/*
 * Copyright 2002-2012 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.context.annotation;

import java.util.LinkedHashSet;
import java.util.Set;

import org.springframework.beans.factory.annotation.AnnotatedBeanDefinition;
import org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor;
import org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanDefinitionHolder;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.util.ClassUtils;

import static org.springframework.context.annotation.MetadataUtils.*;

/**
 * Utility class that allows for convenient registration of common
 * {@link org.springframework.beans.factory.config.BeanPostProcessor} and
 * {@link org.springframework.beans.factory.config.BeanFactoryPostProcessor}
 * definitions for annotation-based configuration.
 *
 * @author Mark Fisher
 * @author Juergen Hoeller
 * @author Chris Beams
 * @since 2.5
 * @see CommonAnnotationBeanPostProcessor
 * @see org.springframework.context.annotation.ConfigurationClassPostProcessor
 * @see org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor
 * @see org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor
 * @see org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor
 */
public class AnnotationConfigUtils {

	/**
	 * The bean name of the internally managed Configuration annotation processor.
	 */
	public static final String CONFIGURATION_ANNOTATION_PROCESSOR_BEAN_NAME =
			"org.springframework.context.annotation.internalConfigurationAnnotationProcessor";

	/**
	 * The bean name of the internally managed BeanNameGenerator for use when processing
	 * {@link Configuration} classes. Set by {@link AnnotationConfigApplicationContext}
	 * and {@code AnnotationConfigWebApplicationContext} during bootstrap in order to make
	 * any custom name generation strategy available to the underlying
	 * {@link ConfigurationClassPostProcessor}.
	 * @since 3.1.1
	 */
	public static final String CONFIGURATION_BEAN_NAME_GENERATOR =
			"org.springframework.context.annotation.internalConfigurationBeanNameGenerator";

	/**
	 * The bean name of the internally managed Autowired annotation processor.
	 */
	public static final String AUTOWIRED_ANNOTATION_PROCESSOR_BEAN_NAME =
			"org.springframework.context.annotation.internalAutowiredAnnotationProcessor";

	/**
	 * The bean name of the internally managed Required annotation processor.
	 */
	public static final String REQUIRED_ANNOTATION_PROCESSOR_BEAN_NAME =
			"org.springframework.context.annotation.internalRequiredAnnotationProcessor";

	/**
	 * The bean name of the internally managed JSR-250 annotation processor.
	 */
	public static final String COMMON_ANNOTATION_PROCESSOR_BEAN_NAME =
			"org.springframework.context.annotation.internalCommonAnnotationProcessor";

	/**
	 * The bean name of the internally managed Scheduled annotation processor.
	 */
	public static final String SCHEDULED_ANNOTATION_PROCESSOR_BEAN_NAME =
			"org.springframework.context.annotation.internalScheduledAnnotationProcessor";

	/**
	 * The bean name of the internally managed Async annotation processor.
	 */
	public static final String ASYNC_ANNOTATION_PROCESSOR_BEAN_NAME =
			"org.springframework.context.annotation.internalAsyncAnnotationProcessor";

	/**
	 * The bean name of the internally managed AspectJ async execution aspect.
	 */
	public static final String ASYNC_EXECUTION_ASPECT_BEAN_NAME =
			"org.springframework.scheduling.config.internalAsyncExecutionAspect";

	/**
	 * The class name of the AspectJ async execution aspect.
	 */
	public static final String ASYNC_EXECUTION_ASPECT_CLASS_NAME =
			"org.springframework.scheduling.aspectj.AnnotationAsyncExecutionAspect";

	/**
	 * The name of the AspectJ async execution aspect @{@code Configuration} class.
	 */
	public static final String ASYNC_EXECUTION_ASPECT_CONFIGURATION_CLASS_NAME =
			"org.springframework.scheduling.aspectj.AspectJAsyncConfiguration";

	/**
	 * The bean name of the internally managed cache advisor.
	 */
	public static final String CACHE_ADVISOR_BEAN_NAME =
			"org.springframework.cache.config.internalCacheAdvisor";

	/**
	 * The bean name of the internally managed cache aspect.
	 */
	public static final String CACHE_ASPECT_BEAN_NAME =
			"org.springframework.cache.config.internalCacheAspect";

	/**
	 * The class name of the AspectJ caching aspect.
	 */
	public static final String CACHE_ASPECT_CLASS_NAME =
			"org.springframework.cache.aspectj.AnnotationCacheAspect";

	/**
	 * The name of the AspectJ caching aspect @{@code Configuration} class.
	 */
	public static final String CACHE_ASPECT_CONFIGURATION_CLASS_NAME =
			"org.springframework.cache.aspectj.AspectJCachingConfiguration";

	/**
	 * The bean name of the internally managed JPA annotation processor.
	 */
	public static final String PERSISTENCE_ANNOTATION_PROCESSOR_BEAN_NAME =
			"org.springframework.context.annotation.internalPersistenceAnnotationProcessor";


	private static final String PERSISTENCE_ANNOTATION_PROCESSOR_CLASS_NAME =
			"org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor";


	private static final boolean jsr250Present =
			ClassUtils.isPresent("javax.annotation.Resource", AnnotationConfigUtils.class.getClassLoader());

	private static final boolean jpaPresent =
			ClassUtils.isPresent("javax.persistence.EntityManagerFactory", AnnotationConfigUtils.class.getClassLoader()) &&
			ClassUtils.isPresent(PERSISTENCE_ANNOTATION_PROCESSOR_CLASS_NAME, AnnotationConfigUtils.class.getClassLoader());


