/*!
 * This program is free software; you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
 * or from the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * 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 Lesser General Public License for more details.
 *
 * Copyright (c) 2002-2013 Pentaho Corporation..  All rights reserved.
 */

package org.pentaho.reporting.engine.classic.core.layout.process;

import org.pentaho.reporting.engine.classic.core.layout.model.RenderBox;
import org.pentaho.reporting.engine.classic.core.layout.model.RenderNode;
import org.pentaho.reporting.engine.classic.core.states.ReportStateKey;

public class FindOldestProcessKeyStep extends IterateSimpleStructureProcessStep {
  private ReportStateKey key;
  private boolean finishedPaginate;

  public FindOldestProcessKeyStep() {
  }

  public ReportStateKey find( final RenderBox box ) {
    if ( box.isProcessKeyCacheValid() ) {
      return box.getProcessKeyCached();
    }

    key = null;
    finishedPaginate = box.isFinishedPaginate();
    startProcessing( box );
    box.setProcessKeyCached( key );
    return key;
  }

  protected void processOtherNode( final RenderNode node ) {
    final ReportStateKey stateKey = node.getStateKey();
    if ( stateKey == null || stateKey.isInlineSubReportState() ) {
      return;
    }

    if ( key == null ) {
      key = stateKey;
      return;
    }

    if ( stateKey.getSequenceCounter() > key.getSequenceCounter() ) {
      key = stateKey;
    }
  }

  protected boolean startBox( final RenderBox box ) {
    if ( box.isProcessKeyCacheValid() ) {
      key = box.getProcessKeyCached();
      return false;
    }

    processOtherNode( box );
    if ( finishedPaginate == true ) {
      box.setFinishedPaginate( true );
    }
    return true;
  }

  protected void finishBox( final RenderBox box ) {
    box.setProcessKeyCached( key );
  }
}