/*
 * Copyright 2002-2016 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.security.config.method;

import org.springframework.aop.config.AbstractInterceptorDrivenBeanDefinitionDecorator;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanDefinitionHolder;
import org.springframework.beans.factory.config.RuntimeBeanReference;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.ManagedMap;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.beans.factory.xml.BeanDefinitionDecorator;
import org.springframework.beans.factory.xml.ParserContext;
import org.springframework.security.access.SecurityConfig;
import org.springframework.security.access.intercept.aopalliance.MethodSecurityInterceptor;
import org.springframework.security.access.method.MapBasedMethodSecurityMetadataSource;
import org.springframework.security.config.BeanIds;
import org.springframework.security.config.Elements;
import org.springframework.util.StringUtils;
import org.springframework.util.xml.DomUtils;
import org.w3c.dom.Element;
import org.w3c.dom.Node;

import java.util.*;

/**
 * @author Luke Taylor
 * @author Ben Alex
 *
 */
public class InterceptMethodsBeanDefinitionDecorator implements BeanDefinitionDecorator {
	private final BeanDefinitionDecorator delegate = new InternalInterceptMethodsBeanDefinitionDecorator();

	public BeanDefinitionHolder decorate(Node node, BeanDefinitionHolder definition,
			ParserContext parserContext) {
		MethodConfigUtils.registerDefaultMethodAccessManagerIfNecessary(parserContext);

		return delegate.decorate(node, definition, parserContext);
	}
}

/**
 * This is the real class which does the work. We need access to the ParserContext in
 * order to do bean registration.
 */
class InternalInterceptMethodsBeanDefinitionDecorator extends
		AbstractInterceptorDrivenBeanDefinitionDecorator {
	static final String ATT_METHOD = "method";
	static final String ATT_ACCESS = "access";
	private static final String ATT_ACCESS_MGR = "access-decision-manager-ref";

	protected BeanDefinition createInterceptorDefinition(Node node) {
		Element interceptMethodsElt = (Element) node;
		BeanDefinitionBuilder interceptor = BeanDefinitionBuilder
				.rootBeanDefinition(MethodSecurityInterceptor.class);

		// Default to autowiring to pick up after invocation mgr
		interceptor.setAutowireMode(RootBeanDefinition.AUTOWIRE_BY_TYPE);

		String accessManagerId = interceptMethodsElt.getAttribute(ATT_ACCESS_MGR);

		if (!StringUtils.hasText(accessManagerId)) {
			accessManagerId = BeanIds.METHOD_ACCESS_MANAGER;
		}

		interceptor.addPropertyValue("accessDecisionManager", new RuntimeBeanReference(
				accessManagerId));
		interceptor.addPropertyValue("authenticationManager", new RuntimeBeanReference(
				BeanIds.AUTHENTICATION_MANAGER));

		// Lookup parent bean information

		String parentBeanClass = ((Element) node.getParentNode()).getAttribute("class");

		// Parse the included methods
		List<Element> methods = DomUtils.getChildElementsByTagName(interceptMethodsElt,
				Elements.PROTECT);
		Map<String, BeanDefinition> mappings = new ManagedMap<String, BeanDefinition>();

		for (Element protectmethodElt : methods) {
			BeanDefinitionBuilder attributeBuilder = BeanDefinitionBuilder
					.rootBeanDefinition(SecurityConfig.class);
			attributeBuilder.setFactoryMethod("createListFromCommaDelimitedString");
			attributeBuilder.addConstructorArgValue(protectmethodElt
					.getAttribute(ATT_ACCESS));

			// Support inference of class names
			String methodName = protectmethodElt.getAttribute(ATT_METHOD);

			if (methodName.lastIndexOf(".") == -1) {
				if (parentBeanClass != null && !"".equals(parentBeanClass)) {
					methodName = parentBeanClass + "." + methodName;
				}
			}

			mappings.put(methodName, attributeBuilder.getBeanDefinition());
		}

		BeanDefinition metadataSource = new RootBeanDefinition(
				MapBasedMethodSecurityMetadataSource.class);
		metadataSource.getConstructorArgumentValues().addGenericArgumentValue(mappings);
		interceptor.addPropertyValue("securityMetadataSource", metadataSource);

		return interceptor.getBeanDefinition();
	}
}
