#ifndef __MOBIUS_CRYPT_HASH_BLOCK_H__
#define __MOBIUS_CRYPT_HASH_BLOCK_H__

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
// Mobius Forensic Toolkit
// Copyright (C) 2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018 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/crypt/hash_base.h>
#include <cstddef>

namespace mobius
{
namespace crypt
{
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief Abstract base class for block hashes
//! \author Eduardo Aguiar
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
class hash_block : public hash_base
{
public:
  explicit hash_block (std::size_t);
  virtual void reset () noexcept;
  const mobius::bytearray get_digest () override final;

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  //! \brief update hash for a given data block
  //! \param first input iterator to the first element
  //! \param last input iterator to the element after the last one
  //! \return input iterator updated
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  template <typename InputIterator> InputIterator
  update (InputIterator first, InputIterator last) noexcept
  {
    while (first != last)
      {
        data_[idx_++] = *first;
        ++first;

        if (idx_ == block_size_)
          {
            update_block (data_);
            idx_ = 0;
          }
      }

    return first;
  }

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  //! \brief update hash for a given bytearray
  //! \param data bytearray
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  void
  update (const mobius::bytearray& data) override
  {
    update (data.begin (), data.end ());
  }

protected:
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  // abstract methods
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  virtual void update_block (const mobius::bytearray&) noexcept = 0;
  virtual const mobius::bytearray evaluate (const mobius::bytearray&) = 0;

private:
  mobius::bytearray data_;
  mobius::bytearray digest_;
  std::size_t block_size_;
  std::size_t idx_;
};

} // namespace crypt
} // namespace mobius

#endif
