#include "server.hh"

/* Misc. very usefull functions */

/* Explodes a string into substrings based on separator sep. Returns a string vector. */
inline vector<string> explode(string input, char sep)
{
  vector<string> vs;
  string tmp;
  unsigned int i;

  for (i = 0 ; i < input.size() ; i++)
    if (input[i] == sep)
      {
	vs.push_back(tmp);
	tmp.clear();
      }
    else
      {
	tmp.push_back(input[i]);
      }

  //Last entry, did not encounter a separator.
  vs.push_back(tmp);
  tmp.clear();

  return vs;
}

/* Function to convert a string to an integer */
inline int string2int(string nb)
{
  istringstream iss(nb);

  int tmp;
  iss >> tmp;
  return tmp;
}

/* Function to convert a string to an unsigned integer */
inline unsigned int string2uint(string nb)
{
  istringstream iss(nb);

  unsigned int tmp;
  iss >> tmp;
  return tmp;
}

/* Function to convert a string to a float */
inline float string2float(string nb)
{
  istringstream iss(nb);

  float tmp;
  iss >> tmp;
  return tmp;
}

/* Function extracts ints from string */
inline vector<int> extractValues(string buff)
{
  unsigned int ptr = 0;
  vector<int> ret;
  string tmp_field;

  if (buff[buff.size()-1] != ';')
    buff.push_back(';');

  while (ptr < buff.size())
    {
      if (buff[ptr] != ';')
	tmp_field.push_back(buff[ptr]);
      else
	{
	  ret.push_back(string2int(tmp_field));
	  tmp_field.clear();
	}
      ptr++;
    }
  return ret;
}

inline vector<string> extractReferencePointInfoFromBuffer(string buffer_in)
{
  unsigned int i = 0;
  string tmp_field;
  vector<string> ret;

  /* Extract coordinates */
  /* x */
  while (buffer_in[i] != ';')
    {
      tmp_field.push_back(buffer_in[i]);
      i++;
    }
  ret.push_back(tmp_field);
  tmp_field.clear();
  i++; //go after the ';'

  /* y */
  while (buffer_in[i] != ';')
    {
      tmp_field.push_back(buffer_in[i]);
      i++;
    }
  ret.push_back(tmp_field);
  tmp_field.clear();
  i++;

  /* Extract direction (not used now) */
  while (buffer_in[i] != ';')
    {
      tmp_field.push_back(buffer_in[i]);
      i++;
    }
  ret.push_back(tmp_field);
  tmp_field.clear();
  i++;

  /* Extract mac address */
  while (buffer_in[i] != ';')
    {
      tmp_field.push_back(buffer_in[i]);
      i++;
    }
  ret.push_back(tmp_field);
  tmp_field.clear();
  i++;

  /* Extract scan list */
  while (i < buffer_in.size())
    {
      tmp_field.push_back(buffer_in[i]);
      i++;
    }
  ret.push_back(tmp_field);
  tmp_field.clear();

  /* Return the vector with each data */
  return ret;
}
/* ***************************************************************** */


//Server::Server(string ip_addr, int listen_port, int send_port) // FIXME : paramètre send_port inutilisé
Server::Server(string ip_addr, int listen_port)
{
  /* Open socket */
  sockListen = socket(PF_INET, SOCK_DGRAM, 0);
  sockSend = socket(PF_INET, SOCK_DGRAM, 0);

  /* Set addr */
  server_addr.sin_family = AF_INET;
  server_addr.sin_port = htons(listen_port);
  server_addr.sin_addr.s_addr = inet_addr(ip_addr.c_str());
  memset(server_addr.sin_zero, '\0', sizeof(server_addr.sin_zero));

  /* Bind */
  bind(sockListen, (struct sockaddr *)&server_addr, sizeof(server_addr));
}

