module Miscutils where

import IO

import System.IO

import Control.Concurrent

import Control.Concurrent.STM

import Control.Exception (finally)

data ClientInfo =

	ClientInfo

	{

		chan :: TChan String,

		handle :: Handle,

		nick :: String,

		room :: String,

		isMaster :: Bool

	}

data RoomInfo =

	RoomInfo

	{

		name :: String,

		password :: String

	}

sendMsg :: Handle -> String -> IO()

sendMsg clientHandle str = finally (return ()) (hPutStrLn clientHandle str >> hFlush clientHandle) -- catch exception when client tries to send to other

sendAll :: [Handle] -> String -> IO[()]

sendAll clientsList str = mapM (\x -> sendMsg x str) clientsList

sendOthers :: [Handle] -> Handle -> String -> IO[()]

sendOthers clientsList clientHandle str = sendAll (filter (/= clientHandle) clientsList) str

extractCmd :: String -> (String, [String])

extractCmd str = if ws == [] then ("", []) else (head ws, tail ws)

		where ws = words str

manipState :: TVar[a] -> ([a] -> [a]) -> IO()

manipState state op =

	atomically $ do

			ls <- readTVar state

			writeTVar state $ op ls

manipState2 :: TVar[ClientInfo] -> TVar[RoomInfo] -> ([ClientInfo] -> [RoomInfo] -> ([ClientInfo], [RoomInfo], Bool)) -> IO Bool

manipState2 state1 state2 op =

	atomically $ do

			ls1 <- readTVar state1

			ls2 <- readTVar state2

			let (ol1, ol2, res) = op ls1 ls2

			writeTVar state1 ol1

			writeTVar state2 ol2

			return res

tselect :: [ClientInfo] -> STM (String, ClientInfo)

tselect = foldl orElse retry . map (\ci -> (flip (,) ci) `fmap` readTChan (chan ci))