/*
 * Copyright 2002-2019 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.test.context.junit4.hybrid;

import org.springframework.beans.factory.support.BeanDefinitionReader;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.annotation.AnnotatedBeanDefinitionReader;
import org.springframework.context.support.GenericApplicationContext;
import org.springframework.test.context.ContextConfigurationAttributes;
import org.springframework.test.context.MergedContextConfiguration;
import org.springframework.test.context.SmartContextLoader;
import org.springframework.test.context.support.AbstractGenericContextLoader;
import org.springframework.util.Assert;

import static org.springframework.test.context.support.AnnotationConfigContextLoaderUtils.detectDefaultConfigurationClasses;

/**
 * Hybrid {@link SmartContextLoader} that supports path-based and class-based
 * resources simultaneously.
 * <p>This test loader is inspired by Spring Boot.
 * <p>Detects defaults for XML configuration and annotated classes.
 * <p>Beans from XML configuration always override those from annotated classes.
 *
 * @author Sam Brannen
 * @since 4.0.4
 */
public class HybridContextLoader extends AbstractGenericContextLoader {

	@Override
	protected void validateMergedContextConfiguration(MergedContextConfiguration mergedConfig) {
		Assert.isTrue(mergedConfig.hasClasses() || mergedConfig.hasLocations(), getClass().getSimpleName()
				+ " requires either classes or locations");
	}

	@Override
	public void processContextConfiguration(ContextConfigurationAttributes configAttributes) {
		// Detect default XML configuration files:
		super.processContextConfiguration(configAttributes);

		// Detect default configuration classes:
		if (!configAttributes.hasClasses() && isGenerateDefaultLocations()) {
			configAttributes.setClasses(detectDefaultConfigurationClasses(configAttributes.getDeclaringClass()));
		}
	}

	@Override
	protected void loadBeanDefinitions(GenericApplicationContext context, MergedContextConfiguration mergedConfig) {
		// Order doesn't matter: <bean> always wins over @Bean.
		new XmlBeanDefinitionReader(context).loadBeanDefinitions(mergedConfig.getLocations());
		new AnnotatedBeanDefinitionReader(context).register(mergedConfig.getClasses());
	}

	@Override
	protected BeanDefinitionReader createBeanDefinitionReader(GenericApplicationContext context) {
		throw new UnsupportedOperationException(getClass().getSimpleName() + " doesn't support this");
	}

	@Override
	protected String getResourceSuffix() {
		return "-context.xml";
	}

}
