/*
    * 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 org.apache.any23.extractor.html;
  
  import org.apache.any23.extractor.ExtractionContext;
  import org.apache.any23.extractor.ExtractionException;
  import org.apache.any23.extractor.ExtractionParameters;
  import org.apache.any23.extractor.ExtractionResult;
  import org.apache.any23.extractor.ExtractorDescription;
  import org.apache.any23.extractor.ExtractorFactory;
  import org.apache.any23.extractor.IssueReport;
  import org.apache.any23.extractor.SimpleExtractorFactory;
  import org.apache.any23.rdf.PopularPrefixes;
  import org.apache.any23.vocab.XHTML;
  import org.apache.any23.extractor.Extractor.TagSoupDOMExtractor;
  import org.openrdf.model.URI;
  import org.w3c.dom.Document;
  import org.w3c.dom.Node;
  
  import java.io.IOException;
  import java.util.Arrays;
  
  /**
   * Extractor for the <a href="http://microformats.org/wiki/rel-license">rel-license</a>
   * microformat.
   * <p/>
   *
   * @author Gabriele Renzi
   * @author Richard Cyganiak
   */
  public class LicenseExtractor implements TagSoupDOMExtractor {
  
      private static final XHTML vXHTML = XHTML.getInstance();
  
      public final static ExtractorFactory<LicenseExtractor> factory =
              SimpleExtractorFactory.create(
                      "html-mf-license",
                      PopularPrefixes.createSubset("xhtml"),
                      Arrays.asList("text/html;q=0.01", "application/xhtml+xml;q=0.01"),
                      "example-mf-license.html",
                      LicenseExtractor.class
              );
  
      public void run(
              ExtractionParameters extractionParameters,
              ExtractionContext extractionContext,
              Document in,
              ExtractionResult out
      ) throws IOException, ExtractionException {
          HTMLDocument document = new HTMLDocument(in);
          final URI documentURI = extractionContext.getDocumentURI();
          for (Node node : DomUtils.findAll(in, "//A[@rel='license']/@href")) {
              String link = node.getNodeValue();
              if ("".equals(link)) {
                  out.notifyIssue(
                          IssueReport.IssueLevel.Warning,
                          String.format(
                                  "Invalid license link detected within document %s.",
                                  documentURI.toString()
                          ),
                          0, 0
                  );
                  continue;
              }
              out.writeTriple(documentURI, vXHTML.license, document.resolveURI(link));
          }
      }
  
      public ExtractorDescription getDescription() {
          return factory;
      }
      
  }