/*
 * 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.server.endpoint.mapping;

import java.lang.reflect.Method;
import javax.xml.namespace.QName;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.Assert;
import org.springframework.ws.WebServiceMessage;
import org.springframework.ws.context.MessageContext;
import org.springframework.ws.server.endpoint.support.PayloadRootUtils;

/**
 * Simple subclass of {@link AbstractMethodEndpointMapping} that maps from the local name of the request payload to
 * methods. Endpoint beans are registered using the {@code endpoints} property; the endpoint methods that start
 * with {@code methodPrefix} and end with {@code methodSuffix} will be registered.
 *
 * <p>Endpoints typically have the following form:
 * <pre>
 * public class MyEndpoint{
 *
 *	  public Source handleMyMessage(Source source) {
 *		 ...
 *	  }
 * }
 * </pre>
 * This method will handle any message that has the {@code MyMessage} as a payload root local name.
 *
 * @author Arjen Poutsma
 * @see #setEndpoints(Object[])
 * @since 1.0.0
 */
public class SimpleMethodEndpointMapping extends AbstractMethodEndpointMapping<String> implements InitializingBean {

	/** Default method prefix. */
	public static final String DEFAULT_METHOD_PREFIX = "handle";

	/** Default method suffix. */
	public static final String DEFAULT_METHOD_SUFFIX = "";

	private Object[] endpoints;

	private String methodPrefix = DEFAULT_METHOD_PREFIX;

	private String methodSuffix = DEFAULT_METHOD_SUFFIX;

	private TransformerFactory transformerFactory;

	public Object[] getEndpoints() {
		return endpoints;
	}

	/**
	 * Sets the endpoints. The endpoint methods that start with {@code methodPrefix} and end with
	 * {@code methodSuffix} will be registered.
	 */
	public void setEndpoints(Object[] endpoints) {
		this.endpoints = endpoints;
	}

	/** Returns the method prefix. */
	public String getMethodPrefix() {
		return methodPrefix;
	}

	/**
	 * Sets the method prefix. All methods with names starting with this string will be registered. Default is
	 * "{@code handle}".
	 *
	 * @see #DEFAULT_METHOD_PREFIX
	 */
	public void setMethodPrefix(String methodPrefix) {
		this.methodPrefix = methodPrefix;
	}

	/** Returns the method suffix. */
	public String getMethodSuffix() {
		return methodSuffix;
	}

	/**
	 * Sets the method suffix. All methods with names ending with this string will be registered. Default is "" (i.e. no
	 * suffix).
	 *
	 * @see #DEFAULT_METHOD_SUFFIX
	 */
	public void setMethodSuffix(String methodSuffix) {
		this.methodSuffix = methodSuffix;
	}

	@Override
	public final void afterPropertiesSet() throws Exception {
		Assert.notEmpty(getEndpoints(), "'endpoints' is required");
		transformerFactory = TransformerFactory.newInstance();
		for (int i = 0; i < getEndpoints().length; i++) {
			registerMethods(getEndpoints()[i]);
		}
	}

	/** Returns the name of the given method, with the prefix and suffix stripped off. */
	@Override
	protected String getLookupKeyForMethod(Method method) {
		String methodName = method.getName();
		String prefix = getMethodPrefix();
		String suffix = getMethodSuffix();
		if (methodName.startsWith(prefix) && methodName.endsWith(suffix)) {
			return methodName.substring(prefix.length(), methodName.length() - suffix.length());
		}
		else {
			return null;
		}
	}

	/** Returns the local part of the payload root element of the request. */
	@Override
	protected String getLookupKeyForMessage(MessageContext messageContext)
			throws TransformerException {
		WebServiceMessage request = messageContext.getRequest();
		QName rootQName = PayloadRootUtils.getPayloadRootQName(request.getPayloadSource(), transformerFactory);
		return rootQName.getLocalPart();
	}
}