{-# LANGUAGE Rank2Types #-}
module Main where

import Codec.Sarsi (Event)
import Codec.Sarsi.SBT.Machine (eventProcess)
import Data.Machine (ProcessT, (<~), autoM, runT_)
import Sarsi (getBroker, getTopic)
import Sarsi.Producer (produce)
import System.Environment (getArgs)
import System.Exit (ExitCode, exitWith)
import System.Process (StdStream(..), shell, std_in, std_out)
import System.Process.Machine (ProcessMachines, callProcessMachines)
import System.IO (BufferMode(NoBuffering), hSetBuffering, stdin, stdout)
import System.IO.Machine (byChunk)

import qualified Data.List as List
import qualified Data.Text.IO as TextIO
import qualified Sarsi as Sarsi

title :: String
title = concat [Sarsi.title, "-sbt"]

-- TODO Contribute to machines-process
mStdOut_ :: ProcessT IO a b -> ProcessMachines a a0 k0 -> IO ()
mStdOut_ mp (_, Just stdOut, _)  = runT_ $ mp <~ stdOut
mStdOut_ _  _                    = return ()

producer :: String -> ProcessT IO Event Event -> IO (ExitCode)
producer cmd sink = do
  (ec, _) <- callProcessMachines byChunk createProc (mStdOut_ pipeline)
  return ec
    where
      pipeline = sink <~ eventProcess <~ echoText stdout
      echoText h = autoM $ (\txt -> TextIO.hPutStr h txt >> return txt)
      createProc  = (shell cmd) { std_in = Inherit, std_out = CreatePipe }

main :: IO ()
main = do
  hSetBuffering stdin NoBuffering
  hSetBuffering stdout NoBuffering
  args  <- getArgs
  b     <- getBroker
  t     <- getTopic b "."
  ec    <- produce t $ producer $ concat $ List.intersperse " " ("sbt":args)
  exitWith ec