/*

 *   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();

    }

  }

}