/*

  *   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.config;

 import java.util.logging.Level;

 import org.sonews.util.Log;

 import org.sonews.storage.StorageBackendException;

 import org.sonews.storage.StorageManager;

 import org.sonews.util.TimeoutMap;

 /**

  * Provides access to the program wide configuration that is stored within

  * the server's database.

  * @author Christian Lins

  * @since sonews/0.5.0

  */

 class BackendConfig extends AbstractConfig

 {

   private static BackendConfig instance = new BackendConfig();

   public static BackendConfig getInstance()

   {

     return instance;

   }

   private final TimeoutMap<String, String> values 

     = new TimeoutMap<String, String>();

   private BackendConfig()

   {

     super();

   }

   /**

    * Returns the config value for the given key or the defaultValue if the

    * key is not found in config.

    * @param key

    * @param defaultValue

    * @return

    */

   @Override

   public String get(String key, String defaultValue)

   {

     try

     {

       String configValue = values.get(key);

       if(configValue == null)

       {

         if(StorageManager.current() == null)

         {

           Log.get().warning("BackendConfig not available, using default.");

           return defaultValue;

         }

         configValue = StorageManager.current().getConfigValue(key);

         if(configValue == null)

         {

           return defaultValue;

         }

         else

         {

           values.put(key, configValue);

           return configValue;

         }

       }

       else

       {

         return configValue;

       }

     }

     catch(StorageBackendException ex)

     {

       Log.get().log(Level.SEVERE, "Storage backend problem", ex);

       return defaultValue;

     }

   }

   /**

    * Sets the config value which is identified by the given key.

    * @param key

    * @param value

    */

   public void set(String key, String value)

   {

     values.put(key, value);

     try

     {

       // Write values to database

       StorageManager.current().setConfigValue(key, value);

     }

     catch(StorageBackendException ex)

     {

       ex.printStackTrace();

     }

   }

 }