Server::~Server()
{
  client_list.clear();
  reference_point_list.clear();
  access_point_list.clear();
  close(sockListen);
  close(sockSend);
}

void Server::send_to_client(int cl)
{
  /* Do not forget to implement later: usefull for a demo */
}

int Server::receive_data()
{
  /* Do not forget to implement later: usefull for a demo */
  return 0;
}

bool Server::pointExists(float x, float y, float z)const
{
  Point p(x, y, z);
  unsigned int i;

  for (i = 0 ; i < reference_point_list.size() ; i++)
    if (p == reference_point_list[i].getCoordinates())
      return true;

  return false;
}

/* Do not forget to call pointExists() before this one */
unsigned int Server::pointIndex(float x, float y, float z)const
{
  Point p(x, y, z);
  unsigned int i;

  for (i = 0 ; i < reference_point_list.size() ; i++)
    if (p == reference_point_list[i].getCoordinates())
      return i;

  return 0; // Should never happen
}

bool Server::pointExists(Point p)const
{
  unsigned int i;

  for (i = 0 ; i < reference_point_list.size() ; i++)
    if (p == reference_point_list[i].getCoordinates())
      return true;

  return false;
}

bool Server::apExists(string ap_addr)const
{
  unsigned int i;

  for (i = 0 ; i < access_point_list.size() ; i++)
    if (access_point_list[i].getApAddr() == ap_addr)
      return true;

  return false;
}

unsigned int Server::apIndex(string ap_addr)const
{
  unsigned int i;

  for (i = 0 ; i < access_point_list.size() ; i++)
    if (access_point_list[i].getApAddr() == ap_addr)
      return i;

  return 0; // Should never happen
}

/* Do not forget to call pointExists() before this one */
unsigned int Server::pointIndex(Point p)const
{
  unsigned int i;

  for (i = 0 ; i < reference_point_list.size() ; i++)
    if (p == reference_point_list[i].getCoordinates())
      return i;

  return 0; // Should never happen
}

/* return -1 if point does not exist, which should never happen */
vector<Point> Server::getkClosestInSs(vector<Measurement> m, unsigned int k, bool ignore_point, Point point_ignored)const
{
  unsigned int i, j, min_idx;
  vector<float> distances_vector;
  vector<Point> points_vector;
  Point tmp_pt;
  float tmp_distance = 0, dist_max = 10000000, tmp_min;

  for (i = 0 ; i < reference_point_list.size() ; i++)
    if (!ignore_point||(reference_point_list[i].getCoordinates() != point_ignored))
      {
	tmp_distance = reference_point_list[i].getSsSquareDistance(m);
	/* if not k points, add it */
	if(distances_vector.size() < k)
	  {
	    distances_vector.push_back(tmp_distance);
	    points_vector.push_back(reference_point_list[i].getCoordinates());
	    dist_max = (dist_max > tmp_distance)?tmp_distance:dist_max;
	  }
	else
	  {
	    /* if tmp_dst < dist_max, should add it and remove previous greatest dist. */
	    if(dist_max > tmp_distance)
	      {
		/* remove old max */
		for (j = 0 ; j < distances_vector.size() ; j++)
		  if (distances_vector[j] == dist_max)
		    {
		      dist_max = tmp_distance;
		      distances_vector.erase(distances_vector.begin() + j);
		      points_vector.erase(points_vector.begin() + j);
		      distances_vector.push_back(tmp_distance);
		      points_vector.push_back(reference_point_list[i].getCoordinates());
		      break;
		    }
	      }
	    /* Else nothing needs to be done */
	  }
      }

  /* Sorts the vector */
  for (i = 0 ; i < distances_vector.size() - 1 ; i++)
    {
      tmp_min = distances_vector[i];
      min_idx = i;
      for (j = i+1 ; j < distances_vector.size() ; j++)
	if (tmp_min > distances_vector[j])
	  {
	    tmp_min = distances_vector[j];
	    min_idx = j;
	  }

      if (min_idx != i)
	{
	  /* Swap points */
	  tmp_pt = points_vector[i];
	  points_vector[i] = points_vector[min_idx];
	  points_vector[min_idx] = tmp_pt;

