/*
    *  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.cmdl;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.Iterator;
  import java.util.LinkedList;
  
  import org.xnap.XNap;
  import org.xnap.util.FileHelper;
  
  /***
   * Provides a set of common commands and static helper methods.
   */
  public class CommandHelper {
  
      //--- Data Field(s) ---
  
      //--- Constructor(s) ---
      
      //--- Method(s) ---
  
      /***
       * Adds some default commands to the {@link Executer}.
       */
      public static void init()
      {
  		Executer.add(new HelpCmd());
  		Executer.add(new LicenseCmd());
  		Executer.add(new ReadmeCmd());
  		Executer.add(new StartGUICmd());
  		Executer.add(new StopGUICmd());
      }
  
  	/***
  	 * Prints <code>filename</code> to <code>console</code>.
  	 */
      public static void printFile(String filename, Console console)
      {
  		InputStream inStream = FileHelper.getResourceAsStream(filename);
  		if (inStream == null) {
  			console.println("File " + filename + " not found");
  			return;
  		}
  
  		BufferedReader in = null;
  		try {
  			in = new BufferedReader(new InputStreamReader(inStream));
  			
  			String s;
  			while ((s = in.readLine()) != null) {
  				console.println(s);
  			}
  		}
  		catch(IOException e) {
  			console.println("error: " + e.getMessage());
  		}
  		finally {
  			if (in != null) {
  				try {
  					in.close();
  				}
  				catch (IOException e) {
  				}
  			}
  		}
      }
  
  	//--- Inner Class(es) ---
  
      private static class HelpCmd extends AbstractCommand 
      {
  		public HelpCmd()
  		{
  			putValue(CMD, "help");
  			putValue(ALIASES, new String[] { "h", "?" });
 			putValue(PARAMETER, "[command]");
 			putValue(SHORT_HELP, "Shows help about command.");
 		}
 	
 		public void execute(String command, Console console)
 			throws SyntaxException
 		{
 			String[] argv = tokenize(command);
 
 			if (argv.length == 1) {
 				LinkedList list 
 					= new LinkedList(Arrays.asList(console.getCommands()));
 				Collections.sort(list, new CommandComparator());
 				for (Iterator i = list.iterator(); i.hasNext();) {
 					Command cmd = (Command)i.next();
 					console.println(cmd.getCommand() + " - " 
 									+ cmd.getShortHelp());
 				}
 			}
 			else if (argv.length == 2) {
 				Command cmd = console.getCommand(argv[1]);
 				if (cmd != null) {
 					console.println("Command    : " + cmd.getCommand() + " "
 									+ cmd.getParameter());
 
 					String[] aliases = cmd.getAliases();
 					if (aliases != null) {
 						StringBuffer sb = new StringBuffer();
 						for (int i = 0; i < aliases.length; i++) {
 							sb.append(" ");
 							sb.append(aliases[i]);
 						}
 						console.println("Aliases    :" + sb.toString());
 					}
 					console.println("Description: " + cmd.getLongHelp());
 				}
 				else {
 					console.println("Command not found.");
 				}
 			}
 			else {
 				throw new SyntaxException();
 			}
 		}
     }
 
     private static class LicenseCmd extends AbstractCommand
     {
 		public LicenseCmd()
 		{
 			putValue(CMD, "license");
 			putValue(SHORT_HELP, "Print license.");
 		}
 	
 		public void execute(String command, Console console)
 		{
 			printFile("COPYING", console);
 		}
     }
 
     private static class ReadmeCmd extends AbstractCommand
     {
 		public ReadmeCmd()
 		{
 			putValue(CMD, "readme");
 			putValue(SHORT_HELP, "Print readme.");
 		}
 	
 		public void execute(String command, Console console)
 		{
 			printFile("README", console);
 		}
     }
 
     private static class StartGUICmd extends AbstractCommand
     {
 		public StartGUICmd()
 		{
 			putValue(CMD, "startgui");
 			putValue(SHORT_HELP, "Starts the GUI.");
 		}
 	
 		public void execute(String command, Console console)
 		{
 			XNap.startGUI();
 		}
     }
 
     private static class StopGUICmd extends AbstractCommand
     {
 		public StopGUICmd()
 		{
 			putValue(CMD, "stopgui");
 			putValue(SHORT_HELP, "Stops the GUI.");
 		}
 	
 		public void execute(String command, Console console)
 		{
 			XNap.stopGUI();
 		}
     }
 
 	/***
      * Compares {@link Command} objects by name.
      */
     private static class CommandComparator implements Comparator
     {
 
 		public int compare(Object o1, Object o2) 
 		{
 			return ((Command)o1).getCommand().compareToIgnoreCase
 				(((Command)o2).getCommand());
 		}
 
 	}
     
 }