content: {-
      Copyright 2016 Markus Ongyerth
  
      This file is part of Monky.
  
      Monky is free software: you can redistribute it and/or modify
      it under the terms of the GNU Lesser General Public License as published by
      the Free Software Foundation, either version 3 of the License, or
      (at your option) any later version.
  
      Monky is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU Lesser General Public License for more details.
  
      You should have received a copy of the GNU Lesser General Public License
      along with Monky.  If not, see <http://www.gnu.org/licenses/>.
  -}
  {-|
  Module      : Monky.Examples.File
  Description : Display the first line in a file each tick
  Maintainer  : ongy
  Stability   : testing
  Portability : Linux
  
  -}
  module Monky.Examples.File
    ( FileHandle
    , getFileHandle
    )
  where
  
  import Monky.Modules
  import Monky.Utility (fopen, readLine, File)
  
  import qualified Data.Text.Encoding as T
  
  -- |The handle type for this module
  newtype FileHandle = FH File
  
  getFile :: FileHandle -> File
  getFile (FH f) = f
  
  -- |Get the file handle
  getFileHandle
    :: String -- ^Path to the file
    -> IO FileHandle
  getFileHandle = fmap FH . fopen
  
  instance PollModule FileHandle where
    getOutput h = do
      line <- readLine . getFile $ h
      return [MonkyPlain $ T.decodeUtf8 line]
  
  -- TODO EvtModule with inotify?
  