/*
physfs_stream.hpp
    Copyright (C) 2009 Poul Sander
        Copied from Warzone 2100
        http://svn.gna.org/viewcvs/warzone/branches/sound/lib/sound/general/physfs_stream.hpp?rev=3623
	Copyright (C) 2007 Warzone Resurrection Project
	Copyright (C) 2007 Giel van Schijndel <me@mortis.eu>
	Originally part of SuperTux:
	http://svn.berlios.de/svnroot/repos/supertux/trunk/supertux/src/physfs/physfs_stream.cpp revision 4176
	Copyright (C) 2006 Matthias Braun <matze@braunis.de>

    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
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    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

    Poul Sander
    R�veh�jvej 36, V. 1111
    2800 Kgs. Lyngby
    DENMARK
    blockattack@poulsander.com
*/

#ifndef __INCLUDED_PHYSFS_STREAM_HPP__
#define __INCLUDED_PHYSFS_STREAM_HPP__

#define BUF_SIZE 1024

#include <physfs.h>
#include <streambuf>
#include <istream>
#include <ostream>
/*Compared to Warzone 2100 boost:array has been replaced by vector to limit
 the compile requirements*/
#include <vector>

/** This an implementation of "File-based streams" as described in the
 *  ISO/IEC 14882:1998(E) C++ Standard in chapter 27 "Input/output library",
 *  section 8 "File-based streams". This implementation however uses PhysicsFS
 *  instead of the C-library's FILE functions. Also this implementation lacks
 *  an implementation of basic_fstream because PhysicsFS does not support
 *  opening a file both for reading as well as writing.
 *
 *  This header contains similar classes and typedefs as <fstream> does. Both
 *  similar in names as well as operation, the main difference is that these
 *  classes do _not_ reside in namespace std.
 */
namespace PhysFS
{
    /** Typedefinitions mandated by the C++ standard in section 27.8.1
     */
    template<typename _CharT, typename _Traits = std::char_traits<_CharT> >
        class physfs_filebuf;
    typedef physfs_filebuf<char>        filebuf;
    typedef physfs_filebuf<wchar_t>     wfilebuf;

    template<typename _CharT, typename _Traits = std::char_traits<_CharT> >
        class physfs_ifstream;
    typedef physfs_ifstream<char>       ifstream;
    typedef physfs_ifstream<wchar_t>    wifstream;

    template<typename _CharT, typename _Traits = std::char_traits<_CharT> >
        class physfs_ofstream;
    typedef physfs_ofstream<char>       ofstream;
    typedef physfs_ofstream<wchar_t>    wofstream;

    /** This class implements a C++ streambuf object for physfs files.
     *  So that you can use normal istream and ostream operations on them.
     *  This class is similar to std::basic_filebuf as defined in
     *  section 27.8.1.1, except in name.
     */
    template<typename _CharT, typename _Traits>
    class physfs_filebuf : public std::basic_streambuf<_CharT, _Traits>
    {
        public:
            // Types:
            typedef _CharT                                  char_type;
            typedef _Traits                                 traits_type;
            typedef typename traits_type::int_type          int_type;
            typedef typename traits_type::pos_type          pos_type;
            typedef typename traits_type::off_type          off_type;

            typedef std::basic_streambuf<_CharT, _Traits>   __streambuf_type;
            typedef physfs_filebuf<_CharT, _Traits>         __filebuf_type;

            physfs_filebuf() :
                _file(0)
            {
                _buf.resize(BUF_SIZE);
            }

            virtual ~physfs_filebuf()
            {
                close();
            }

            bool is_open() const throw()
            {
                return (_file != 0);
            }

            __filebuf_type* open(const char* fileName, std::ios_base::openmode mode)
            {
                // Return failure if this file buf is open already
                if (is_open() != false)
                    return 0;

                // Return failure if we are requested to open a file in an unsupported mode
                if (!(mode & std::ios_base::binary) ||
                    (mode & std::ios_base::in &&
                     mode & std::ios_base::out))
                    return 0;