	  /* Swap distances */
	  distances_vector[min_idx] = distances_vector[i];
	  distances_vector[i] = tmp_min;
	}
    }

  return points_vector;
}

Point Server::getkWeightedInSs(vector<Measurement> m, unsigned int k, bool ignore_point, Point point_ignored)const
{
  unsigned int i, j;
  vector<float> distances_vector;
  vector<Point> points_vector;
  float tmp_distance = 0, dist_max = 10000000;
  Point ret;
  float total = 0, x = 0, y = 0, z = 0;

  for (i = 0 ; i < reference_point_list.size() ; i++)
    if (!ignore_point || (reference_point_list[i].getCoordinates() != point_ignored))
      {
	tmp_distance = reference_point_list[i].getSsSquareDistance(m);
	/* if not k points, add it */
	if (distances_vector.size() < k)
	  {
	    distances_vector.push_back(tmp_distance);
	    points_vector.push_back(reference_point_list[i].getCoordinates());
	    dist_max = (dist_max > tmp_distance) ? tmp_distance : dist_max;
	  }
	else
	  {
	    /* if tmp_dst < dist_max, should add it and remove previous greatest dist. */
	    if (dist_max > tmp_distance)
	      {
		/* remove old max */
		for (j = 0 ; j < distances_vector.size() ; j++)
		  if(distances_vector[j] == dist_max)
		    {
		      dist_max = tmp_distance;
		      distances_vector.erase(distances_vector.begin() + j);
		      points_vector.erase(points_vector.begin() + j);
		      distances_vector.push_back(tmp_distance);
		      points_vector.push_back(reference_point_list[i].getCoordinates());
		      break;
		    }
	      }
	    /* Else nothing needs to be done */
	  }
      }
  for (i = 0 ; i < distances_vector.size() ; i++)
    total += distances_vector[i];

  for (i = 0 ; i < distances_vector.size() ; i++)
    {
      x += points_vector[i].getX() * distances_vector[i] / total;
      y += points_vector[i].getY() * distances_vector[i] / total;
      z += points_vector[i].getZ() * distances_vector[i] / total;
    }

  ret.setX(x);
  ret.setY(y);
  ret.setZ(z);

  return ret;
}

Point Server::kPointsAverage(vector<Point> vp)const
{
  unsigned int i;
  float x=0, y=0, z=0;
  Point p;

  for (i = 0 ; i < vp.size() ; i++)
    {
      x += vp[i].getX();
      y += vp[i].getY();
      z += vp[i].getZ();
    }
  p.setX(x / (float) vp.size());
  p.setY(y / (float) vp.size());
  p.setZ(z / (float) vp.size());

  return p;
}

Point Server::fbcm(vector<Measurement> m, int client_idx)const
{
  Point ret(0, 0, 0);
  vector<string> addr;
  vector<float> dist_vect;
  vector<Point> centres;
  unsigned int i, ap_idx;
  float constant_term, minmax_res, minmax_max;
  float x = MINMAX_X_START, y = MINMAX_Y_START;

  i = 0;
  //cout << "FBCM: ";
  for (i = 0 ; i < m.size() ; i++)
    if (apExists(m[i].getMacAddr()))
      {
	ap_idx = apIndex(m[i].getMacAddr());
	//cout << "AP idx: " << ap_idx << " ";
	centres.push_back(access_point_list[ap_idx].getCoordinates());
	addr.push_back(m[i].getMacAddr());
	constant_term = access_point_list[ap_idx].getOutputPower() + access_point_list[ap_idx].getAntennaGain() + 2;
	constant_term += 20 * log10((300000000.0 / (float) access_point_list[ap_idx].getFrequency()) / (4*M_PI));
	//end of expr. should be: client_list[client_idx].getAntennaGain() instead of 2.
	//cout << "20log(" << (300000000.0 / (float) access_point_list[ap_idx].getFrequency()) / (4*M_PI) << ") = ";
	//cout << constant_term << " ";
	dist_vect.push_back(pow(10, (constant_term - m[i].getAverage()) / (10 * access_point_list[ap_idx].getFriisIndex())));
	//cout << endl;
      }

