/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe 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.
    *
   * MyCoRe 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 MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.datamodel.ifs2;
  
  import java.io.IOException;
  import java.util.Date;
  
  import org.jdom2.JDOMException;
  import org.mycore.common.MCRUsageException;
  import org.mycore.common.content.MCRByteContent;
  import org.mycore.common.content.MCRContent;
  import org.mycore.common.content.streams.MCRByteArrayOutputStream;
  import org.mycore.datamodel.common.MCRAbstractMetadataVersion;
  import org.tmatesoft.svn.core.SVNException;
  import org.tmatesoft.svn.core.io.SVNRepository;
  
  import jakarta.xml.bind.annotation.XmlAccessType;
  import jakarta.xml.bind.annotation.XmlAccessorType;
  import jakarta.xml.bind.annotation.XmlRootElement;
  
  /**
   * Provides information about a stored version of metadata and allows to
   * retrieve that version from SVN
   * 
   * @author Frank Lützenkirchen
   */
  @XmlRootElement(name = "revision")
  @XmlAccessorType(XmlAccessType.FIELD)
  public class MCRMetadataVersion extends MCRAbstractMetadataVersion<MCRVersionedMetadata> {
  
      public MCRMetadataVersion(MCRVersionedMetadata vm, String revision, String user, Date date, char type) {
          super(vm, revision, user, date, type);
      }
  
      /**
       * Retrieves this version of the metadata
       * 
       * @return the metadata document as it was in this version
       * @throws MCRUsageException
       *             if this is a deleted version, which can not be retrieved
       */
      @Override
      public MCRContent retrieve() throws IOException {
          if (getType() == DELETED) {
              String msg = "You can not retrieve a deleted version, retrieve a previous version instead";
              throw new MCRUsageException(msg);
          }
          try {
              SVNRepository repository = vm.getStore().getRepository();
              MCRByteArrayOutputStream baos = new MCRByteArrayOutputStream();
              repository.getFile(vm.getStore().getSlotPath(vm.getID()), Long.parseLong(getRevision()), null, baos);
              baos.close();
              return new MCRByteContent(baos.getBuffer(), 0, baos.size(), getDate().getTime());
          } catch (SVNException e) {
              throw new IOException(e);
          }
      }
  
      /**
       * Replaces the current version of the metadata object with this version,
       * which means that a new version is created that is identical to this old
       * version. The stored metadata document is updated to this old version of
       * the metadata.
       */
      @Override
      public void restore() throws IOException, JDOMException {
          vm.update(retrieve());
      }
  }