/*

  * 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.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.notifyError(

                         ExtractionResult.ErrorLevel.WARN,

                         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;

     }

 }