Evaluator.java

/* 
 * Copyright (c) Henrik Niehaus
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice, 
 *    this list of conditions and the following disclaimer in the documentation 
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of the project (Lazy Bones) nor the names of its 
 *    contributors may be used to endorse or promote products derived from this 
 *    software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package lazybones.programmanager.evaluation;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import lazybones.LazyBonesTimer;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import devplugin.Program;

public class Evaluator {

    private static transient Logger logger = LoggerFactory.getLogger(Evaluator.class);

    private final List<Criterion> criteria = new ArrayList<Criterion>();

    private final List<Result> results = new ArrayList<Result>();

    public Evaluator() {
        criteria.add(new TitleCriterion());
        criteria.add(new DurationCriterion());
        criteria.add(new StarttimeCriterion());
    }

    /**
     * Evaluates a collection of programs concerning their equality to a timer with the help of several criteria
     * 
     * @param candidates
     * @param timer
     * @return the most equal program
     */
    public Result evaluate(Collection<Program> candidates, LazyBonesTimer timer) {
        results.clear();
        for (Iterator<Program> iterator = candidates.iterator(); iterator.hasNext();) {
            Program program = iterator.next();
            int factors = 0;
            int total = 0;
            for (Criterion criterion : criteria) {
                int percentage = Math.max(0, criterion.evaluate(program, timer));
                total += percentage * criterion.getBoost();
                factors += criterion.getBoost();
            }

            int percentage = total / factors;
            logger.trace("Total percentage for timer {} and prog {}: {}", new Object[] { timer.getTitle(), program.getTitle(), percentage });
            results.add(new Result(program, percentage));
        }

        if (results.size() > 0) {
            Collections.sort(results);
            return results.get(results.size() - 1);
        } else {
            return null;
        }
    }
}