/*!
 * \file 
 * \brief Definition of a CRC code class
 * \author Tony Ottosson
 *
 * $Date: 2006-07-12 11:31:45 +0200 (Wed, 12 Jul 2006) $
 * $Revision: 523 $
 *
 * -------------------------------------------------------------------------
 *
 * IT++ - C++ library of mathematical, signal processing, speech processing,
 *        and communications classes and functions
 *
 * Copyright (C) 1995-2006  (see AUTHORS file for a list of contributors)
 *
 * 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 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, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * -------------------------------------------------------------------------
 */

#ifndef CRC_H
#define CRC_H

//#include "vec.h"


namespace itpp {

  class CRC_Code {
  public:

    //! Default Constructor
    CRC_Code() { reverse_parity = false; }

    /*! 
      \brief Set CRC code to one of the standardpolynomials using the 
			string value.
      \param code Possible values: CRC-4, CRC-7, CRC-8, CRC-12,
      CRC-24, CRC-32, CCITT-4, CCITT-5, CCITT-6, CCITT-16, CCITT-32,
      WCDMA-8, WCDMA-12, WCDMA-16, WCDMA-24, ATM-8, ANSI-16, SDLC-16
    */
    CRC_Code(const std::string &code) { reverse_parity = false; set_code(code); }

    //! Set an arbitary polynomial in bvec form. Start with highest order terms.
    void set_generator(const bvec &poly);

    //! Set CRC code to one of the standardpolynomials using the string value.
    void set_code(const std::string &code);

    //! Calulate the parity bits
    void parity(const bvec &in_bits, bvec &out);

    //! Return true if parity checks OK otherwise flase
    bool check_parity(const bvec &coded_bits);

    //! Calculate and add parity to the in_bits.
    void encode(const bvec &in_bits, bvec &out);

    //! Returns the in_bits vector with parity added
    bvec encode(const bvec &in_bits);

    //! Return true if parity checks OK otherwise flase. Also returns the message part in out. 
    bool decode(const bvec &coded_bits, bvec &out);

    //! Return true if parity checks OK otherwise flase. Also returns the message part in bits.
    bool decode(bvec &bits);

  private:
    bool reverse_parity;
    bvec polynomial;
    int no_parity;
  };

} // namespace itpp

#endif // #ifndef CRC_H