import Control.Monad.IO.Class (liftIO)

import Control.Monad.State.Strict (StateT(..), get, put)

import Data.Function ((&))

import Data.Word (Word8)

import System.Environment (getArgs)

import System.IO (Handle, IOMode(..), openFile, hClose)

import Streamly.Data.Stream (Stream)

import qualified Streamly.Data.Fold as Fold

import qualified Streamly.Data.Stream as Stream

import qualified Streamly.Internal.Data.Stream as Stream (refoldMany)

import qualified Streamly.Internal.Data.Refold.Type as Refold (take)

import qualified Streamly.FileSystem.Handle as Handle

import qualified Streamly.Internal.FileSystem.Handle as Handle (writer)

newHandle :: StateT (Maybe (Handle, Int)) IO Handle

newHandle = do

old <- get

idx <- case old of

Nothing -> return 0

Just (h, i) -> liftIO (hClose h) >> return (i + 1)

h <- liftIO $ openFile ("output-" ++ show idx ++ ".txt") WriteMode

put (Just (h, idx))

return h

splitFile :: Handle -> IO ()

splitFile inHandle =

(Handle.read inHandle :: Stream IO Word8) -- Stream IO Word8

& Stream.liftInner -- Stream (StateT (Maybe (Handle, Int)) IO) Word8

-- Stream (StateT (Maybe (Handle, Int)) IO) ()

& Stream.refoldMany (Refold.take (180 * mb) Handle.writer) newHandle

& Stream.runStateT (return Nothing) -- Stream IO (Maybe (Handle, Int), ())

& fmap snd -- Stream IO ()

& Stream.fold Fold.drain -- Stream IO ()

where

mb = 1024 * 1024

main :: IO ()

main = do

name <- fmap head getArgs

src <- openFile name ReadMode

splitFile src