///////////////////////////////////////////////////////////////////////////////
//
// File: Forcing.h
//
// For more information, please see: http://www.nektar.info
//
// The MIT License
//
// Copyright (c) 2006 Division of Applied Mathematics, Brown University (USA),
// Department of Aeronautics, Imperial College London (UK), and Scientific
// Computing and Imaging Institute, University of Utah (USA).
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
// Description: Abstract base class for advection.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef NEKTAR_SOLVERUTILS_FORCING
#define NEKTAR_SOLVERUTILS_FORCING

#include <string>

#include <LibUtilities/BasicUtils/NekFactory.hpp>
#include <LibUtilities/BasicUtils/SharedArray.hpp>
#include <MultiRegions/ExpList.h>
#include <SolverUtils/Core/SessionFunction.h>
#include <SolverUtils/SolverUtilsDeclspec.h>

namespace Nektar::SolverUtils
{
//  Forward declaration
class Forcing;
class EquationSystem;

/// A shared pointer to an EquationSystem object
SOLVER_UTILS_EXPORT typedef std::shared_ptr<Forcing> ForcingSharedPtr;

/// Declaration of the forcing factory
typedef LibUtilities::NekFactory<
    std::string, Forcing, const LibUtilities::SessionReaderSharedPtr &,
    const std::weak_ptr<EquationSystem> &,
    const Array<OneD, MultiRegions::ExpListSharedPtr> &, const unsigned int &,
    const TiXmlElement *>
    ForcingFactory;

/// Declaration of the forcing factory singleton
SOLVER_UTILS_EXPORT ForcingFactory &GetForcingFactory();

/**
 * @class Forcing
 * @brief Defines a forcing term to be explicitly applied.
 */
class Forcing
{
public:
    /// Initialise the forcing object
    SOLVER_UTILS_EXPORT void InitObject(
        const Array<OneD, MultiRegions::ExpListSharedPtr> &pFields,
        const unsigned int &pNumForcingFields, const TiXmlElement *pForce)
    {
        v_InitObject(pFields, pNumForcingFields, pForce);
    }

    /// Apply the forcing
    SOLVER_UTILS_EXPORT void Apply(
        const Array<OneD, MultiRegions::ExpListSharedPtr> &fields,
        const Array<OneD, Array<OneD, NekDouble>> &inarray,
        Array<OneD, Array<OneD, NekDouble>> &outarray, const NekDouble &time)
    {
        v_Apply(fields, inarray, outarray, time);
    }

    /// Change the advection velocity before applying the forcing.
    /// For example, subtracting the frame velocity from the
    /// advection velocity in the MovingRefercenceFrame.
    SOLVER_UTILS_EXPORT void PreApply(
        const Array<OneD, MultiRegions::ExpListSharedPtr> &fields,
        const Array<OneD, Array<OneD, NekDouble>> &inarray,
        Array<OneD, Array<OneD, NekDouble>> &outarray, const NekDouble &time)
    {
        v_PreApply(fields, inarray, outarray, time);
    }

    /// Apply the forcing
    SOLVER_UTILS_EXPORT void ApplyCoeff(
        const Array<OneD, MultiRegions::ExpListSharedPtr> &fields,
        const Array<OneD, Array<OneD, NekDouble>> &inarray,
        Array<OneD, Array<OneD, NekDouble>> &outarray, const NekDouble &time)
    {
        v_ApplyCoeff(fields, inarray, outarray, time);
    }

    SOLVER_UTILS_EXPORT static std::vector<ForcingSharedPtr> Load(
        const LibUtilities::SessionReaderSharedPtr &pSession,
        const std::weak_ptr<EquationSystem> &pEquation,
        const Array<OneD, MultiRegions::ExpListSharedPtr> &pFields,
        const unsigned int &pNumForcingFields = 0);

    SOLVER_UTILS_EXPORT const Array<OneD, const Array<OneD, NekDouble>> &
    GetForces();

    SOLVER_UTILS_EXPORT Array<OneD, Array<OneD, NekDouble>> &UpdateForces();

protected:
    /// Session reader
    LibUtilities::SessionReaderSharedPtr m_session;
    /// Weak pointer to equation system using this forcing
    const std::weak_ptr<EquationSystem> m_equ;
    /// Evaluated forcing function
    Array<OneD, Array<OneD, NekDouble>> m_Forcing;
    /// Number of variables
    int m_NumVariable;
    /// Map of known SessionFunctions
    std::map<std::string, SolverUtils::SessionFunctionSharedPtr>
        m_sessionFunctions;

    /// Constructor
    SOLVER_UTILS_EXPORT Forcing(
        const LibUtilities::SessionReaderSharedPtr &pSession,
        const std::weak_ptr<EquationSystem> &pEquation);

    SOLVER_UTILS_EXPORT virtual ~Forcing() = default;

    SOLVER_UTILS_EXPORT virtual void v_InitObject(
        const Array<OneD, MultiRegions::ExpListSharedPtr> &pFields,
        const unsigned int &pNumForcingFields, const TiXmlElement *pForce) = 0;

    SOLVER_UTILS_EXPORT virtual void v_Apply(
        const Array<OneD, MultiRegions::ExpListSharedPtr> &fields,
        const Array<OneD, Array<OneD, NekDouble>> &inarray,
        Array<OneD, Array<OneD, NekDouble>> &outarray,
        const NekDouble &time) = 0;

    SOLVER_UTILS_EXPORT virtual void v_PreApply(
        const Array<OneD, MultiRegions::ExpListSharedPtr> &fields,
        const Array<OneD, Array<OneD, NekDouble>> &inarray,
        Array<OneD, Array<OneD, NekDouble>> &outarray, const NekDouble &time);

    SOLVER_UTILS_EXPORT virtual void v_ApplyCoeff(
        const Array<OneD, MultiRegions::ExpListSharedPtr> &fields,
        const Array<OneD, Array<OneD, NekDouble>> &inarray,
        Array<OneD, Array<OneD, NekDouble>> &outarray, const NekDouble &time);

    /// Get a SessionFunction by name
    SOLVER_UTILS_EXPORT SessionFunctionSharedPtr
    GetFunction(const Array<OneD, MultiRegions::ExpListSharedPtr> &pFields,
                const LibUtilities::SessionReaderSharedPtr &pSession,
                std::string pName, bool pCache = false);

    SOLVER_UTILS_EXPORT void EvaluateTimeFunction(
        LibUtilities::SessionReaderSharedPtr pSession, std::string pFieldName,
        Array<OneD, NekDouble> &pArray, const std::string &pFunctionName,
        NekDouble pTime = NekDouble(0));

    SOLVER_UTILS_EXPORT void EvaluateTimeFunction(
        const NekDouble pTime, const LibUtilities::EquationSharedPtr &pEqn,
        Array<OneD, NekDouble> &pArray);
};
} // namespace Nektar::SolverUtils

#endif