                // Open the file
                if (mode & std::ios_base::out &&
                    mode & std::ios_base::app)
                {
                    _file = PHYSFS_openAppend(fileName);
                    _writeStream = true;
                }
                else if (mode & std::ios_base::out)
                {
                    _file = PHYSFS_openWrite(fileName);
                    _writeStream = true;
                }
                else if (mode & std::ios_base::in)
                {
                    _file = PHYSFS_openRead(fileName);
                    _writeStream = false;
                }
                else
                {
                    return 0;
                }

                if (!_file)
                    return 0;

                if (mode & std::ios_base::ate &&
                    mode & std::ios_base::in)
                {
                    if (!PHYSFS_seek(_file, PHYSFS_fileLength(_file)))
                    {
                        close();
                        return 0;
                    }
                }

                return this;
            }

            __filebuf_type* close()
            {
                // Return failure if this file buf is closed already
                if (is_open() == false)
                    return 0;

                sync();

                if (!PHYSFS_close(_file))
                {
                    return 0;
                }

                _file = 0;

                return this;
            }

        protected:
            // Read stuff:
            virtual int_type underflow()
            {
                if (!is_open() || _writeStream)
                    return traits_type::eof();

                if(PHYSFS_eof(_file))
                {
                    return traits_type::eof();
                }

                PHYSFS_sint64 objectsRead = PHYSFS_read(_file, &*_buf.begin(), sizeof(char_type), BUF_SIZE);

                if(objectsRead <= 0)
                {
                    return traits_type::eof();
                }

                char_type* xend = (static_cast<size_t> (objectsRead) == BUF_SIZE) ? &*_buf.end() : &_buf[objectsRead];
                this->setg(&*_buf.begin(), &*_buf.begin(), xend);

                return traits_type::to_int_type(_buf.front());
            }

            virtual pos_type seekpos(pos_type pos, std::ios_base::openmode)
            {
                if (!is_open() || _writeStream)
                    return pos_type(off_type(-1));

                if(PHYSFS_seek(_file, static_cast<PHYSFS_uint64> (pos)) == 0)
                {
                    return pos_type(off_type(-1));
                }

                // the seek invalidated the buffer
                this->setg(&*_buf.begin(), &*_buf.begin(), &*_buf.begin());
                return pos;
            }

            virtual pos_type seekoff(off_type off, std::ios_base::seekdir dir, std::ios_base::openmode mode)
            {
                if (!is_open() || _writeStream)
                    return pos_type(off_type(-1));

                off_type pos = off;

                switch (dir)
                {
                    case std::ios_base::beg:
                        break;

                    case std::ios_base::cur:
                    {
                        PHYSFS_sint64 ptell = PHYSFS_tell(_file);
                        pos_type buf_tell = static_cast<pos_type> (ptell) - static_cast<pos_type> (__streambuf_type::egptr() - __streambuf_type::gptr());
                        if(off == 0)
                        {
                            return buf_tell;
                        }

                        pos += static_cast<off_type> (buf_tell);
                        break;
                    }

                    case std::ios_base::end:
                        pos = static_cast<off_type> (PHYSFS_fileLength(_file)) - pos;
                        break;

                    default:
                        //assert(!"invalid seekdirection");
                        return pos_type(off_type(-1));
                }

                return seekpos(static_cast<pos_type> (pos), mode);
            }

            // Write stuff:
            virtual int_type overflow(int_type c = traits_type::eof())
            {
                if (!is_open() || !_writeStream)
                    return traits_type::eof();

                size_t size = __streambuf_type::pptr() - __streambuf_type::pbase();
                if(size == 0)
                    return 0;

                PHYSFS_sint64 res = PHYSFS_write(_file, __streambuf_type::pbase(), sizeof(char_type), size);

                if(res <= 0)
                    return traits_type::eof();

                if(!traits_type::eq_int_type(c, traits_type::eof()))
                {
                    PHYSFS_sint64 res = PHYSFS_write(_file, &c, sizeof(char_type), 1);

                    if(res <= 0)
                        return traits_type::eof();
                }

                char_type* xend = (static_cast<size_t> (res) == BUF_SIZE) ? &*_buf.end() : &_buf[res];
                this->setp(&*_buf.begin(), xend);
                return 0;
            }

            virtual int sync()
            {
                if (!is_open() || !_writeStream)
                    return -1;

                return overflow(traits_type::eof());
            }

            virtual std::streamsize showmanyc()
            {
                if (!is_open() || _writeStream)
                    return -1;

