/*
    * Copyright 2008-2010 Digital Enterprise Research Institute (DERI)
    *
    * Licensed 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.deri.any23.extractor.html;
  
  import org.deri.any23.extractor.ExtractionException;
  import org.deri.any23.extractor.ExtractionResult;
  import org.deri.any23.extractor.ExtractorDescription;
  import org.deri.any23.extractor.ExtractorFactory;
  import org.deri.any23.extractor.SimpleExtractorFactory;
  import org.deri.any23.extractor.TagSoupExtractionResult;
  import org.deri.any23.rdf.PopularPrefixes;
  import org.deri.any23.vocab.DCTERMS;
  import org.deri.any23.vocab.REVIEW;
  import org.deri.any23.vocab.VCARD;
  import org.openrdf.model.BNode;
  import org.openrdf.model.Resource;
  import org.openrdf.model.vocabulary.RDF;
  import org.w3c.dom.Node;
  
  import java.util.Arrays;
  import java.util.List;
  
  import static org.deri.any23.extractor.html.HTMLDocument.TextField;
  
  /**
   * Extractor for the <a href="http://microformats.org/wiki/hreview">hReview</a>
   * microformat.
   *
   * @author Gabriele Renzi
   */
  public class HReviewExtractor extends EntityBasedMicroformatExtractor {
  
      private static final REVIEW  vREVIEW  = REVIEW.getInstance();
      private static final VCARD   vVCARD   = VCARD.getInstance();
      private static final DCTERMS vDCTERMS = DCTERMS.getInstance();
  
      public final static ExtractorFactory<HReviewExtractor> factory =
              SimpleExtractorFactory.create(
                      "html-mf-hreview",
                      PopularPrefixes.createSubset("rdf", "vcard", "rev"),
                      Arrays.asList("text/html;q=0.1", "application/xhtml+xml;q=0.1"),
                      null,
                      HReviewExtractor.class
              );
  
      public ExtractorDescription getDescription() {
          return factory;
      }
  
      protected String getBaseClassName() {
          return "hreview";
      }
  
      @Override
      protected void resetExtractor() {
          // Empty.
      }
  
      protected boolean extractEntity(Node node, ExtractionResult out) throws ExtractionException {
          BNode rev = getBlankNodeFor(node);
          out.writeTriple(rev, RDF.TYPE, vREVIEW.Review);
          final HTMLDocument fragment = new HTMLDocument(node);
          addRating(fragment, rev);
          addSummary(fragment, rev);
          addTime(fragment, rev);
          addType(fragment, rev);
          addDescription(fragment, rev);
          addItem(fragment, rev);
          addReviewer(fragment, rev);
  
          final TagSoupExtractionResult tser = (TagSoupExtractionResult) out;
          tser.addResourceRoot(
                  DomUtils.getXPathListForNode(node),
                  rev,
                  this.getClass()
          );
  
          return true;
      }
  
      private void addType(HTMLDocument doc, Resource rev) {
          TextField value = doc.getSingularTextField("type");
          conditionallyAddStringProperty(
                  value.source(),
                  rev, vREVIEW.type, value.value()
         );
     }
 
     private void addReviewer(HTMLDocument doc, Resource rev) {
         List<Node> nodes = doc.findAllByClassName("reviewer");
         if (nodes.size() > 0) {
             Node node0 = nodes.get(0);
             addBNodeProperty(
                     node0,
                     rev, vREVIEW.reviewer, getBlankNodeFor(node0)
             );
         }
     }
 
     private void addItem(HTMLDocument root, BNode rev) throws ExtractionException {
         List<Node> nodes = root.findAllByClassName("item");
         for (Node node : nodes) {
             Resource item = findDummy(new HTMLDocument(node));
             addBNodeProperty(
                     node,
                     item, vREVIEW.hasReview, rev
             );
         }
     }
 
     private Resource findDummy(HTMLDocument item) throws ExtractionException {
         Resource blank = getBlankNodeFor(item.getDocument());
         TextField val = item.getSingularTextField("fn");
         conditionallyAddStringProperty(
                 val.source(),
                 blank, vVCARD.fn, val.value()
         );
         final TextField url = item.getSingularUrlField("url");
         conditionallyAddResourceProperty(blank, vVCARD.url, getHTMLDocument().resolveURI(url.value()));
         TextField pics[] = item.getPluralUrlField("photo");
         for (TextField pic : pics) {
             addURIProperty(blank, vVCARD.photo, getHTMLDocument().resolveURI(pic.value()));
         }
         return blank;
     }
 
     private void addRating(HTMLDocument doc, Resource rev) {
         HTMLDocument.TextField value = doc.getSingularTextField("rating");
         conditionallyAddStringProperty(
                 value.source(), rev, vREVIEW.rating, value.value()
         );
     }
 
     private void addSummary(HTMLDocument doc, Resource rev) {
         TextField value = doc.getSingularTextField("summary");
         conditionallyAddStringProperty(
                 value.source(),
                 rev, vREVIEW.title, value.value()
         );
     }
 
     private void addTime(HTMLDocument doc, Resource rev) {
         TextField value = doc.getSingularTextField("dtreviewed");
         conditionallyAddStringProperty(
                 value.source(),
                 rev, vDCTERMS.date, value.value()
         );
     }
 
     private void addDescription(HTMLDocument doc, Resource rev) {
         TextField value = doc.getSingularTextField("description");
         conditionallyAddStringProperty(
                 value.source(),
                 rev, vREVIEW.text, value.value()
         );
     }
 
 }