#ifndef ESOLVER_H

#define ESOLVER_H

#include "source_base/matrix.h"

#include "source_cell/unitcell.h"

struct Input_para;

namespace ModuleESolver

{

class ESolver

{

public:

ESolver()

{

classname = "ESolver";

}

virtual ~ESolver()

{

//****************************************************

// do not add any codes in this deconstructor funcion

//****************************************************

}

//! initialize the energy solver by using input parameters and cell modules

virtual void before_all_runners(UnitCell& ucell, const Input_para& inp) = 0;

//! run energy solver

virtual void runner(UnitCell& cell, const int istep) = 0;

//! perform post processing calculations

virtual void after_all_runners(UnitCell& ucell) = 0;

//! deal with exx and other calculation than scf/md/relax/cell-relax:

//! such as nscf, get_wf and get_pchg

virtual void others(UnitCell& ucell, const int istep) {};

//! calculate total energy of a given system

virtual double cal_energy() = 0;

//! calcualte forces for the atoms in the given cell

virtual void cal_force(UnitCell& ucell, ModuleBase::matrix& force) = 0;

//! calcualte stress of given cell

virtual void cal_stress(UnitCell& ucell, ModuleBase::matrix& stress) = 0;

bool conv_esolver = true; // whether esolver is converged

std::string classname;

};

/**

* @brief A subrutine called in init_esolver()

* This function returns type of ESolver

* Based on PARAM.inp.basis_type and PARAM.inp.esolver_type

*

* @return [out] std::string The type of ESolver

*/

std::string determine_type();

/**

* @brief Determine and initialize an ESolver based on input information.

*

* This function determines the type of ESolver to create based on input information and initializes

* the corresponding ESolver child class. It supports various ESolver types including ksdft_pw,

* ksdft_lcao, ksdft_lcao_tddft, sdft_pw, ofdft, lj_pot, and dp_pot.

*

* @return [out] A pointer to an ESolver object that will be initialized.

*/

ESolver* init_esolver(const Input_para& inp, UnitCell& ucell);

} // namespace ModuleESolver

#endif