/*
* JGAAP -- a graphical program for stylometric authorship attribution
* Copyright (C) 2009,2011 by Patrick Juola
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.jgaap.backend;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.jgaap.generics.DistanceFunction;
/**
*
* Instances new Distance Functions based on display name.
* If parameters are also passed in the form DisplayName|name:value|name:value they are added to the Distance Function before it is returned
*
* @author Michael Ryan
* @since 5.0.0
*/
public class DistanceFunctions {
private static final ImmutableList<DistanceFunction> DISTANCE_FUNCTIONS = loadDistanceFunctions();
private static final ImmutableMap<String, DistanceFunction> distanceFunctions = loadDistanceFunctionsMap();
/**
* A read-only list of the DistanceFunctions
*/
public static List<DistanceFunction> getDistanceFunctions() {
return DISTANCE_FUNCTIONS;
}
private static ImmutableList<DistanceFunction> loadDistanceFunctions() {
List<Object> objects = AutoPopulate.findObjects("com.jgaap.distances", DistanceFunction.class);
for(Object tmp : AutoPopulate.findClasses("com.jgaap.generics", DistanceFunction.class)){
objects.addAll(AutoPopulate.findObjects("com.jgaap.distances", (Class<?>)tmp));
}
List<DistanceFunction> distances = new ArrayList<DistanceFunction>(objects.size());
for (Object tmpD : objects) {
distances.add((DistanceFunction) tmpD);
}
Collections.sort(distances);
return ImmutableList.copyOf(distances);
}
private static ImmutableMap<String, DistanceFunction> loadDistanceFunctionsMap() {
// Load the distance functions dynamically
ImmutableMap.Builder<String, DistanceFunction> builder = ImmutableMap.builder();
for(DistanceFunction distanceFunction: DISTANCE_FUNCTIONS){
builder.put(distanceFunction.displayName().toLowerCase().trim(), distanceFunction);
}
return builder.build();
}
public static DistanceFunction getDistanceFunction(String action) throws Exception{
DistanceFunction distanceFunction;
String[] tmp = action.split("\\|", 2);
action = tmp[0].trim().toLowerCase();
if(distanceFunctions.containsKey(action)){
distanceFunction= distanceFunctions.get(action).getClass().newInstance();
}else{
throw new Exception("Distance Function "+action+" was not found!");
}
if(tmp.length > 1) {
distanceFunction.setParameters(tmp[1]);
}
return distanceFunction;
}
}