//
   //  ========================================================================
   //  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.server.handler;
  
  import java.io.IOException;
  import java.net.HttpURLConnection;
  import java.net.InetSocketAddress;
  import java.net.SocketException;
  import java.net.URL;
  
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.eclipse.jetty.server.Connector;
  import org.eclipse.jetty.server.NetworkConnector;
  import org.eclipse.jetty.server.Request;
  import org.eclipse.jetty.server.Server;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  /* ------------------------------------------------------------ */
  /**
   * A handler that shuts the server down on a valid request. Used to do "soft" restarts from Java. If _exitJvm ist set to true a hard System.exit() call is being
   * made.
   *
   * This handler is a contribution from Johannes Brodwall: https://bugs.eclipse.org/bugs/show_bug.cgi?id=357687
   *
   * Usage:
   *
   * <pre>
      Server server = new Server(8080);
      HandlerList handlers = new HandlerList();
      handlers.setHandlers(new Handler[]
      { someOtherHandler, new ShutdownHandler(&quot;secret password&quot;) });
      server.setHandler(handlers);
      server.start();
     </pre>
   *
     <pre>
     public static void attemptShutdown(int port, String shutdownCookie) {
          try {
              URL url = new URL("http://localhost:" + port + "/shutdown?token=" + shutdownCookie);
              HttpURLConnection connection = (HttpURLConnection)url.openConnection();
              connection.setRequestMethod("POST");
              connection.getResponseCode();
              logger.info("Shutting down " + url + ": " + connection.getResponseMessage());
          } catch (SocketException e) {
              logger.debug("Not running");
              // Okay - the server is not running
          } catch (IOException e) {
              throw new RuntimeException(e);
          }
      }
    </pre>
   */
  public class ShutdownHandler extends HandlerWrapper
  {
      private static final Logger LOG = Log.getLogger(ShutdownHandler.class);
  
      private final String _shutdownToken;
      private boolean _sendShutdownAtStart;
      private boolean _exitJvm = false;
  
  
      /**
       * Creates a listener that lets the server be shut down remotely (but only from localhost).
       *
       * @param server
       *            the Jetty instance that should be shut down
       * @param shutdownToken
       *            a secret password to avoid unauthorized shutdown attempts
       */
      @Deprecated
      public ShutdownHandler(Server server, String shutdownToken)
      {
          this(shutdownToken);
      }
  
      public ShutdownHandler(String shutdownToken)
      {
          this(shutdownToken,false,false);
      }
     
     /**
      * @param shutdownToken
      * @param sendShutdownAtStart If true, a shutdown is sent as a HTTP post
      * during startup, which will shutdown any previously running instances of
      * this server with an identically configured ShutdownHandler
      */
     public ShutdownHandler(String shutdownToken, boolean exitJVM, boolean sendShutdownAtStart)
     {
         this._shutdownToken = shutdownToken;
         setExitJvm(exitJVM);
         setSendShutdownAtStart(sendShutdownAtStart);
     }
     
 
     public void sendShutdown() throws IOException
     {
         URL url = new URL(getServerUrl() + "/shutdown?token=" + _shutdownToken);
         try
         {
             HttpURLConnection connection = (HttpURLConnection)url.openConnection();
             connection.setRequestMethod("POST");
             connection.getResponseCode();
             LOG.info("Shutting down " + url + ": " + connection.getResponseMessage());
         }
         catch (SocketException e)
         {
             LOG.debug("Not running");
             // Okay - the server is not running
         }
         catch (IOException e)
         {
             throw new RuntimeException(e);
         }
     }
 
     @SuppressWarnings("resource")
     private String getServerUrl()
     {
         NetworkConnector connector=null;
         for (Connector c: getServer().getConnectors())
         {
             if (c instanceof NetworkConnector)
             {
                 connector=(NetworkConnector)c;
                 break;
             }
         }
 
         if (connector==null)
             return "http://localhost";
 
         return "http://localhost:" + connector.getPort();
     }
     
     
     @Override
     protected void doStart() throws Exception
     {
         super.doStart();
         if (_sendShutdownAtStart)
             sendShutdown();
     }
     
     @Override
     public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
     {
         if (!target.equals("/shutdown"))
         {
             super.handle(target,baseRequest,request,response);
             return;
         }
 
         if (!request.getMethod().equals("POST"))
         {
             response.sendError(HttpServletResponse.SC_BAD_REQUEST);
             return;
         }
         if (!hasCorrectSecurityToken(request))
         {
             LOG.warn("Unauthorized tokenless shutdown attempt from " + request.getRemoteAddr());
             response.sendError(HttpServletResponse.SC_UNAUTHORIZED);
             return;
         }
         if (!requestFromLocalhost(baseRequest))
         {
             LOG.warn("Unauthorized non-loopback shutdown attempt from " + request.getRemoteAddr());
             response.sendError(HttpServletResponse.SC_UNAUTHORIZED);
             return;
         }
 
         LOG.info("Shutting down by request from " + request.getRemoteAddr());
 
         final Server server=getServer();
         new Thread()
         {
             @Override
             public void run ()
             {
                 try
                 {
                     shutdownServer(server);
                 }
                 catch (InterruptedException e)
                 {
                     LOG.ignore(e);
                 }
                 catch (Exception e)
                 {
                     throw new RuntimeException("Shutting down server",e);
                 }
             }
         }.start();
     }
 
     private boolean requestFromLocalhost(Request request)
     {
         InetSocketAddress addr = request.getRemoteInetSocketAddress();
         if (addr == null)
         {
             return false;
         }
         return addr.getAddress().isLoopbackAddress();
     }
 
     private boolean hasCorrectSecurityToken(HttpServletRequest request)
     {
         String tok = request.getParameter("token");
         if (LOG.isDebugEnabled())
             LOG.debug("Token: {}", tok);
         return _shutdownToken.equals(tok);
     }
 
     private void shutdownServer(Server server) throws Exception
     {
         server.stop();
 
         if (_exitJvm)
         {
             System.exit(0);
         }
     }
 
     public void setExitJvm(boolean exitJvm)
     {
         this._exitJvm = exitJvm;
     }
 
     public boolean isSendShutdownAtStart()
     {
         return _sendShutdownAtStart;
     }
 
     public void setSendShutdownAtStart(boolean sendShutdownAtStart)
     {
         _sendShutdownAtStart = sendShutdownAtStart;
     }
 
     public String getShutdownToken()
     {
         return _shutdownToken;
     }
 
     public boolean isExitJvm()
     {
         return _exitJvm;
     }
 
 }