module Main (main) where

import IPS (Bytes, makeBytes)
import qualified IPS
import System.Environment
import System.IO
import qualified Data.ByteString as ByteString
import qualified Data.Vector.Storable as Vector

main :: IO ()
main = do
  args <- getArgs
  case args of
    [inf, ipsf, outf] -> do
      buf <- readBytes inf
      ips <- either error id <$> IPS.read ipsf
      writeBytes outf $ IPS.apply ips buf
    _ -> error "usage: $0 <in> <ips> <out>"

readBytes :: FilePath -> IO Bytes
readBytes f = makeBytes <$> ByteString.readFile f

writeBytes :: FilePath -> Bytes -> IO ()
writeBytes f buf =
  withFile f WriteMode \h ->
  Vector.unsafeWith buf \ptr ->
  hPutBuf h ptr (Vector.length buf)