  /* Then: min-max */
  minmax_res = 1000000;
  for (x = MINMAX_X_START ; x < MINMAX_X_STOP ; x += MINMAX_STEP)
    for (y = MINMAX_Y_START ; y < MINMAX_Y_STOP ; y += MINMAX_STEP)
      {
	minmax_max = 0;
	for (i = 0 ; i < centres.size() ; i++)
	  if ((centres[i].squareDistance(x, y, 3) - (dist_vect[i]*dist_vect[i])) > minmax_max)
	    minmax_max = centres[i].squareDistance(x, y, 3) - (dist_vect[i] * dist_vect[i]);
	if (minmax_max < minmax_res)
	  {
	    ret.setX(x);
	    ret.setY(y);
	    minmax_res = minmax_max;
	  }
      }

  /* Clear all vectors */
  addr.clear();
  dist_vect.clear();
  centres.clear();

  /* Return position */
  return ret;
}

Point Server::interlink(vector<Measurement> m, int client_idx)const
{
  Point ret(0, 0, 0);
  vector<string> addr;
  vector<float> dist_vect;
  vector<Point> centres;
  unsigned int i, ap_idx;
  float constant_term, minmax_res, minmax_max;
  float x = MINMAX_X_START, y = MINMAX_Y_START;

  i = 0;
  for (i = 0 ; i < m.size() ; i++)
    if (apExists(m[i].getMacAddr()))
      {
	ap_idx = apIndex(m[i].getMacAddr());
	centres.push_back(access_point_list[ap_idx].getCoordinates());
	addr.push_back(m[i].getMacAddr());
	constant_term = access_point_list[ap_idx].getOutputPower() + access_point_list[ap_idx].getAntennaGain();
	constant_term += 20 * log10((300000000.0 / (float) access_point_list[ap_idx].getFrequency()) / (4*M_PI)) + 2;
	//end of expr. should be: client_list[client_idx].getAntennaGain() instead of 2.
	dist_vect.push_back(pow(10, (constant_term - m[i].getAverage()) / 35));
      }

  /* Then: min-max */
  minmax_res = 1000000;
  for (x = MINMAX_X_START ; x < MINMAX_X_STOP ; x += MINMAX_STEP)
    for (y = MINMAX_Y_START ; y < MINMAX_Y_STOP ; y += MINMAX_STEP)
      {
	minmax_max = 0;
	for (i = 0 ; i < centres.size() ; i++)
	  if ((centres[i].squareDistance(x, y, 3) - (dist_vect[i] * dist_vect[i])) > minmax_max)
	    minmax_max = centres[i].squareDistance(x, y, 3) - (dist_vect[i] * dist_vect[i]) ;
	if (minmax_max < minmax_res)
	  {
	    ret.setX(x);
	    ret.setY(y);
	    minmax_res = minmax_max;
	  }
      }

  /* Clear all vectors */
  addr.clear();
  dist_vect.clear();
  centres.clear();

  /* Return position */
  return ret;
}

void Server::makeReferencePointListFromFile(string filename)
{
  ifstream input_file;
  char buffer[BUFFER_LENGTH];
  string lecture_fichier;
  ReferencePoint rp;
  Point tmp_point;
  float x, y;
  unsigned int i, pt_idx;
  string cpp_buffer, tmp_mes;
  vector<int> measures_vector;
  vector<string> infos;

  input_file.open(filename.c_str()) ;
  if (input_file.fail())
    {
      cerr << "Error opening input file « " << filename << " » !" << endl ;
      return ;
    }

