/* Copyright 2020 Remi Lehe
 *
 * This file is part of WarpX.
 *
 * License: BSD-3-Clause-LBNL
 */

#include "WarpXAlgorithmSelection.H"
#ifdef WARPX_DIM_RZ
#    include "FiniteDifferenceAlgorithms/CylindricalYeeAlgorithm.H"
#else
#    include "FiniteDifferenceAlgorithms/YeeAlgorithm.H"
#    include "FiniteDifferenceAlgorithms/CKCAlgorithm.H"
#    include "FiniteDifferenceAlgorithms/NodalAlgorithm.H"
#endif
#include "FiniteDifferenceSolver.H"
#include "WarpX.H"

/* \brief Initialize the finite-difference Maxwell solver (for a given refinement level)
 *
 * This function initializes the stencil coefficients for the chosen finite-difference algorithm
 *
 * \param fdtd_algo Identifies the chosen algorithm, as defined in WarpXAlgorithmSelection.H
 * \param cell_size Cell size along each dimension, for the chosen refinement level
 * \param do_nodal  Whether the solver is applied to a nodal or staggered grid
 */
FiniteDifferenceSolver::FiniteDifferenceSolver (
    int const fdtd_algo,
    std::array<amrex::Real,3> cell_size,
    bool do_nodal ) {

    // Register the type of finite-difference algorithm
    m_fdtd_algo = fdtd_algo;
    m_do_nodal = do_nodal;

    // Calculate coefficients of finite-difference stencil
#ifdef WARPX_DIM_RZ
    m_dr = cell_size[0];
    m_nmodes = WarpX::GetInstance().n_rz_azimuthal_modes;
    m_rmin = WarpX::GetInstance().Geom(0).ProbLo(0);
    if (fdtd_algo == MaxwellSolverAlgo::Yee) {

        CylindricalYeeAlgorithm::InitializeStencilCoefficients( cell_size,
            stencil_coefs_r, stencil_coefs_z );
#else
    if (do_nodal) {

        NodalAlgorithm::InitializeStencilCoefficients( cell_size,
            stencil_coefs_x, stencil_coefs_y, stencil_coefs_z );

    } else if (fdtd_algo == MaxwellSolverAlgo::Yee) {

        YeeAlgorithm::InitializeStencilCoefficients( cell_size,
            stencil_coefs_x, stencil_coefs_y, stencil_coefs_z );

    } else if (fdtd_algo == MaxwellSolverAlgo::CKC) {

        CKCAlgorithm::InitializeStencilCoefficients( cell_size,
            stencil_coefs_x, stencil_coefs_y, stencil_coefs_z );

#endif
    } else {
        amrex::Abort("Unknown algorithm");
    }
};