	/**
	 * Register all relevant annotation post processors in the given registry.
	 * @param registry the registry to operate on
	 */
	public static void registerAnnotationConfigProcessors(BeanDefinitionRegistry registry) {
		registerAnnotationConfigProcessors(registry, null);
	}

	/**
	 * Register all relevant annotation post processors in the given registry.
	 * @param registry the registry to operate on
	 * @param source the configuration source element (already extracted)
	 * that this registration was triggered from. May be <code>null</code>.
	 * @return a Set of BeanDefinitionHolders, containing all bean definitions
	 * that have actually been registered by this call
	 */
	public static Set<BeanDefinitionHolder> registerAnnotationConfigProcessors(
			BeanDefinitionRegistry registry, Object source) {

		Set<BeanDefinitionHolder> beanDefs = new LinkedHashSet<BeanDefinitionHolder>(4);

		if (!registry.containsBeanDefinition(CONFIGURATION_ANNOTATION_PROCESSOR_BEAN_NAME)) {
			RootBeanDefinition def = new RootBeanDefinition(ConfigurationClassPostProcessor.class);
			def.setSource(source);
			beanDefs.add(registerPostProcessor(registry, def, CONFIGURATION_ANNOTATION_PROCESSOR_BEAN_NAME));
		}

		if (!registry.containsBeanDefinition(AUTOWIRED_ANNOTATION_PROCESSOR_BEAN_NAME)) {
			RootBeanDefinition def = new RootBeanDefinition(AutowiredAnnotationBeanPostProcessor.class);
			def.setSource(source);
			beanDefs.add(registerPostProcessor(registry, def, AUTOWIRED_ANNOTATION_PROCESSOR_BEAN_NAME));
		}

		if (!registry.containsBeanDefinition(REQUIRED_ANNOTATION_PROCESSOR_BEAN_NAME)) {
			RootBeanDefinition def = new RootBeanDefinition(RequiredAnnotationBeanPostProcessor.class);
			def.setSource(source);
			beanDefs.add(registerPostProcessor(registry, def, REQUIRED_ANNOTATION_PROCESSOR_BEAN_NAME));
		}

		// Check for JSR-250 support, and if present add the CommonAnnotationBeanPostProcessor.
		if (jsr250Present && !registry.containsBeanDefinition(COMMON_ANNOTATION_PROCESSOR_BEAN_NAME)) {
			RootBeanDefinition def = new RootBeanDefinition(CommonAnnotationBeanPostProcessor.class);
			def.setSource(source);
			beanDefs.add(registerPostProcessor(registry, def, COMMON_ANNOTATION_PROCESSOR_BEAN_NAME));
		}

		// Check for JPA support, and if present add the PersistenceAnnotationBeanPostProcessor.
		if (jpaPresent && !registry.containsBeanDefinition(PERSISTENCE_ANNOTATION_PROCESSOR_BEAN_NAME)) {
			RootBeanDefinition def = new RootBeanDefinition();
			try {
				ClassLoader cl = AnnotationConfigUtils.class.getClassLoader();
				def.setBeanClass(cl.loadClass(PERSISTENCE_ANNOTATION_PROCESSOR_CLASS_NAME));
			}
			catch (ClassNotFoundException ex) {
				throw new IllegalStateException(
						"Cannot load optional framework class: " + PERSISTENCE_ANNOTATION_PROCESSOR_CLASS_NAME, ex);
			}
			def.setSource(source);
			beanDefs.add(registerPostProcessor(registry, def, PERSISTENCE_ANNOTATION_PROCESSOR_BEAN_NAME));
		}

		return beanDefs;
	}

	private static BeanDefinitionHolder registerPostProcessor(
			BeanDefinitionRegistry registry, RootBeanDefinition definition, String beanName) {

		definition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
		registry.registerBeanDefinition(beanName, definition);
		return new BeanDefinitionHolder(definition, beanName);
	}

	static void processCommonDefinitionAnnotations(AnnotatedBeanDefinition abd) {
		AnnotationMetadata metadata = abd.getMetadata();
		if (metadata.isAnnotated(Primary.class.getName())) {
			abd.setPrimary(true);
		}
		if (metadata.isAnnotated(Lazy.class.getName())) {
			abd.setLazyInit(attributesFor(metadata, Lazy.class).getBoolean("value"));
		}
		if (metadata.isAnnotated(DependsOn.class.getName())) {
			abd.setDependsOn(attributesFor(metadata, DependsOn.class).getStringArray("value"));
		}
		if (abd instanceof AbstractBeanDefinition) {
			if (metadata.isAnnotated(Role.class.getName())) {
				Integer role = attributesFor(metadata, Role.class).getNumber("value");
				((AbstractBeanDefinition)abd).setRole(role);
			}
		}
	}

	static BeanDefinitionHolder applyScopedProxyMode(
			ScopeMetadata metadata, BeanDefinitionHolder definition, BeanDefinitionRegistry registry) {

		ScopedProxyMode scopedProxyMode = metadata.getScopedProxyMode();
		if (scopedProxyMode.equals(ScopedProxyMode.NO)) {
			return definition;
		}
		boolean proxyTargetClass = scopedProxyMode.equals(ScopedProxyMode.TARGET_CLASS);
		return ScopedProxyCreator.createScopedProxy(definition, registry, proxyTargetClass);
	}


}
