/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Middleware LLC.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 *
 */

package com.sismics.util.jpa;

import org.hibernate.cfg.Environment;
import org.hibernate.engine.jdbc.spi.SqlExceptionHelper;
import org.hibernate.internal.util.config.ConfigurationHelper;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.service.internal.StandardServiceRegistryImpl;
import org.hibernate.service.jdbc.connections.spi.ConnectionProvider;
import org.hibernate.tool.hbm2ddl.ConnectionHelper;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

/**
 * A {@link ConnectionHelper} implementation based on an internally
 * built and managed {@link ConnectionProvider}.
 *
 * @author Steve Ebersole
 */
class ManagedProviderConnectionHelper implements ConnectionHelper {
    private Properties cfgProperties;
    private StandardServiceRegistryImpl serviceRegistry;
    private Connection connection;

    public ManagedProviderConnectionHelper(Properties cfgProperties) {
        this.cfgProperties = cfgProperties;
    }

    @Override
    public void prepare(boolean needsAutoCommit) throws SQLException {
        serviceRegistry = createServiceRegistry(cfgProperties);
        connection = serviceRegistry.getService(ConnectionProvider.class).getConnection();
        if (needsAutoCommit && !connection.getAutoCommit()) {
            connection.commit();
            connection.setAutoCommit(true);
        }
    }

    private static StandardServiceRegistryImpl createServiceRegistry(Properties properties) {
        Environment.verifyProperties(properties);
        ConfigurationHelper.resolvePlaceHolders(properties);
        return (StandardServiceRegistryImpl) new ServiceRegistryBuilder().applySettings(properties).buildServiceRegistry();
    }

    @Override
    public Connection getConnection() throws SQLException {
        return connection;
    }

    @Override
    public void release() throws SQLException {
        try {
            releaseConnection();
        } finally {
            releaseServiceRegistry();
        }
    }

    private void releaseConnection() throws SQLException {
        if (connection != null) {
            try {
                new SqlExceptionHelper().logAndClearWarnings(connection);
            } finally {
                try {
                    serviceRegistry.getService(ConnectionProvider.class).closeConnection(connection);
                } finally {
                    connection = null;
                }
            }
        }
    }

    private void releaseServiceRegistry() {
        if (serviceRegistry != null) {
            try {
                serviceRegistry.destroy();
            } finally {
                serviceRegistry = null;
            }
        }
    }
}