/*
 * Copyright 2004-present 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.security.core.annotation;

import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Method;
import java.lang.reflect.Parameter;

import org.jspecify.annotations.Nullable;

import org.springframework.core.annotation.MergedAnnotation;
import org.springframework.util.Assert;

/**
 * An abstract class to hide the {@link MergedAnnotation} implementation details.
 *
 * <p>
 * Also handy for allowing each scanner to delegate to another without needing to
 * synthesize twice.
 */
abstract class AbstractSecurityAnnotationScanner<A extends Annotation> implements SecurityAnnotationScanner<A> {

	/**
	 * {@inheritDoc}
	 **/
	@Override
	public @Nullable A scan(Method method, Class<?> targetClass) {
		Assert.notNull(targetClass, "targetClass cannot be null");
		MergedAnnotation<A> annotation = merge(method, targetClass);
		if (annotation == null) {
			return null;
		}
		return annotation.synthesize();
	}

	/**
	 * {@inheritDoc}
	 **/
	@Override
	public @Nullable A scan(Parameter parameter) {
		MergedAnnotation<A> annotation = merge(parameter, null);
		if (annotation == null) {
			return null;
		}
		return annotation.synthesize();
	}

	abstract @Nullable MergedAnnotation<A> merge(AnnotatedElement element, @Nullable Class<?> targetClass);

}
