// BSD License (http://www.galagosearch.org/license)

 package org.galagosearch.core.scoring;

 import java.util.HashMap;

 import java.util.HashSet;

 import java.util.Map;

 import java.util.Set;

 import org.galagosearch.tupleflow.Parameters;

 /**

  *

  * @author trevor

  */

 public class DistributionSmootherFactory {

     public static DistributionSmoother newInstance(Map<String, String> feature, HashMap<String, Double> backgrounds) {

         String smootherName = "dirichlet";

         if (feature.containsKey("smoothing")) {

             smootherName = feature.get("smoothing");

         }

         DistributionSmoother smoother;

         if (smootherName.equals("linear") || smootherName.equals("jm")) {

             double lambda = 0.4;

             if (feature.containsKey("lambda")) {

                 lambda = Double.parseDouble(feature.get("lambda"));

             }

             smoother = new LinearSmoother(lambda, backgrounds);

         } else {

             double mu = 2500;

             if (feature.containsKey("mu")) {

                 mu = Double.parseDouble(feature.get("mu"));

             }

             smoother = new DirichletSmoother(mu, backgrounds);

         }

         return smoother;

     }

     public static DistributionSmoother newInstance(Parameters.Value feature, HashMap<String, Double> backgrounds) {

         Set<String> keys = new HashSet<String>();

         if (feature != null) {

             keys = feature.map().keySet();

         }

         HashMap<String, String> map = new HashMap();

         for (String key : keys) {

             map.put(key, feature.get(key));

         }

         return newInstance(map, backgrounds);

     }

     public static DistributionSmoother newInstance(Parameters.Value feature) {

         return newInstance(feature, new HashMap());

     }

 }