/*
 * This file is part of the Owl Positioning System (OwlPS).
 * OwlPS is a project of the University of Franche-Comté
 * (Université de Franche-Comté), France.
 */


#include "point3d.hh"
#include "posutil.hh"
#include "posexcept.hh"

#include <sstream>
#include <boost/functional/hash.hpp>

using namespace std ;



/* *** Constructors *** */


Point3D::Point3D(const string &source)
{
  float pos[3] ;
  istringstream iss(source) ;

  for (int i = 0 ; i < 2 ; ++i)
    {
      iss >> pos[i] ;
      if (iss.get() != ';')
        throw malformed_input_data(
          "Point3D(string): cannot extract coordinates!") ;
    }
  iss >> pos[2] ;

  set_coordinates(pos) ;
}



/* *** Distance operations *** */


/**
 * The distance is not square rooted after the computation, in order
 * to optimise comparisons.
 */
float Point3D::square_distance(const Point3D &source) const
{
  return
    (x - source.x) * (x - source.x) +
    (y - source.y) * (y - source.y) +
    (z - source.z) * (z - source.z) ;
}


/**
 * The distance is not square rooted after the computation, in order
 * to optimise comparisons.
 */
float Point3D::square_distance(const float _x,
                               const float _y,
                               const float _z) const
{
  return
    (x - _x) * (x - _x) +
    (y - _y) * (y - _y) +
    (z - _z) * (z - _z) ;
}


/**
 * A, B and C are three points, A being the current Point3D (*this).
 * If the points are aligned, the angle returned is always 0° (and not
 * 180°, even in the case where A is on BC).
 * @returns The angle BÂC, in the interval [0, 180] degrees.
 */
double Point3D::angle(const Point3D &b, const Point3D &c) const
{
  double
  sq_ab = square_distance(b),
  sq_ac = square_distance(c),
  sq_bc = b.square_distance(c) ;

  if (sq_ab == 0 || sq_ac == 0 || sq_bc == 0)
    return 0 ;

  double
  ab = sqrt(sq_ab),
  ac = sqrt(sq_ac) ;

  double cos_bac = (sq_ab + sq_ac - sq_bc) / (2 * ab * ac) ;
  double bac = acos(cos_bac) ;

  return PosUtil::rad2deg(bac) ;
}



/* *** Operators *** */


Point3D& Point3D::operator=(const Point3D &source)
{
  if (this == &source)
    return *this ;

  x = source.x ;
  y = source.y ;
  z = source.z ;

  return *this ;
}


bool Point3D::operator==(const Point3D &source) const
{
  if (this == &source)
    return true ;

  return
    x == source.x &&
    y == source.y &&
    z == source.z ;
}


bool Point3D::operator<(const Point3D &source) const
{
  if (x < source.x)
    return true ;
  if (x > source.x)
    return false ;

  if (y < source.y)
    return true ;
  if (y > source.y)
    return false ;

  if (z < source.z)
    return true ;

  return false ;
}


Point3D::operator std::string(void) const
{
  ostringstream oss ;
  oss << *this ;
  return oss.str() ;
}


/**
 * @return \em true if either #x, #y or #z is non-zero.
 * @return \em false if #x, #y and #z are defined to 0.
 */
Point3D::operator bool(void) const
{
  return
    x != 0 &&
    y != 0 &&
    z != 0 ;
}



ostream& operator<<(ostream &os, const Point3D &p)
{
  os << "(" << p.x << ";" << p.y << ";" << p.z << ")" ;
  return os ;
}



size_t hash_value(const Point3D &source)
{
  size_t seed = 0 ;

  boost::hash_combine(seed, source.x) ;
  boost::hash_combine(seed, source.y) ;
  boost::hash_combine(seed, source.z) ;

  return seed ;
}