  while (!input_file.eof())
    {
      input_file.getline(buffer, BUFFER_LENGTH);
      if ((input_file.rdstate() & ifstream::eofbit) == 0)
	{
	  /* Extract fields */
	  cpp_buffer = buffer;
	  infos = extractReferencePointInfoFromBuffer(cpp_buffer);
	  x = string2float(infos[0]);
	  y = string2float(infos[1]);
	  /* Set point coordinates */
	  tmp_point.setX(x);
	  tmp_point.setY(y);
	  tmp_point.setZ(DEFAULT_Z);
	  /* Use C++ string format */
	  if (!pointExists(tmp_point))
	    {
	      rp.setCoordinates(tmp_point);
	      reference_point_list.push_back(rp);
	    }
	  pt_idx = pointIndex(tmp_point);
	  measures_vector = extractValues(infos[4]);
	  for (i = 0 ; i < measures_vector.size() ; i++)
	    reference_point_list[pt_idx].addMeasurement(infos[3], measures_vector[i]);
	}
    }

  input_file.close();
  measures_vector.clear();
}

void Server::makeApListFromFile(string filename)
{
  ifstream input_file;
  char buffer[BUFFER_LENGTH];
  vector<string> ap_infos;
  AccessPoint tmp_ap;

  input_file.open(filename.c_str());
  if (input_file.fail())
    {
      cerr << "Error opening input file « " << filename << " » !" << endl ;
      return ;
    }

  while (!input_file.eof())
    {
      input_file.getline(buffer, BUFFER_LENGTH);
      if ((input_file.rdstate() & ifstream::eofbit) == 0)
	{
	  ap_infos = explode(buffer, ';');
	  cout << buffer << endl;
	  for (unsigned int i=0 ; i < ap_infos.size() ; i++)
	    cout << ap_infos[i] << endl;
	  tmp_ap.setApAddr(ap_infos[0]);
	  tmp_ap.setCoordinates(string2float(ap_infos[1]), string2float(ap_infos[2]), string2float(ap_infos[3]));
	  tmp_ap.setFrequency(string2uint(ap_infos[4]));
	  tmp_ap.setAntennaGain(string2float(ap_infos[5]));
	  tmp_ap.setOutputPower(string2float(ap_infos[6]));
	  access_point_list.push_back(tmp_ap);
	  ap_infos.clear();
	}
    }

  input_file.close();
}

void Server::printReferencePointList()
{
  unsigned int i;

  for (i = 0 ; i < reference_point_list.size() ; i++)
    cout << reference_point_list[i] << endl;
}

void Server::printAccessPointList()
{
  unsigned int i;

  for (i = 0 ; i < access_point_list.size() ; i++)
    cout << access_point_list[i] << endl;
}

void Server::computeFriisFromRefList()
{
  unsigned int i, j;
  vector<float> friis_idx_list;
  Point pt_coords, ap_coords;
  float ap_power, ap_gain, calib_gain = 2, const_term, mes_power, friis_sum;
  unsigned int ap_freq;
  string ap_mac;

  for (i = 0 ; i < access_point_list.size() ; i++)
    {
      ap_power = access_point_list[i].getOutputPower();
      ap_coords = access_point_list[i].getCoordinates();
      ap_freq = access_point_list[i].getFrequency();
      ap_gain = access_point_list[i].getAntennaGain();
      ap_mac = access_point_list[i].getApAddr();

      /* Compute main general term, independant from scans */
      const_term = calib_gain + ap_gain;
      const_term -= 20 * log10(4 * M_PI);
      const_term += 20 * log10 (300000000.0 / ap_freq) + ap_power;

      /* Compute an index for each ref point. List stored in friis_idx_list */
      for (j = 0 ; j < reference_point_list.size() ; j++)
	{
	  pt_coords = reference_point_list[j].getCoordinates();
	  if (reference_point_list[i].getPowerForAp(ap_mac, &mes_power))
	    friis_idx_list.push_back((const_term - mes_power) / (10 * log10(ap_coords.distance(pt_coords))));
	}
      /* Now, compute avg value */
      friis_sum = 0;
      for (j = 0 ; j < friis_idx_list.size() ; j++)
	friis_sum += friis_idx_list[j];
      access_point_list[i].setFriisIndex(friis_sum / friis_idx_list.size());
      cout << access_point_list[i].getApAddr() << " -> " << (friis_sum / friis_idx_list.size()) << endl;
      friis_idx_list.clear();
    }
}


