/*
    * Copyright 2013–2021 Michael Osipov
    *
    * Licensed under the Apache 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.apache.org/licenses/LICENSE-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 net.sf.michaelo.tomcat.realm;
  
  import java.security.Principal;
  import java.security.cert.X509Certificate;
  
  import org.apache.catalina.realm.RealmBase;
  import org.apache.juli.logging.Log;
  import org.apache.juli.logging.LogFactory;
  import org.apache.tomcat.util.res.StringManager;
  import org.ietf.jgss.GSSContext;
  import org.ietf.jgss.GSSName;
  
  /**
   * Base realm which is able to retrieve principals from {@link GSSName GSS names}, fully
   * established {@link GSSContext GSS contexts} or {@link X509Certificate TLS client certificates}.
   */
  public abstract class ActiveDirectoryRealmBase extends RealmBase {
  
  	protected final Log logger = LogFactory.getLog(getClass());
  	protected final StringManager sm = StringManager.getManager(getClass());
  
  	/**
  	 * @return Always {@code null} as this realm has no way of obtaining this
  	 * information.
  	 */
  	@Override
  	protected String getPassword(String username) {
  		// Always return null
  		return null;
  	}
  
  	/**
  	 * @throws UnsupportedOperationException
  	 *             always throws because not implemented
  	 */
  	@Override
  	protected Principal getPrincipal(String username) {
  		throw new UnsupportedOperationException(
  				"getPrincipal(String) is not supported by this realm");
  	}
  
  	@Override
  	protected boolean hasRoleInternal(Principal principal, String role) {
  		if (!(principal instanceof ActiveDirectoryPrincipal))
  			return false;
  
  		ActiveDirectoryPrincipal adp = (ActiveDirectoryPrincipal) principal;
  		return adp.hasRole(role);
  	}
  
  	@Override
  	public String[] getRoles(Principal principal) {
  		if (principal instanceof ActiveDirectoryPrincipal) {
  			return ((ActiveDirectoryPrincipal) principal).getRoles();
  		}
  
  		String className = principal.getClass().getName();
  		throw new IllegalStateException(sm.getString("activeDirectoryRealmBase.cannotGetRoles",
  				principal.getName(), className));
  	}
  
  }