/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2023, 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/config/CLoadableOptions.h>
#include <mrpt/containers/CDynamicGrid.h>
#include <mrpt/img/color_maps.h>
#include <mrpt/maps/CHeightGridMap2D_Base.h>
#include <mrpt/maps/CMetricMap.h>
#include <mrpt/obs/obs_frwds.h>
#include <mrpt/poses/poses_frwds.h>
#include <mrpt/serialization/CSerializable.h>
#include <mrpt/typemeta/TEnumType.h>

namespace mrpt
{
namespace maps
{
/** The contents of each cell in a CHeightGridMap2D map */
struct THeightGridmapCell
{
	/** The current average height (in meters) */
	float h{};
	/** The current standard deviation of the height (in meters) */
	float var{};
	/** Auxiliary variable for storing the incremental mean value (in meters).
	 */
	float u{};
	/** Auxiliary (in meters) */
	float v{};
	/** [For mrSimpleAverage model] The accumulated weight: initially zero if
	 * un-observed, increased by one for each observation */
	uint32_t w{};

	THeightGridmapCell() = default;
};

/** Digital Elevation Model (DEM), a mesh or grid representation of a surface
 * which keeps the estimated height for each (x,y) location.
 *  Important implemented features are the insertion of 2D laser scans (from
 * arbitrary 6D poses) and the exportation as 3D scenes.
 *
 * Each cell contains the up-to-date average height from measured falling in
 * that cell. Algorithms that can be used:
 *   - mrSimpleAverage: Each cell only stores the current average value.
 *
 *  This class implements generic version of
 * mrpt::maps::CMetric::insertObservation() accepting these types of sensory
 * data:
 *   - mrpt::obs::CObservation2DRangeScan: 2D range scans
 *   - mrpt::obs::CObservationVelodyneScan
 *
 * \ingroup mrpt_maps_grp
 */
class CHeightGridMap2D
	: public mrpt::maps::CMetricMap,
	  public mrpt::containers::CDynamicGrid<THeightGridmapCell>,
	  public CHeightGridMap2D_Base
{
	DEFINE_SERIALIZABLE(CHeightGridMap2D, mrpt::maps)
   public:
	/** Calls the base CMetricMap::clear
	 * Declared here to avoid ambiguity between the two clear() in both base
	 * classes.
	 */
	inline void clear() { CMetricMap::clear(); }
	float cell2float(const THeightGridmapCell& c) const override
	{
		return float(c.h);
	}

	/** Returns a short description of the map. */
	std::string asString() const override
	{
		return mrpt::format(
			"HeightGridMap2D, extending from (%f,%f) to (%f,%f), resolution=%f",
			getXMin(), getYMin(), getXMax(), getYMax(), getResolution());
	}

	/** The type of map representation to be used.
	 *  See mrpt::maps::CHeightGridMap2D for discussion.
	 */
	enum TMapRepresentation
	{
		mrSimpleAverage = 0
	};

	/** Constructor */
	CHeightGridMap2D(
		TMapRepresentation mapType = mrSimpleAverage, double x_min = -2,
		double x_max = 2, double y_min = -2, double y_max = 2,
		double resolution = 0.1);

	/** Returns true if the map is empty/no observation has been inserted. */
	bool isEmpty() const override;

	/** Parameters related with inserting observations into the map */
	struct TInsertionOptions : public mrpt::config::CLoadableOptions
	{
		/** Default values loader */
		TInsertionOptions();

		void loadFromConfigFile(
			const mrpt::config::CConfigFileBase& source,
			const std::string& section) override;  // See base docs
		void dumpToTextStream(
			std::ostream& out) const override;	// See base docs

		/** Whether to perform filtering by z-coordinate (default=false):
		 * coordinates are always RELATIVE to the robot for this filter.vvv */
		bool filterByHeight{false};
		/** Only when filterByHeight is true: coordinates are always RELATIVE to
		 * the robot for this filter. */
		float z_min{-0.5}, z_max{0.5};

		mrpt::img::TColormap colorMap{mrpt::img::cmJET};
	} insertionOptions;

	/** See docs in base class: in this class it always returns 0 */
	float compute3DMatchingRatio(
		const mrpt::maps::CMetricMap* otherMap,
		const mrpt::poses::CPose3D& otherMapPose,
		const TMatchingRatioParams& params) const override;

	void saveMetricMapRepresentationToFile(const std::string& filNamePrefix)
		const override;	 // See base class docs

	/** Returns a 3D object representing the map: by default, it will be a
	 * mrpt::opengl::CMesh object, unless
	 *   it is specified otherwise in
	 * mrpt::global_settings::HEIGHTGRIDMAP_EXPORT3D_AS_MESH */
	void getVisualizationInto(
		mrpt::opengl::CSetOfObjects& outObj) const override;

	/** Return the type of the gas distribution map, according to parameters
	 * passed on construction */
	TMapRepresentation getMapType();

	/** Return the number of cells with at least one height data inserted. */
	size_t countObservedCells() const;

	bool insertIndividualPoint(
		const double x, const double y, const double z,
		const CHeightGridMap2D_Base::TPointInsertParams& params =
			CHeightGridMap2D_Base::TPointInsertParams()) override;
	double dem_get_resolution() const override;
	size_t dem_get_size_x() const override;
	size_t dem_get_size_y() const override;
	bool dem_get_z_by_cell(size_t cx, size_t cy, double& z_out) const override;
	bool dem_get_z(
		const double x, const double y, double& z_out) const override;
	void dem_update_map() override;

	/** The map representation type of this map */
	TMapRepresentation m_mapType;

	// See docs in base class
	void internal_clear() override;
	bool internal_insertObservation(
		const mrpt::obs::CObservation& obs,
		const std::optional<const mrpt::poses::CPose3D>& robotPose =
			std::nullopt) override;
	double internal_computeObservationLikelihood(
		const mrpt::obs::CObservation& obs,
		const mrpt::poses::CPose3D& takenFrom) const override;

	MAP_DEFINITION_START(CHeightGridMap2D)
	/** See CHeightGridMap2D::CHeightGridMap2D */
	double min_x{-2}, max_x{2}, min_y{-2}, max_y{2}, resolution{0.10f};
	/** The kind of map representation (see CHeightGridMap2D::CHeightGridMap2D)
	 */
	mrpt::maps::CHeightGridMap2D::TMapRepresentation mapType{
		CHeightGridMap2D::mrSimpleAverage};
	mrpt::maps::CHeightGridMap2D::TInsertionOptions insertionOpts;
	MAP_DEFINITION_END(CHeightGridMap2D)
};

}  // namespace maps

namespace global_settings
{
/** If set to true (default), mrpt::maps::CHeightGridMap2D will be exported as a
 *opengl::CMesh, otherwise, as a opengl::CPointCloudColoured
 * Affects to:
 *		- CHeightGridMap2D::getAs3DObject
 */
void HEIGHTGRIDMAP_EXPORT3D_AS_MESH(bool value);
bool HEIGHTGRIDMAP_EXPORT3D_AS_MESH();
}  // namespace global_settings
}  // namespace mrpt

MRPT_ENUM_TYPE_BEGIN(maps::CHeightGridMap2D::TMapRepresentation)
MRPT_FILL_ENUM_MEMBER(
	maps::CHeightGridMap2D::TMapRepresentation, mrSimpleAverage);
MRPT_ENUM_TYPE_END()
