/****************************************************************************/
// Eclipse SUMO, Simulation of Urban MObility; see https://eclipse.dev/sumo
// Copyright (C) 2001-2026 German Aerospace Center (DLR) and others.
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0/
// This Source Code may also be made available under the following Secondary
// Licenses when the conditions for such availability set forth in the Eclipse
// Public License 2.0 are satisfied: GNU General Public License, version 2
// or later which is available at
// https://www.gnu.org/licenses/old-licenses/gpl-2.0-standalone.html
// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
/****************************************************************************/
/// @file    MSCFModel_Kerner.h
/// @author  Daniel Krajzewicz
/// @author  Michael Behrisch
/// @date    03.04.2010
///
// car-following model by B. Kerner
/****************************************************************************/
#pragma once
#include <config.h>

#include "MSCFModel.h"
#include <utils/xml/SUMOXMLDefinitions.h>


// ===========================================================================
// class definitions
// ===========================================================================
/** @class MSCFModel_Kerner
 * @brief car-following model by B. Kerner
 * @see MSCFModel
 */
class MSCFModel_Kerner : public MSCFModel {
public:
    /** @brief Constructor
     *  @param[in] vtype the type for which this model is built and also the parameter object to configure this model
     */
    MSCFModel_Kerner(const MSVehicleType* vtype);


    /// @brief Destructor
    ~MSCFModel_Kerner();


    /// @name Implementations of the MSCFModel interface
    /// @{

    /** @brief Applies interaction with stops and lane changing model influences
     * @param[in] veh The ego vehicle
     * @param[in] vPos The possible velocity
     * @return The velocity after applying interactions with stops and lane change model influences
     */
    double finalizeSpeed(MSVehicle* const veh, double vPos) const;

    /** @brief Computes the vehicle's safe speed (no dawdling)
     * @param[in] veh The vehicle (EGO)
     * @param[in] speed The vehicle's speed
     * @param[in] gap2pred The (net) distance to the LEADER
     * @param[in] predSpeed The speed of LEADER
     * @return EGO's safe speed
     * @see MSCFModel::ffeV
     */
    double followSpeed(const MSVehicle* const veh, double speed, double gap2pred,
                       double predSpeed, double predMaxDecel, const MSVehicle* const pred = 0, const CalcReason usage = CalcReason::CURRENT) const;


    /** @brief Computes the vehicle's safe speed for approaching a non-moving obstacle (no dawdling)
     * @param[in] veh The vehicle (EGO)
     * @param[in] gap2pred The (net) distance to the obstacle
     * @return EGO's safe speed for approaching a non-moving obstacle
     * @see MSCFModel::ffeS
     * @todo generic Interface, models can call for the values they need
     */
    double stopSpeed(const MSVehicle* const veh, const double speed, double gap2pred, double decel, const CalcReason usage = CalcReason::CURRENT) const;


    /** @brief Returns the model's name
     * @return The model's name
     * @see MSCFModel::getModelName
     */
    int getModelID() const {
        return SUMO_TAG_CF_BKERNER;
    }
    /// @}



    /** @brief Duplicates the car-following model
     * @param[in] vtype The vehicle type this model belongs to (1:1)
     * @return A duplicate of this car-following model
     */
    MSCFModel* duplicate(const MSVehicleType* vtype) const;


    MSCFModel::VehicleVariables* createVehicleVariables() const;


private:
    class VehicleVariables : public MSCFModel::VehicleVariables {
    public:
        double rand;

        /** @brief Saves the vehicle variables
         * @param[in] out The OutputDevice to write the information into
         */
        void saveState(OutputDevice& out, const MSCFModel& cfm) const;

        /** @brief Loads the state of the vehicle variables from the given description
         * @param[in] attrs XML attributes describing the current state
         */
        void loadState(const SUMOSAXAttributes& attrs);
    };

    /** @brief Returns the "safe" velocity
     * @param[in] gap2pred The (net) distance to the LEADER
     * @param[in] predSpeed The LEADER's speed
     * @return the safe velocity
     */
    double _v(const MSVehicle* const veh, double speed, double vfree, double gap, double predSpeed) const;



private:
    /// @name model parameter
    /// @{
    /// @brief Kerner's k
    double myK;

    /// @brief Kerner's phi
    double myPhi;

    /// @brief The precomputed value for myDecel*myTau
    double myTauDecel;
    /// @}

};
