/**
 * @author xichao.dong   
 * @email 406592176@qq.com
 * @date 2014-8-15 上午8:50:38 
 * @company (开发公司)    珠海市冰川软件有限公司
 * @copyright (版权)    本文件归属珠海市冰川软件有限公司所有
 * @version V1.0
 * @modify (修改) : 2014-8-15 上午8:50:38  xichao.dong 
 * @Review (审核人) ：xichao.dong 
 */
package com.glacier.basic.util;

import java.sql.Connection;
import java.sql.SQLException;

import javax.sql.DataSource;

import org.apache.commons.lang3.StringUtils;
import org.hibernate.Hibernate;
import org.hibernate.dialect.H2Dialect;
import org.hibernate.dialect.MySQL5InnoDBDialect;
import org.hibernate.dialect.Oracle10gDialect;

/**
 * @ClassName: Hibernates 
 * @Description: TODO(这里用一句话描述这个类的作用) 
 * @author xichao.dong	
 * @email 406592176@qq.com
 * @date 2014-8-15 上午11:15:19
 */
public class Hibernates {

    public static final String DATETIME_TYPE = "org.jadira.usertype.dateandtime.joda.PersistentDateTime";

    /**
     * Initialize the lazy property value.
     * 
     * eg.
     * Hibernates.initLazyProperty(user.getGroups()); 
     */
    public static void initLazyProperty(Object proxyedPropertyValue) {
        Hibernate.initialize(proxyedPropertyValue);
    }

    /**
     * 从DataSoure中取出connection, 根据connection的metadata中的jdbcUrl判断Dialect类型.
     * 仅支持Oracle, H2, MySql，如需更多数据库类型，请仿照此类自行编写。
     */
    public static String getDialect(DataSource dataSource) {
        String jdbcUrl = getJdbcUrlFromDataSource(dataSource);

        // 根据jdbc url判断dialect
        if (StringUtils.contains(jdbcUrl, ":h2:")) {
            return H2Dialect.class.getName();
        } else if (StringUtils.contains(jdbcUrl, ":mysql:")) {
            return MySQL5InnoDBDialect.class.getName();
        } else if (StringUtils.contains(jdbcUrl, ":oracle:")) {
            return Oracle10gDialect.class.getName();
        } else {
            throw new IllegalArgumentException("Unknown Database of " + jdbcUrl);
        }
    }

    private static String getJdbcUrlFromDataSource(DataSource dataSource) {
        Connection connection = null;
        try {
            connection = dataSource.getConnection();
            if (connection == null) {
                throw new IllegalStateException("Connection returned by DataSource [" + dataSource + "] was null");
            }
            return connection.getMetaData().getURL();
        } catch (SQLException e) {
            throw new RuntimeException("Could not get database url", e);
        } finally {
            if (connection != null) {
                try {
                    connection.close();
                } catch (SQLException e) {
                }
            }
        }
    }
}