/***************************************************************************
                          merger.cpp  -  description
                             -------------------
    begin                : Sun Mar 24 2002
    copyright            : (C) 2002-2007 by Joachim Eibl
    email                : joachim.eibl at gmx.de
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#include "merger.h"

#include <assert.h>

Merger::Merger( const DiffList* pDiffListAB, const DiffList* pDiffListCA )
: md1( pDiffListAB, 0 ), md2( pDiffListCA, 1 )
{
}


Merger::MergeData::MergeData( const DiffList* p, int i )
: d(0,0,0)
{
   idx=i;
   pDiffList = p;
   if ( p!=0 )
   {
      it=p->begin();
      update();
   }
}

bool Merger::MergeData::eq()
{
   return pDiffList==0 || d.nofEquals > 0;
}

bool Merger::MergeData::isEnd()
{
   return ( pDiffList==0 || ( it==pDiffList->end() && d.nofEquals==0 && 
      ( idx == 0 ? d.diff1==0 : d.diff2==0 )
      ) );  
}

void Merger::MergeData::update()
{
   if ( d.nofEquals > 0 )
      --d.nofEquals;
   else if ( idx==0 && d.diff1 > 0 )
      --d.diff1;
   else if ( idx==1 && d.diff2 > 0 )
      --d.diff2; 

   while( d.nofEquals == 0  && ((idx==0 && d.diff1 == 0) || (idx==1 && d.diff2 == 0)) 
       && pDiffList!=0  &&  it != pDiffList->end() )
   {
      d = *it;
      ++it;
   }
}

void Merger::next()
{
   md1.update();
   md2.update();
}

int Merger::whatChanged()
{
   int changed = 0;
   changed |= md1.eq()  ?  0 : 1;
   changed |= md2.eq()  ?  0 : 2;
   return changed;
}

bool Merger::isEndReached()
{
   return md1.isEnd() && md2.isEnd();
}
