/*
 * Copyright 2002-2020 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
 *
 *      https://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.beans.factory;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;

import org.junit.jupiter.api.Test;

import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.core.io.Resource;
import org.springframework.core.testfixture.stereotype.Component;
import org.springframework.util.Assert;

import static org.assertj.core.api.Assertions.assertThat;
import static org.springframework.core.testfixture.io.ResourceTestUtils.qualifiedResource;

/**
 * @author Rob Harrop
 * @author Juergen Hoeller
 * @author Chris Beams
 */
public class FactoryBeanTests {

	private static final Class<?> CLASS = FactoryBeanTests.class;
	private static final Resource RETURNS_NULL_CONTEXT = qualifiedResource(CLASS, "returnsNull.xml");
	private static final Resource WITH_AUTOWIRING_CONTEXT = qualifiedResource(CLASS, "withAutowiring.xml");
	private static final Resource ABSTRACT_CONTEXT = qualifiedResource(CLASS, "abstract.xml");
	private static final Resource CIRCULAR_CONTEXT = qualifiedResource(CLASS, "circular.xml");


	@Test
	public void testFactoryBeanReturnsNull() throws Exception {
		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
		new XmlBeanDefinitionReader(factory).loadBeanDefinitions(RETURNS_NULL_CONTEXT);

		assertThat(factory.getBean("factoryBean").toString()).isEqualTo("null");
	}

	@Test
	public void testFactoryBeansWithAutowiring() throws Exception {
		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
		new XmlBeanDefinitionReader(factory).loadBeanDefinitions(WITH_AUTOWIRING_CONTEXT);

		BeanFactoryPostProcessor ppc = (BeanFactoryPostProcessor) factory.getBean("propertyPlaceholderConfigurer");
		ppc.postProcessBeanFactory(factory);

		assertThat(factory.getType("betaFactory")).isNull();

		Alpha alpha = (Alpha) factory.getBean("alpha");
		Beta beta = (Beta) factory.getBean("beta");
		Gamma gamma = (Gamma) factory.getBean("gamma");
		Gamma gamma2 = (Gamma) factory.getBean("gammaFactory");

		assertThat(alpha.getBeta()).isSameAs(beta);
		assertThat(beta.getGamma()).isSameAs(gamma);
		assertThat(beta.getGamma()).isSameAs(gamma2);
		assertThat(beta.getName()).isEqualTo("yourName");
	}

	@Test
	public void testFactoryBeansWithIntermediateFactoryBeanAutowiringFailure() throws Exception {
		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
		new XmlBeanDefinitionReader(factory).loadBeanDefinitions(WITH_AUTOWIRING_CONTEXT);

		BeanFactoryPostProcessor ppc = (BeanFactoryPostProcessor) factory.getBean("propertyPlaceholderConfigurer");
		ppc.postProcessBeanFactory(factory);

		Beta beta = (Beta) factory.getBean("beta");
		Alpha alpha = (Alpha) factory.getBean("alpha");
		Gamma gamma = (Gamma) factory.getBean("gamma");
		assertThat(alpha.getBeta()).isSameAs(beta);
		assertThat(beta.getGamma()).isSameAs(gamma);
	}

	@Test
	public void testAbstractFactoryBeanViaAnnotation() throws Exception {
		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
		new XmlBeanDefinitionReader(factory).loadBeanDefinitions(ABSTRACT_CONTEXT);
		factory.getBeansWithAnnotation(Component.class);
	}

	@Test
	public void testAbstractFactoryBeanViaType() throws Exception {
		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
		new XmlBeanDefinitionReader(factory).loadBeanDefinitions(ABSTRACT_CONTEXT);
		factory.getBeansOfType(AbstractFactoryBean.class);
	}

	@Test
	public void testCircularReferenceWithPostProcessor() {
		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
		new XmlBeanDefinitionReader(factory).loadBeanDefinitions(CIRCULAR_CONTEXT);

		CountingPostProcessor counter = new CountingPostProcessor();
		factory.addBeanPostProcessor(counter);

