/**

  * 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.krad.web.filter;

 import java.io.IOException;

 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;

 /**

  * Automatically logs in with the user specified via filter init parameter {@link AutoLoginFilter#USER_PARAM_NAME}.

  * <p>

  * There are no guarantees made that the user specified is a valid user in the system.

  * </p>

  * <p>

  * In rice this Filter can be used via config like that following assuming the bootstrap filter is used: <br />

  * {@code <param name="filter.login.class">org.kuali.kra.test.infrastructure.AutoLoginFilter</param>} <br />

  * {@code <param name="filtermapping.login.1">/*</param>} <br />

  * {@code <param name="filter.login.autouser">admin</param>} <br />

  * </p>

  */

 public class AutoLoginFilter implements Filter {

         public static final String USER_PARAM_NAME = "autouser";

         private FilterConfig filterConfig;

         /** {@inheritDoc} */

         public void init(FilterConfig config) throws ServletException {

             this.filterConfig = config;

         }

         /** {@inheritDoc} */

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

                 if (filterConfig.getInitParameter(USER_PARAM_NAME) == null) {

                     throw new IllegalStateException("the " + USER_PARAM_NAME + " param is not set");

                 }

             chain.doFilter(new HttpServletRequestWrapper((HttpServletRequest) request) {

             @Override

             public String getRemoteUser() {

                 return AutoLoginFilter.this.filterConfig.getInitParameter(USER_PARAM_NAME);

             }

         }, response);

         }

         /** {@inheritDoc} */

         public void destroy() {

             this.filterConfig = null;

         }

 }