/**
    * Copyright 2004-2013 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.hr;
  
  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;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.krad.web.filter.AutoLoginFilter;
  
  /**
   * 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 TestAutoLoginFilter implements Filter {
      public static final String USER_PARAM_NAME = "autouser";
      public static String OVERRIDE_ID = "";
  
      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 {
          String username = StringUtils.isBlank(OVERRIDE_ID) ? filterConfig.getInitParameter(USER_PARAM_NAME) : OVERRIDE_ID;
          if (username == null) {
              throw new IllegalStateException("the " + USER_PARAM_NAME + " param is not set");
          }
  
          chain.doFilter(new HttpServletRequestWrapper((HttpServletRequest) request) {
              @Override
              public String getRemoteUser() {
                  String username = TestAutoLoginFilter.OVERRIDE_ID;
                  if (StringUtils.isBlank(username)) {
                      username = TestAutoLoginFilter.this.filterConfig.getInitParameter(USER_PARAM_NAME);
                  }
                  return username;
              }
          }, response);
      }
  
      /** {@inheritDoc} */
      public void destroy() {
          this.filterConfig = null;
      }
  }