/**
 * @file   com_check_residual.cpp
 * @author Julian Iseringhausen <isering@ins.uni-bonn.de>
 * @date   Mon Apr 18 12:31:37 2011
 *
 * @brief  Checks if the residual is small enough to stop
 *         execution.
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <cmath>
#include <cstdio>

#include "base/command.hpp"
#include "base/factory.hpp"
#include "base/object.hpp"
#include "comm/comm.hpp"
#include "grid/multigrid.hpp"
#include "mg.hpp"

using namespace VMG;

class VMGCommandCheckResidual : public Command
{
public:
  Request Run(Command::argument_vector arguments)
  {
    const vmg_float res = MG::GetComm()->ComputeResidualNorm(*MG::GetSol(), *MG::GetRhs());
    const vmg_float& precision = MG::GetFactory().GetObject("PRECISION")->Cast< ObjectStorage<vmg_float> >()->Val();

#ifdef DEBUG
    if (MG::GetComm()->Rank() == 0)
      printf("Multigrid: Residual: %e\n", res);
#endif

    if (fabs(res) < precision)
      return StopCycleLater;
    else
      return Continue;
  }

  static const char* Name() {return "CheckResidual";}
  static int Arguments() {return 0;}
};

CREATE_INITIALIZER(VMGCommandCheckResidual);