/*
 * Copyright 2012 LinkedIn, Inc
 * 
 * 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 azkaban.user;

/**
 * Interface for the UserManager. Implementors will have to handle the retrieval
 * of the User object given the username and password.
 * 
 * The constructor will be called with a azkaban.utils.Props object passed as the only
 * parameter. If such a constructor doesn't exist, than the UserManager instantiation may
 * fail.
 */
public interface UserManager {
	/**
	 * Retrieves the user given the username and password to authenticate against.
	 * 
	 * @param username
	 * @param password
	 * @return
	 * @throws UserManagerException If the username/password combination doesn't exist.
	 */
	public User getUser(String username, String password) throws UserManagerException;
	
	/**
	 * Returns true if the user is valid. This is used when adding permissions for users
	 * 
	 * @param username
	 * @return
	 */
	public boolean validateUser(String username);

	/**
	 * Returns true if the group is valid. This is used when adding permissions for groups.
	 * 
	 * @param group
	 * @return
	 */
	public boolean validateGroup(String group);
	
	/**
	 * Returns the user role. This may return null.
	 * 
	 * @param roleName
	 * @return
	 */
	public Role getRole(String roleName);
}
