// Copyright (C) 2005, 2006 International Business Machines and others.
// All Rights Reserved.
// This code is published under the Common Public License.
//
// $Id: IpWsmpSolverInterface.hpp 965 2007-04-26 19:44:18Z andreasw $
//
// Authors:  Carl Laird, Andreas Waechter     IBM    2005-03-17


#ifndef __IPWSMPSOLVERINTERFACE_HPP__
#define __IPWSMPSOLVERINTERFACE_HPP__

#include "IpSparseSymLinearSolverInterface.hpp"

namespace Ipopt
{

  /** Interface to the linear solver Wsmp, derived from
   *  SparseSymLinearSolverInterface.  For details, see description of
   *  SparseSymLinearSolverInterface base class.
   */
  class WsmpSolverInterface: public SparseSymLinearSolverInterface
  {
  public:
    /** @name Constructor/Destructor */
    //@{
    /** Constructor */
    WsmpSolverInterface();

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

    /** overloaded from AlgorithmStrategyObject */
    bool InitializeImpl(const OptionsList& options,
                        const std::string& prefix);


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

    /** Method returing 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.
     *  Returns 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;
    }
    //@}

    /** Methods for IpoptType */
    //@{
    static void RegisterOptions(SmartPtr<RegisteredOptions> roptions);
    //@}

    /** Query whether the indices of linearly dependent rows/columns
     *  can be determined by this linear solver. */
    virtual bool ProvidesDegeneracyDetection() const;

    /** This method determines the list of row indices of the linearly
     *  dependent rows. */
    virtual ESymSolverStatus DetermineDependentRows(const Index* ia,
        const Index* ja,
        std::list<Index>& c_deps);

  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 */
    WsmpSolverInterface(const WsmpSolverInterface&);

    /** Overloaded Equals Operator */
    void operator=(const WsmpSolverInterface&);
    //@}

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

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

    /** @name Solver specific options */
    //@{
    /** Option that controls the matching strategy. */
    Index wsmp_num_threads_;
    /** Ordering option for WSSMP (is IPARM(16)) */
    Index wsmp_ordering_option_;
    /** Pivol tolerance */
    Number wsmp_pivtol_;
    /** Maximal pivot tolerance */
    Number wsmp_pivtolmax_;
    /** Indicating which of WSMP's scaling methods should be used. */
    Index wsmp_scaling_;
    /** WSMP's singularity threshold.  The smaller this value the less
     *  likely a matrix is declared singular. */
    Number wsmp_singularity_threshold_;
    /** iteration number in which matrices are to be written out */
    Index wsmp_write_matrix_iteration_;
    //@}

    /** Counter for matrix file numbers */
    Index matrix_file_number_;

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

    /** @name Initialization flags */
    //@{
    /** Flag indicating if internal data is initialized.
     *  For initialization, this object needs to have seen a matrix */
    bool initialized_;
    /** Flag indicating if the matrix has to be refactorized because
     *  the pivot tolerance has been changed. */
    bool pivtol_changed_;
    /** Flag indicating whether symbolic factorization and order has
     *  already been performed. */
    bool have_symbolic_factorization_;
    //@}

    /** @name Solver specific information */
    //@{
    /** Integer parameter array for WSSMP. */
    ipfint* IPARM_;
    /** Double precision parameter array for WSSMP. */
    double* DPARM_;
    /** WSSMP's permutation vector */
    ipfint* PERM_;
    /** WSSMP's inverse permutation vector */
    ipfint* INVP_;
    /** WSSMP's internal MRP array */
    ipfint* MRP_;
    //@}

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

    /** Call Wsmp to really do the analysis phase. */
    ESymSolverStatus InternalSymFact(const Index* ia, const Index* ja);

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

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

} // namespace Ipopt
#endif
