/* -*- c++ -*- */
/*
 * Copyright 2004 Free Software Foundation, Inc.
 * 
 * This file is part of GNU Radio
 * 
 * GNU Radio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 * 
 * GNU Radio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <float.h>
#include <stdexcept>
#include "trellis_calc_metric.h"

void calc_metric_s(int O, int D, const std::vector<short> &TABLE, const short *in, float *metric, trellis_metric_type_t type)
{
  float minm = FLT_MAX;
  int minmi = 0;

  switch (type){
  case TRELLIS_EUCLIDEAN:
    for(int o=0;o<O;o++) {
      metric[o]=0.0;
      for (int m=0;m<D;m++) {
        float s=in[m]-TABLE[o*D+m];
        metric[o]+=s*s;
      }
    }
    break;
  case TRELLIS_HARD_SYMBOL:
    for(int o=0;o<O;o++) {
      metric[o]=0.0;
      for (int m=0;m<D;m++) {
        float s=in[m]-TABLE[o*D+m];
        metric[o]+=s*s;
      }
      if(metric[o]<minm) {
        minm=metric[o];
        minmi=o;
      }
    }
    for(int o=0;o<O;o++) {
      metric[o] = (o==minmi?0.0:1.0);
    }
    break;
  case TRELLIS_HARD_BIT:
    throw std::runtime_error ("Invalid metric type (not yet implemented).");
    break;
  default:
    throw std::runtime_error ("Invalid metric type.");
  }
}



void calc_metric_i(int O, int D, const std::vector<int> &TABLE, const int *in, float *metric, trellis_metric_type_t type)
{
  float minm = FLT_MAX;
  int minmi = 0;

  switch (type){
  case TRELLIS_EUCLIDEAN:
    for(int o=0;o<O;o++) {
      metric[o]=0.0;
      for (int m=0;m<D;m++) {
        float s=in[m]-TABLE[o*D+m];
        metric[o]+=s*s;
      }
    }
    break;
  case TRELLIS_HARD_SYMBOL:
    for(int o=0;o<O;o++) {
      metric[o]=0.0;
      for (int m=0;m<D;m++) {
        float s=in[m]-TABLE[o*D+m];
        metric[o]+=s*s;
      }
      if(metric[o]<minm) {
        minm=metric[o];
        minmi=o;
      }
    }
    for(int o=0;o<O;o++) {
      metric[o] = (o==minmi?0.0:1.0);
    }
    break;
  case TRELLIS_HARD_BIT:
    throw std::runtime_error ("Invalid metric type (not yet implemented).");
    break;
  default:
    throw std::runtime_error ("Invalid metric type.");
  }
}



void calc_metric_f(int O, int D, const std::vector<float> &TABLE, const float *in, float *metric, trellis_metric_type_t type)
{
  float minm = FLT_MAX;
  int minmi = 0;

  switch (type){
  case TRELLIS_EUCLIDEAN:
    for(int o=0;o<O;o++) {
      metric[o]=0.0;
      for (int m=0;m<D;m++) {
        float s=in[m]-TABLE[o*D+m];
        metric[o]+=s*s;
      }
    } 
    break;
  case TRELLIS_HARD_SYMBOL:
    for(int o=0;o<O;o++) {
      metric[o]=0.0;
      for (int m=0;m<D;m++) {
        float s=in[m]-TABLE[o*D+m];
        metric[o]+=s*s;
      }
      if(metric[o]<minm) {
        minm=metric[o];
        minmi=o;
      }
    }
    for(int o=0;o<O;o++) {
      metric[o] = (o==minmi?0.0:1.0);
    }
    break;
  case TRELLIS_HARD_BIT:
    throw std::runtime_error ("Invalid metric type (not yet implemented).");
    break;
  default:
    throw std::runtime_error ("Invalid metric type.");
  }
}


void calc_metric_c(int O, int D, const std::vector<gr_complex> &TABLE, const gr_complex *in, float *metric, trellis_metric_type_t type)
{
  float minm = FLT_MAX;
  int minmi = 0;

  switch (type){
  case TRELLIS_EUCLIDEAN:
    for(int o=0;o<O;o++) {
      metric[o]=0.0;
      for (int m=0;m<D;m++) {
        gr_complex s=in[m]-TABLE[o*D+m];
        metric[o]+=s.real()*s.real()+s.imag()*s.imag();
      }
    }
  case TRELLIS_HARD_SYMBOL:
    for(int o=0;o<O;o++) {
      metric[o]=0.0;
      for (int m=0;m<D;m++) {
        gr_complex s=in[m]-TABLE[o*D+m];
        metric[o]+=s.real()*s.real()+s.imag()*s.imag();
      }
      if(metric[o]<minm) {
        minm=metric[o];
        minmi=o;
      }
    }
    for(int o=0;o<O;o++) {
      metric[o] = (o==minmi?0.0:1.0);
    }
    break;
  case TRELLIS_HARD_BIT:
    throw std::runtime_error ("Invalid metric type (not yet implemented).");
    break;
  default:
    throw std::runtime_error ("Invalid metric type.");
  }
}