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#ifndef ROCALUTION_MULTIGRID_RUGE_STUEBEN_AMG_HPP_
#define ROCALUTION_MULTIGRID_RUGE_STUEBEN_AMG_HPP_

#include "../solver.hpp"
#include "base_amg.hpp"

#include <vector>

namespace rocalution
{

    /** \ingroup solver_module
  * \class RugeStuebenAMG
  * \brief Ruge-Stueben Algebraic MultiGrid Method
  * \details
  * The Ruge-Stueben Algebraic MultiGrid method is based on the classic Ruge-Stueben
  * coarsening with direct interpolation. The solver provides high-efficiency in terms of
  * complexity of the solver (i.e. number of iterations). However, most of the time it
  * has a higher building step and requires higher memory usage.
  * \cite stuben
  *
  * \tparam OperatorType - can be LocalMatrix
  * \tparam VectorType - can be LocalVector
  * \tparam ValueType - can be float, double, std::complex<float> or std::complex<double>
  */
    template <class OperatorType, class VectorType, typename ValueType>
    class RugeStuebenAMG : public BaseAMG<OperatorType, VectorType, ValueType>
    {
    public:
        RugeStuebenAMG();
        virtual ~RugeStuebenAMG();

        virtual void Print(void) const;
        virtual void BuildSmoothers(void);

        /** \brief Set coupling strength */
        void SetCouplingStrength(ValueType eps);

        virtual void ReBuildNumeric(void);

    protected:
        virtual void Aggregate_(const OperatorType&  op,
                                Operator<ValueType>* pro,
                                Operator<ValueType>* res,
                                OperatorType*        coarse);

        virtual void PrintStart_(void) const;
        virtual void PrintEnd_(void) const;

    private:
        /** \brief Coupling strength */
        ValueType eps_;
    };

} // namespace rocalution

#endif // ROCALUTION_MULTIGRID_RUGE_STUEBEN_AMG_HPP_