//
// aegis - project change supervisor
// Copyright (C) 1999, 2002, 2005, 2006, 2008, 2011 Peter Miller
//
// 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 3 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, see <http://www.gnu.org/licenses/>.
//

#ifndef LIBAEGIS_OUTPUT_FILTER_BASE64_H
#define LIBAEGIS_OUTPUT_FILTER_BASE64_H

#include <libaegis/output/filter.h>

/**
  * The output_filter_base64 class is used to represent the processing
  * necessary to MIME BASE64 encode an output stream.
  */
class output_filter_base64:
    public output_filter
{
public:
    /**
      * The destructor.
      */
    virtual ~output_filter_base64();

    /**
      * The create class method is used to create new dynamically
      * allocated instances of this class.
      *
      * @param deeper
      *     The deeper output, the place this filter writes the filtered
      *     output.
      */
    static pointer create(const output::pointer &deeper);

protected:
    // See base class for documentation.
    nstring type_name(void) const;

    // See base class for documentation.
    long ftell_inner(void) const;

    // See base class for documentation.
    void write_inner(const void *data, size_t length);

    // See base class for documentation.
    void end_of_line_inner(void);

private:
    /**
      * The constructor.  It's private on purpose, use the "create"
      * class method instead.
      *
      * @param deeper
      *     The deeper output, the place this filter writes the filtered
      *     output.
      */
    output_filter_base64(const output::pointer &deeper);

    /**
      * The residual_value instance variable is used to remember the
      * as-yet-unwritten bits of the value.
      */
    unsigned int residual_value;

    /**
      * The residual_bits instance variable is used to remember the
      * number of bits held by the residual_value instance variable.
      */
    int residual_bits;

    /**
      * The output_column instance variable is used to remember what
      * column the output is up to.
      */
    int output_column;

    /**
      * The pos instance variable is used to remember the file position.
      */
    long pos;

    /**
      * The bol instance variable is used to remember whether or not we
      * are positioned at the beginning of a line.
      */
    bool bol;

    /**
      * The default constructor.  Do not use.
      */
    output_filter_base64();

    /**
      * The copy constructor.  Do not use.
      */
    output_filter_base64(const output_filter_base64 &);

    /**
      * The assignment operator.  Do not use.
      */
    output_filter_base64 operator=(const output_filter_base64 &);
};

#endif // LIBAEGIS_OUTPUT_FILTER_BASE64_H