/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2011, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.db;

import java.sql.Connection;
import java.sql.SQLException;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

// PortableRemoteObject was introduced in JDK 1.3. We won't use it.
// import javax.rmi.PortableRemoteObject;
import javax.sql.DataSource;

/**
 * The <id>JNDIConnectionSource</id> is an implementation of
 * {@link ConnectionSource} that obtains a {@link javax.sql.DataSource} from a
 * JNDI provider and uses it to obtain a {@link java.sql.Connection}. It is
 * primarily designed to be used inside of J2EE application servers or
 * application server clients, assuming the application server supports remote
 * access of {@link javax.sql.DataSource}s. In this way one can take advantage
 * of connection pooling and whatever other goodies the application server
 * provides.
 * <p>
 * For more information about this component, please refer to the online manual at
 * http://logback.qos.ch/manual/appenders.html#DBAppender
 * 
 * @author <a href="mailto:rdecampo@twcny.rr.com">Ray DeCampo</a>
 */
public class JNDIConnectionSource extends ConnectionSourceBase {
  private String jndiLocation = null;
  private DataSource dataSource = null;

  public void start() {
    if (jndiLocation == null) {
      addError("No JNDI location specified for JNDIConnectionSource.");
    }
    discoverConnectionProperties();
  }


  public Connection getConnection() throws SQLException {
    Connection conn = null;
    try {
      if (dataSource == null) {
        dataSource = lookupDataSource();
      }
      if(getUser() != null) {
        addWarn("Ignoring property [user] with value ["+getUser()+"] for obtaining a connection from a DataSource.");
      }
      conn = dataSource.getConnection();
    } catch (final NamingException ne) {
      addError("Error while getting data source", ne);
      throw new SQLException("NamingException while looking up DataSource: "
          + ne.getMessage());
    } catch (final ClassCastException cce) {
      addError("ClassCastException while looking up DataSource.", cce);
      throw new SQLException("ClassCastException while looking up DataSource: "
          + cce.getMessage());
    }

    return conn;
  }

  /**
   * Returns the jndiLocation.
   * 
   * @return String
   */
  public String getJndiLocation() {
    return jndiLocation;
  }

  /**
   * Sets the jndiLocation.
   * 
   * @param jndiLocation
   *          The jndiLocation to set
   */
  public void setJndiLocation(String jndiLocation) {
    this.jndiLocation = jndiLocation;
  }

  private DataSource lookupDataSource() throws NamingException, SQLException {
    addInfo("Looking up ["+jndiLocation+"] in JNDI");
    DataSource ds;
    Context initialContext = new InitialContext();
    Object obj = initialContext.lookup(jndiLocation);

    // PortableRemoteObject was introduced in JDK 1.3. We won't use it.
    // ds = (DataSource)PortableRemoteObject.narrow(obj, DataSource.class);
    ds = (DataSource) obj;

    if (ds == null) {
      throw new SQLException("Failed to obtain data source from JNDI location "
          + jndiLocation);
    } else {
      return ds;
    }
  }
}
