/**
   * Query SPARQL endpoint with a SELECT query
   *
   * @param qExec QueryExecution encapsulating the query
   * @return model retrieved by querying the endpoint
   */
  private Model getSelectModel(QueryExecution qExec) {
    Model model = ModelFactory.createDefaultModel();
    Graph graph = model.getGraph();
    ResultSet results = qExec.execSelect();

    while (results.hasNext()) {
      QuerySolution sol = results.next();
      String subject;
      String predicate;
      RDFNode object;

      try {
        subject = sol.getResource("s").toString();
        predicate = sol.getResource("p").toString();
        object = sol.get("o");
      } catch (NoSuchElementException e) {
        logger.error("SELECT query does not return a (?s ?p ?o) Triple");
        continue;
      }

      Node objNode;
      if (object.isLiteral()) {
        Literal obj = object.asLiteral();
        objNode = NodeFactory.createLiteral(obj.getString(), obj.getDatatype());
      } else {
        objNode = NodeFactory.createLiteral(object.toString());
      }

      graph.add(
          new Triple(NodeFactory.createURI(subject), NodeFactory.createURI(predicate), objNode));
    }

    return model;
  }
  /**
   * Builds a String result for Elastic Search from an RDFNode
   *
   * @param node An RDFNode representing the value of a property for a given resource
   * @return If the RDFNode has a Literal value, among Boolean, Byte, Double, Float, Integer Long,
   *     Short, this value is returned, converted to String
   *     <p>If the RDFNode has a String Literal value, this value will be returned, surrounded by
   *     double quotes
   *     <p>If the RDFNode has a Resource value (URI) and toDescribeURIs is set to true, the value
   *     of @getLabelForUri for the resource is returned, surrounded by double quotes. Otherwise,
   *     the URI will be returned
   */
  private String getStringForResult(RDFNode node, boolean getNodeLabel) {
    String result = "";
    boolean quote = false;

    if (node.isLiteral()) {
      Object literalValue = node.asLiteral().getValue();
      try {
        Class<?> literalJavaClass = node.asLiteral().getDatatype().getJavaClass();

        if (literalJavaClass.equals(Boolean.class)
            || Number.class.isAssignableFrom(literalJavaClass)) {

          result += literalValue;
        } else {
          result = EEASettings.parseForJson(node.asLiteral().getLexicalForm());
          quote = true;
        }
      } catch (java.lang.NullPointerException npe) {
        result = EEASettings.parseForJson(node.asLiteral().getLexicalForm());
        quote = true;
      }

    } else if (node.isResource()) {
      result = node.asResource().getURI();
      if (getNodeLabel) {
        result = getLabelForUri(result);
      }
      quote = true;
    }
    if (quote) {
      result = "\"" + result + "\"";
    }
    return result;
  }
  /**
   * Get JSON map for a given resource by applying the river settings
   *
   * @param rs resource being processed
   * @param properties properties to be indexed
   * @param model model returned by the indexing query
   * @param getPropLabel if set to true all URI property values will be indexed as their label. The
   *     label is taken as the value of one of the properties set in {@link #uriDescriptionList}.
   * @return map of properties to be indexed for res
   */
  private Map<String, ArrayList<String>> getJsonMap(
      Resource rs, Set<Property> properties, Model model, boolean getPropLabel) {
    Map<String, ArrayList<String>> jsonMap = new HashMap<String, ArrayList<String>>();
    ArrayList<String> results = new ArrayList<String>();

    if (addUriForResource) {
      results.add("\"" + rs.toString() + "\"");
      jsonMap.put("http://www.w3.org/1999/02/22-rdf-syntax-ns#about", results);
    }

    Set<String> rdfLanguages = new HashSet<String>();

    for (Property prop : properties) {
      NodeIterator niter = model.listObjectsOfProperty(rs, prop);
      String property = prop.toString();
      results = new ArrayList<String>();

      String lang;
      String currValue;

      while (niter.hasNext()) {
        RDFNode node = niter.next();
        currValue = getStringForResult(node, getPropLabel);
        if (addLanguage) {
          if (node.isLiteral()) {
            lang = node.asLiteral().getLanguage();
            if (!lang.isEmpty()) {
              rdfLanguages.add("\"" + lang + "\"");
            }
          }
        }

        String shortValue = currValue;

        int currLen = currValue.length();
        // Unquote string
        if (currLen > 1) shortValue = currValue.substring(1, currLen - 1);

        // If either whiteMap does contains shortValue
        // or blackMap contains the value
        // skip adding it to the index
        boolean whiteMapCond =
            whiteMap.containsKey(property) && !whiteMap.get(property).contains(shortValue);
        boolean blackMapCond =
            blackMap.containsKey(property) && blackMap.get(property).contains(shortValue);

        if (whiteMapCond || blackMapCond) {
          continue;
        }

        if (normalizeObj.containsKey(shortValue)) {
          results.add("\"" + normalizeObj.get(shortValue) + "\"");
        } else {
          results.add(currValue);
        }
      }

      // Do not index empty properties
      if (results.isEmpty()) continue;

      if (normalizeProp.containsKey(property)) {
        property = normalizeProp.get(property);
        if (jsonMap.containsKey(property)) {
          jsonMap.get(property).addAll(results);
        } else {
          jsonMap.put(property, results);
        }
      } else {
        jsonMap.put(property, results);
      }
    }

    if (addLanguage) {
      if (rdfLanguages.isEmpty() && !language.isEmpty()) rdfLanguages.add(language);
      if (!rdfLanguages.isEmpty()) jsonMap.put("language", new ArrayList<String>(rdfLanguages));
    }

    for (Map.Entry<String, String> it : normalizeMissing.entrySet()) {
      if (!jsonMap.containsKey(it.getKey())) {
        ArrayList<String> res = new ArrayList<String>();
        res.add("\"" + it.getValue() + "\"");
        jsonMap.put(it.getKey(), res);
      }
    }

    return jsonMap;
  }