/*
 * $Header: /home/cvspublic/jakarta-tomcat/src/share/org/apache/tomcat/core/Attic/RequestInterceptor.java,v 1.11 2000/06/22 19:49:36 costin Exp $
 * $Revision: 1.11 $
 * $Date: 2000/06/22 19:49:36 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:  
 *       "This product includes software developed by the 
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * [Additional notices, if required by prior licensing conditions]
 *
 */ 


package org.apache.tomcat.core;
import javax.servlet.Servlet;
import java.util.*;

/**
 * Provide a mechanism to customize the request processing.
 *
 * @author costin@dnt.ro
 */
public interface RequestInterceptor {
    public static final int OK=0;

    /** Will detect the context path for a request.
     *  It need to set: context, contextPath, lookupPath
     *
     *  A possible use for this would be a "user-home" interceptor
     *  that will implement ~costin servlets ( add and map them at run time).
     */
    public int contextMap(Request request);

    
    /** Handle mappings inside a context.
     *  You are required to respect the mappings in web.xml.
     */
    public int requestMap(Request request);

    
    /** 
     *  This callback is used to extract and verify the user identity
     *  and credentials.
     *
     *  It will set the RemoteUser field if it can authenticate.
     *  The auth event is generated by a user asking for the remote
     *  user field of by tomcat if a request requires authenticated
     *  id.
     */
    public int authenticate(Request request, Response response);


    /**
     *  Will check if the current ( authenticated ) user is authorized
     *  to access a resource, by checking if it have one of the
     *  required roles.
     *
     *  This is used by tomcat to delegate the authorization to modules.
     *  The authorize is called by isUserInRole() and by ContextManager
     *  if the request have security constraints.
     *
     *  @returns 0 if the module can't take a decision
     *           401 If the user is not authorized ( doesn't have
     *               any of the required roles )
     *           200 If the user have the right roles. No further module
     *               will be called.
     */
    public int authorize(Request request, Response response,
			 String reqRoles[]);


    /** Called before service method is invoked. 
     */
    public int preService(Request request, Response response);

    /** New Session notification - called when the servlet
	asks for a new session. You can do all kind of stuff with
	this notification - the most important is create a session
	object. This will be the base for controling the
	session allocation.
    */
    public int newSessionRequest( Request request, Response response);

    /** Called before the first body write, and before sending
     *  the headers. The interceptor have a chance to change the
     *  output headers. 
     */
    public int beforeBody( Request request, Response response);

    
    /** Called before the output buffer is commited.
     */
    public int beforeCommit( Request request, Response response);

    
    /** Called after the output stream is closed ( either by servlet
     *  or automatically at end of service ).
     */
    public int afterBody( Request request, Response response);

    
    /** Called after service method ends. Log is a particular use.
     */
    public int postService(Request request, Response response);

    /** Will return the methods fow which this interceptor is interested
     *  in notification.
     *  This will be used by ContextManager to call only the interceptors
     *  that are interested, avoiding empty calls.
     *  ( not implemented yet ). 
     */
    public String[] getMethods();
}

/*
      IIS equiv:
      
      Authenticate=  SF_NOTIFY_AUTHETNICATION
      beforeBody =   SF_NOTIFY_SEND_RESPONSE.
      beforeCommit = SF_NOTIFY_SEND_RAW_DATA
      afterBody =    SF_NOTIFY_END_OF_REQUEST
      postService =  SF_NOTIFY_LOG
      getMethods  =  FILTER_VERSION.dwFlags

      Missing:
      pre/postConnection == SF_NOTIFY_END_OF_NET_SESSION

      afterReceive() == SF_NOTIFY_READ_RAW_DATA

      accessDenied() == SF_NOTIFY_ACCESS_DENIED

      afterHeaders() == SF_NOTIFY_PREPROC_HEADERS

      Return codes in IIS :
      FINISHED disconect the session, we're don
      FINISHED_KEEP_CON - keep the connection open if possible
      NEXT_NOTIFICATION - go to next in chain
      HANDLED_NOTIFICATION - stop the chain
      ERROR - send an error
      READ_NEXT - do another read ( for stream filter )
*/ 

/* 
   NES equiv:

*/

/* Apaceh equiv:
 */
