/*
 * Copyright 2012-2019 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.boot.context;

import java.io.IOException;
import java.util.Collection;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.MetadataReaderFactory;
import org.springframework.core.type.filter.TypeFilter;

Provides exclusion TypeFilters that are loaded from the BeanFactory and automatically applied to SpringBootApplication scanning. Can also be used directly with @ComponentScan as follows: 
@ComponentScan(excludeFilters = @Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class))

 Implementations should provide a subclass registered with BeanFactory and override the match(MetadataReader, MetadataReaderFactory) method. They should also implement a valid hashCode and equals methods so that they can be used as part of Spring test's application context caches. 
 Note that TypeExcludeFilters are initialized very early in the application lifecycle, they should generally not have dependencies on any other beans. They are primarily used internally to support spring-boot-test. 
Author:
Phillip Webb
Since:
1.4.0/**
 * Provides exclusion {@link TypeFilter TypeFilters} that are loaded from the
 * {@link BeanFactory} and automatically applied to {@code SpringBootApplication}
 * scanning. Can also be used directly with {@code @ComponentScan} as follows:
 * <pre class="code">
 * &#064;ComponentScan(excludeFilters = @Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class))
 * </pre>
 * <p>
 * Implementations should provide a subclass registered with {@link BeanFactory} and
 * override the {@link #match(MetadataReader, MetadataReaderFactory)} method. They should
 * also implement a valid {@link #hashCode() hashCode} and {@link #equals(Object) equals}
 * methods so that they can be used as part of Spring test's application context caches.
 * <p>
 * Note that {@code TypeExcludeFilters} are initialized very early in the application
 * lifecycle, they should generally not have dependencies on any other beans. They are
 * primarily used internally to support {@code spring-boot-test}.
 *
 * @author Phillip Webb
 * @since 1.4.0
 */
public class TypeExcludeFilter implements TypeFilter, BeanFactoryAware {

	private BeanFactory beanFactory;

	private Collection<TypeExcludeFilter> delegates;

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

	@Override
	public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory)
			throws IOException {
		if (this.beanFactory instanceof ListableBeanFactory && getClass() == TypeExcludeFilter.class) {
			for (TypeExcludeFilter delegate : getDelegates()) {
				if (delegate.match(metadataReader, metadataReaderFactory)) {
					return true;
				}
			}
		}
		return false;
	}

	private Collection<TypeExcludeFilter> getDelegates() {
		Collection<TypeExcludeFilter> delegates = this.delegates;
		if (delegates == null) {
			delegates = ((ListableBeanFactory) this.beanFactory).getBeansOfType(TypeExcludeFilter.class).values();
			this.delegates = delegates;
		}
		return delegates;
	}

	@Override
	public boolean equals(Object obj) {
		throw new IllegalStateException("TypeExcludeFilter " + getClass() + " has not implemented equals");
	}

	@Override
	public int hashCode() {
		throw new IllegalStateException("TypeExcludeFilter " + getClass() + " has not implemented hashCode");
	}

}