/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you under the Educational
    * Community 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://opensource.org/licenses/ecl2.txt
   *
   * 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.opencastproject.metadata.mpeg7;
  
  import org.opencastproject.metadata.api.CatalogService;
  import org.opencastproject.util.XmlSafeParser;
  
  import org.apache.commons.io.output.ByteArrayOutputStream;
  import org.osgi.service.component.annotations.Component;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  
  import javax.xml.transform.Transformer;
  import javax.xml.transform.dom.DOMSource;
  import javax.xml.transform.stream.StreamResult;
  
  /**
   * Loads {@link Mpeg7Catalog}s
   */
  @Component(
      immediate = true,
      service = { Mpeg7CatalogService.class,CatalogService.class },
      property = {
          "service.description=Mpeg7 Catalog Service"
      }
  )
  public class Mpeg7CatalogService implements CatalogService<Mpeg7Catalog> {
  
    public InputStream serialize(Mpeg7Catalog catalog) throws IOException {
      try {
        Transformer tf = XmlSafeParser.newTransformerFactory().newTransformer();
        DOMSource xmlSource = new DOMSource(catalog.toXml());
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        tf.transform(xmlSource, new StreamResult(out));
        return new ByteArrayInputStream(out.toByteArray());
      } catch (Exception e) {
        throw new IOException(e);
      }
    }
  
    public Mpeg7Catalog load(InputStream in) throws IOException {
      if (in == null)
        throw new IllegalArgumentException("Stream must not be null");
      return new Mpeg7CatalogImpl(in);
    }
  
    public Mpeg7Catalog newInstance() {
      return new Mpeg7CatalogImpl();
    }
  
  }