/* Menes - C++ High-Level Utility Library
 * Copyright (C) 2005  Jay Freeman (saurik)
*/

/*
 *        Redistribution and use in source and binary
 * forms, with or without modification, are permitted
 * provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the
 *    above copyright notice, this list of conditions
 *    and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the
 *    above copyright notice, this list of conditions
 *    and the following disclaimer in the documentation
 *    and/or other materials provided with the
 *    distribution.
 * 3. The name of the author may not be used to endorse
 *    or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef MENES_ENC_ENCODE_TRIGRAPH_HPP
#define MENES_ENC_ENCODE_TRIGRAPH_HPP

#include "cxx/platform.hpp"
#include "enc/linkage.hpp"

#ifdef MENES_PRAGMA_ONCE
#pragma once
#endif

#include "ios/streams.hpp"

namespace enc {

class TrigraphDecoder :
    public ios::WriterWriter
{
  private:
    unsigned questions_;

  public:
    TrigraphDecoder(const _R<ios::Writer> &writer) :
        ios::WriterWriter(writer),
        questions_(0)
    {
    }

    ~TrigraphDecoder() {
        if (!std::uncaught_exception())
            writer_->WriteFully("??", questions_);
    }

    size_t Write(const byte_t *data, size_t length) {
        _forall (unsigned, i, 0, length) {
            byte_t value(data[i]);

            if (questions_ != 2)
                if (value == '?')
                    ++questions_;
                else
                    ios::Put(*writer_, value);
            else {
                switch (value) {
                    case '=':  ios::Put(*writer_, '#');  break;
                    case '/':  ios::Put(*writer_, '\\'); break;
                    case '\'': ios::Put(*writer_, '^');  break;
                    case '(':  ios::Put(*writer_, '[');  break;
                    case ')':  ios::Put(*writer_, ']');  break;
                    case '!':  ios::Put(*writer_, '|');  break;
                    case '<':  ios::Put(*writer_, '{');  break;
                    case '>':  ios::Put(*writer_, '}');  break;
                    case '-':  ios::Put(*writer_, '~');  break;

                    default:
                        writer_->WriteFully("??", questions_);
                        ios::Put(*writer_, value);
                    break;
                }

                questions_ = 0;
            }
        }

        return length;
    }

    void Flush() {
    }
};

}

#endif//MENES_ENC_ENCODE_TRIGRAPH_HPP