//===========================================================================
//  $Name: arts++-1-1-a12 $
//  $Id: ArtsBgp4AsPathSegment.hh,v 1.2 2004/04/21 23:51:25 kkeys Exp $
//===========================================================================
//  Copyright Notice
//
//  By accessing this software, arts++, you are duly informed
//  of and agree to be bound by the conditions described below in this
//  notice:
//
//  This software product, arts++, is developed by Daniel W. McRobb, and
//  copyrighted(C) 1998 by the University of California, San Diego
//  (UCSD), with all rights reserved.  UCSD administers the CAIDA grant,
//  NCR-9711092, under which part of this code was developed.
//
//  There is no charge for arts++ software.  You can redistribute it
//  and/or modify it under the terms of the GNU Lesser General Public
//  License, Version 2.1, February 1999, which is incorporated by
//  reference herein.
//
//  arts++ is distributed WITHOUT ANY WARRANTY, IMPLIED OR EXPRESS, OF
//  MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE or that the use
//  of it will not infringe on any third party's intellectual
//  property rights.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with arts++.  Copies can also be obtained from:
//
//    http://www.gnu.org/copyleft/lesser.html
//
//  or by writing to:
//
//  Free Software Foundation, Inc.
//  59 Temple Place, Suite 330
//  Boston, MA 02111-1307
//  USA
//
//  Or contact:
//
//    info@caida.org
//===========================================================================

#ifndef _ARTSBGP4ASPATHSEGMENT_HH_
#define _ARTSBGP4ASPATHSEGMENT_HH_

extern "C" {
#include "caida_t.h"
}

#include <vector>

//---------------------------------------------------------------------------
//  class ArtsBgp4AsPathSegment
//---------------------------------------------------------------------------
//!  This class abstracts an AS path segement in a BGP AS path attribute.
//!  An AS path segment may be of type SET or SEQUENCE; a SET segment is
//!  unordered while a SEQUENCE segment is ordered.  See RFC 1771 for
//!  more details.
//---------------------------------------------------------------------------
class ArtsBgp4AsPathSegment
{
public:
  //-------------------------------------------------------------------------
  //!  Define some static constants for AS path segment types.
  //-------------------------------------------------------------------------
  static const uint8_t k_segmentTypeSet      = 1;
  static const uint8_t k_segmentTypeSequence = 2;
  
  //--------------------------------------------------------------------------
  //                         ArtsBgp4AsPathSegment()
  //..........................................................................
  //!  constructor
  //--------------------------------------------------------------------------
  ArtsBgp4AsPathSegment();

  //--------------------------------------------------------------------------
  //   ArtsBgp4AsPathSegment(const ArtsBgp4AsPathSegment & asPathSegment)
  //..........................................................................
  //!  copy constructor
  //--------------------------------------------------------------------------
  ArtsBgp4AsPathSegment(const ArtsBgp4AsPathSegment & asPathSegment);

  //--------------------------------------------------------------------------
  //                        ~ArtsBgp4AsPathSegment()
  //..........................................................................
  //!  destructor
  //--------------------------------------------------------------------------
  ~ArtsBgp4AsPathSegment();

  //-------------------------------------------------------------------------
  //                          uint8_t Type() const
  //.........................................................................
  //!  Returns the type of the segment (1 == SET, 2 == SEQUENCE).
  //-------------------------------------------------------------------------
  uint8_t Type() const;
  
  //-------------------------------------------------------------------------
  //                       uint8_t Type(uint8_t type)
  //.........................................................................
  //!  Sets and returns the type of the segment (1 == SET, 2 == SEQUENCE).
  //-------------------------------------------------------------------------
  uint8_t Type(uint8_t type);
  
  //-------------------------------------------------------------------------
  //                      std::vector<uint16_t> & AS() const
  //.........................................................................
  //!  Returns a reference to the vector of AS numbers in the segment.
  //!  Note that this member can be called on a const object though we
  //!  don't return a const reference; the vector of AS numbers is
  //!  mutable.
  //-------------------------------------------------------------------------
  std::vector<uint16_t> & AS() const;

