/**
 * Copyright 2007-2016, Kaazing Corporation. All rights reserved.
 *
 * 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 org.kaazing.gateway.security.auth;

import java.io.IOException;
import java.util.function.Function;

import javax.security.auth.Subject;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.UnsupportedCallbackException;

import org.kaazing.gateway.server.spi.security.NamedSubjectCallback;

public class NamedSubjectCallbackHandler implements CallbackHandler {

	private final Function<String, Subject> subjects;

    public NamedSubjectCallbackHandler(Function<String, Subject> subjects) {
        this.subjects = subjects;
    }

    @Override
    public void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException {
            for (Callback callback : callbacks) {
                if (callback instanceof NamedSubjectCallback) {
                    NamedSubjectCallback subjectCB = (NamedSubjectCallback) callback;
					String realm = subjectCB.getName();
					subjectCB.setSubject(subjects.apply(realm));
                } else {
                    throw new UnsupportedCallbackException(callback);
                }
            }
    }
}
