/*
    * #%L
    * SUMARiS
    * %%
    * Copyright (C) 2019 SUMARiS Consortium
    * %%
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as
    * published by the Free Software Foundation, either version 3 of the
   * License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/gpl-3.0.html>.
   * #L%
   */
  
  package net.sumaris.rdf.util;
  
  import de.uni_stuttgart.vis.vowl.owl2vowl.Owl2Vowl;
  import net.sumaris.core.exception.SumarisTechnicalException;
  import net.sumaris.core.util.StringUtils;
  import org.apache.jena.rdf.model.Model;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  
  public class ModelUtils {
  
      protected ModelUtils() {
          // Helper class
      }
  
  
      public static String toJenaOutputFormat(String userFormat) {
          if (StringUtils.isBlank(userFormat)) {
              return "RDF/XML";
          }
  
          switch(userFormat.toLowerCase()) {
              case "rdf":
                  return "RDF/XML";
              case "json":
                  return "RDF/JSON";
              case "n3":
                  return "N3";
              case "trig":
                  return "TriG";
              case "trix":
                  return "TriX";
              case "jsonld":
              case "json-ld":
                  return "JSON-LD";
              case "ttl":
                  return "TURTLE";
              default:
                  return userFormat.toUpperCase();
          }
      }
  
      /**
       * Serialize model in requested format
       *
       * @param model  input model
       * @param format output format if null then output to RDF/XML
       * @return a string representation of the model
       */
      public static String modelToString(Model model, String format) {
  
          format = toJenaOutputFormat(format);
  
          // Special case for VOWL format
          if ("VOWL".equalsIgnoreCase(format)) {
              try (
                      ByteArrayOutputStream bos = new ByteArrayOutputStream(1024);
              ) {
                  model.write(bos);
                  bos.flush();
  
                  return new Owl2Vowl(new ByteArrayInputStream(bos.toByteArray())).getJsonAsString();
              } catch (Exception e) {
                  throw new SumarisTechnicalException("Error converting model into VOWL", e);
              }
          }
  
          // Other case
          else {
              try (final ByteArrayOutputStream os = new ByteArrayOutputStream()) {
                  if (format == null) {
                      model.write(os);
                  } else {
                      model.write(os, format);
                  }
                 os.flush();
                 os.close();
                 return new String(os.toByteArray(), "UTF8");
             } catch (IOException e) {
                 throw new SumarisTechnicalException("Unable to serialize model to string: " + e.getMessage(), e);
             }
         }
     }
 }