/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package opennlp.tools.sentiment;

import opennlp.tools.util.eval.Evaluator;
import opennlp.tools.util.eval.FMeasure;

/**
 * The {@link SentimentEvaluator} measures the performance of
 * the given {@link SentimentME} with the provided reference
 * {@link SentimentSample}s.
 *
 * @see Evaluator
 * @see SentimentME
 * @see SentimentSample
 */
public class SentimentEvaluator extends Evaluator<SentimentSample> {

  private final FMeasure fmeasure = new FMeasure();

  private final SentimentME sentiment;

  /**
   * Initializes the current instance.
   *
   * @param sentiment The {@link SentimentME} to be used for predicting sentiment.
   * @param listeners The {@link SentimentEvaluationMonitor evaluation sample listeners}.
   */
  public SentimentEvaluator(SentimentME sentiment, SentimentEvaluationMonitor... listeners) {
    super(listeners);
    this.sentiment = sentiment;
  }

  /**
   * {@inheritDoc}
   */
  @Override
  protected SentimentSample processSample(SentimentSample reference) {
    String prediction = sentiment.predict(reference.getSentence());
    String label = reference.getSentiment();

    fmeasure.updateScores(new String[] { label }, new String[] { prediction });

    return new SentimentSample(prediction, reference.getSentence());
  }

  public FMeasure getFMeasure() {
    return fmeasure;
  }

}
