// Copyright (C) 2008 International Business Machines and others.
// All Rights Reserved.
// This code is published under the Eclipse Public License.
//
// Authors:  Andreas Waechter            IBM    2008-09-18
//            based on IpPardisoSolverInterface.hpp rev 1119

#ifndef __IPITERATIVEPARDISOSOLVERINTERFACE_HPP__
#define __IPITERATIVEPARDISOSOLVERINTERFACE_HPP__

#include "IpSparseSymLinearSolverInterface.hpp"
#include "IpInexactCq.hpp"
#include "IpIterativeSolverTerminationTester.hpp"

namespace Ipopt
{

/** Interface to the linear solver Pardiso, derived from
 *  SparseSymLinearSolverInterface.
 */
class IterativePardisoSolverInterface: public SparseSymLinearSolverInterface
{
public:
   /** @name Constructor/Destructor */
   ///@{
   /** Constructor */
   IterativePardisoSolverInterface(
      IterativeSolverTerminationTester& normal_tester,
      IterativeSolverTerminationTester& pd_tester
   );

   /** Destructor */
   virtual ~IterativePardisoSolverInterface();
   ///@}

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

   /** @name Methods for requesting solution of the linear system. */
   ///@{
   /** Method for initializing internal structures. */
   virtual ESymSolverStatus InitializeStructure(
      Index        dim,
      Index        nonzeros,
      const Index* ia,
      const Index* ja
   );

   /** Method returning an internal array into which the nonzero
    *  elements are to be stored.
    */
   virtual double* GetValuesArrayPtr();

   /** Solve operation for multiple right hand sides. */
   virtual ESymSolverStatus MultiSolve(
      bool         new_matrix,
      const Index* ia,
      const Index* ja,
      Index        nrhs,
      double*      rhs_vals,
      bool         check_NegEVals,
      Index        numberOfNegEVals
   );

   /** Number of negative eigenvalues detected during last
    *  factorization.
    */
   virtual Index NumberOfNegEVals() const;
   ///@}

   //* @name Options of Linear solver */
   ///@{
   /** Request to increase quality of solution for next solve.
    */
   virtual bool IncreaseQuality();

   /** Query whether inertia is computed by linear solver.
    *
    *  @return true, if linear solver provides inertia
    */
   virtual bool ProvidesInertia() const
   {
      return true;
   }

   /** Query of requested matrix type that the linear solver
    *  understands.
    */
   EMatrixFormat MatrixFormat() const
   {
      return CSR_Format_1_Offset;
   }
   ///@}

   static void RegisterOptions(
      SmartPtr<RegisteredOptions> roptions
   );

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.
    */
   ///@{
   /** Default Constructor */
   IterativePardisoSolverInterface();

   /** Copy Constructor */
   IterativePardisoSolverInterface(
      const IterativePardisoSolverInterface&
   );

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

   /** @name Information about the matrix */
   ///@{
   /** Number of rows and columns of the matrix */
   Index dim_;

   /** Number of nonzeros of the matrix in triplet representation. */
   Index nonzeros_;

   /** Array for storing the values of the matrix. */
   double* a_;
   ///@}

   /** @name Information about most recent factorization/solve */
   ///@{
   /** Number of negative eigenvalues */
   Index negevals_;
   ///@}

   /** @name Solver specific options */
   ///@{
   /** Type for matching strategies */
   enum PardisoMatchingStrategy
   {
      COMPLETE,
      COMPLETE2x2,
      CONSTRAINT
   };
   /** Option that controls the matching strategy. */
   PardisoMatchingStrategy match_strat_;
   /** Flag indicating if symbolic factorization has already been
    *  performed.
    */
   bool have_symbolic_factorization_;
   /** Flag indicating whether the symbolic factorization should only
    *  be done after perturbed elements, if the inertia was wrong.
    */
   bool pardiso_redo_symbolic_fact_only_if_inertia_wrong_;
   /** Flag indicating whether repeated perturbed elements even after
    *  a new symbolic factorization should be interpreted as a
    *  singular matrix.
    */
   bool pardiso_repeated_perturbation_means_singular_;
   /** Flag indicating if the inertia is always assumed to be correct. */
   bool skip_inertia_check_;
   /** Maximal number of decreases of drop tolerance during one solve. */
   Index pardiso_max_droptol_corrections_;
   ///@}

   /** Options for the preconditioner */
   ///@{
   Index pardiso_max_iter_;
   Number pardiso_iter_relative_tol_;
   Index pardiso_iter_coarse_size_;
   Index pardiso_iter_max_levels_;
   Number pardiso_iter_dropping_factor_;
   Number pardiso_iter_dropping_schur_;
   Index pardiso_iter_max_row_fill_;
   Number pardiso_iter_inverse_norm_factor_;

   Index normal_pardiso_max_iter_;
   Number normal_pardiso_iter_relative_tol_;
   Index normal_pardiso_iter_coarse_size_;
   Index normal_pardiso_iter_max_levels_;
   Number normal_pardiso_iter_dropping_factor_;
   Number normal_pardiso_iter_dropping_schur_;
   Index normal_pardiso_iter_max_row_fill_;
   Number normal_pardiso_iter_inverse_norm_factor_;
   ///@}

   /** Decrease factor for dropping tolerances */
   Number decr_factor_;

   /** Actually used dropping tolerances */
   ///@{
   Number pardiso_iter_dropping_factor_used_;
   Number pardiso_iter_dropping_schur_used_;
   Number normal_pardiso_iter_dropping_factor_used_;
   Number normal_pardiso_iter_dropping_schur_used_;
   ///@}

   /** @name Initialization flags */
   ///@{
   /** Flag indicating if internal data is initialized.
    *
    *  For initialization, this object needs to have seen a matrix.
    */
   bool initialized_;
   ///@}

   /** @name Solver specific information */
   ///@{
   /** Internal data address pointers. */
   void** PT_;
   /** Maximal number of factors with identical nonzero structure.
    *
    * Here, we only store one factorization. Is always 1.
    */
   ipfint MAXFCT_;
   /** Actual matrix for the solution phase. Is always 1. */
   ipfint MNUM_;
   /** Matrix type; real and symmetric indefinite.  Is always -2. */
   ipfint MTYPE_;
   /** Parameter and info array for Pardiso. */
   ipfint* IPARM_;
   /** Parameter and info array for Pardiso. */
   double* DPARM_;
   /** Message level. */
   ipfint MSGLVL_;
   ///@}

   /**@name Some counters for debugging */
   ///@{
   Index debug_last_iter_;
   Index debug_cnt_;
   ///@}

   /** @name Internal functions */
   ///@{
   /** Call Pardiso to do the analysis phase. */
   ESymSolverStatus SymbolicFactorization(
      const Index* ia,
      const Index* ja
   );

   /** Call Pardiso to factorize the Matrix. */
   ESymSolverStatus Factorization(
      const Index* ia,
      const Index* ja,
      bool         check_NegEVals,
      Index        numberOfNegEVals
   );

   /** Call Pardiso to do the Solve.
    */
   ESymSolverStatus Solve(
      const Index* ia,
      const Index* ja,
      Index        nrhs,
      double*      rhs_vals
   );
   ///@}

   /** 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;
   }

   /** Termination tester for normal step computation */
   SmartPtr<IterativeSolverTerminationTester> normal_tester_;

   /** Termination tester for primal-dual step computation */
   SmartPtr<IterativeSolverTerminationTester> pd_tester_;

};

} // namespace Ipopt

#endif
