/*
 * Copyright 2013-2020 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.data.repository.support;

import static org.springframework.data.util.Optionals.*;

import java.util.Map;
import java.util.Optional;
import java.util.concurrent.ConcurrentHashMap;

import org.springframework.core.convert.ConversionService;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.data.repository.core.RepositoryInformation;
import org.springframework.format.support.DefaultFormattingConversionService;
import org.springframework.util.Assert;

Default implementation of RepositoryInvokerFactory to inspect the requested repository type and create a matching RepositoryInvoker that suits the repository best. That means, the more concrete the base interface of the repository is, the more concrete will the actual invoker become - which means it will favor concrete method invocations over reflection ones. 
Author:
Oliver Gierke, Christoph Strobl
Since:
1.10/**
 * Default implementation of {@link RepositoryInvokerFactory} to inspect the requested repository type and create a
 * matching {@link RepositoryInvoker} that suits the repository best. That means, the more concrete the base interface
 * of the repository is, the more concrete will the actual invoker become - which means it will favor concrete method
 * invocations over reflection ones.
 *
 * @author Oliver Gierke
 * @author Christoph Strobl
 * @since 1.10
 */
public class DefaultRepositoryInvokerFactory implements RepositoryInvokerFactory {

	private final Repositories repositories;
	private final ConversionService conversionService;
	private final Map<Class<?>, RepositoryInvoker> invokers;

	
Creates a new DefaultRepositoryInvokerFactory for the given Repositories. 
Params:
repositories – must not be null./**
	 * Creates a new {@link DefaultRepositoryInvokerFactory} for the given {@link Repositories}.
	 *
	 * @param repositories must not be {@literal null}.
	 */
	public DefaultRepositoryInvokerFactory(Repositories repositories) {
		this(repositories, new DefaultFormattingConversionService());
	}

	
Creates a new DefaultRepositoryInvokerFactory for the given Repositories and ConversionService. 
Params:
repositories – must not be null.
conversionService – must not be null./**
	 * Creates a new {@link DefaultRepositoryInvokerFactory} for the given {@link Repositories} and
	 * {@link ConversionService}.
	 *
	 * @param repositories must not be {@literal null}.
	 * @param conversionService must not be {@literal null}.
	 */
	public DefaultRepositoryInvokerFactory(Repositories repositories, ConversionService conversionService) {

		Assert.notNull(repositories, "Repositories must not be null!");
		Assert.notNull(conversionService, "ConversionService must not be null!");

		this.repositories = repositories;
		this.conversionService = conversionService;
		this.invokers = new ConcurrentHashMap<>();
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.data.rest.core.invoke.RepositoryInvokerFactory#getInvokerFor(java.lang.Class)
	 */
	@Override
	public RepositoryInvoker getInvokerFor(Class<?> domainType) {
		return invokers.computeIfAbsent(domainType, this::prepareInvokers);
	}

	
Creates a RepositoryInvoker for the repository managing the given domain type. 
Params:
domainType – 
Returns:
/**
	 * Creates a {@link RepositoryInvoker} for the repository managing the given domain type.
	 *
	 * @param domainType
	 * @return
	 */
	private RepositoryInvoker prepareInvokers(Class<?> domainType) {

		Optional<RepositoryInformation> information = repositories.getRepositoryInformationFor(domainType);
		Optional<Object> repository = repositories.getRepositoryFor(domainType);

		return mapIfAllPresent(information, repository, this::createInvoker)//
				.orElseThrow(
						() -> new IllegalArgumentException(String.format("No repository found for domain type: %s", domainType)));
	}

	@SuppressWarnings("unchecked")
	protected RepositoryInvoker createInvoker(RepositoryInformation information, Object repository) {

		if (repository instanceof PagingAndSortingRepository) {
			return new PagingAndSortingRepositoryInvoker((PagingAndSortingRepository<Object, Object>) repository, information,
					conversionService);
		} else if (repository instanceof CrudRepository) {
			return new CrudRepositoryInvoker((CrudRepository<Object, Object>) repository, information, conversionService);
		} else {
			return new ReflectionRepositoryInvoker(repository, information, conversionService);
		}
	}
}