/*
 * This file is part of the Owl Positioning System (OwlPS).
 * OwlPS is a project of the University of Franche-Comte
 * (Université de Franche-Comté), France.
 *
 * Copyright © Université de Franche-Comté 2007-2012.
 *
 * Corresponding author: Matteo Cypriani <mcy@lm7.fr>
 *
 ***********************************************************************
 *
 * This software is governed by the CeCILL license under French law and
 * abiding by the rules of distribution of free software. You can use,
 * modify and/or redistribute the software under the terms of the CeCILL
 * license as circulated by CEA, CNRS and INRIA at the following URL:
 * http://www.cecill.info
 *
 * As a counterpart to the access to the source code and rights to copy,
 * modify and redistribute granted by the license, users are provided
 * only with a limited warranty and the software's authors, the holder
 * of the economic rights, and the successive licensors have only
 * limited liability.
 *
 * In this respect, the user's attention is drawn to the risks
 * associated with loading, using, modifying and/or developing or
 * reproducing the software by the user in light of its specific status
 * of free software, that may mean that it is complicated to manipulate,
 * and that also therefore means that it is reserved for developers and
 * experienced professionals having in-depth computer knowledge. Users
 * are therefore encouraged to load and test the software's suitability
 * as regards their requirements in conditions enabling the security of
 * their systems and/or data to be ensured and, more generally, to use
 * and operate it in the same conditions as regards security.
 *
 * The fact that you are presently reading this means that you have had
 * knowledge of the CeCILL license and that you accept its terms.
 *
 ***********************************************************************
 */


#include "accesspoint.hh"
#include "stock.hh"
#include "posexcept.hh"

using namespace std ;
using std::tr1::unordered_map ;



/* *** Operations *** */


double AccessPoint::friis_constant_term() const
{
  double wavelength =
    static_cast<double>(PosUtil::LIGHT_SPEED) / frequency ;
  return antenna_gain + 20 * log10(wavelength) - 20 * log10(4 * M_PI) ;
}


/**
 * @param trx The transmitter AP.
 * @returns The percentage of calibration packets sent by \em trx and
 * received by the AP.
 * @returns 0 if no packet were received from \em trx.
 */
float AccessPoint::
received_calibration_from_ap(const AccessPoint &trx) const
{
  if (this == &trx)
    return 100 ;

  // If no reference point is associated with trx, no AP received
  // any calibration from it:
  const ReferencePoint *ref_trx ;
  try
    {
      ref_trx = &Stock::get_reference_point(trx.coordinates) ;
    }
  catch (element_not_found &e)
    {
      return 0 ;
    }

  // Check if trx sent a calibration request:
  const vector<CalibrationRequest*> &ref_requests =
    ref_trx->get_requests(trx.mac_addr) ;
  if (ref_requests.empty())
    return 0 ;

  // Count the number of messages sent by trx and the number of
  // messages actually received by the AP:
  unsigned int
  received_packets = 0,
  expected_packets = 0 ;
  for (vector<CalibrationRequest*>::const_iterator cr =
         ref_requests.begin() ; cr != ref_requests.end() ; ++cr)
    {
      const Measurement *const measurement =
        (*cr)->get_measurement(mac_addr) ;
      if (! measurement)
        continue ;
      received_packets += measurement->get_nb_ss() ;
      expected_packets += (*cr)->get_nb_packets() ;
    }

  if (expected_packets == 0)
    return 0 ;

  // Compute the score (percent):
  float score = received_packets * 100.0 / expected_packets ;
  return score ;
}



/* *** Operators *** */


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

  this->WifiDevice::operator=(source) ;
  coordinates = source.coordinates ;
  frequency = source.frequency ;
  friis_index = source.friis_index ;

  return *this ;
}


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

  return
    this->WifiDevice::operator==(source) &&
    coordinates == source.coordinates &&
    frequency == source.frequency &&
    friis_index == source.friis_index ;
}



ostream &operator<<(ostream &os, const AccessPoint &ap)
{
  os
      << "Coordinates: " << ap.coordinates << '\n'
      << "Frequency: " << ap.frequency << " Hz" << '\n'
      << "Friis index: " << ap.friis_index << '\n'
      << (WifiDevice) ap ;

  return os ;
}