/*
 * Copyright 2018 onwards - Sunit Katkar (sunitkatkar@gmail.com)
 *
 * 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
 *
 *      http://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 com.meineDomain.tenancy.tenant.config;

import java.util.HashMap;
import java.util.Map;

import javax.persistence.EntityManagerFactory;

import org.hibernate.MultiTenancyStrategy;
import org.hibernate.context.spi.CurrentTenantIdentifierResolver;
import org.hibernate.engine.jdbc.connections.spi.MultiTenantConnectionProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.JpaVendorAdapter;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import com.meineDomain.model.i2s.Brand;
import com.meineDomain.model.tenancy.MasterTenant;
import com.meineDomain.tenancy.master.repository.MasterTenantRepository;

/**
 * This is the tenant data sources configuration which sets up the multitenancy.
 *
 * @author Sunit Katkar, sunitkatkar@gmail.com
 *         (https://sunitkatkar.blogspot.com/)
 * @since ver 1.0 (May 2018)
 * @version 1.0
 */
@Configuration
@EnableTransactionManagement
@ComponentScan(basePackages = { "com.meineDomain.tenancy.tenant.repository", "com.meineDomain.tenancy.tenant.model" })
@EnableJpaRepositories(basePackages = { "com.meineDomain.tenancy.repositories", "com.meineDomain.tenancy.tenant.repository",
	"com.meineDomain.tenancy.tenant.service" }, entityManagerFactoryRef = "tenantEntityManagerFactory", transactionManagerRef = "tenantTransactionManager")
public class TenantDatabaseConfig {

	private static final Logger LOG = LoggerFactory.getLogger(TenantDatabaseConfig.class);

	@Value("${spring.jpa.properties.hibernate.show_sql}")
	boolean show_sql;

	@Bean(name = "tenantJpaVendorAdapter")
	public JpaVendorAdapter jpaVendorAdapter() {
		return new HibernateJpaVendorAdapter();
	}

	@Bean(name = "tenantTransactionManager")
	public JpaTransactionManager transactionManager(@Qualifier("tenantEntityManagerFactory") EntityManagerFactory tenantEntityManager) {
		JpaTransactionManager transactionManager = new JpaTransactionManager();
		transactionManager.setEntityManagerFactory(tenantEntityManager);
		return transactionManager;
	}

	/**
	 * The multi tenant connection provider
	 *
	 * @return
	 */
	@Bean(name = "datasourceBasedMultitenantConnectionProvider")
	@ConditionalOnBean(name = "masterEntityManagerFactory")
	public MultiTenantConnectionProvider multiTenantConnectionProvider() {
		// Autowires the multi connection provider
		return new DataSourceBasedMultiTenantConnectionProviderImpl();
	}

	/**
	 * The current tenant identifier resolver
	 *
	 * @return
	 */
	@Bean(name = "currentTenantIdentifierResolver")
	public CurrentTenantIdentifierResolver currentTenantIdentifierResolver() {
		return new CurrentTenantIdentifierResolverImpl();
	}

	/**
	 * Creates the entity manager factory bean which is required to access the
	 * JPA functionalities provided by the JPA persistence provider, i.e.
	 * Hibernate in this case.
	 *
	 * @param connectionProvider
	 * @param tenantResolver
	 * @return
	 */
	@Bean(name = "tenantEntityManagerFactory")
	@ConditionalOnBean(name = "datasourceBasedMultitenantConnectionProvider")
	public LocalContainerEntityManagerFactoryBean entityManagerFactory(
		@Qualifier("datasourceBasedMultitenantConnectionProvider") MultiTenantConnectionProvider connectionProvider,
		@Qualifier("currentTenantIdentifierResolver") CurrentTenantIdentifierResolver tenantResolver) {

		LocalContainerEntityManagerFactoryBean emfBean = new LocalContainerEntityManagerFactoryBean();
		// All tenant related entities, repositories and service classes must be scanned
		emfBean.setPackagesToScan(new String[] { MasterTenantRepository.class.getPackage().getName(), Brand.class.getPackage().getName(),
			MasterTenant.class.getPackage().getName() });
		emfBean.setJpaVendorAdapter(jpaVendorAdapter());
		emfBean.setPersistenceUnitName("tenantdb-persistence-unit");
		Map<String, Object> properties = new HashMap<>();
		properties.put(org.hibernate.cfg.Environment.MULTI_TENANT, MultiTenancyStrategy.SCHEMA);
		properties.put(org.hibernate.cfg.Environment.MULTI_TENANT_CONNECTION_PROVIDER, connectionProvider);
		properties.put(org.hibernate.cfg.Environment.MULTI_TENANT_IDENTIFIER_RESOLVER, tenantResolver);
		// ImprovedNamingStrategy is deprecated and unsupported in Hibernate 5
		// properties.put("hibernate.ejb.naming_strategy",
		// "org.hibernate.cfg.ImprovedNamingStrategy");
		properties.put(org.hibernate.cfg.Environment.DIALECT, "org.hibernate.dialect.MySQL5Dialect");
		properties.put(org.hibernate.cfg.Environment.SHOW_SQL, show_sql);
		properties.put(org.hibernate.cfg.Environment.FORMAT_SQL, show_sql);
		// properties.put(org.hibernate.cfg.Environment.HBM2DDL_AUTO, "update");

		emfBean.setJpaPropertyMap(properties);
		LOG.info("tenantEntityManagerFactory set up successfully!");
		return emfBean;
	}
}