/*****************************************************************************
 * Copyright (c) 2006, 2007 g-Eclipse Consortium 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Initial development of the original code was made for the
 * g-Eclipse project founded by European Union
 * project number: FP6-IST-034327  http://www.geclipse.eu/
 *
 * Contributors:
 *    Mathias Stuempert - initial API and implementation
 *****************************************************************************/

package eu.geclipse.core.internal.model;

import java.util.ArrayList;
import java.util.List;

import eu.geclipse.core.model.IConnectionManager;
import eu.geclipse.core.model.IGridConnection;
import eu.geclipse.core.model.IGridElement;

/**
 * Internal implementation of the
 * {@link eu.geclipse.core.model.IConnectionManager} interface.
 * This is not intended to be accessible from the outside. Instead
 * the {@link eu.geclipse.core.model.GridModel#getConnectionManager()}
 * method should be used.
 * 
 * This class is used as a singleton.
 */
public class ConnectionManager
    extends AbstractGridElementManager
    implements IConnectionManager {
  
  /**
   * The name of this manager. This is also used as the storage area.
   */
  public static final String NAME = ".connections"; //$NON-NLS-1$
  
  /**
   * The singleton.
   */
  private static ConnectionManager singleton;
  
  private ConnectionManager() {
    // empty implementation
  }
  
  /**
   * Get the singleton instance of the <code>ConnectionManager</code>.
   * 
   * @return The singleton.
   */
  public static ConnectionManager getManager() {
    if ( singleton == null ) {
      singleton = new ConnectionManager();
    }
    return singleton;
  }
  
  /* (non-Javadoc)
   * @see eu.geclipse.core.model.IGridElementManager#canManage(eu.geclipse.core.model.IGridElement)
   */
  public boolean canManage( final IGridElement element ) {
    boolean canManage = false;
    if( element instanceof IGridConnection ) {
      canManage = true;
    }
    return canManage;
  }
  
  /*
   * (non-Javadoc)
   * 
   * @see eu.geclipse.core.model.IConnectionManager#getGlobalConnections()
   */
  public IGridConnection[] getGlobalConnections() {
    
    List< IGridConnection > result = new ArrayList< IGridConnection >();
    IGridElement[] children = getChildren( null );
    
    for ( IGridElement child : children ) {
      if ( child instanceof IGridConnection ) {
        IGridConnection connection
          = ( IGridConnection ) child;
        if ( connection.isGlobal() ) {
          result.add( connection );
        }
      }
    }
    
    IGridConnection[] gConnections
      = result.isEmpty()
      ? null
      : result.toArray( new IGridConnection[ result.size() ] );
    
    return gConnections;
    
  }
  
  /* (non-Javadoc)
   * @see eu.geclipse.core.internal.model.AbstractGridElementManager#getName()
   */
  public String getName() {
    return NAME;
  }

}