/**
    *    Copyright 2009-2015 the original author or authors.
    *
    *    Licensed under the Apache License, Version 2.0 (the "License");
    *    you may not use this file except in compliance with the License.
    *    You may obtain a copy of the License at
    *
    *       http://www.apache.org/licenses/LICENSE-2.0
    *
   *    Unless required by applicable law or agreed to in writing, software
   *    distributed under the License is distributed on an "AS IS" BASIS,
   *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *    See the License for the specific language governing permissions and
   *    limitations under the License.
   */
  package org.apache.ibatis.datasource.unpooled;
  
  import java.io.PrintWriter;
  import java.sql.Connection;
  import java.sql.Driver;
  import java.sql.DriverManager;
  import java.sql.DriverPropertyInfo;
  import java.sql.SQLException;
  import java.util.Enumeration;
  import java.util.Map;
  import java.util.Properties;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.logging.Logger;
  
  import javax.sql.DataSource;
  
  import org.apache.ibatis.io.Resources;
  
  /**
   * @author Clinton Begin
   * @author Eduardo Macarron
   */
  public class UnpooledDataSource implements DataSource {
    
    private ClassLoader driverClassLoader;
    private Properties driverProperties;
    private static Map<String, Driver> registeredDrivers = new ConcurrentHashMap<String, Driver>();
  
    private String driver;
    private String url;
    private String username;
    private String password;
  
    private Boolean autoCommit;
    private Integer defaultTransactionIsolationLevel;
  
    static {
      Enumeration<Driver> drivers = DriverManager.getDrivers();
      while (drivers.hasMoreElements()) {
        Driver driver = drivers.nextElement();
        registeredDrivers.put(driver.getClass().getName(), driver);
      }
    }
  
    public UnpooledDataSource() {
    }
  
    public UnpooledDataSource(String driver, String url, String username, String password) {
      this.driver = driver;
      this.url = url;
      this.username = username;
      this.password = password;
    }
  
    public UnpooledDataSource(String driver, String url, Properties driverProperties) {
      this.driver = driver;
      this.url = url;
      this.driverProperties = driverProperties;
    }
  
    public UnpooledDataSource(ClassLoader driverClassLoader, String driver, String url, String username, String password) {
      this.driverClassLoader = driverClassLoader;
      this.driver = driver;
      this.url = url;
      this.username = username;
      this.password = password;
    }
  
    public UnpooledDataSource(ClassLoader driverClassLoader, String driver, String url, Properties driverProperties) {
      this.driverClassLoader = driverClassLoader;
      this.driver = driver;
      this.url = url;
      this.driverProperties = driverProperties;
    }
  
    @Override
    public Connection getConnection() throws SQLException {
      return doGetConnection(username, password);
    }
  
    @Override
    public Connection getConnection(String username, String password) throws SQLException {
      return doGetConnection(username, password);
    }
 
   @Override
   public void setLoginTimeout(int loginTimeout) throws SQLException {
     DriverManager.setLoginTimeout(loginTimeout);
   }
 
   @Override
   public int getLoginTimeout() throws SQLException {
     return DriverManager.getLoginTimeout();
   }
 
   @Override
   public void setLogWriter(PrintWriter logWriter) throws SQLException {
     DriverManager.setLogWriter(logWriter);
   }
 
   @Override
   public PrintWriter getLogWriter() throws SQLException {
     return DriverManager.getLogWriter();
   }
 
   public ClassLoader getDriverClassLoader() {
     return driverClassLoader;
   }
 
   public void setDriverClassLoader(ClassLoader driverClassLoader) {
     this.driverClassLoader = driverClassLoader;
   }
 
   public Properties getDriverProperties() {
     return driverProperties;
   }
 
   public void setDriverProperties(Properties driverProperties) {
     this.driverProperties = driverProperties;
   }
 
   public String getDriver() {
     return driver;
   }
 
   public synchronized void setDriver(String driver) {
     this.driver = driver;
   }
 
