/*
 * Copyright 2008-2020 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.jpa.repository.support;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.springframework.beans.factory.ObjectProvider;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.jpa.repository.query.EscapeCharacter;
import org.springframework.data.mapping.context.MappingContext;
import org.springframework.data.querydsl.EntityPathResolver;
import org.springframework.data.querydsl.SimpleEntityPathResolver;
import org.springframework.data.repository.Repository;
import org.springframework.data.repository.core.support.RepositoryFactorySupport;
import org.springframework.data.repository.core.support.TransactionalRepositoryFactoryBeanSupport;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

Special adapter for Springs FactoryBean interface to allow easy setup of repository factories via Spring configuration. 
Author:
Oliver Gierke, Eberhard Wolff, Mark Paluch, Jens Schauder
Type parameters:
<T> – the type of the repository/**
 * Special adapter for Springs {@link org.springframework.beans.factory.FactoryBean} interface to allow easy setup of
 * repository factories via Spring configuration.
 *
 * @author Oliver Gierke
 * @author Eberhard Wolff
 * @author Mark Paluch
 * @author Jens Schauder
 * @param <T> the type of the repository
 */
public class JpaRepositoryFactoryBean<T extends Repository<S, ID>, S, ID>
		extends TransactionalRepositoryFactoryBeanSupport<T, S, ID> {

	private @Nullable EntityManager entityManager;
	private EntityPathResolver entityPathResolver;
	private EscapeCharacter escapeCharacter = EscapeCharacter.DEFAULT;

	
Creates a new JpaRepositoryFactoryBean for the given repository interface. 
Params:
repositoryInterface – must not be null./**
	 * Creates a new {@link JpaRepositoryFactoryBean} for the given repository interface.
	 *
	 * @param repositoryInterface must not be {@literal null}.
	 */
	public JpaRepositoryFactoryBean(Class<? extends T> repositoryInterface) {
		super(repositoryInterface);
	}

	
The EntityManager to be used. 
Params:
entityManager – the entityManager to set/**
	 * The {@link EntityManager} to be used.
	 *
	 * @param entityManager the entityManager to set
	 */
	@PersistenceContext
	public void setEntityManager(EntityManager entityManager) {
		this.entityManager = entityManager;
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport#setMappingContext(org.springframework.data.mapping.context.MappingContext)
	 */
	@Override
	public void setMappingContext(MappingContext<?, ?> mappingContext) {
		super.setMappingContext(mappingContext);
	}

	
Configures the EntityPathResolver to be used. Will expect a canonical bean to be present but fallback to SimpleEntityPathResolver.INSTANCE in case none is available. 
Params:
resolver – must not be null./**
	 * Configures the {@link EntityPathResolver} to be used. Will expect a canonical bean to be present but fallback to
	 * {@link SimpleEntityPathResolver#INSTANCE} in case none is available.
	 *
	 * @param resolver must not be {@literal null}.
	 */
	@Autowired
	public void setEntityPathResolver(ObjectProvider<EntityPathResolver> resolver) {
		this.entityPathResolver = resolver.getIfAvailable(() -> SimpleEntityPathResolver.INSTANCE);
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.data.repository.core.support.TransactionalRepositoryFactoryBeanSupport#doCreateRepositoryFactory()
	 */
	@Override
	protected RepositoryFactorySupport doCreateRepositoryFactory() {

		Assert.state(entityManager != null, "EntityManager must not be null!");

		return createRepositoryFactory(entityManager);
	}

	
Returns a RepositoryFactorySupport. /**
	 * Returns a {@link RepositoryFactorySupport}.
	 */
	protected RepositoryFactorySupport createRepositoryFactory(EntityManager entityManager) {

		JpaRepositoryFactory jpaRepositoryFactory = new JpaRepositoryFactory(entityManager);
		jpaRepositoryFactory.setEntityPathResolver(entityPathResolver);
		jpaRepositoryFactory.setEscapeCharacter(escapeCharacter);
		return jpaRepositoryFactory;
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
	 */
	@Override
	public void afterPropertiesSet() {

		Assert.state(entityManager != null, "EntityManager must not be null!");

		super.afterPropertiesSet();
	}

	public void setEscapeCharacter(char escapeCharacter) {

		this.escapeCharacter = EscapeCharacter.of(escapeCharacter);
	}
}