/**
    * Copyright 2010 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.student.security.kim;
  
  import org.kuali.student.security.spring.KSRiceDefaultUserDetailsService;
  
  import org.springframework.dao.DataAccessException;
  import org.springframework.security.authentication.AuthenticationProvider;
  import org.springframework.security.authentication.AuthenticationServiceException;
  import org.springframework.security.authentication.BadCredentialsException;
  import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
  import org.springframework.security.authentication.dao.AbstractUserDetailsAuthenticationProvider;
  import org.springframework.security.authentication.dao.DaoAuthenticationProvider;
  import org.springframework.security.authentication.dao.SaltSource;
  import org.springframework.security.authentication.encoding.PasswordEncoder;
  import org.springframework.security.authentication.encoding.PlaintextPasswordEncoder;
  import org.springframework.security.core.AuthenticationException;
  import org.springframework.security.core.userdetails.UserDetails;
  import org.springframework.security.core.userdetails.UserDetailsService;
  import org.springframework.util.Assert;
  
  
  /**
   * An {@link AuthenticationProvider} implementation that retrieves user details
   * from an {@link UserDetailsService}. Slightly modified from {@link DaoAuthenticationProvider}
   * 
   * @author Kuali Student Team
   *
   */
  public class KimAuthenticationProvider extends AbstractUserDetailsAuthenticationProvider {
      
      //~ Instance fields ================================================================================================
  
      private PasswordEncoder passwordEncoder = new PlaintextPasswordEncoder();
  
      private SaltSource saltSource;
  
      private UserDetailsService userDetailsService;
  
      private boolean includeDetailsObject = true;
  
      //~ Methods ========================================================================================================
  
      protected void additionalAuthenticationChecks(UserDetails userDetails,
              UsernamePasswordAuthenticationToken authentication) throws AuthenticationException {
          Object salt = null;
          if (this.saltSource != null) {
              salt = this.saltSource.getSalt(userDetails);
          }
  
          if (authentication.getCredentials() == null) {
              throw new BadCredentialsException(messages.getMessage(
                      "AbstractUserDetailsAuthenticationProvider.badCredentials", "Bad credentials"),
                      includeDetailsObject ? userDetails : null);
          }
  
          String presentedPassword = authentication.getCredentials().toString();
  
          if (!passwordEncoder.isPasswordValid(userDetails.getPassword(), presentedPassword, salt)) {
              throw new BadCredentialsException(messages.getMessage(
                      "AbstractUserDetailsAuthenticationProvider.badCredentials", "Bad credentials"),
                      includeDetailsObject ? userDetails : null);
          }
      }
  
      protected void doAfterPropertiesSet() throws Exception {
          Assert.notNull(this.userDetailsService, "A UserDetailsService must be set");
      }
  
      protected final UserDetails retrieveUser(String username, UsernamePasswordAuthenticationToken authentication)
              throws AuthenticationException {
          UserDetails loadedUser;
  
          UserDetailsService ksRiceDefaultUserDetailsService = this.getUserDetailsService();
          if(!(ksRiceDefaultUserDetailsService instanceof KSRiceDefaultUserDetailsService)){
              throw new AuthenticationServiceException(
                  "UserDetailsService is not an an instance of KSRiceDefaultUserDetailsService");
          }
          
          try {
              //loadedUser = this.getUserDetailsService().loadUserByUsername(username);
              loadedUser = ((KSRiceDefaultUserDetailsService)ksRiceDefaultUserDetailsService).loadUserByUsernameAndToken(username, authentication);
          }
          catch (DataAccessException repositoryProblem) {
              throw new AuthenticationServiceException(repositoryProblem.getMessage(), repositoryProblem);
          }
 
         if (loadedUser == null) {
             throw new AuthenticationServiceException(
                     "UserDetailsService returned null, which is an interface contract violation");
         }
         return loadedUser;
     }
 
     /**
      * Sets the PasswordEncoder instance to be used to encode and validate passwords.
      * If not set, {@link PlaintextPasswordEncoder} will be used by default.
      *
      * @param passwordEncoder The passwordEncoder to use
      */
     public void setPasswordEncoder(PasswordEncoder passwordEncoder) {
         this.passwordEncoder = passwordEncoder;
     }
 
     protected PasswordEncoder getPasswordEncoder() {
         return passwordEncoder;
     }
 
     /**
      * The source of salts to use when decoding passwords. <code>null</code>
      * is a valid value, meaning the <code>DaoAuthenticationProvider</code>
      * will present <code>null</code> to the relevant <code>PasswordEncoder</code>.
      *
      * @param saltSource to use when attempting to decode passwords via the <code>PasswordEncoder</code>
      */
     public void setSaltSource(SaltSource saltSource) {
         this.saltSource = saltSource;
     }
 
     protected SaltSource getSaltSource() {
         return saltSource;
     }
 
     public void setUserDetailsService(UserDetailsService userDetailsService) {
         this.userDetailsService = userDetailsService;
     }
 
     protected UserDetailsService getUserDetailsService() {
         return userDetailsService;
     }
 
     protected boolean isIncludeDetailsObject() {
         return includeDetailsObject;
     }
 }