EmacsServer.hs

module EmacsServer where

import Network.Socket hiding (recv,send)
import Network.Socket.ByteString
import Data.ByteString.Char8
import Control.Monad
import Control.Exception

type ComputeCandidate = String -> Int -> IO [String]

emacsServer :: ComputeCandidate -> IO ()
emacsServer f = do
    sock <- socket AF_INET Stream defaultProtocol
    setSocketOption sock ReuseAddr 1
    bind sock (SockAddrInet 50000 0)
    listen sock 5
    acceptLoop f sock `finally` close sock

acceptLoop :: ComputeCandidate -> Socket -> IO ()
acceptLoop computeCand sock = forever $ do
    (conn, _) <- accept sock
    cursorPos <- getCursorPos conn
    print cursorPos
    (conn, _) <- accept sock
    str <- getSource conn
    print str
    candidateList <- computeCand str cursorPos
    print candidateList
    (conn, _) <- accept sock
    sendCandidateList conn candidateList

str2int :: String -> Int
str2int str = read str :: Int

getCursorPos :: Socket -> IO Int
getCursorPos conn = do
    str <- recv conn 64
    return (str2int (unpack str))

getSource :: Socket -> IO String
getSource conn = do
    str <- recv conn 64
    if Data.ByteString.Char8.length str == 0 then
      return (unpack str)
    else do
      aaa <- getSource conn
      return ((unpack str) ++ aaa)

-- computeCand :: String -> Int -> IO [String]
-- computeCand str cursorPos = do 
--     return ["test"]

sendCandidateList :: Socket -> [String] -> IO ()
sendCandidateList conn [] = close conn
sendCandidateList conn (x:xs) = do
    _ <- send conn (pack ("\n" ++ x))
    print x
    sendCandidateList conn xs