//
   //  ========================================================================
   //  Copyright (c) 1995-2016 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.util.Arrays;
  import java.util.List;
  
  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.HandlerContainer;
  import org.eclipse.jetty.server.Request;
  import org.eclipse.jetty.server.Server;
  import org.eclipse.jetty.util.ArrayUtil;
  import org.eclipse.jetty.util.MultiException;
  import org.eclipse.jetty.util.annotation.ManagedAttribute;
  import org.eclipse.jetty.util.annotation.ManagedObject;
  
  /* ------------------------------------------------------------ */
  /** 
   * 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.
   */
  @ManagedObject("Handler of multiple handlers")
  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.
       */
      @Override
      @ManagedAttribute(value="Wrapped handlers", readonly=true)
      public Handler[] getHandlers()
      {
          return _handlers;
      }
  
      /* ------------------------------------------------------------ */
      /**
       * @param handlers The handlers to set.
       */
      public void setHandlers(Handler[] handlers)
      {
          if (!_mutableWhenRunning && isStarted())
              throw new IllegalStateException(STARTED);
  
          if (handlers!=null)
          {
              // check for loops
              for (Handler handler:handlers)
                  if (handler == this || (handler instanceof HandlerContainer &&
                      Arrays.asList(((HandlerContainer)handler).getChildHandlers()).contains(this)))
                          throw new IllegalStateException("setHandler loop");
            
              // Set server
              for (Handler handler:handlers)
                  if (handler.getServer()!=getServer())
                      handler.setServer(getServer());
          }
          Handler[] old=_handlers;;
          _handlers = handlers;
         updateBeans(old, handlers);
     }
 
     /* ------------------------------------------------------------ */
     /**
      * @see Handler#handle(String, Request, HttpServletRequest, HttpServletResponse)
      */
     @Override
     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);
             }
 
         }
     }
 
     /* ------------------------------------------------------------ */
     /* 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(ArrayUtil.addToArray(getHandlers(), handler, Handler.class));
     }
 
     /* ------------------------------------------------------------ */
     public void removeHandler(Handler handler)
     {
         Handler[] handlers = getHandlers();
 
         if (handlers!=null && handlers.length>0 )
             setHandlers(ArrayUtil.removeFromArray(handlers, handler));
     }
 
     /* ------------------------------------------------------------ */
     @Override
     protected void expandChildren(List<Handler> list, Class<?> byClass)
     {
         if (getHandlers()!=null)
             for (Handler h:getHandlers())
                 expandHandler(h, list, byClass);
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public void destroy()
     {
         if (!isStopped())
             throw new IllegalStateException("!STOPPED");
         Handler[] children=getChildHandlers();
         setHandlers(null);
         for (Handler child: children)
             child.destroy();
         super.destroy();
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public String toString()
     {
         Handler[] handlers=getHandlers();
         return super.toString()+(handlers==null?"[]":Arrays.asList(getHandlers()).toString());
     }
 }