/*
    *  XNap - A P2P framework and client.
    *
    *  See the file AUTHORS for copyright information.
    *
    *  This program is free software; you can redistribute it and/or modify
    *  it under the terms of the GNU General Public License as published by
    *  the Free Software Foundation.
    *
   *  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 General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.xnap.i18n;
  
  import java.text.MessageFormat;
  import java.util.Locale;
  import java.util.MissingResourceException;
  import java.util.ResourceBundle;
  
  import org.xnap.*;
  
  /***
   * Provides methods for internationalization.
   */
  public class I18n {
  
      //--- Constant(s) ---
  
      //--- Data field(s) ---
  
      /*** Reference to the current localization bundle. */
      private static ResourceBundle resources;
  
      //--- Method(s) ---
  
      /***
       * Returns the currently used message bundle.
       */
      public static final ResourceBundle getResources()
      {
  		return resources;
      }
  
      /***
       * Loads a resource bundle from location, using the default locale.
       */
      public static final void setResources(String location) 
      {
  		setResources(ResourceBundle.getBundle(location, Locale.getDefault()));
      }
  
      /***
       * Sets the resource bundle.
       */
      public static final void setResources(ResourceBundle resources) 
      {
  		I18n.resources = resources;
      }
  	
  	/***
  	 * Marks <code>text</code> to be translated, but doesn't translate it.
  	 *
  	 */
  	public static final String marktr(String text)
  	{
  		return text;
  	}
      
      /***
       * Returns <code>text</code> translated into the currently selected
       * language. Every user-visible string in the program must be wrapped
       * into this function.  
       */
      public static final String tr(String text)
      {
  		try {
  			return resources.getString(text);
  		}
  		catch (MissingResourceException e) {
  			//System.err.println("missing translation key: \"" + text + "\"");
  			//e.printStackTrace(System.err);
  			return text;
  		}
  		catch (NullPointerException e) {
  			// the message bundle has not been loaded yet
  			return text;
  		}
      }
  
      /***
       * Returns <code>text</code> translated into the currently selected
       * language. 
      *
      * <p>The first occurence of {0} is replaced by <code>o1.toString()</code>.
      */
     public static final String tr(String text, Object o1)
     {
 		return MessageFormat.format(tr(text), new Object[] { o1 });
     }
 
 	/***
 	 * Disambiguates translation keys.
 	 *
 	 * @param comment the text translated + a disambiguation hint in brackets.
 	 * @param text the ambiguous key string
 	 */
 	public static final String trc(String comment, String text)
 	{
 		return Locale.getDefault().equals(Locale.ENGLISH) ? text
 			: XNap.tr(comment);
 	}
 
     /***
      * Returns <code>text</code> translated into the currently selected
      * language. 
      *
      * <p>The first occurence of {0} is replaced by <code>o1.toString()</code>.
      * The first occurence of {1} is replaced by <code>o2.toString()</code>.
      */
     public static final String tr(String text, Object o1, Object o2)
     {
 		return MessageFormat.format(tr(text), new Object[] { o1, o2 });
     }
 
     /***
      * Returns <code>text</code> translated into the currently selected
      * language. 
      *
      * <p>The first occurence of {0} is replaced by <code>o1.toString()</code>.
      * The first occurence of {1} is replaced by <code>o2.toString()</code>.
      * The first occurence of {2} is replaced by <code>o3.toString()</code>.
      */
     public static final String tr(String text, Object o1, Object o2,
 								  Object o3)
     {
 		return MessageFormat.format(tr(text), 
 									new Object[] { o1, o2, o3 });
     }
 
 	/***
 	 * Returns <code>text</code> translated into the currently selected
 	 * language. 
 	 *
 	 * <p>The first occurence of {0} is replaced by <code>o1.toString()</code>.
 	 * The first occurence of {1} is replaced by <code>o2.toString()</code>.
 	 * The first occurence of {2} is replaced by <code>o3.toString()</code>.
 	 * The first occurence of {3} is replaced by <code>o4.toString()</code>.
 	 */
 	public static final String tr(String text, Object o1, Object o2,
 								  Object o3, Object o4)
 	{
 		return MessageFormat.format(tr(text), 
 									new Object[] { o1, o2, o3, o4 });
 	}
 
     /***
      * Returns <code>text</code> translated into the currently selected
      * language. Prepends and appends <code>padding</code> whitespaces.
      */
     public static final String tr(String text, int padding)
     {
 		String s = tr(text);
 		if (padding <= 0) {
 			return s;
 		}
 		StringBuffer sb = new StringBuffer(s.length() + padding * 2);
 		append(sb, " ", padding);
 		sb.append(s);
 		append(sb, " ", padding);
 		return sb.toString();
     }
 
     /***
      * Returns <code>text</code> translated into the currently selected
      * language. Prepends <code>lpadding</code> whitespaces. Appends
      * <code>rpadding</code> whitespaces.
      */
     public static final String tr(String text, int lpadding, int rpadding)
     {
 		String s = tr(text);
 		StringBuffer sb = new StringBuffer(s.length() + lpadding + rpadding);
 		append(sb, " ", lpadding);
 		sb.append(s);
 		append(sb, " ", rpadding);
 		return sb.toString();
     }
 
     private static final void append(StringBuffer sb, String s, int count)
     {
 		for (int i = 0; i < count; i++) {
 			sb.append(s);
 		}
     }
 }