package com.vci.server.base.persistence.dao;

import java.io.File;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.util.List;
import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.impl.SessionImpl;
import org.hibernate.jdbc.JDBCContext;

import com.vci.common.log.ServerWithLog4j;
import com.vci.corba.common.data.VCIInvocationInfo;

/**
 * Configures and provides access to Hibernate sessions, tied to the current 
 * thread of execution. Follows the Thread Local Session pattern, see 
 * {@link http://hibernate.org/42.html }.
 * @author Administrator
 *
 */
public class HibernateSessionFactory {

	/**
	 *
     * Location of hibernate.cfg.xml file. Location should be on the classpath 
     * as Hibernate uses #resourceAsStream style lookup for its configuration 
     * file. The default classpath location of the hibernate config file is in 
     * the default package. Use #setConfigFile() to update the location of the 
     * configuration file for the current session. 
     */
	//private static final Log log = LogFactory.getLog(HibernateSessionFactory.class);
	private static String CONFIG_FILE_LOCATION="properties/hibernate.cfg.xml";
	private static String MAP_FILE_RESOURCE="/properties/hibernate.map.xml";
	//private static String MAP_FILE_RESOURCE="hibernate.map.xml";
	
	private static final ThreadLocal<VciSession> threadLocal = new ThreadLocal<VciSession>();
	private static Configuration configuration = new Configuration();  
	private static SessionFactory sessionFactory; 
	
	private static DbType _dbType = DbType.Unknow;
	
	static {
		try {
			ServerWithLog4j.logger.info("Init Hibernate");
			
			File file = new File(CONFIG_FILE_LOCATION);
			
			configuration.configure(file);
			
			ServerWithLog4j.logger.info("加载Hibernate对象映射:Begin");
			loadHbmFiles();
			ServerWithLog4j.logger.info("加载Hibernate对象映射:End");
			
			sessionFactory = configuration.buildSessionFactory();
		} catch (Exception e) {
			ServerWithLog4j.logger.error("Error Creating SessionFactory", e);
			e.printStackTrace();
		}
	}
	
	private HibernateSessionFactory() {
		
	}
	
	/**
	 * Return the ThreadLocal session instance. Lazy initialize
	 * the <code>SessionFactory</code> if needed.
	 * @return
	 * @throws HibernateException
	 */
	public static synchronized Session getSession() throws HibernateException {
		VciSession vciSession = (VciSession) threadLocal.get();
		if (vciSession == null) {
			vciSession = new VciSession();
		}
		if (vciSession.getSession() == null || !vciSession.getSession().isOpen()) {
			if (sessionFactory == null) {
				rebuildSessionFactory();
			}
			Session session = (sessionFactory != null) ? sessionFactory.openSession() : null;
			vciSession.setSession(session);
			threadLocal.set(vciSession);
			
			ServerWithLog4j.logger.debug("--> Open Session");
		}
		
		return vciSession.getSession();
	}
	
	public static void setVciSessionInfo(VCIInvocationInfo info) {
		VciSession vciSession = (VciSession) threadLocal.get();
		if (vciSession == null) {
			vciSession = new VciSession();
			threadLocal.set(vciSession);
		}
		vciSession.setVciInfo(info);
	}
	
	public static VCIInvocationInfo getVciSessionInfo() {
		VciSession vciSession = (VciSession) threadLocal.get();
		if (vciSession == null) {
			return null;
		}
		VCIInvocationInfo vii = vciSession.getVciInfo();
		if (vii == null) {
			vii = new VCIInvocationInfo();
		}
		
		return vii;
	}
	
	/**
	 * Rebuild hibernate session factory
	 *
	 */
	public static void rebuildSessionFactory() {
		try {
			File file = new File(CONFIG_FILE_LOCATION);
			configuration.configure(file);

			ServerWithLog4j.logger.info("加载Hibernate对象映射:Begin");
			loadHbmFiles();
			ServerWithLog4j.logger.info("加载Hibernate对象映射:End");
	        
			sessionFactory = configuration.buildSessionFactory();
		} catch (Exception e) {
			ServerWithLog4j.logger.error("Error Rebuild SessionFactory", e);
			e.printStackTrace();
		}
	}
	
