/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2024, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */
#pragma once

#include <mrpt/obs/obs_frwds.h>
#include <mrpt/opengl/CSetOfObjects.h>
#include <mrpt/poses/CPosePDFParticles.h>
#include <mrpt/slam/PF_implementations_data.h>
#include <mrpt/slam/TMonteCarloLocalizationParams.h>

namespace mrpt
{
namespace maps
{
class COccupancyGridMap2D;
}

/** \ingroup mrpt_slam_grp */
namespace slam
{
/** Declares a class that represents a Probability Density Function (PDF) over a
 * 2D pose (x,y,phi), using a set of weighted samples.
 *
 *  This class also implements particle filtering for robot localization. See
 * the MRPT
 *   application "app/pf-localization" for an example of usage.
 *
 * \sa CMonteCarloLocalization3D, CPose2D, CPosePDF, CPoseGaussianPDF,
 * CParticleFilterCapable
 * \ingroup mrpt_slam_grp
 */
class CMonteCarloLocalization2D :
    public mrpt::poses::CPosePDFParticles,
    public PF_implementation<
        mrpt::math::TPose2D,
        CMonteCarloLocalization2D,
        mrpt::poses::CPosePDFParticles::PARTICLE_STORAGE>
{
 public:
  /** MCL parameters */
  TMonteCarloLocalizationParams options;

  /** Constructor
   * \param M The number of m_particles.
   */
  CMonteCarloLocalization2D(size_t M = 1);

  /** Destructor */
  ~CMonteCarloLocalization2D() override;

  /** Reset the PDF to an uniformly distributed one, but only in the
   * free-space
   *   of a given 2D occupancy-grid-map. Orientation is randomly generated in
   * the whole 2*PI range.
   * \param theMap The occupancy grid map
   * \param freeCellsThreshold The minimum free-probability to consider a
   * cell as empty (default is 0.7)
   * \param particlesCount If set to -1 the number of m_particles remains
   * unchanged.
   * \param x_min The limits of the area to look for free cells.
   * \param x_max The limits of the area to look for free cells.
   * \param y_min The limits of the area to look for free cells.
   * \param y_max The limits of the area to look for free cells.
   * \param phi_min The limits of the area to look for free cells.
   * \param phi_max The limits of the area to look for free cells.
   *  \sa resetDeterm32inistic
   * \exception std::exception On any error (no free cell found in map,
   * map=nullptr, etc...)
   */
  void resetUniformFreeSpace(
      mrpt::maps::COccupancyGridMap2D* theMap,
      const double freeCellsThreshold = 0.7,
      const int particlesCount = -1,
      const double x_min = -1e10f,
      const double x_max = 1e10f,
      const double y_min = -1e10f,
      const double y_max = 1e10f,
      const double phi_min = -M_PI,
      const double phi_max = M_PI);

  /** Update the m_particles, predicting the posterior of robot pose and map
   * after a movement command.
   *  This method has additional configuration parameters in "options".
   *  Performs the update stage of the RBPF, using the sensed CSensoryFrame:
   *
   *   \param action This is a pointer to CActionCollection, containing the
   * pose change the robot has been commanded.
   *   \param observation This must be a pointer to a CSensoryFrame object,
   * with robot sensed observations.
   *
   * \sa options
   */
  void prediction_and_update_pfStandardProposal(
      const mrpt::obs::CActionCollection* action,
      const mrpt::obs::CSensoryFrame* observation,
      const bayes::CParticleFilter::TParticleFilterOptions& PF_options) override;

  /** Update the m_particles, predicting the posterior of robot pose and map
   * after a movement command.
   *  This method has additional configuration parameters in "options".
   *  Performs the update stage of the RBPF, using the sensed CSensoryFrame:
   *
   *   \param Action This is a pointer to CActionCollection, containing the
   * pose change the robot has been commanded.
   *   \param observation This must be a pointer to a CSensoryFrame object,
   * with robot sensed observations.
   *
   * \sa options
   */
  void prediction_and_update_pfAuxiliaryPFStandard(
      const mrpt::obs::CActionCollection* action,
      const mrpt::obs::CSensoryFrame* observation,
      const bayes::CParticleFilter::TParticleFilterOptions& PF_options) override;

  /** Update the m_particles, predicting the posterior of robot pose and map
   * after a movement command.
   *  This method has additional configuration parameters in "options".
   *  Performs the update stage of the RBPF, using the sensed CSensoryFrame:
   *
   *   \param Action This is a pointer to CActionCollection, containing the
   * pose change the robot has been commanded.
   *   \param observation This must be a pointer to a CSensoryFrame object,
   * with robot sensed observations.
   *
   * \sa options
   */
  void prediction_and_update_pfAuxiliaryPFOptimal(
      const mrpt::obs::CActionCollection* action,
      const mrpt::obs::CSensoryFrame* observation,
      const bayes::CParticleFilter::TParticleFilterOptions& PF_options) override;

  /** Returns a 3D representation of this PDF.
   * \note Needs the mrpt-opengl library, and using
   * mrpt::opengl::CSetOfObjects::Ptr as template argument.
   */
  mrpt::opengl::CSetOfObjects::Ptr getVisualization() const
  {
    return mrpt::opengl::CSetOfObjects::posePDF2opengl(*this);
  }

  // protected:
  /** \name Virtual methods that the PF_implementations assume exist.
    @{ */
  /** Return the robot pose for the i'th particle. is_valid is
   * always true in this class. */
  mrpt::math::TPose3D getLastPose(size_t i, bool& is_valid_pose) const override;

  void PF_SLAM_implementation_custom_update_particle_with_new_pose(
      mrpt::math::TPose2D* particleData, const mrpt::math::TPose3D& newPose) const override;

  // We'll redefine this one:
  void PF_SLAM_implementation_replaceByNewParticleSet(
      CParticleList& old_particles,
      const std::vector<mrpt::math::TPose3D>& newParticles,
      const std::vector<double>& newParticlesWeight,
      const std::vector<size_t>& newParticlesDerivedFromIdx) const override;

  /** Evaluate the observation likelihood for one particle at a given location
   */
  double PF_SLAM_computeObservationLikelihoodForParticle(
      const mrpt::bayes::CParticleFilter::TParticleFilterOptions& PF_options,
      size_t particleIndexForMap,
      const mrpt::obs::CSensoryFrame& observation,
      const mrpt::poses::CPose3D& x) const override;
  /** @} */

};  // End of class def.

}  // namespace slam
}  // namespace mrpt
