/*
    * #%L
    * bitrepository-access-client
    * *
    * $Id$
    * $HeadURL$
    * %%
    * Copyright (C) 2010 - 2011 The State and University Library, The Royal Library and The State Archives, Denmark
    * %%
   * This program is free software: you can redistribute it and/or modify
   * it under the terms of the GNU Lesser General Public License as 
   * published by the Free Software Foundation, either version 2.1 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 Lesser Public License for more details.
   * 
   * You should have received a copy of the GNU General Lesser Public 
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/lgpl-2.1.html>.
   * #L%
   */
  package org.bitrepository.alarm;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileReader;
  import java.io.IOException;
  import java.util.Properties;
  
  import org.bitrepository.alarm.handling.handlers.AlarmStorer;
  import org.bitrepository.alarm.store.AlarmDatabaseManager;
  import org.bitrepository.alarm.store.AlarmServiceDAO;
  import org.bitrepository.alarm.store.AlarmStore;
  import org.bitrepository.common.settings.Settings;
  import org.bitrepository.common.settings.XMLFileSettingsLoader;
  import org.bitrepository.protocol.ProtocolComponentFactory;
  import org.bitrepository.protocol.messagebus.MessageBus;
  import org.bitrepository.protocol.security.BasicMessageAuthenticator;
  import org.bitrepository.protocol.security.BasicMessageSigner;
  import org.bitrepository.protocol.security.BasicOperationAuthorizor;
  import org.bitrepository.protocol.security.BasicSecurityManager;
  import org.bitrepository.protocol.security.MessageAuthenticator;
  import org.bitrepository.protocol.security.MessageSigner;
  import org.bitrepository.protocol.security.OperationAuthorizor;
  import org.bitrepository.protocol.security.PermissionStore;
  import org.bitrepository.protocol.security.SecurityManager;
  import org.bitrepository.service.ServiceSettingsProvider;
  import org.bitrepository.service.contributor.ContributorMediator;
  import org.bitrepository.service.contributor.SimpleContributorMediator;
  import org.bitrepository.service.database.DatabaseManager;
  import org.bitrepository.settings.referencesettings.ServiceType;
  
  /**
   * Class for launching an alarm service.
   */
  public class AlarmServiceFactory {
      /** The alarm service. 
       * @see #getAlarmService().*/
      private static AlarmService alarmService;
      /** The path to the directory containing the configuration files.*/
      private static String configurationDir;
      /** The path to the private key file.*/
      private static String privateKeyFile;
      
      /** The properties file holding implementation specifics for the alarm service. */
      private static final String CONFIGFILE = "alarmservice.properties";
      /** Property key to tell where to locate the path and filename to the private key file. */
      private static final String PRIVATE_KEY_FILE = "org.bitrepository.alarm-service.privateKeyFile";
          
      /**
       * Private constructor as the class is meant to be used in a static way.
       */
      private AlarmServiceFactory() { }
      
      /**
       * Initialize the factory with configuration. 
       * @param confDir String containing the path to the AlarmService's configuration directory
       */
      public static synchronized void init(String confDir) {
          configurationDir = confDir;
      }
      
      /**
       * Factory method to retrieve AlarmService  
       * @return The AlarmService.
       */
      public static synchronized AlarmService getAlarmService() {
          if(alarmService == null) {
              MessageAuthenticator authenticator;
              MessageSigner signer;
              OperationAuthorizor authorizer;
              PermissionStore permissionStore;
              SecurityManager securityManager;
              ServiceSettingsProvider settingsLoader =
                      new ServiceSettingsProvider(new XMLFileSettingsLoader(configurationDir), ServiceType.ALARM_SERVICE);
  
             Settings settings = settingsLoader.getSettings();
             try {
                 loadProperties();
                 permissionStore = new PermissionStore();
                 authenticator = new BasicMessageAuthenticator(permissionStore);
                 signer = new BasicMessageSigner();
                 authorizer = new BasicOperationAuthorizor(permissionStore);
                 securityManager = new BasicSecurityManager(settings.getRepositorySettings(), privateKeyFile,
                         authenticator, signer, authorizer, permissionStore, 
                         settings.getReferenceSettings().getAlarmServiceSettings().getID());
                 
                 MessageBus messageBus = ProtocolComponentFactory.getInstance().getMessageBus(settings, 
                         securityManager);
                 ContributorMediator contributorMediator = new SimpleContributorMediator(messageBus, settings, null);
                 
                 DatabaseManager alarmDatabaseManager = new AlarmDatabaseManager(
                         settings.getReferenceSettings().getAlarmServiceSettings().getAlarmServiceDatabase());
                 AlarmStore store = new AlarmServiceDAO(alarmDatabaseManager);
                 alarmService = new BasicAlarmService(messageBus, settings, store, contributorMediator);
                 
                 // Add the default handler for putting the alarms into the database.
                 alarmService.addHandler(new AlarmStorer(store));
             } catch (IOException e) {
                 throw new RuntimeException(e);
             }
         }
         
         return alarmService;
     }
     
     /**
      * Loads the properties.
      * @throws IOException If any input/output issues occurs.
      */
     private static void loadProperties() throws IOException {
         Properties properties = new Properties();
         File propertiesFile = new File(configurationDir, CONFIGFILE);
         BufferedReader propertiesReader = new BufferedReader(new FileReader(propertiesFile));
         properties.load(propertiesReader);
         privateKeyFile = properties.getProperty(PRIVATE_KEY_FILE);
     }
 }