/*
    * #%L
    * Bitrepository Monitoring Service
    * %%
    * Copyright (C) 2010 - 2012 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.monitoringservice.alarm;
  
  import java.math.BigInteger;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  import org.bitrepository.bitrepositoryelements.Alarm;
  import org.bitrepository.bitrepositoryelements.AlarmCode;
  import org.bitrepository.common.settings.Settings;
  import org.bitrepository.monitoringservice.status.ComponentStatus;
  import org.bitrepository.monitoringservice.status.StatusStore;
  import org.bitrepository.protocol.messagebus.MessageSender;
  import org.bitrepository.service.AlarmDispatcher;
  import org.bitrepository.settings.referencesettings.AlarmLevel;
  
  /**
   * Class for the monitoring service keep a watch on non responding components, and send alarms if needed.
   */
  public class BasicMonitoringServiceAlerter extends AlarmDispatcher implements MonitorAlerter {
      /** The store for the status results from the components.*/
      private final StatusStore statusStore;
      /** The maximum number of missing replies before an alarm is dispatched.*/
      private final BigInteger maxRetries;
      
      /**
       * @param statusStore The store for the status results from the components.
       * @param sender Used for sending the alarms.
       * @param alarmLevel Only send alarms at this alarms level or higher.
       * @param statusStore Used to maintain the status of the components.
       */
      public BasicMonitoringServiceAlerter(
          Settings settings, MessageSender sender, AlarmLevel alarmLevel, StatusStore statusStore) {
          super(settings, sender, alarmLevel);
          this.statusStore = statusStore;
          maxRetries = settings.getReferenceSettings().getMonitoringServiceSettings().getMaxRetries();
      }
      
      @Override
      public void checkStatuses() {
          Map<String, ComponentStatus> statusMap = statusStore.getStatusMap();
          List<String> nonRespondingComponents = new ArrayList<String>();
          for(String ID : statusMap.keySet()) {
              ComponentStatus componentStatus = statusMap.get(ID);
              if(componentStatus.getNumberOfMissingReplies() >= maxRetries.intValue()) {
                  componentStatus.markAsUnresponsive();
                  if(!componentStatus.hasAlarmed()) {
                  	nonRespondingComponents.add(ID);
                  	componentStatus.alarmed();
                  }
              }
          }
          
          if(!nonRespondingComponents.isEmpty()) {
              Alarm alarm = new Alarm();
              alarm.setAlarmCode(AlarmCode.COMPONENT_FAILURE);
              alarm.setAlarmText("The following components has become unresponsive: " 
                      + nonRespondingComponents.toString());
              error(alarm);
          }
      }
  }