#ifndef _OWLPS_POSITIONING_WAYPOINT_HH_
#define _OWLPS_POSITIONING_WAYPOINT_HH_

class Building ;

#include "point3d.hh"

#include <boost/tr1/unordered_set.hpp>
#include <ostream>
#include <stdexcept>

/// Represents a junction point between several rooms (i.e. Area)
/**
 * A Waypoint is defined by its coordinates and linked to the buildings
 * it belongs to. You \em should always construct a Waypoint with at least
 * one associated Building, but you \em can not do so, for instance in an
 * automatic construction (container…).
 */
class Waypoint: public Point3D
{
protected:
  /// List of Building associated with the Waypoint
  std::tr1::unordered_set<Building*> buildings ;

public:
  Waypoint(const Building *_b = NULL, const float &_x = 0,
           const float &_y = 0, const float &_z = 0) ;

  Waypoint(const Building *_b, const Point3D &p) ;

  Waypoint(const Point3D &p): Point3D(p) {}

  Waypoint(const Waypoint &wp): Point3D(wp), buildings(wp.buildings) {}

  ~Waypoint(void) ;

  /** @name Read accessors */
  //@{
  /// #buildings's first element read accessor
  Building* get_1st_building(void) const ;
  const std::tr1::unordered_set<Building*>& get_buildings(void) const ;
  //@}

  /** @name Write accessors */
  //@{
  /// Adds a Building to the \link #buildings building list\endlink
  void add_building(const Building *_b) ;
  /// Adds the Building list of \em source to #buildings
  void add_buildings(const Waypoint &source) ;
  /// Removes a Building from #buildings
  void remove_building(const Building *_b) ;
  //@}

  /** @name Operators */
  //@{
  Waypoint& operator=(const Waypoint &wp) ;
  bool operator==(const Waypoint &wp) const ;
  bool operator!=(const Waypoint &wp) const ;
  operator std::string(void) const ;
  //@}

  /// Displays a Waypoint
  friend std::ostream& operator<<(std::ostream &os, const Waypoint &wp) ;
} ;



/* *** Read accessors *** */


/**
 * @return A pointer to the first Building associated with the Waypoint
 * (i.e. the first element of #buildings). If #buildings is empty, NULL
 * is returned.
 */
inline Building* Waypoint::get_1st_building() const
{
  if (buildings.empty())
    return NULL ;
  return *buildings.begin() ;
}


inline const std::tr1::unordered_set<Building*>&
Waypoint::get_buildings() const
{
  return buildings ;
}



/* *** Write accessors *** */


/**
 * @param _b A pointer to the Building to add. If it is
 * NULL, nothing will be done.
 * The memory pointed by this pointer must not be deallocated before
 * the Waypoint destruction (do \em not pass a pointer to a local
 * variable!).
 */
inline void Waypoint::add_building(const Building *_b)
{
  if (_b != NULL)
    buildings.insert(const_cast<Building*>(_b)) ;
}


inline void Waypoint::remove_building(const Building *_b)
{
  if (_b != NULL)
    buildings.erase(const_cast<Building*>(_b)) ;
}


inline void Waypoint::add_buildings(const Waypoint &source)
{
  buildings.insert(source.buildings.begin(), source.buildings.end()) ;
}



/* *** Operators *** */


inline bool Waypoint::operator!=(const Waypoint &wp) const
{
  return !(*this == wp) ;
}



#endif // _OWLPS_POSITIONING_WAYPOINT_HH_