// Dstl (c) Crown Copyright 2017
package uk.gov.dstl.baleen.annotators.regex;

import java.util.Collections;
import java.util.regex.Matcher;

import org.apache.uima.jcas.JCas;

import com.google.common.collect.ImmutableSet;

import uk.gov.dstl.baleen.annotators.regex.helpers.AbstractRegexAnnotator;
import uk.gov.dstl.baleen.core.pipelines.orderers.AnalysisEngineAction;
import uk.gov.dstl.baleen.types.common.CommsIdentifier;

/**
 * Annotate e-mail addresses within a document using regular expressions
 *
 * <p>Look for text matching the following regular expression and annotate it as a CommsIdentifier
 * with type 'email':
 *
 * <pre>[A-Z0-9._%+-]+@([A-Z0-9.-]+[.][A-Z]{2,6})</pre>
 *
 * <p>This will capture the vast majority of valid e-mail addresses, although it will not capture
 * every valid e-mail address as defined in RFC 2822. No checking is done to determine whether
 * extracted e-mail addresses exist or not.
 */
public class Email extends AbstractRegexAnnotator<CommsIdentifier> {
  private static final String EMAIL_REGEX = "[A-Z0-9._%+-]+@([A-Z0-9.-]+[.][A-Z]{2,6})";

  /** New instance. */
  public Email() {
    super(EMAIL_REGEX, false, 1.0);
  }

  @Override
  protected CommsIdentifier create(JCas jCas, Matcher matcher) {
    CommsIdentifier ci = new CommsIdentifier(jCas);
    ci.setSubType("email");
    return ci;
  }

  @Override
  public AnalysisEngineAction getAction() {
    return new AnalysisEngineAction(Collections.emptySet(), ImmutableSet.of(CommsIdentifier.class));
  }
}
