/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * 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
 * OpenSceneGraph Public License for more details.
*/

/* This file is derived from the libb64 project which itself was released to public domain.
 * For details, see http://sourceforge.net/projects/libb64. Original code by Chris Venter
 * c++ wrapper for a base64 encoding and decoding algorithm
*/

#ifndef OSGDB_CONVERTBASE64_H
#define OSGDB_CONVERTBASE64_H 1

#include <iostream>
#include <string>
#include <vector>

#include <osgDB/Export>

namespace osgDB
{
    const int BUFFERSIZE = 8192;

    typedef enum
    {
        step_a, step_b, step_c, step_d
    } base64_decodestep;

    typedef enum
    {
        step_A, step_B, step_C
    } base64_encodestep;

    typedef struct
    {
        base64_encodestep step;
        char result;
        int stepcount;
    } base64_encodestate;

    inline void base64_init_encodestate(base64_encodestate* state_in)
    {
        state_in->step = step_A;
        state_in->result = 0;
        state_in->stepcount = 0;
    }


    typedef struct
    {
        base64_decodestep step;
        char plainchar;
    } base64_decodestate;

    inline void base64_init_decodestate(base64_decodestate* state_in)
    {
        state_in->step = step_a;
        state_in->plainchar = 0;
    }

    class OSGDB_EXPORT Base64encoder
    {
    public:
        Base64encoder(int buffersize_in = BUFFERSIZE):
            _buffersize(buffersize_in)
        {
            base64_init_encodestate(&_state);
        }

        int encode(char value_in);

        int encode(const char* code_in, const int length_in, char* plaintext_out);

        int encode_end(char* plaintext_out);

        void encode(std::istream& istream_in, std::ostream& ostream_in);

        void encode(const char* chars_in, int length_in, std::string& code_out);

    private:
        base64_encodestate _state;
        int _buffersize;
    };

    class OSGDB_EXPORT Base64decoder
    {
    public:
        Base64decoder(int buffersize_in = BUFFERSIZE):
            _buffersize(buffersize_in)
        {
            base64_init_decodestate(&_state);
        }

        int decode(char value_in);

        int decode(const char* code_in, const int length_in, char* plaintext_out);

        void decode(std::istream& istream_in, std::ostream& ostream_in);

        // Decode strings, returns one char* of appropriate size
        // Note that deallocation of char* is up to the caller of this method
        char* decode(const std::vector<std::string>& str_in, std::vector<unsigned int>& pos_out);

    private:
        base64_decodestate _state;
        int _buffersize;
    };

} // namespace osgDB

#endif // BASE64_DECODE_H

