/**
    * Copyright 2011-2013 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.osedu.org/licenses/ECL-2.0
    *
    * 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.mobility.security.authn.interceptors;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.log4j.Logger;
  import org.kuali.mobility.security.user.api.User;
  import org.kuali.mobility.security.authn.util.AuthenticationConstants;
  import org.kuali.mobility.security.authn.util.AuthenticationMapper;
  import org.springframework.web.servlet.HandlerInterceptor;
  import org.springframework.web.servlet.ModelAndView;
  
  /**
   * The AuthenticationInterceptor is a check against the authentication 
   * xml properties file to see if a particular URL must use authentication.  
   * If it does and there is no user in the session then it forces a 
   * redirection.  It is a backup for the SSO filters (CAS/CoSIgn/Shibboleth/etc) 
   * to protect a resource.  If you somehow got to this filter without satisfying 
   * SSO, it will step in and send you to SSO to log in.
   *
   */
  public class AuthenticationInterceptor implements HandlerInterceptor {
  
  	private static final Logger LOG = Logger.getLogger( AuthenticationInterceptor.class);
  	
  	private AuthenticationMapper authenticationMapper;
  	
  	@Override
  	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
  		User user = (User)request.getSession(true).getAttribute( AuthenticationConstants.KME_USER_KEY );
  
  		boolean passThrough = true;
  		if( getAuthenticationMapper().requiresAuthentication( request.getServletPath() ) )
  		{
  			if( user == null )
  			{
  				LOG.info( "User object not found in session.  This should not happen." );
  				doLogin( request, response );
  				passThrough=false;
  			}
  			else if( user.isPublicUser() )
  			{
  				user.setRequestURL(request.getServletPath());
  				doLogin( request, response );
  				passThrough=false;
  			}
  		}
  		return passThrough;
  	}
  
      @Override
      public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {}
  
      @Override
      public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {}
  
  	private void doLogin(HttpServletRequest request, HttpServletResponse response) throws Exception
  	{
  		if( getAuthenticationMapper().getLoginURL().startsWith( "http:" ) )
  		{
  			response.sendRedirect( getAuthenticationMapper().getLoginURL() );
  		}
  		else
  		{
  			response.sendRedirect( request.getContextPath() + getAuthenticationMapper().getLoginURL() );
  		}
  	}
  
  	public AuthenticationMapper getAuthenticationMapper() {
  		return authenticationMapper;
  	}
  
  	public void setAuthenticationMapper(AuthenticationMapper authenticationMapper) {
  		this.authenticationMapper = authenticationMapper;
  	}
  	
  }