/**
 * \file zfstream.hxx
 * A C++ I/O streams interface to the zlib gz* functions.
 */

// Written by Bernie Bright, 1998
// Based on zlib/contrib/iostream/ by Kevin Ruland <kevin@rodin.wustl.edu>
//
// Copyright (C) 1998  Bernie Bright - bbright@c031.aone.net.au
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library 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
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the
// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA  02111-1307, USA.
//
// $Id$

#ifndef _zfstream_hxx
#define _zfstream_hxx

#include <simgear/compiler.h>

#include <zlib.h>

// At least Irix needs this
#ifdef SG_HAVE_NATIVE_SGI_COMPILERS
#include <char_traits.h>
SG_USING_STD(char_traits);
#endif

#ifdef SG_HAVE_STD_INCLUDES

#  include <streambuf>
#  include <istream>

#  define ios_openmode ios_base::openmode
#  define ios_in       ios_base::in
#  define ios_out      ios_base::out
#  define ios_app      ios_base::app
#  define ios_binary   ios_base::binary

#  define ios_seekdir  ios_base::seekdir

#  define ios_badbit   ios_base::badbit
#  define ios_failbit  ios_base::failbit

SG_USING_STD(streambuf);
SG_USING_STD(ios_base);
SG_USING_STD(streampos);
SG_USING_STD(streamoff);

#else

#  ifdef SG_HAVE_STREAMBUF
#    include <streambuf.h>
#    include <istream.h>
#  else
#    include <iostream.h>
#  endif

//#  define ios_openmode ios::open_mode
#  define ios_openmode int
#  define ios_in       ios::in
#  define ios_out      ios::out
#  define ios_app      ios::app

#if defined(__GNUC__) && __GNUC_MINOR__ < 8
#  define ios_binary   ios::bin
#elif defined( SG_HAVE_NATIVE_SGI_COMPILERS )
#  define ios_binary   0
#else
#  define ios_binary   ios::binary
#endif

#  define ios_seekdir  ios::seek_dir

#  define ios_badbit   ios::badbit
#  define ios_failbit  ios::failbit

#  include <simgear/sg_traits.hxx>

#endif // SG_HAVE_STD_INCLUDES

/**
 * A C++ I/O streams interface to the zlib gz* functions.
 */
class gzfilebuf : public streambuf
{
public:

#ifndef SG_HAVE_STD_INCLUDES
    typedef char_traits<char>           traits_type;
    typedef char_traits<char>::int_type int_type;
    // typedef char_traits<char>::pos_type pos_type;
    // typedef char_traits<char>::off_type off_type;
#endif

    /** Constructor */
    gzfilebuf();

    /** Destructor */
    virtual ~gzfilebuf();

    /**
     * Open a stream
     * @param name file name
     * @param io_mode mdoe flags
     * @return file stream
     */
    gzfilebuf* open( const char* name, ios_openmode io_mode );

    /** 
     * Attach to an existing file descriptor
     * @param file_descriptor file descriptor
     * @param io_mode mode flags
     * @return file stream
     */
    gzfilebuf* attach( int file_descriptor, ios_openmode io_mode );

    /** Close stream */
    gzfilebuf* close();

    // int setcompressionlevel( int comp_level );
    // int setcompressionstrategy( int comp_strategy );

    /** @return true if open, false otherwise */
    bool is_open() const { return (file != NULL); }

    /** @return stream position */
    virtual streampos seekoff( streamoff off, ios_seekdir way, int which );

    /** sync the stream */
    virtual int sync();

protected:

    virtual int_type underflow();
    virtual int_type overflow( int_type c = traits_type::eof() );

private:

    int_type flushbuf();
    int fillbuf();

    // Convert io_mode to "rwab" string.
    void cvt_iomode( char* mode_str, ios_openmode io_mode );

private:

    gzFile file;
    ios_openmode mode;
    bool own_file_descriptor;

    // Get (input) buffer.
    int ibuf_size;
    char* ibuffer;

    enum { page_size = 4096 };

private:
    // Not defined
    gzfilebuf( const gzfilebuf& );
    void operator= ( const gzfilebuf& );
};

/**
 * document me
 */
struct gzifstream_base
{
    gzifstream_base() {}

    gzfilebuf gzbuf;
};

#endif // _zfstream_hxx

