/*
 * Copyright 2008 the original author or authors.
 *
 * 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.springframework.ws.soap.security.callback;

import java.io.IOException;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.UnsupportedCallbackException;

/**
 * Represents a chain of <code>CallbackHandler</code>s. For each callback, each of the handlers is called in term. If a
 * handler throws a <code>UnsupportedCallbackException</code>, the next handler is tried.
 *
 * @author Arjen Poutsma
 * @since 1.5.0
 */
public class CallbackHandlerChain extends AbstractCallbackHandler {

    private final CallbackHandler[] callbackHandlers;

    public CallbackHandlerChain(CallbackHandler[] callbackHandlers) {
        this.callbackHandlers = callbackHandlers;
    }

    public CallbackHandler[] getCallbackHandlers() {
        return callbackHandlers;
    }

    protected void handleInternal(Callback callback) throws IOException, UnsupportedCallbackException {
        boolean allUnsupported = true;
        for (int i = 0; i < callbackHandlers.length; i++) {
            CallbackHandler callbackHandler = callbackHandlers[i];
            try {
                callbackHandler.handle(new Callback[]{callback});
                allUnsupported = false;
            }
            catch (UnsupportedCallbackException ex) {
                // if an UnsupportedCallbackException occurs, go to the next handler
            }
        }
        if (allUnsupported) {
            throw new UnsupportedCallbackException(callback);
        }
    }
}