		BeanImpl1 impl1 = factory.getBean(BeanImpl1.class);
		assertThat(impl1).isNotNull();
		assertThat(impl1.getImpl2()).isNotNull();
		assertThat(impl1.getImpl2()).isNotNull();
		assertThat(impl1.getImpl2().getImpl1()).isSameAs(impl1);
		assertThat(counter.getCount("bean1")).isEqualTo(1);
		assertThat(counter.getCount("bean2")).isEqualTo(1);
	}


	public static class NullReturningFactoryBean implements FactoryBean<Object> {

		@Override
		public Object getObject() {
			return null;
		}

		@Override
		public Class<?> getObjectType() {
			return null;
		}

		@Override
		public boolean isSingleton() {
			return true;
		}
	}


	public static class Alpha implements InitializingBean {

		private Beta beta;

		public void setBeta(Beta beta) {
			this.beta = beta;
		}

		public Beta getBeta() {
			return beta;
		}

		@Override
		public void afterPropertiesSet() {
			Assert.notNull(beta, "'beta' property is required");
		}
	}


	public static class Beta implements InitializingBean {

		private Gamma gamma;

		private String name;

		public void setGamma(Gamma gamma) {
			this.gamma = gamma;
		}

		public Gamma getGamma() {
			return gamma;
		}

		public void setName(String name) {
			this.name = name;
		}

		public String getName() {
			return name;
		}

		@Override
		public void afterPropertiesSet() {
			Assert.notNull(gamma, "'gamma' property is required");
		}
	}


	public static class Gamma {
	}


	@Component
	public static class BetaFactoryBean implements FactoryBean<Object> {

		public BetaFactoryBean(Alpha alpha) {
		}

		private Beta beta;

		public void setBeta(Beta beta) {
			this.beta = beta;
		}

		@Override
		public Object getObject() {
			return this.beta;
		}

		@Override
		public Class<?> getObjectType() {
			return null;
		}

		@Override
		public boolean isSingleton() {
			return true;
		}
	}


	public abstract static class AbstractFactoryBean implements FactoryBean<Object> {
	}


	public static class PassThroughFactoryBean<T> implements FactoryBean<T>, BeanFactoryAware {

		private Class<T> type;

		private String instanceName;

		private BeanFactory beanFactory;

		private T instance;

		public PassThroughFactoryBean(Class<T> type) {
			this.type = type;
		}

		public void setInstanceName(String instanceName) {
			this.instanceName = instanceName;
		}

		@Override
		public void setBeanFactory(BeanFactory beanFactory) {
			this.beanFactory = beanFactory;
		}

		@Override
		public T getObject() {
			if (instance == null) {
				instance = beanFactory.getBean(instanceName, type);
			}
			return instance;
		}

		@Override
		public Class<?> getObjectType() {
			return type;
		}

		@Override
		public boolean isSingleton() {
			return true;
		}
	}


	public static class CountingPostProcessor implements BeanPostProcessor {

		private final Map<String, AtomicInteger> count = new HashMap<>();

		@Override
		public Object postProcessBeforeInitialization(Object bean, String beanName) {
			return bean;
		}

		@Override
		public Object postProcessAfterInitialization(Object bean, String beanName) {
			if (bean instanceof FactoryBean) {
				return bean;
			}
			AtomicInteger c = count.get(beanName);
			if (c == null) {
				c = new AtomicInteger();
				count.put(beanName, c);
			}
			c.incrementAndGet();
			return bean;
		}

		public int getCount(String beanName) {
			AtomicInteger c = count.get(beanName);
			if (c != null) {
				return c.intValue();
			}
			else {
				return 0;
			}
		}
	}


	public static class BeanImpl1 {

		private BeanImpl2 impl2;

		public BeanImpl2 getImpl2() {
			return impl2;
		}

		public void setImpl2(BeanImpl2 impl2) {
			this.impl2 = impl2;
		}
	}


	public static class BeanImpl2 {

		private BeanImpl1 impl1;

		public BeanImpl1 getImpl1() {
			return impl1;
		}

		public void setImpl1(BeanImpl1 impl1) {
			this.impl1 = impl1;
		}
	}

}
