/**
 * 
 */
package com.primeton.dams.utils.template;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.InitializingBean;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 * 数据库辨认，如将全称的“Microsoft SQL Server”辨认为简称“SQLServer”
 * @author user
 * @version 2.2 2010-10-21
 */
@Slf4j
public class DatabaseRecognizer implements InitializingBean {

	/**
	 * 需要辨认的数据库名称，KEY为全称，VALUE为简称
	 */
	private Map<String,String> databaseNames = new HashMap<String, String>();

	/**
	 * 当前数据库类型
	 */
	String dbType;

	/**
	 * 当前元数据系统所使用的数据库的产品名称，如“Microsoft SQL Server”、“DB2/NT”、“DB2/LINUX”、“DB2/SUN”
	 */
	String currentDatabaseProductName;
	
	/**
	 * 当前元数据系统所使用的数据库的产品版本
	 */
	String currentDatabaseProductVersion;


	@Override
	public void afterPropertiesSet() throws Exception {

	}


	/**
	 * 获取数据库连接并取得数据库名称，然后选择合适的与数据库相关的Spring配置文件
	 * @param dataSource dataSource
	 * @return Spring配置文件名
	 */
	public String determineDatabase(DataSource dataSource) {
		String databaseName = null;
		try (Connection conn = dataSource.getConnection()){
			DatabaseMetaData meta = conn.getMetaData();
			databaseName = meta.getDatabaseProductName();
			if(databaseName.equals("DM DBMS")){
				databaseName = "DM";
			}
			String productVersion = meta.getDatabaseProductVersion();
			if (log.isInfoEnabled()) {
				log.info("Current Database is " + databaseName + ", Version is " + productVersion);
			}
			setCurrentDatabaseProductName(databaseName);
			setCurrentDatabaseProductVersion(productVersion);
			databaseName = StringUtils.lowerCase(getDatabaseName(databaseName));
			this.dbType = databaseName;
		} catch (SQLException e) {
			String s = "Cannot determine the database brand name: " + databaseName;
			log.error(s, e);
			throw new IllegalArgumentException(s, e);
		}
		return databaseName;
	}

	/**
	 * 返回数据库的简称
	 * @param dbFullName 数据库全称
	 * @return 简称，若没有找到则返回dbFullName
	 */
	public String getDatabaseName(String dbFullName) {
		if (databaseNames.containsKey(dbFullName)) {
			// 名称全匹配的情况
			return databaseNames.get(dbFullName);
		}
		for (Iterator<String> it = databaseNames.keySet().iterator(); it.hasNext();) {
			String key = it.next();
			// 忽略大小写，匹配一次
			if(StringUtils.equalsIgnoreCase(dbFullName, key)) {
				return databaseNames.get(key);
			}
			// 正则表达式匹配，如DB2的产品名称可能返回不一样，如：DB2/NT, DB2/LINUX, DB2/SUN
			if (dbFullName.matches(key)) {
				return databaseNames.get(key);
			}
		}
		return dbFullName;
	}

	/**
	 * 返回当前元数据系统所使用的数据库的产品名称，如“Microsoft SQL Server”、“DB2/NT”、“DB2/LINUX”
	 * @return
	 */
	public String getCurrentDatabaseProductName() {
		return this.currentDatabaseProductName;
	}

	/**
	 * 设置当前元数据系统所使用的数据库的产品名称
	 * @param currentDatabaseProductName
	 */
	public void setCurrentDatabaseProductName(String currentDatabaseProductName) {
		this.currentDatabaseProductName = currentDatabaseProductName;
	}

	public String getCurrentDatabaseProductVersion() {
		return currentDatabaseProductVersion;
	}

	public void setCurrentDatabaseProductVersion(
			String currentDatabaseProductVersion) {
		this.currentDatabaseProductVersion = currentDatabaseProductVersion;
	}
	
	public Map<String, String> getDatabaseNames() {
		return databaseNames;
	}

	public void setDatabaseNames(Map<String, String> databaseNames) {
		this.databaseNames = databaseNames;
	}


	public String getDbType() {
		return dbType;
	}

	public void setDbType(String dbType) {
		this.dbType = dbType;
	}
}