#include <stdio.h>
#include <stdlib.h>
#include "LikelihoodTable.h"

double LikelihoodTable::CalcLikelihood (double response)
{
  double likelihood = 0;
  int bin_num = (int) ((response - minResponse) / bin_width);

  if (bin_num >= 0 && bin_num < num_bins) { // within the valid histogram region
	likelihood = bins[bin_num];
  }

  // Make sure likelihood is always positive
  if (likelihood == 0) {
	likelihood += VERY_SMALL;
  }

  return likelihood;
}

LikelihoodTable::LikelihoodTable (void)
{
  bins = NULL;
}

LikelihoodTable::LikelihoodTable ( const char *filename)
{
  FILE *fp = fopen(filename, "rt");
  char line[1024];

  if (fp == NULL) {
//    printf("Couldn't open %s\n", filename);
	  throw "Couldn't open LikelihoodTable";
    abort();
  }
  
  // Read parameters 
  fgets(line, sizeof(line), fp); 
  minResponse = atof(line);
  fgets(line, sizeof(line), fp); 
  bin_width = atof(line);
  fgets(line, sizeof(line), fp); 
  num_bins = atoi(line);
  //printf("%f %f %d\n", minResponse, bin_width, num_bins);
  bins = new double[100];
  
  // Read bins
  int bin_idx = 0;
  while (fgets(line, sizeof(line), fp) != NULL && bin_idx < num_bins) {
	//printf(line);
	bins[bin_idx] = atof(line);
	//printf("%d %f\n", bin_idx, bins[bin_idx]);
	bin_idx++;
  }
  fclose(fp);
}

// Delete bins
LikelihoodTable::~LikelihoodTable ()
{
  if (bins != NULL) {
	// HUH --- doesn't work
//	delete bins;
  }
}