#include <string>
#include <iostream>
#include <iomanip>

#include "JTools/JCombinatorics.hh"
#include "Jeep/JParser.hh"
#include "Jeep/JMessage.hh"


/**
 * \file
 * Example program to test combinatorics of pairs of indices (class JTOOLS::JCombinatorics).
 * \author mdejong
 */
int main(int argc, char **argv)
{
  using namespace std;

  int     numberOfElements;
  int     debug;

  try { 

    JParser<> zap("Example program to test combinatorics of pairs of indices.");
    
    zap['n'] = make_field(numberOfElements);
    zap['d'] = make_field(debug)           = 1;

    zap(argc, argv);
  }
  catch(const exception &error) {
    FATAL(error.what() << endl);
  }


  using namespace JPP;

  if (numberOfElements <= 0) {
    FATAL("Number of elements " << numberOfElements << " <= 0" << endl);
  }


  JCombinatorics combinatorics(numberOfElements);

  int n = 0;

  for (int i = 0; i != (int) combinatorics.getNumberOfPairs(); ++i) {

    STATUS("event: " << setw(8) << i << '\r'); DEBUG(endl);

    JCombinatorics::pair_type pair = combinatorics.getPair(i);

    if (i != combinatorics.getIndex(pair.first, pair.second)) {

      ++n;

      ERROR(endl                   << ' ' << 
	    setw(3) << pair.first  << ' ' <<
	    setw(3) << pair.second << ' ' <<
	    setw(4) << combinatorics.getIndex(pair.first, pair.second) << endl);
    }
  }
  DEBUG(endl); 

  NOTICE("Number of elements " << setw(8) << right << numberOfElements                 << endl);
  NOTICE("Number of pairs    " << setw(8) << right << combinatorics.getNumberOfPairs() << endl);
  NOTICE("Number of errors   " << setw(8) << right << n                                << endl);

  ASSERT(n == 0);
}