/*
 * Copyright 2005-2014 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.xwss.callback;

import java.io.IOException;
import java.security.cert.X509Certificate;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.UnsupportedCallbackException;

import com.sun.xml.wss.impl.callback.CertificateValidationCallback;
import com.sun.xml.wss.impl.callback.PasswordValidationCallback;
import com.sun.xml.wss.impl.callback.TimestampValidationCallback;

import org.springframework.ws.soap.security.callback.CallbackHandlerChain;

/**
 * Represents a chain of {@code CallbackHandler}s. For each callback, each of the handlers is called in term. If a
 * handler throws a {@code UnsupportedCallbackException}, the next handler is tried.
 *
 * @author Arjen Poutsma
 * @since 1.0.0
 */
public class XwssCallbackHandlerChain extends CallbackHandlerChain {

	public XwssCallbackHandlerChain(CallbackHandler[] callbackHandlers) {
		super(callbackHandlers);
	}

	@Override
	protected void handleInternal(Callback callback) throws IOException, UnsupportedCallbackException {
		if (callback instanceof CertificateValidationCallback) {
			handleCertificateValidationCallback((CertificateValidationCallback) callback);
		}
		else if (callback instanceof PasswordValidationCallback) {
			handlePasswordValidationCallback((PasswordValidationCallback) callback);
		}
		else if (callback instanceof TimestampValidationCallback) {
			handleTimestampValidationCallback((TimestampValidationCallback) callback);
		}
		else {
			super.handleInternal(callback);
		}
	}

	private void handleCertificateValidationCallback(CertificateValidationCallback callback) {
		callback.setValidator(new CertificateValidatorChain(callback));
	}

	private void handlePasswordValidationCallback(PasswordValidationCallback callback) {
		callback.setValidator(new PasswordValidatorChain(callback));
	}

	private void handleTimestampValidationCallback(TimestampValidationCallback callback) {
		callback.setValidator(new TimestampValidatorChain(callback));
	}

	private class TimestampValidatorChain implements TimestampValidationCallback.TimestampValidator {

		private TimestampValidationCallback callback;

		private TimestampValidatorChain(TimestampValidationCallback callback) {
			this.callback = callback;
		}

		@Override
		public void validate(TimestampValidationCallback.Request request)
				throws TimestampValidationCallback.TimestampValidationException {
			for (int i = 0; i < getCallbackHandlers().length; i++) {
				CallbackHandler callbackHandler = getCallbackHandlers()[i];
				try {
					callbackHandler.handle(new Callback[]{callback});
					callback.getResult();
				}
				catch (IOException e) {
					throw new TimestampValidationCallback.TimestampValidationException(e);
				}
				catch (UnsupportedCallbackException e) {
					// ignore
				}
			}
		}
	}

	private class PasswordValidatorChain implements PasswordValidationCallback.PasswordValidator {

		private PasswordValidationCallback callback;

		private PasswordValidatorChain(PasswordValidationCallback callback) {
			this.callback = callback;
		}

		@Override
		public boolean validate(PasswordValidationCallback.Request request)
				throws PasswordValidationCallback.PasswordValidationException {
			boolean allUnsupported = true;
			for (int i = 0; i < getCallbackHandlers().length; i++) {
				CallbackHandler callbackHandler = getCallbackHandlers()[i];
				try {
					callbackHandler.handle(new Callback[]{callback});
					allUnsupported = false;
					if (!callback.getResult()) {
						return false;
					}
				}
				catch (IOException e) {
					throw new PasswordValidationCallback.PasswordValidationException(e);
				}
				catch (UnsupportedCallbackException e) {
					// ignore
				}
			}
			return !allUnsupported;
		}
	}

	private class CertificateValidatorChain implements CertificateValidationCallback.CertificateValidator {

		private CertificateValidationCallback callback;

		private CertificateValidatorChain(CertificateValidationCallback callback) {
			this.callback = callback;
		}

		@Override
		public boolean validate(X509Certificate certificate)
				throws CertificateValidationCallback.CertificateValidationException {
			boolean allUnsupported = true;
			for (int i = 0; i < getCallbackHandlers().length; i++) {
				CallbackHandler callbackHandler = getCallbackHandlers()[i];
				try {
					callbackHandler.handle(new Callback[]{callback});
					allUnsupported = false;
					if (!callback.getResult()) {
						return false;
					}
				}
				catch (IOException e) {
					throw new CertificateValidationCallback.CertificateValidationException(e);
				}
				catch (UnsupportedCallbackException e) {
					// ignore
				}
			}
			return !allUnsupported;
		}
	}
}