/**
 * 
 */
package com.agilemaster.asdtiang.study;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import org.hibernate.engine.jdbc.connections.spi.ConnectionProvider;
import org.hibernate.internal.util.ConfigHelper;
import org.hibernate.service.spi.Configurable;
import org.hibernate.service.spi.Stoppable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;

/**
 * https://github.com/alibaba/druid/issues/592
 * <pre>
 * Druid通过实现Hibernate接口ConnectionProvider提供对hibernate的支持：
 * public class DruidConnectionProvider implements ConnectionProvider, Configurable,Stoppable {
 * 在最新版中Druid1.0.6中，继承的是org.hibernate.service.jdbc.connections.spi.ConnectionProvider,
 * Hibernate4.3的ConnectionProvider接口声明已经被修改为：
 * org.hibernate.engine.jdbc.connections.spi.ConnectionProvider
 * </pre>
 * 
 * 在hibernate.properties中不使用Druid的ConnectionProvider，而使用重新定义的ConnectionProvider：
 * <pre><i>
 * 	#Druid::注意这里配置的ConnectionProvider！！！ 第一次，配置错误了导致直接加不成功的异常！！
 * 	#hibernate.connection.provider_class=com.alibaba.druid.support.hibernate.DruidConnectionProvider
 * </i></pre>
 * 
 * @author 呙长伟
 * @date 2014年7月16日
 */
public class DruidConnectionProvider implements ConnectionProvider, Configurable, Stoppable {
	private static final Logger logger = LoggerFactory.getLogger(DruidConnectionProvider.class);
    private static final long serialVersionUID = 1026193803901107651L;

    private DruidDataSource   dataSource;
    private static final String CONFIG_FILE_PREFIX="/hibernate-";
    /**
     * 在vm加入参数指定添加的hibernate配置文件.该配置文件会覆盖hibernate.properties中对应配置.
     * 参数名为: db.conf.value
     * 例如vm加入参数    -Ddb.conf.value=dev
     * 则对应的增加配置文件名为: hibernate-dev.properties
     */
    private static final String CONFIG_VAR_NAME="db.conf.value";

    public DruidConnectionProvider(){
        dataSource = new DruidDataSource();
    }

    @SuppressWarnings("rawtypes")
    @Override
    public boolean isUnwrappableAs(Class unwrapType) {
        return dataSource.isWrapperFor(unwrapType);
    }

    @Override
    public <T> T unwrap(Class<T> unwrapType) {
        return dataSource.unwrap(unwrapType);
    }

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

    @Override
    public void closeConnection(Connection conn) throws SQLException {
        conn.close();
    }

    @Override
    public boolean supportsAggressiveRelease() {
        return false;
    }
    @SuppressWarnings("rawtypes")
    private Map propertiesToMap(Properties properties){
    	Map<String, String> map = new HashMap<String, String>();
    	for (final String name: properties.stringPropertyNames())
    	    map.put(name, properties.getProperty(name));
		return map;
    }

    @SuppressWarnings({ "rawtypes", "unchecked" })
    @Override
    public void configure(Map configurationValues) {
    	String configValue = System.getProperty(CONFIG_VAR_NAME);
    	if(null!=configValue){
    		String fileName = CONFIG_FILE_PREFIX + configValue+".properties";
    		Properties tempProperties = new Properties();
    			InputStream stream = ConfigHelper.getResourceAsStream( fileName );
    			try {
    				tempProperties.load(stream);
    				configurationValues.putAll(propertiesToMap(tempProperties));
    				logger.info("load hibernate config from file:"+ fileName + " success");
    			}
    			catch (Exception e) {
    				logger.warn("load properties form config wrong",e);
    			}
    			finally {
    				try{
    					stream.close();
    				}
    				catch (IOException ioe){
    					logger.error("load properties form config io error",ioe);
    				}
    			}
    	}
    	logger.info("DruidDataSource init:: "+configurationValues);
        try {
            DruidDataSourceFactory.config(dataSource, configurationValues);
        } catch (SQLException e) {
            throw new IllegalArgumentException("config error", e);
        }
    }

    @Override
    public void stop() {
        dataSource.close();
    }

}