/*
    * Tentackle - https://tentackle.org
    *
    * This library is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
    * License as published by the Free Software Foundation; either
    * version 2.1 of the License, or (at your option) any later version.
    *
    * This library 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
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.tentackle.dbms.trip;
  
  import org.tentackle.dbms.DbModificationTracker;
  import org.tentackle.misc.IdSerialNameTuple;
  import org.tentackle.misc.IdSerialTuple;
  import org.tentackle.session.MasterSerial;
  import org.tentackle.session.MasterSerialEvent;
  import org.tentackle.session.MasterSerialListEvent;
  import org.tentackle.session.ModificationTracker;
  
  import java.util.List;
  
  /**
   * Remote delegate implementation for {@link DbModificationTracker}.
   *
   * @param <T> the modification tracker class
   * @author  harald
   */
  public class DbModificationTrackerRemoteDelegateImpl<T extends DbModificationTracker>
               extends RemoteDbDelegateImpl<T>
               implements DbModificationTrackerRemoteDelegate {
  
    public DbModificationTrackerRemoteDelegateImpl(RemoteDbSessionImpl session, Class<T> clazz) {
      super(session, clazz);
    }
  
  
    @Override
    public void configureRemoteSession() {
      getServerSession().setModificationTrackerSession(true);
    }
  
    @Override
    public MasterSerial selectMasterSerial() {
      DbModificationTracker tracker = (DbModificationTracker) ModificationTracker.getInstance();
      return createMasterSerial(tracker.getMasterSerial(), tracker.getGeneration());
    }
  
    @Override
    public IdSerialTuple selectIdSerialForName(String tableName) {
      return ((DbModificationTracker) ModificationTracker.getInstance()).getIdSerialForName(tableName);
    }
  
    @Override
    public List<IdSerialTuple> selectAllIdSerials() {
      return ((DbModificationTracker) ModificationTracker.getInstance()).getAllIdSerials();
    }
  
    @Override
    public List<IdSerialNameTuple> selectAllIdSerialNames() {
      return ((DbModificationTracker) ModificationTracker.getInstance()).getAllIdSerialNames();
    }
  
  
    /**
     * Creates the master serial object from a long serial.
     * <p>
     * If {@link MasterSerialEvent}s are registered for this remote session,
     * the next event will be polled from the queue, its serial set, and that event returned.
     *
     * @param serial the long master serial
     * @param generation the generation of the modification table
     * @return the master serial object
     */
    protected MasterSerial createMasterSerial(long serial, long generation) {
      MasterSerialEvent masterSerialEvent = getServerSession().pollMasterSerialEvent();
      if (masterSerialEvent != null) {
        masterSerialEvent.setSerial(serial);
        MasterSerialEvent nextEvent = getServerSession().pollMasterSerialEvent();
        if (nextEvent != null) {
          MasterSerialListEvent listEvent = new MasterSerialListEvent();
          listEvent.setSerial(serial);
          listEvent.add(masterSerialEvent);
          while (nextEvent != null) {
            nextEvent.setSerial(serial);
            listEvent.add(nextEvent);
            nextEvent = getServerSession().pollMasterSerialEvent();
          }
          // could be reduced to one element due to MasterSerialEvent.isOverridingOlderEvents(), see MasterSerialListEvent.add()
          masterSerialEvent = listEvent.size() == 1 ? listEvent.get(0) : listEvent;
        }
       return masterSerialEvent;
     }
     return new DefaultMasterSerial(serial, generation);
   }
 
 }