/*

  *   SONEWS News Server

  *   see AUTHORS for the list of contributors

  *

  *   This program is free software: you can redistribute it and/or modify

  *   it under the terms of the GNU General Public License as published by

  *   the Free Software Foundation, either version 3 of the License, or

  *   (at your option) any later version.

  *

  *   This program is distributed in the hope that it will be useful,

  *   but WITHOUT ANY WARRANTY; without even the implied warranty of

  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  *   GNU General Public License for more details.

  *

  *   You should have received a copy of the GNU General Public License

  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.

  */

 package org.sonews.daemon;

 import java.io.FileInputStream;

 import java.io.FileNotFoundException;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.util.Properties;

 import org.sonews.util.AbstractConfig;

 /**

  * Manages the bootstrap configuration. It MUST contain all config values

  * that are needed to establish a database connection.

  * For further configuration values use the Config class instead as that class

  * stores its values within the database.

  * @author Christian Lins

  * @since sonews/0.5.0

  */

 public final class BootstrapConfig extends AbstractConfig

 {

   /** Key constant. If value is "true" every I/O is written to logfile 

    * (which is a lot!) 

    */

   public static final String DEBUG              = "sonews.debug";

   /** Key constant. Value is classname of the JDBC driver */

   public static final String STORAGE_DBMSDRIVER = "sonews.storage.dbmsdriver";

   /** Key constant. Value is JDBC connect String to the database. */

   public static final String STORAGE_DATABASE   = "sonews.storage.database";

   /** Key constant. Value is the username for the DBMS. */

   public static final String STORAGE_USER       = "sonews.storage.user";

   /** Key constant. Value is the password for the DBMS. */

   public static final String STORAGE_PASSWORD   = "sonews.storage.password";

   /** Key constant. Value is the name of the host which is allowed to use the

    *  XDAEMON command; default: "localhost" */

   public static final String XDAEMON_HOST       = "sonews.xdaemon.host";

   /** The config key for the filename of the logfile */

   public static final String LOGFILE = "sonews.log";

   /** The filename of the config file that is loaded on startup */

   public static volatile String FILE               = "sonews.conf";

   private static final Properties defaultConfig = new Properties();

   private static BootstrapConfig instance = null;

   static

   {

     // Set some default values

     defaultConfig.setProperty(STORAGE_DATABASE, "jdbc:mysql://localhost/sonews");

     defaultConfig.setProperty(STORAGE_DBMSDRIVER, "com.mysql.jdbc.Driver");

     defaultConfig.setProperty(STORAGE_USER, "sonews_user");

     defaultConfig.setProperty(STORAGE_PASSWORD, "mysecret");

     defaultConfig.setProperty(DEBUG, "false");

   }

   /**

    * Note: this method is not thread-safe

    * @return A Config instance

    */

   public static synchronized BootstrapConfig getInstance()

   {

     if(instance == null)

     {

       instance = new BootstrapConfig();

     }

     return instance;

   }

   // Every config instance is initialized with the default values.

   private final Properties settings = (Properties)defaultConfig.clone();

   /**

    * Config is a singelton class with only one instance at time.

    * So the constructor is private to prevent the creation of more

    * then one Config instance.

    * @see Config.getInstance() to retrieve an instance of Config

    */

   private BootstrapConfig()

   {

     try

     {

       // Load settings from file

       load();

     }

     catch(IOException ex)

     {

       ex.printStackTrace();

     }

   }

   /**

    * Loads the configuration from the config file. By default this is done

    * by the (private) constructor but it can be useful to reload the config

    * by invoking this method.

    * @throws IOException

    */

   public void load() 

     throws IOException

   {

     FileInputStream in = null;

     try

     {

       in = new FileInputStream(FILE);

       settings.load(in);

     }

     catch (FileNotFoundException e)

     {

       // MUST NOT use Log otherwise endless loop

       System.err.println(e.getMessage());

       save();

     }

     finally

     {

       if(in != null)

         in.close();

     }

   }

   /**

    * Saves this Config to the config file. By default this is done

    * at program end.

    * @throws FileNotFoundException

    * @throws IOException

    */

   public void save() throws FileNotFoundException, IOException

   {

     FileOutputStream out = null;

     try

     {

       out = new FileOutputStream(FILE);

       settings.store(out, "SONEWS Config File");

       out.flush();

     }

     catch(IOException ex)

     {

       throw ex;

     }

     finally

     {

       if(out != null)

         out.close();

     }

   }

   /**

    * Returns the value that is stored within this config

    * identified by the given key. If the key cannot be found

    * the default value is returned.

    * @param key Key to identify the value.

    * @param def The default value that is returned if the key

    * is not found in this Config.

    * @return

    */

   public String get(String key, String def)

   {

     return settings.getProperty(key, def);

   }

   /**

    * Sets the value for a given key.

    * @param key

    * @param value

    */

   public void set(final String key, final String value)

   {

     settings.setProperty(key, value);

   }

 }