  //--------------------------------------------------------------------------
  //            std::istream & read(std::istream & is, uint8_t version = 0)         
  //..........................................................................
  //!  Reads the ArtsBgp4AsPathSegment from an istream.  Returns a reference
  //!  to the istream.
  //--------------------------------------------------------------------------
  std::istream & read(std::istream & is, uint8_t version = 0);

  //--------------------------------------------------------------------------
  //                  int read(int fd, uint8_t version = 0)
  //..........................................................................
  //!  Reads the ArtsBgp4AsPathSegment from a file descriptor.  Returns the
  //!  number of bytes read on success, -1 on failure.
  //--------------------------------------------------------------------------
  int read(int fd, uint8_t version = 0);
  
  //--------------------------------------------------------------------------
  //        std::ostream & write(std::ostream & os, uint8_t version = 0) const
  //..........................................................................
  //!  Writes the ArtsBgp4AsPathSegment to an ostream.  Returns a reference
  //!  to the ostream.
  //--------------------------------------------------------------------------
  std::ostream & write(std::ostream & os, uint8_t version = 0) const;

  //--------------------------------------------------------------------------
  //              int write(int fd, uint8_t version = 0) const
  //..........................................................................
  //!  Writes the ArtsBgp4AsPathSegment to a file descriptor.  Returns the
  //!  number of bytes written on success, -1 on failure.
  //--------------------------------------------------------------------------
  int write(int fd, uint8_t version = 0) const;

  //--------------------------------------------------------------------------
  //                uint32_t Length(uint8_t version = 0) const               
  //..........................................................................
  //!  Returns the number of bytes required to write the
  //!  ArtsBgp4AsPathSegment to disk.
  //--------------------------------------------------------------------------
  uint32_t Length(uint8_t version = 0) const;

  //--------------------------------------------------------------------------
  //                         void AddAs(uint16_t as)                         
  //..........................................................................
  //!  Appends an AS number to the segment.
  //--------------------------------------------------------------------------
  void AddAs(uint16_t as);

  //--------------------------------------------------------------------------
  //                              void Unique()
  //..........................................................................
  //!  If the segment is a sequence segment (not an AS_SET), removes
  //!  adjacent duplicate AS numbers from the segment.
  //--------------------------------------------------------------------------
  void Unique();

  //--------------------------------------------------------------------------
  //      ArtsBgp4AsPathSegment &                         
  //      operator = (const ArtsBgp4AsPathSegment & bgp4AsPathSegment)
  //..........................................................................
  //!  Overloaded = operator, deep-copies an ArtsBgp4AsPathSegment.
  //--------------------------------------------------------------------------
  ArtsBgp4AsPathSegment &
  operator = (const ArtsBgp4AsPathSegment & asPathSegment);

  //--------------------------------------------------------------------------
  //       friend std::ostream &                            
  //       operator << (std::ostream& os,                   
  //                    const ArtsBgp4AsPathSegment & bgpAsPathSegment)
  //..........................................................................
  //!  Writes the contents of an ArtsBgp4AsPathSegment to an ostream in
  //!  a human-friendly form.
  //--------------------------------------------------------------------------
  friend std::ostream &
  operator << (std::ostream& os,
               const ArtsBgp4AsPathSegment & bgpAsPathSegment);

  #ifndef NDEBUG
    //------------------------------------------------------------------------
    //                       static uint32_t NumObjects()                      
    //........................................................................
    //  
    //------------------------------------------------------------------------
    static uint32_t NumObjects()
    {
      return(_numObjects);
    }
  #endif  // NDEBUG
  
private:
  uint8_t                   _type;   // the segment type
  mutable std::vector<uint16_t>  _AS;     // the segment AS numbers

  static uint32_t           _numObjects;
};

#endif  // _ARTSBGP4ASPATHSEGMENT_HH_