   public String getUrl() {
     return url;
   }
 
   public void setUrl(String url) {
     this.url = url;
   }
 
   public String getUsername() {
     return username;
   }
 
   public void setUsername(String username) {
     this.username = username;
   }
 
   public String getPassword() {
     return password;
   }
 
   public void setPassword(String password) {
     this.password = password;
   }
 
   public Boolean isAutoCommit() {
     return autoCommit;
   }
 
   public void setAutoCommit(Boolean autoCommit) {
     this.autoCommit = autoCommit;
   }
 
   public Integer getDefaultTransactionIsolationLevel() {
     return defaultTransactionIsolationLevel;
   }
 
   public void setDefaultTransactionIsolationLevel(Integer defaultTransactionIsolationLevel) {
     this.defaultTransactionIsolationLevel = defaultTransactionIsolationLevel;
   }
 
   private Connection doGetConnection(String username, String password) throws SQLException {
     Properties props = new Properties();
     if (driverProperties != null) {
       props.putAll(driverProperties);
     }
     if (username != null) {
       props.setProperty("user", username);
     }
     if (password != null) {
       props.setProperty("password", password);
     }
     return doGetConnection(props);
   }
 
   private Connection doGetConnection(Properties properties) throws SQLException {
     initializeDriver();
     Connection connection = DriverManager.getConnection(url, properties);
     configureConnection(connection);
     return connection;
   }
 
   private synchronized void initializeDriver() throws SQLException {
     if (!registeredDrivers.containsKey(driver)) {
       Class<?> driverType;
       try {
         if (driverClassLoader != null) {
           driverType = Class.forName(driver, true, driverClassLoader);
         } else {
           driverType = Resources.classForName(driver);
         }
         // DriverManager requires the driver to be loaded via the system ClassLoader.
         // http://www.kfu.com/~nsayer/Java/dyn-jdbc.html
         Driver driverInstance = (Driver)driverType.newInstance();
         DriverManager.registerDriver(new DriverProxy(driverInstance));
         registeredDrivers.put(driver, driverInstance);
       } catch (Exception e) {
         throw new SQLException("Error setting driver on UnpooledDataSource. Cause: " + e);
       }
     }
   }
 
   private void configureConnection(Connection conn) throws SQLException {
     if (autoCommit != null && autoCommit != conn.getAutoCommit()) {
       conn.setAutoCommit(autoCommit);
     }
     if (defaultTransactionIsolationLevel != null) {
       conn.setTransactionIsolation(defaultTransactionIsolationLevel);
     }
   }
 
   private static class DriverProxy implements Driver {
     private Driver driver;
 
     DriverProxy(Driver d) {
       this.driver = d;
     }
 
     @Override
     public boolean acceptsURL(String u) throws SQLException {
       return this.driver.acceptsURL(u);
     }
 
     @Override
     public Connection connect(String u, Properties p) throws SQLException {
       return this.driver.connect(u, p);
     }
 
     @Override
     public int getMajorVersion() {
       return this.driver.getMajorVersion();
     }
 
     @Override
     public int getMinorVersion() {
       return this.driver.getMinorVersion();
     }
 
     @Override
     public DriverPropertyInfo[] getPropertyInfo(String u, Properties p) throws SQLException {
       return this.driver.getPropertyInfo(u, p);
     }
 
     @Override
     public boolean jdbcCompliant() {
       return this.driver.jdbcCompliant();
     }
 
     // @Override only valid jdk7+
     public Logger getParentLogger() {
       return Logger.getLogger(Logger.GLOBAL_LOGGER_NAME);
     }
   }
 
   @Override
   public <T> T unwrap(Class<T> iface) throws SQLException {
     throw new SQLException(getClass().getName() + " is not a wrapper.");
   }
 
   @Override
   public boolean isWrapperFor(Class<?> iface) throws SQLException {
     return false;
   }
 
   // @Override only valid jdk7+
   public Logger getParentLogger() {
     // requires JDK version 1.6
     return Logger.getLogger(Logger.GLOBAL_LOGGER_NAME);
   }
 
 }