/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 jakarta.security.auth.message;

import javax.security.auth.Subject;

/**
 * Provides server-side authentication of requests and response signing.
 * <p>
 * This interface defines the contract for authenticating incoming requests
 * and optionally securing outgoing responses in a server-side context.
 * Implementations are typically obtained through a {@link jakarta.security.auth.message.config.ServerAuthContext}.
 */
public interface ServerAuth {

    /**
     * Validate the request.
     *
     * @param messageInfo    The associated request and response
     * @param clientSubject  The subject that represents the source of the request
     * @param serviceSubject The subject that represents the recipient of the request
     *
     * @return An AuthStatus instance that represents the result of the validation
     *
     * @throws AuthException If a failure occurred in a manner that prevented the failure from being communicated via
     *                           messageInfo
     */
    AuthStatus validateRequest(MessageInfo messageInfo, Subject clientSubject, Subject serviceSubject)
            throws AuthException;

    /**
     * Secure (authenticate) the response.
     *
     * @param messageInfo    The associated request and response
     * @param serviceSubject The subject that represents the source of the response
     *
     * @return An AuthStatus instance that represents the result of the authentication
     *
     * @throws AuthException If a failure occurred in a manner that prevented the failure from being communicated via
     *                           messageInfo
     */
    default AuthStatus secureResponse(MessageInfo messageInfo, Subject serviceSubject) throws AuthException {
        return AuthStatus.SUCCESS;
    }

    /**
     * Remove principals and/or credentials from the subject that were previously added by this authentication
     * mechanism.
     *
     * @param messageInfo The associated request and response
     * @param subject     The subject to clean
     *
     * @throws AuthException If a failure occurred
     */
    default void cleanSubject(MessageInfo messageInfo, Subject subject) throws AuthException {
        // NO-OP
    }
}