// ========================================================================
   // Copyright (c) 2004-2009 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 javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.eclipse.jetty.server.Handler;
  import org.eclipse.jetty.server.Request;
  import org.eclipse.jetty.server.Server;
  import org.eclipse.jetty.util.LazyList;
  import org.eclipse.jetty.util.MultiException;
  
  /* ------------------------------------------------------------ */
  /** A collection of handlers.  
   * <p>
   * The default implementations  calls all handlers in list order, 
   * regardless of the response status or exceptions. Derived implementation
   * may alter the order or the conditions of calling the contained 
   * handlers.
   * <p>
   * 
   * @org.apache.xbean.XBean
   */
  public class HandlerCollection extends AbstractHandlerContainer
  {
      private final boolean _mutableWhenRunning;
      private volatile Handler[] _handlers;
  
      /* ------------------------------------------------------------ */
      public HandlerCollection()
      {
          _mutableWhenRunning=false;
      }
      
      /* ------------------------------------------------------------ */
      public HandlerCollection(boolean mutableWhenRunning)
      {
          _mutableWhenRunning=mutableWhenRunning;
      }
  
      /* ------------------------------------------------------------ */
      /**
       * @return Returns the handlers.
       */
      public Handler[] getHandlers()
      {
          return _handlers;
      }
      
      /* ------------------------------------------------------------ */
      /**
       * 
       * @param handlers The handlers to set.
       */
      public void setHandlers(Handler[] handlers)
      {
          if (!_mutableWhenRunning && isStarted())
              throw new IllegalStateException(STARTED);
          
          Handler [] old_handlers = _handlers==null?null:_handlers.clone();
          
          if (getServer()!=null)
              getServer().getContainer().update(this, old_handlers, handlers, "handler");
          
          Server server = getServer();
          MultiException mex = new MultiException();
          for (int i=0;handlers!=null && i<handlers.length;i++)
          {
              if (handlers[i].getServer()!=server)
                  handlers[i].setServer(server);
          }
  
          // handlers is volatile
          _handlers = handlers;
  
          // stop old handlers
          for (int i=0;old_handlers!=null && i<old_handlers.length;i++)
          {
              if (old_handlers[i]!=null)
              {
                  try
                  {
                      if (old_handlers[i].isStarted())
                          old_handlers[i].stop();
                 }
                 catch (Throwable e)
                 {
                     mex.add(e);
                 }
             }
         }
                 
         mex.ifExceptionThrowRuntime();
     }
 
     /* ------------------------------------------------------------ */
     /* 
      * @see org.eclipse.jetty.server.server.EventHandler#handle(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
      */
     public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) 
         throws IOException, ServletException
     {
         if (_handlers!=null && isStarted())
         {
             MultiException mex=null;
             
             for (int i=0;i<_handlers.length;i++)
             {
                 try
                 {
                     _handlers[i].handle(target,baseRequest, request, response);
                 }
                 catch(IOException e)
                 {
                     throw e;
                 }
                 catch(RuntimeException e)
                 {
                     throw e;
                 }
                 catch(Exception e)
                 {
                     if (mex==null)
                         mex=new MultiException();
                     mex.add(e);
                 }
             }
             if (mex!=null)
             {
                 if (mex.size()==1)
                     throw new ServletException(mex.getThrowable(0));
                 else
                     throw new ServletException(mex);
             }
             
         }    
     }
 
     /* ------------------------------------------------------------ */
     /* 
      * @see org.eclipse.jetty.server.server.handler.AbstractHandler#doStart()
      */
     protected void doStart() throws Exception
     {
         MultiException mex=new MultiException();
         if (_handlers!=null)
         {
             for (int i=0;i<_handlers.length;i++)
                 try{_handlers[i].start();}catch(Throwable e){mex.add(e);}
         }
         super.doStart();
         mex.ifExceptionThrow();
     }
 
     /* ------------------------------------------------------------ */
     /* 
      * @see org.eclipse.jetty.server.server.handler.AbstractHandler#doStop()
      */
     protected void doStop() throws Exception
     {
         MultiException mex=new MultiException();
         try { super.doStop(); } catch(Throwable e){mex.add(e);}
         if (_handlers!=null)
         {
             for (int i=_handlers.length;i-->0;)
                 try{_handlers[i].stop();}catch(Throwable e){mex.add(e);}
         }
         mex.ifExceptionThrow();
     }
     
     /* ------------------------------------------------------------ */
     public void setServer(Server server)
     {
         if (isStarted())
             throw new IllegalStateException(STARTED);
         
         Server old_server=getServer();
         
         super.setServer(server);
 
         Handler[] h=getHandlers();
         for (int i=0;h!=null && i<h.length;i++)
             h[i].setServer(server);
         
         if (server!=null && server!=old_server)
             server.getContainer().update(this, null,_handlers, "handler");
         
     }
 
     /* ------------------------------------------------------------ */
     /* Add a handler.
      * This implementation adds the passed handler to the end of the existing collection of handlers. 
      * @see org.eclipse.jetty.server.server.HandlerContainer#addHandler(org.eclipse.jetty.server.server.Handler)
      */
     public void addHandler(Handler handler)
     {
         setHandlers((Handler[])LazyList.addToArray(getHandlers(), handler, Handler.class));
     }
     
     /* ------------------------------------------------------------ */
     public void removeHandler(Handler handler)
     {
         Handler[] handlers = getHandlers();
         
         if (handlers!=null && handlers.length>0 )
             setHandlers((Handler[])LazyList.removeFromArray(handlers, handler));
     }
 
     /* ------------------------------------------------------------ */
     protected Object expandChildren(Object list, Class byClass)
     {
         Handler[] handlers = getHandlers();
         for (int i=0;handlers!=null && i<handlers.length;i++)
             list=expandHandler(handlers[i], list, byClass);
         return list;
     }
 
 
 }