-- | This module defines a connection interface. It could be a regular
-- network connection, TLS connection, a mock or anything else.

module Database.MongoDB.Internal.Connection (
    Connection(..),
    fromHandle,
) where

import Prelude hiding (read)
import Data.ByteString (ByteString)
import qualified Data.ByteString as ByteString
import System.IO

-- | Abstract connection interface
--
-- `read` should return `ByteString.null` on EOF
data Connection = Connection {
    read  :: Int -> IO ByteString,
    write :: ByteString -> IO (),
    flush :: IO (),
    close :: IO ()}

fromHandle :: Handle -> IO Connection
-- ^ Make connection form handle
fromHandle handle = do
  return Connection
    { read  = ByteString.hGet handle
    , write = ByteString.hPut handle
    , flush = hFlush handle
    , close = hClose handle
    }