/*
 * Copyright (C) 2009 eXo Platform SAS.
 *
 * This 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 software 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 software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.exoplatform.commons.utils;

import org.exoplatform.services.log.ExoLogger;
import org.exoplatform.services.log.Log;

import java.util.ResourceBundle;

/**
 * Jul 18, 2004
 * 
 * @author Tuan Nguyen
 * @version $Id: ExpressionUtil.java,v 1.1 2004/07/21 19:59:11 tuan08 Exp $
 */
public class ExpressionUtil
{

   private static final Log LOG = ExoLogger.getLogger("exo.kernel.commons.ExpressionUtil");

   static public String getExpressionValue(ResourceBundle res, String key)
   {
      if (res == null)
         return key;
      if (!isResourceBindingExpression(key))
         return key;
      String value = key;
      key = key.substring(2, key.length() - 1);
      try
      {
         value = res.getString(key);
      }
      catch (java.util.MissingResourceException ex)
      {
         if (LOG.isTraceEnabled())
         {
            LOG.trace("An exception occurred: " + ex.getMessage());
         }
      }
      return value;
   }

   static public boolean isResourceBindingExpression(String key)
   {
      if (key == null || key.length() < 3)
         return false;
      if (key.charAt(0) == '#' && key.charAt(1) == '{' && key.charAt(key.length() - 1) == '}')
      {
         return true;
      }
      return false;
   }

   static public String getValue(ResourceBundle res, String key)
   {
      try
      {
         return res.getString(key);
      }
      catch (java.util.MissingResourceException ex)
      {
         if (LOG.isTraceEnabled())
         {
            LOG.trace("An exception occurred: " + ex.getMessage());
         }
      }
      return key;
   }

   static public boolean isDataBindingExpression(String key)
   {
      if (key == null || key.length() < 3)
         return false;
      if (key.charAt(0) == '$' && key.charAt(1) == '{' && key.charAt(key.length() - 1) == '}')
      {
         return true;
      }
      return false;
   }

   static public String removeBindingExpression(String key)
   {
      key = key.substring(2, key.length() - 1);
      return key;
   }
}
