{-# LANGUAGE OverlappingInstances#-}

{- arch-tag: GZip files
Copyright (C) 2005 John Goerzen <jgoerzen@complete.org>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

{- |
   Module     : MissingPy.FileArchive.GZip
   Copyright  : Copyright (C) 2005 John Goerzen
   License    : GNU GPL, version 2 or above

   Maintainer : John Goerzen,
   Maintainer : jgoerzen\@complete.org
   Stability  : provisional
   Portability: portable

Support for GZip files

Written by John Goerzen, jgoerzen\@complete.org

module MissingPy.FileArchive.GZip (openGz

import Python.Types
import Python.Utils
import Python.Objects
import Python.Interpreter
import System.IO
import System.IO.Error
import Python.Exceptions
import System.IO.HVIO
import Foreign.C.Types
import Python.Objects.File

{- |Open a GZip file.  The compression level should be from 1
(least compression) to 9 (most compression).  This is ignored when the
file is opened read-only.

Once opened, the functions defined in 'System.IO.HVIO' can be used to 
work with it. -}
openGz :: FilePath              -- ^ File to open
       -> IOMode                -- ^ Mode to open with
       -> Int                   -- ^ Compression Level
       -> IO PyFile             -- ^ Resulting handle
openGz fp mode level =
    do ofp <- toPyObject fp
       omode <- toPyObject (openModeConv mode)
       ocl <- toPyObject ((fromIntegral level)::CLong)
       pyImport "gzip"
       obj <- callByName "gzip.open" [ofp, omode, ocl] []
       return $ mkPyFile obj