/**
  * @RDE_HEADER@
  * LineOfSightCalculation (L400)
  * $Id$
  * $HeadURL$
  * $Author$
  * Created by N. Thoden, NLE, 06.04.2020
  */

#pragma once

#include <ElevationMap/situationmapelevationmap_export.h>
#include <Common/situation_map_logging.h>

#include <LtsUtilsCore/qpoint3d.h>
using Point3D = LtsUtils::QPoint3D;  ///< x = lon ; y = lat , z = elevation/altitude in meters


namespace SituationMap
{

// forward
class ElevationMap;

//----------------------------------------------------------------------------
/*!
  \brief Define visibility.
 */
enum class LineOfSightVisibility
{
  Undefined,        /*!< no data at that location? */
  Visible,
  Obstructed
};
//----------------------------------------------------------------------------

//----------------------------------------------------------------------------
class SITUATIONMAPELEVATIONMAP_EXPORT ObserverTargetData
{
public:
  explicit ObserverTargetData(const Point3D &oberserver = Point3D(),   // z-value: incl. observerHeight
                              const Point3D &target     = Point3D())   // z-value: incl. targetHeight
    : m_oberserver(oberserver)
    , m_target(target)
  {}

  const Point3D &observer() const             { return m_oberserver;           }
  const Point3D &target() const               { return m_target;               }

  const Point3D &obstacle() const             { return m_obstacle;             }
  void setObstacle(const Point3D &obstacle)   { m_obstacle = obstacle;         }

  LineOfSightVisibility lineOfSightVisibility() const                   { return m_visible;               }
  void setLineOfSightVisibility(const LineOfSightVisibility &visible)   { m_visible = visible;            }

  bool isObserverAndTargetValid() const       { return (!m_oberserver.isNull()) && (!m_target.isNull());  }

private:
  Point3D m_oberserver;
  Point3D m_target;

  Point3D m_obstacle;
  LineOfSightVisibility m_visible = LineOfSightVisibility::Undefined;
};
//----------------------------------------------------------------------------

class SITUATIONMAPELEVATIONMAP_EXPORT LineOfSightCalculation
{
public:
  explicit LineOfSightCalculation(ElevationMap *elevationMap);
  ~LineOfSightCalculation();

  bool calculate(ObserverTargetData &observerTarget, unsigned int sampleIntervallMeter = 5);

protected:
  static Point3D movePoint(const Point3D &oberserver,
                           const Point3D &target,
                           double distanceFromObserverToTargetAsFraction);

  static double distanceMeter(const Point3D &oberserver,
                              const Point3D &target);


private:
  LOGGER_T      m_logger;      ///< Interface of the Logging-Facility
  ElevationMap *m_elevationMap = nullptr;

  ObserverTargetData m_observerTarget;
};

} // namespace SituationMap