                PHYSFS_sint64 fileSize = PHYSFS_fileLength(_file);

                return static_cast<int> (fileSize);
            }

        private:
            PHYSFS_file* _file;
            bool _writeStream;
            vector<char_type> _buf;
    };

    /** This class implements a C++ istream object for physfs files.
     *  This class is similar to std::basic_ifstream as defined in
     *  section 27.8.1.5, except in name.
     */
    template<typename _CharT, typename _Traits>
    class physfs_ifstream : public std::basic_istream<_CharT, _Traits>
    {
        public:
            // Types:
            typedef _CharT                                  char_type;
            typedef _Traits                                 traits_type;
            typedef typename traits_type::int_type          int_type;
            typedef typename traits_type::pos_type          pos_type;
            typedef typename traits_type::off_type          off_type;

            typedef physfs_filebuf<_CharT, _Traits>         __filebuf_type;
            typedef std::basic_istream<_CharT, _Traits>     __istream_type;

            physfs_ifstream() throw() :
                __istream_type(&_sb)
            {
            }

            explicit physfs_ifstream(const char* fileName, std::ios_base::openmode mode = std::ios_base::binary) :
                __istream_type(&_sb)
            {
                open(fileName, mode);
            }

            const __filebuf_type* rdbuf() const throw()
            {
                return &_sb;
            }

            __filebuf_type* rdbuf() throw()
            {
                return &_sb;
            }

            bool is_open() const throw()
            {
                return rdbuf()->is_open();
            }

            void open(const char* fileName, std::ios_base::openmode mode = std::ios_base::binary)
            {
                if (!rdbuf()->open(fileName, mode | std::ios_base::in))
                {
                    __istream_type::setstate(std::ios_base::failbit);
                }
            }

            void close()
            {
                if (!rdbuf()->close())
                {
                    __istream_type::setstate(std::ios_base::failbit);
                }
            }

        private:
            __filebuf_type _sb;
    };

    /** This class implements a C++ ostream object for physfs files.
     *  This class is similar to std::basic_ofstream as defined in
     *  section 27.8.1.8, except in name.
     */
    template<typename _CharT, typename _Traits>
    class physfs_ofstream : public std::basic_ostream<_CharT, _Traits>
    {
        public:
            // Types:
            typedef _CharT                                  char_type;
            typedef _Traits                                 traits_type;
            typedef typename traits_type::int_type          int_type;
            typedef typename traits_type::pos_type          pos_type;
            typedef typename traits_type::off_type          off_type;

            typedef physfs_filebuf<_CharT, _Traits>         __filebuf_type;
            typedef std::basic_ostream<_CharT, _Traits>     __ostream_type;

            physfs_ofstream() throw() :
                __ostream_type(&_sb)
            {
            }

            explicit physfs_ofstream(const char* fileName, std::ios_base::openmode mode = std::ios_base::binary) :
                __ostream_type(&_sb)
            {
                open(fileName, mode);
            }

            const __filebuf_type* rdbuf() const throw()
            {
                return &_sb;
            }

            __filebuf_type* rdbuf() throw()
            {
                return &_sb;
            }

            bool is_open() const throw()
            {
                return rdbuf()->is_open();
            }

            void open(const char* fileName, std::ios_base::openmode mode = std::ios_base::binary)
            {
                if (!rdbuf()->open(fileName, mode | std::ios_base::out))
                {
                    __ostream_type::setstate(std::ios_base::failbit);
                }
            }

            void close()
            {
                if (!rdbuf()->close())
                {
                    __ostream_type::setstate(std::ios_base::failbit);
                }
            }

        private:
            __filebuf_type _sb;
    };
}

#endif // __INCLUDED_PHYSFS_STREAM_HPP__