// PropStat.cpp

#include "PropStat.h"

#include <iostream>
#include <cassert>

using trf::PropStat;

const double DEFAULT_PATH_DISTANCE = 1.e30;

//**********************************************************************

// constructor
PropStat::PropStat()
: _success(false), _s(0.0) { }

//**********************************************************************

// set the propagation distance
void PropStat::set_path_distance(double s) {
  _success = true;
  _s = s;
}

//**********************************************************************

// set successful propagation forward
void PropStat::set_forward() {
  _success = true;
  _s = DEFAULT_PATH_DISTANCE;
}

//**********************************************************************

// set successful propagation backward
void PropStat::set_backward() {
  _success = true;
  _s = -DEFAULT_PATH_DISTANCE;
}

//**********************************************************************

// set successful propagation to the same position
void PropStat::set_same() {
  _success = true;
  _s = 0.0;
}

//**********************************************************************

// was propagation successful?
bool PropStat::success() const {
  return _success;
}

//**********************************************************************

// did track move forward?
bool PropStat::forward() const {
  return _success && _s>0.0;
}

//**********************************************************************

// did track move backward?
bool PropStat::backward() const {
  return _success && _s<0.0;
}

//**********************************************************************

// did track propagate succesfully without moving?
bool PropStat::same() const {
  return _success && _s==0.0;
}

//**********************************************************************

// dhow far did we go?
double PropStat::path_distance() const {
  assert( _success );
  return _s;
}

//**********************************************************************

std::ostream& operator<<(std::ostream& stream, const PropStat& pst ) {
  if ( pst.forward() ) stream << "successful forward propagation";
  if ( pst.backward() ) stream << "successful backward propagation";
  if ( pst.same() ) stream << "successful propagation with no movement";
  if ( ! pst.success() ) stream << "propagation failed";
  if ( pst.success() ) stream << " " << pst.path_distance();
  return stream;
}

//**********************************************************************