#ifndef MOBIUS_IO_READER_EVALUATOR_H
#define MOBIUS_IO_READER_EVALUATOR_H

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
// Mobius Forensic Toolkit
// Copyright (C) 2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020,2021 Eduardo Aguiar
//
// 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, 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/>.
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
#include <mobius/io/reader_impl_base.h>
#include <mobius/io/reader.h>

namespace mobius
{
namespace io
{
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief reader_impl_evaluator template
//! \author Eduardo Aguiar
// This template class allows us to create a write object, passing another
// write object (called client reader) and a functor, which will be called
// at every write operation.
//
// That way, it is possible, for example, to evaluate a hash value automatically
// when writing to the client reader.
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
template <typename T>
class reader_impl_evaluator : public reader_impl_base
{
public:
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  // copy/move constructors
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  reader_impl_evaluator (const reader_impl_evaluator&) = default;
  reader_impl_evaluator (reader_impl_evaluator&&) = default;

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  // assignment operators
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  reader_impl_evaluator& operator= (const reader_impl_evaluator&) = default;
  reader_impl_evaluator& operator= (reader_impl_evaluator&&) = default;

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  // main constructor
  //! \param reader client reader
  //! \param functor evaluation functor
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  reader_impl_evaluator (mobius::io::reader reader, T& functor)
    : reader_ (reader),
      functor_ (functor)
  {
  }

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  //! \brief check if reader is seekable
  //! \return true/false
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  bool
  is_seekable () const override
  {
    return reader_.is_seekable ();
  }

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  //! \brief get current read position
  //! \return read position in bytes from the beginning of data
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  offset_type
  tell () const override
  {
    return reader_.tell ();
  }

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  //! \brief set read position
  //! \param offset offset in bytes
  //! \param w either beginning, current or end
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  void
  seek (offset_type offset, whence_type whence = whence_type::beginning) override
  {
    reader_.seek (offset, whence);
  }

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  //! \brief get stream size, if available
  //! \return stream size in bytes
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  size_type
  get_size () const override
  {
    return reader_.get_size ();
  }

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  //! \brief check if end-of-file (EOF) is reached
  //! \return true/false
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  bool
  eof () const override
  {
    return reader_.eof ();
  }

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  //! \brief Get default block size
  //! \return Block size in bytes
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  size_type
  get_block_size () const override
  {
    return reader_.get_block_size ();
  }

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  //! \brief read bytes from reader
  //! \param size size in bytes
  //! \param bytearray containing data
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  mobius::bytearray
  read (size_type size) override
  {
    const mobius::bytearray data = reader_.read (size);
    functor_ (data);
    return data;
  }

private:
  mobius::io::reader reader_;            // nested reader
  T& functor_;                           // filter object (unctor)
};

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief create new reader object, with filter functor
//! \author Eduardo Aguiar
//! \param reader client reader
//! \param functor functor object
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
template <typename T> const mobius::io::reader
reader_evaluator (mobius::io::reader reader, T& functor)
{
  return mobius::io::reader (std::make_shared <reader_impl_evaluator<T>> (reader, functor));
}

} // namespace io
} // namespace mobius

#endif
