/**
 * 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 org.apache.activemq.shiro.subject;

import org.apache.activemq.shiro.ConnectionReference;
import org.apache.shiro.subject.Subject;

/**
 * A {@code ConnectionSubjectFactory} creates a {@code Subject} instance that represents the connection client's identity.
 * <p/>
 * Most implementations will simply use the {@link Subject.Builder Subject.Builder} to create an anonymous
 * {@code Subject} instance and let a downstream {@link org.apache.activemq.shiro.authc.AuthenticationFilter} authenticate the {@code Subject} based on
 * any credentials associated with the connection.  After authentication, the {@code Subject} will have an identity, and
 * this is the expected flow for most connection clients.
 * <p/>
 * However, if there is some other data associated with the connection that can be inspected to create a
 * {@code Subject} instance beyond what the {@link DefaultConnectionSubjectFactory} provides, this interface allows that
 * logic to be plugged in as necessary.
 *
 * @see DefaultConnectionSubjectFactory
 * @since 5.10.0
 */
public interface ConnectionSubjectFactory {

    /**
     * Creates a {@code Subject} instance representing the connection client.  It is common for {@code Subject} instances
     * returned from this method to be anonymous until a downstream {@link org.apache.activemq.shiro.authc.AuthenticationFilter} authenticates the
     * subject to associate an identity.
     *
     * @param ref a reference to the client's connection metadata
     * @return a {@code Subject} instance representing the connection client.
     */
    Subject createSubject(ConnectionReference ref);
}