module Programs.TcpEchoIterServer where

import Control.Concurrent

import Control.Exception

import Control.Monad

import Control.Monad.Trans

import Data.IterIO

import Data.IterIO.Inum

import Network

import System.IO

import System.IO.Error (isEOFError)

import qualified Data.ByteString.Lazy as L

import qualified Data.ByteString.Lazy.Char8 as C

iterHandle' :: (MonadIO m) => Handle -> IO (Iter L.ByteString m (), Onum L.ByteString m a)

iterHandle' = iterHandle

main = withSocketsDo $ do

  sListen <- listenOn (PortNumber 8000)

  putStrLn "Listening on Port 8000"

  forkIO $ forever $ do

    (sSession, hostname, port) <- accept sListen

    hSetBuffering sSession NoBuffering

    putStrLn ("Connected to " ++ hostname ++ ":" ++ show port)

    forkIO $ do

      (iter, enum) <- iterHandle' sSession

      enum |$ inumLines .| inumReverse .| inumUnlines .| iter

  putStrLn "Press <CTRL-D> to quit."

  exitOnCtrlD

iterLines :: (Monad m) => Iter L.ByteString m [L.ByteString]

iterLines = do

  line <- lineI

  return [line]

iterUnlines :: (Monad m) => Iter [L.ByteString] m L.ByteString

iterUnlines = (L.concat . (++ [C.pack "\n"])) `liftM` dataI

iterReverse :: (Monad m) => Iter [L.ByteString] m [L.ByteString]

iterReverse = do

  lines <- dataI

  return (map L.reverse lines)

inumLines = mkInum iterLines

inumUnlines = mkInum iterUnlines

inumReverse = mkInum iterReverse

exitOnCtrlD = try getLine >>= either

  (\e -> unless (isEOFError e) $ ioError e)

  (const exitOnCtrlD)

iterReverse :: (Monad m) => Iter L.ByteString m L.ByteString

iterReverse = do

  line <- dataI

  return (L.reverse line)

inumReverse = mkInum iterReverse

enum |$ inumLines .| {-- inumReverse goes in here somehow --} .| inumUnlines .| iter