/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  * http://www.opensource.org/licenses/ecl2.php

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.kew.web;

 import org.kuali.rice.kim.api.identity.IdentityService;

 import org.kuali.rice.kim.api.identity.principal.Principal;

 import org.kuali.rice.kim.api.services.KimApiServiceLocator;

 import org.kuali.rice.krad.UserSession;

 import org.kuali.rice.krad.util.KRADUtils;

 import javax.servlet.Filter;

 import javax.servlet.FilterChain;

 import javax.servlet.FilterConfig;

 import javax.servlet.ServletException;

 import javax.servlet.ServletRequest;

 import javax.servlet.ServletResponse;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletRequestWrapper;

 import javax.servlet.http.HttpServletResponse;

 import java.io.IOException;

 /**

  * A login filter which forwards to a login page that allows for the desired

  * authentication ID to be entered without the need for a password.

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class DummyLoginFilter implements Filter {

     private String loginPath;

     private boolean showPassword = false;

     @Override

         public void init(FilterConfig config) throws ServletException {

         loginPath = config.getInitParameter("loginPath");

         showPassword = Boolean.valueOf(config.getInitParameter("showPassword")).booleanValue();

         if (loginPath == null) {

             loginPath = "/WEB-INF/jsp/dummy_login.jsp";

         }

     }

         @Override

         public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

                 this.doFilter((HttpServletRequest) request, (HttpServletResponse) response, chain);

         }

         private void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException {

         final UserSession session = KRADUtils.getUserSessionFromRequest(request);

         if (session == null) {

                 IdentityService auth = KimApiServiceLocator.getIdentityService();

                        request.setAttribute("showPasswordField", Boolean.valueOf(showPassword));

             final String user = request.getParameter("__login_user");

             final String password = request.getParameter("__login_pw");

             if (user != null) {

                     // Very simple password checking. Nothing hashed or encrypted. This is strictly for demonstration purposes only.

                     final Principal principal = showPassword ? auth.getPrincipalByPrincipalNameAndPassword(user, password) : auth.getPrincipalByPrincipalName(user);

                     if (principal == null) {

                             handleInvalidLogin(request, response);        

                             return;

                     }

                 // wrap the request with the remote user

                 // UserLoginFilter and WebAuthenticationService will create the session

                 request = new HttpServletRequestWrapper(request) {

                     @Override

                                         public String getRemoteUser() {

                         return user;

                     }

                 };        

             } else {

                 // no session has been established and this is not a login form submission, so forward to login page

                 request.getRequestDispatcher(loginPath).forward(request, response);

                 return;

             }

         } else {

             request = new HttpServletRequestWrapper(request) {

                     @Override

                                         public String getRemoteUser() {

                         return session.getPrincipalName();

                     }

                 };

         }

         chain.doFilter(request, response);

     }

         /**

          * Handles and invalid login attempt.

          *  

          * @param request the incoming request

          * @param response the outgoing response

          * @throws ServletException if unable to handle the invalid login

          * @throws IOException if unable to handle the invalid login

          */

         private void handleInvalidLogin(ServletRequest request, ServletResponse response) throws ServletException, IOException {

                 request.setAttribute("invalidAuth", Boolean.TRUE);

                 request.getRequestDispatcher(loginPath).forward(request, response);

         }

     @Override

         public void destroy() {

             loginPath = null;

     }

 }