	/**
	 * Close the single hibernate session instance.
	 * @throws HibernateException
	 */
	public static void closeSession() throws HibernateException {
		VciSession vcisession = (VciSession) threadLocal.get();
		threadLocal.set(null);
		Session session = vcisession.getSession();
		if (session != null ) {
			session.close();
			session = null;
			
			ServerWithLog4j.logger.debug("<--Close Session");
		}
	}
	
	/**
	 * fetch session factory
	 * 
	 * @return
	 */
	public static SessionFactory getSessionFactory() {
		return sessionFactory;
	}
	
	/**
	 * session factory will be rebuiled in the next call
	 * @param configFile
	 */
	public static void setConfigFile(String configFile) {
		HibernateSessionFactory.CONFIG_FILE_LOCATION = configFile;
		sessionFactory = null;
	}
	
	/**
	 * session factory will be rebuiled in the next call
	 * @param configFile
	 */
	public static void setHbmFiles(String[] files) {
		//_hbmFiles = files;
		
		sessionFactory = null;
	}
	
	/**
	 * fetch hibernate configuration.
	 * @return
	 */
	public static Configuration getConfiguration() {
		return configuration;
	}
	
	/**
	 * 返回绑定到当前线程上下文中的Connection对象
	 * @return 绑定到当前线程上下文中的Connection对象
	 */
	public static java.sql.Connection getSessionConnection(){
		Session session = HibernateSessionFactory.getSession();
		SessionImpl sessionImpl = (SessionImpl)session;
		JDBCContext jdbcContext = sessionImpl.getJDBCContext();
		Connection connection = jdbcContext.getConnectionManager().getConnection();
		return connection; 
	}
	
		
	public static DbType getDbType() {
		
		if (_dbType != DbType.Unknow)
			return _dbType;
		
		Connection con = getSessionConnection();
		try {
			DatabaseMetaData dbmd = con.getMetaData();
			String driveName = dbmd.getDriverName();
			
			String productName = dbmd.getDatabaseProductName();
			
			//System.out.println("===============DBTYPE==============");
			//System.out.println("\tdriveName=" + driveName + ";   productName=" + productName);
			ServerWithLog4j.logger.info("DB driveName=" + driveName + ";   DB ProductName=" + productName);
			//System.out.println("===============DBTYPE==============");

			if (productName.equalsIgnoreCase("Oracle"))	// Oracle 数据库
				_dbType = DbType.ORACL;
			else if (driveName.equalsIgnoreCase("Dm dbms")) // 达梦数据库
				_dbType = DbType.DM8;
			else
				_dbType = DbType.Unknow; // 数据库未知
		} catch (SQLException e) {
			e.printStackTrace();
			_dbType = DbType.Unknow;
		}
		return _dbType;
	}
	
	private static void loadHbmFiles() {
		try {
			//List<InputStream> iss = loadResources(MAP_FILE_RESOURCE, HibernateSessionFactory.class.getClassLoader());
			//List<InputStream> iss = loadResources(MAP_FILE_RESOURCE, null);
	        InputStream is = HibernateSessionFactory.class.getResourceAsStream(MAP_FILE_RESOURCE);
			//for (InputStream is : iss)
	        if (is != null)
	        {
	        	SAXReader reader = new SAXReader();
	        	Document doc;
				doc = reader.read(is);
	        	Element root = doc.getRootElement();
	        	List<?> lst = root.elements("mapping");
	        	
	        	for (Object el : lst) {
	        		Attribute at = ((Element)el).attribute("resource");
	        		if (at != null) {
	        			String hbmFile = at.getValue();
	        			configuration.addResource(hbmFile);
	        		}
	        	}
	        }
		} catch (DocumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			ServerWithLog4j.logger.error("加载对象映射失败", e);
		}        
	}
	
//	private static List<InputStream> loadResources(final String name, final ClassLoader classLoader) throws IOException {
//	    final List<InputStream> list = new ArrayList<InputStream>();
//	    final Enumeration<URL> systemResources = 
//	            (classLoader == null ? ClassLoader.getSystemClassLoader() : classLoader)
//	            .getResources(name);
//	    while (systemResources.hasMoreElements()) {
//	    	ServerWithLog4j.logger.info(MAP_FILE_RESOURCE + ":" + systemResources.nextElement().getPath());
//	    	
//	        list.add(systemResources.nextElement().openStream());
//	    }
//	    return list;
//	}
}