/*
    * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH
    *
    * 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 de.smartics.properties.impl.config.ds.hsql;
  
  import java.io.IOException;
  import java.io.ObjectInputStream;
  
  import javax.sql.DataSource;
  
  import org.hsqldb.jdbc.JDBCDataSource;
  
  /**
   * Data source proxy to create HSQL data sources.
   * <p>
   * Please note that the password passed to this instance is stored. This is
   * necessary in the case of deserialisation where the wrapped data source
   * instance must be recreated. If this provides a security problem, please
   * consider using the
   * {@link de.smartics.properties.spi.config.ds.JndiDataSourceProxy}.
   * </p>
   */
  public final class HSqlDataSourceProxy extends AbstractHSqlDataSourceProxy
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * The class version identifier.
     */
    private static final long serialVersionUID = 1L;
  
    // --- members --------------------------------------------------------------
  
    /**
     * The JDBC URL to connect to.
     *
     * @serial
     */
    private final String connectionUrl;
  
    /**
     * The name of the user to access the data source.
     *
     * @serial
     */
    private final String userName;
  
    /**
     * The password of the user to access the data source. The password is stored
     * within this instance.
     * <p>
     * Please note that the password passed to this instance is stored. This is
     * necessary in the case of deserialisation where the wrapped data source
     * instance must be recreated. If this provides a security problem, please
     * consider using the
     * {@link de.smartics.properties.spi.config.ds.JndiDataSourceProxy}.
     * </p>
     *
     * @serial
     */
    private final String password;
  
    /**
     * The reference to the data source.
     */
    private transient DataSource dataSource;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     *
     * @param connectionUrl the JDBC URL to connect to.
     * @param userName the name of the user to access the data source.
     * @param password the password of the user to access the data source.
     */
    private HSqlDataSourceProxy(final String connectionUrl,
        final String userName, final String password)
    {
      this.connectionUrl = connectionUrl;
      this.userName = userName;
      this.password = password;
      this.dataSource = createDataSource();
   }
 
   // ****************************** Inner Classes *****************************
 
   // ********************************* Methods ********************************
 
   // --- init -----------------------------------------------------------------
 
   private DataSource createDataSource()
   {
     final JDBCDataSource dataSource = new JDBCDataSource();
     dataSource.setDatabase(connectionUrl);
     dataSource.setUser(userName);
     dataSource.setPassword(password);
 
     return dataSource;
   }
 
   // --- factory --------------------------------------------------------------
 
   /**
    * Factory method to create with URL <code>jdbc:hsqldb:mem:configmemdb</code>.
    *
    * @return the proxy instance.
    */
   public static HSqlDataSourceProxy create()
   {
     return create("jdbc:hsqldb:mem:configmemdb");
   }
 
   /**
    * Factory method to create with the given connection URL using user
    * <code>SA</code> and no password.
    *
    * @param connectionUrl the JDBC URL to connect to te database. E.g.
    *          <code>jdbc:hsqldb:file:target/testdb;shutdown=true</code>.
    * @return the proxy instance.
    */
   public static HSqlDataSourceProxy create(final String connectionUrl)
   {
     return create(connectionUrl, "SA", "");
   }
 
   /**
    * Factory method to create with the given connection URL using the given
    * credentials.
    *
    * @param connectionUrl the JDBC URL to connect to te database. E.g.
    *          <code>jdbc:hsqldb:file:target/testdb;shutdown=true</code>.
    * @param userName the name of the database user to connect to the database.
    * @param password the password to the user.
    * @return the proxy instance.
    */
   public static HSqlDataSourceProxy create(final String connectionUrl,
       final String userName, final String password)
   {
     return new HSqlDataSourceProxy(connectionUrl, userName, password);
   }
 
   // --- get&set --------------------------------------------------------------
 
   @Override
   public String getDataSourceId()
   {
     return connectionUrl;
   }
 
   /**
    * Returns the reference to the data source.
    *
    * @return the reference to the data source.
    */
   @Override
   public DataSource getDataSource()
   {
     return dataSource;
   }
 
   // --- business -------------------------------------------------------------
 
   // --- object basics --------------------------------------------------------
 
   /**
    * Reads the object from the given stream.
    *
    * @param in the stream to read from.
    * @throws IOException on read problems.
    * @throws ClassNotFoundException if a class cannot be found.
    */
   private void readObject(final ObjectInputStream in) throws IOException,
     ClassNotFoundException
   {
     in.defaultReadObject();
 
     this.dataSource = createDataSource();
   }
 
   @Override
   public String toString()
   {
     return "(HSQL) " + userName + " @ " + connectionUrl;
   }
 }