// Copyright (C) 2006 International Business Machines and others.
// All Rights Reserved.
// This code is published under the Common Public License.
//
// $Id: TutorialCpp_nlp.hpp 1097 2006-07-17 08:21:46Z andreasw $
//
// Author:  Andreas Waechter               IBM    2006-07-16

//
// This is part of the Ipopt tutorial at DIMACS's COIN-OR workshop.
//
// Implementation of the nlp class for execise problem (skeleton)
//
// param n := 4;
//
// var x {1..n} <= 0, >= -1.5, := -0.5;
//
// minimize obj:
//   sum{i in 1..n} (x[i]-1)^2;
//   ;
//
// subject to constr {i in 2..n-1}:
//   (x[i]^2+1.5*x[i]-i/n)*cos(x[i+1]) - x[i-1] = 0;
//
// The constant term "i/n" in the constraint is supposed to be input data
//

#ifndef __TUTORIALCPP_NLP_HPP__
#define __TUTORIALCPP_NLP_HPP__

#include "IpTNLP.hpp"

using namespace Ipopt;

// This inherits from Ipopt's TNLP
class TutorialCpp_NLP : public TNLP
{
public:
  /** constructor that takes in problem data */
  TutorialCpp_NLP(Index N, const Number* a);

  /** default destructor */
  virtual ~TutorialCpp_NLP();

  /**@name Overloaded from TNLP */
  //@{
  /** Method to return some info about the nlp */
  virtual bool get_nlp_info(Index& n, Index& m, Index& nnz_jac_g,
                            Index& nnz_h_lag, IndexStyleEnum& index_style);

  /** Method to return the bounds for my problem */
  virtual bool get_bounds_info(Index n, Number* x_l, Number* x_u,
                               Index m, Number* g_l, Number* g_u);

  /** Method to return the starting point for the algorithm */
  virtual bool get_starting_point(Index n, bool init_x, Number* x,
                                  bool init_z, Number* z_L, Number* z_U,
                                  Index m, bool init_lambda,
                                  Number* lambda);

  /** Method to return the objective value */
  virtual bool eval_f(Index n, const Number* x, bool new_x, Number& obj_value);

  /** Method to return the gradient of the objective */
  virtual bool eval_grad_f(Index n, const Number* x, bool new_x, Number* grad_f);

  /** Method to return the constraint residuals */
  virtual bool eval_g(Index n, const Number* x, bool new_x, Index m, Number* g);

  /** Method to return:
   *   1) The structure of the jacobian (if "values" is NULL)
   *   2) The values of the jacobian (if "values" is not NULL)
   */
  virtual bool eval_jac_g(Index n, const Number* x, bool new_x,
                          Index m, Index nele_jac, Index* iRow, Index *jCol,
                          Number* values);

  /** Method to return:
   *   1) The structure of the hessian of the lagrangian (if "values" is NULL)
   *   2) The values of the hessian of the lagrangian (if "values" is not NULL)
   */
  virtual bool eval_h(Index n, const Number* x, bool new_x,
                      Number obj_factor, Index m, const Number* lambda,
                      bool new_lambda, Index nele_hess, Index* iRow,
                      Index* jCol, Number* values);

  //@}

  /** @name Solution Methods */
  //@{
  /** This method is called when the algorithm is complete so the TNLP can store/write the solution */
  virtual void finalize_solution(SolverReturn status,
                                 Index n, const Number* x, const Number* z_L, const Number* z_U,
                                 Index m, const Number* g, const Number* lambda,
                                 Number obj_value);
  //@}

private:
  /**@name Methods to block default compiler methods.
   * The compiler automatically generates the following three methods.
   *  Since the default compiler implementation is generally not what
   *  you want (for all but the most simple classes), we usually 
   *  put the declarations of these methods in the private section
   *  and never implement them. This prevents the compiler from
   *  implementing an incorrect "default" behavior without us
   *  knowing. (See Scott Meyers book, "Effective C++")
   *  
   */
  //@{
  TutorialCpp_NLP();
  TutorialCpp_NLP(const TutorialCpp_NLP&);
  TutorialCpp_NLP& operator=(const TutorialCpp_NLP&);
  //@}

  /** @name NLP data */
  //@{
  /** Number of variables */
  Index N_;
  /** Value of constants in constraints */
  Number* a_;
  //@}
};


#endif