHandle cChan

	atomically $ writeTChan acceptChan (ClientInfo cChan cHandle "" 0 "" False)

	acceptLoop servSock acceptChan

listenLoop :: Handle -> TChan String -> IO ()

listenLoop handle chan = do

	str <- hGetLine handle

	atomically $ writeTChan chan str

	listenLoop handle chan

clientLoop :: Handle -> TChan String -> IO ()

clientLoop handle chan =

	listenLoop handle chan

		`catch` (const $ clientOff >> return ())

	where clientOff = atomically $ writeTChan chan "QUIT"

mainLoop :: Socket -> TChan ClientInfo -> [ClientInfo] -> [RoomInfo] -> IO ()

mainLoop servSock acceptChan clients rooms = do

	r <- atomically $ (Left `fmap` readTChan acceptChan) `orElse` (Right `fmap` tselect clients)

	case r of

		Left ci -> do

			mainLoop servSock acceptChan (ci:clients) rooms

		Right (line, client) -> do

			let (mclient, mrooms, recipients, strs) = handleCmd client clients rooms $ words line

			clients' <- forM recipients $

					\ci -> do

							forM_ strs (\str -> hPutStrLn (handle ci) str)

							hFlush (handle ci)

							if (not $ null strs) && (head strs == "ROOMABANDONED") then hClose (handle ci) >> return [ci] else return []

					`catch` const (hClose (handle ci) >> return [ci])

			client' <- if (not $ null strs) && (head strs == "QUIT") then hClose (handle client) >> return [client] else return []

			mainLoop servSock acceptChan (remove (remove (mclient : filter (\cl -> handle cl /= handle client) clients) (concat clients')) client') mrooms

			where

				remove list rmClients = deleteFirstsBy (\ a b -> handle a == handle b) list rmClients

startServer serverSocket = do

	acceptChan <- atomically newTChan

	forkIO $ acceptLoop serverSocket acceptChan

	mainLoop serverSocket acceptChan [] []

main = withSocketsDo $ do

	serverSocket <- listenOn $ Service "hedgewars"

	startServer serverSocket `finally` sClose serverSocket