/*
 * JBoss, Home of Professional Open Source
 * Copyright 2005, JBoss Inc., and individual contributors as indicated
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * 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.jboss.util.propertyeditor;

import java.beans.PropertyEditorSupport;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.jboss.util.NestedRuntimeException;

/**
 * A property editor for {@link java.util.Date}.
 *
 * @author <a href="mailto:jason@planet57.com">Jason Dillon</a>
 * @author <a href="mailto:d_jencks@users.sourceforge.net">David Jencks</a>
 * @author <a href="mailto:scott.stark@jboss.org">Scott Stark</a>
 * @author <a href="mailto:adrian.brock@jboss.org">Adrian Brock</a>
 * @author <a href="mailto:dimitris@jboss.org">Dimitris Andreadis</a>
 * @version <tt>$Revision$</tt>
 */
public class DateEditor extends PropertyEditorSupport
{
   /** The formats to use when parsing the string date */
   private static DateFormat[] formats;
   static
   {
      initialize();
   }

   /**
    * Setup the parsing formats. Offered as a separate static method to allow
    * testing of locale changes, since SimpleDateFormat will use the default
    * locale upon construction. Should not be normally used!
    */
   public static void initialize()
   {
      PrivilegedAction action = new PrivilegedAction()
      {
         public Object run()
         {
            String defaultFormat = System.getProperty("org.jboss.util.propertyeditor.DateEditor.format",
                  "MMM d, yyyy");
            formats = new DateFormat[]
            {
               new SimpleDateFormat(defaultFormat),
               // Tue Jan 04 00:00:00 PST 2005
               new SimpleDateFormat("EEE MMM d HH:mm:ss z yyyy"),
               // Wed, 4 Jul 2001 12:08:56 -0700
               new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z")
            };
            return null;
         }
      };
      AccessController.doPrivileged(action);      
   }

   /** Keep the text version of the date */
   private String text;
   
   /**
    * Sets directly the java.util.Date value
    * 
    * @param value a java.util.Date
    */
   public void setValue(Object value)
   {
      if (value instanceof Date)
      {
         text = null;
         super.setValue(value);
      }
      else
      {
         throw new IllegalArgumentException("setValue() expected java.util.Date value, got "
               + value.getClass().getName());
      }
   }
   
   /**
    * Parse the text into a java.util.Date by trying
    * one by one the registered DateFormat(s).
    * 
    * @param text the string date
    */
   public void setAsText(String text)
   {
      ParseException pe = null;
      
      for (int i = 0; i < formats.length; i++)
      {
         try
         {
            // try to parse the date
            DateFormat df = formats[i];
            Date date = df.parse(text);
            
            // store the date in both forms
            this.text = text;
            super.setValue(date);
            
            // done
            return;
         }
         catch (ParseException e)
         {
            // remember the last seen exception
            pe = e;
         }
      }
      // couldn't parse
      throw new NestedRuntimeException(pe);
   }

   /**
    * Returns either the cached string date, or the stored
    * java.util.Date instance formated to string using the
    * last of the registered DateFormat(s) 
    * 
    * @return date as string
    */
   public String getAsText()
   {
      if (text == null)
      {
         DateFormat df = formats[formats.length - 1];
         Date date = (Date)getValue();
         text = df.format(date);
      }
      return text;
   }
   
}