/*
 *  Function computes new cumulative distances for each running viterbi instance,
 *  Returns the solution (type: Point) of the last ended viterbi.
 *  Distances are grouped by line corresponding to an instance.
 *  vk MUST be the same as last.size() and current.size() !
 */
/*
Point Server::viterbiLike(float ** dists, unsigned short vk, unsigned short vn, vector<Point> last, vector<Point> current)
{
  unsigned int i, j, k;
  float min;
  vector<float> last_dists;
  Point position;
  
  // Compute the ending viterbi: line 0
  for (i = 0 ; i < current.size() ; i++)
    {
      min = dists[0][0] + last[0].distance(current[i]);
      for (j = 1 ; j < last.size() ; j++)
	if ((dists[0][j] + last[j].distance(current[i])) < min)
	  min = dists[0][j] + last[j].distance(current[i]);
      last_dists.push_back(min);
    }

  // Find shortest dist
  min = last_dists[0];
  j = 0;
  for (i = 1 ; i < last_dists.size() ; i++)
    if (last_dists[i] < min)
      {
	min = last_dists[i];
	j = i;
      }

  // Shortest distance determines the true point
  position = current[j];

  // Now, compute the remaining of the distance matrix

}
*/


/* For experimentation purpose only */
void Server::radar_exp()
{
  ofstream logfile;
  vector<Point> solutions;
  Point solution, solution_kw, ref_coords;
  unsigned int i;
  vector<Measurement> vm;

  makeReferencePointListFromFile(DEFAULT_REF_POINT_FILE);
  makeApListFromFile(DEFAULT_AP_FILE);
  computeFriisFromRefList();

  /* Open a log file */
  logfile.open(DEFAULT_LOGFILE);
  if (logfile.fail())
    {
      cerr << "Error opening output file « " << logfile << " » !" << endl ;
      return ;
    }

  /* Column names */
  logfile << "Coordinates\t2-kss\t(Error)\t3-kss\t(Error)\t4-kss\t(Error)\t5-kss\t(Error)\tnss\t(Error)\tInterlink\t(Error)\tFBCM\t(Error)" << endl;

  cout << reference_point_list.size() << " reference points." << endl ;
  for (i = 0 ; i < reference_point_list.size() ; i++)
    {
      /* Get point measurements */
      vm.clear();
      vm = reference_point_list[i].getMeasurementList();
      ref_coords = reference_point_list[i].getCoordinates();

      /* Print point coordinates */
      logfile << ref_coords << "\t";

      /* From 2 to 5 K-weighted-SS */
      solution = getkWeightedInSs(vm, 2, true, ref_coords);
      logfile << solution << "\t" << solution.distance(ref_coords) << "\t";
      solution = getkWeightedInSs(vm, 3, true, ref_coords);
      logfile << solution << "\t" << solution.distance(ref_coords) << "\t";
      solution = getkWeightedInSs(vm, 4, true, ref_coords);
      logfile << solution << "\t" << solution.distance(ref_coords) << "\t";
      solution = getkWeightedInSs(vm, 5, true, ref_coords);
      logfile << solution << "\t" << solution.distance(ref_coords) << "\t";

      /* Nearest in SS */
      solutions = getkClosestInSs(vm, 1, true, ref_coords);
      logfile << solutions[0] << "\t" << solutions[0].distance(ref_coords) << "\t";

      /* Interlink Networks */
      solution = interlink(vm, 0);
      logfile << solution << "\t" << solution.distance(ref_coords) << "\t";

      /* FBCM */
      solution = fbcm(vm, 0);
      logfile << solution << "\t" << solution.distance(ref_coords) << endl;

      solutions.clear();
    }
  logfile.close();
}