// Copyright (C) 2008 International Business Machines and others.
// All Rights Reserved.
// This code is published under the Eclipse Public License.
//
// Authors:  Andreas Waechter            IBM    2008-08-31

#ifndef __IPINEXACTNORMALSTEPCALC_HPP__
#define __IPINEXACTNORMALSTEPCALC_HPP__

#include "IpAlgStrategy.hpp"
#include "IpInexactCq.hpp"

namespace Ipopt
{
/** Base class for computing the normal step for the inexact step
 *  calculation algorithm.
 */
class InexactNormalStepCalculator: public AlgorithmStrategyObject
{
public:
   /**@name Constructors/Destructors */
   ///@{
   /** Default Constructor */
   InexactNormalStepCalculator()
   { }

   /** Destructor */
   virtual ~InexactNormalStepCalculator()
   { }
   ///@}

   virtual bool InitializeImpl(
      const OptionsList& options,
      const std::string& prefix
   ) = 0;

   /** Method for computing the normal step.
    *
    *  The computed step is
    *  returned as normal_x and normal_s, for the x and s variables,
    *  respectively.  These quantities are not slack-scaled.  If the
    *  step cannot be computed, this method returns false.
    */
   virtual bool ComputeNormalStep(
      SmartPtr<Vector>& normal_x,
      SmartPtr<Vector>& normal_s
   ) = 0;

protected:
   /** Method to easily access Inexact data */
   InexactData& InexData()
   {
      InexactData& inexact_data = static_cast<InexactData&>(IpData().AdditionalData());
      DBG_ASSERT(dynamic_cast<InexactData*>(&IpData().AdditionalData()));
      return inexact_data;
   }

   /** Method to easily access Inexact calculated quantities */
   InexactCq& InexCq()
   {
      InexactCq& inexact_cq = static_cast<InexactCq&>(IpCq().AdditionalCq());
      DBG_ASSERT(dynamic_cast<InexactCq*>(&IpCq().AdditionalCq()));
      return inexact_cq;
   }

private:
   /**@name Default Compiler Generated Methods
    * (Hidden to avoid implicit creation/calling).
    *
    * These methods are not implemented and
    * we do not want the compiler to implement
    * them for us, so we declare them private
    * and do not define them. This ensures that
    * they will not be implicitly created/called.
    */
   ///@{
   /** Copy Constructor */
   InexactNormalStepCalculator(
      const InexactNormalStepCalculator&
   );

   /** Overloaded Assignment Operator */
   void operator=(
      const InexactNormalStepCalculator&
   );
   ///@}
};

} // namespace Ipopt

#endif
