/*

  *   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.util;

 import java.util.Calendar;

 import org.sonews.config.Config;

 import org.sonews.storage.Channel;

 import org.sonews.storage.StorageBackendException;

 import org.sonews.storage.StorageManager;

 /**

  * Class that capsulates statistical data gathering.

  * @author Christian Lins

  * @since sonews/0.5.0

  */

 public final class Stats 

 {

   public static final byte CONNECTIONS    = 1;

   public static final byte POSTED_NEWS    = 2;

   public static final byte GATEWAYED_NEWS = 3;

   public static final byte FEEDED_NEWS    = 4;

   public static final byte MLGW_RUNSTART  = 5;

   public static final byte MLGW_RUNEND    = 6;

   private static Stats instance = new Stats();

   public static Stats getInstance()

   {

     return Stats.instance;

   }

   private Stats() {}

   private volatile int connectedClients = 0;

   /**

    * A generic method that writes event data to the storage backend.

    * If event logging is disabled with sonews.eventlog=false this method

    * simply does nothing.

    * @param type

    * @param groupname

    */

   private void addEvent(byte type, String groupname)

   {

     if(Config.inst().get(Config.EVENTLOG, true))

     {

       Channel group = Channel.getByName(groupname);

       if(group != null)

       {

         try

         {

           StorageManager.current().addEvent(

             System.currentTimeMillis(), type, group.getInternalID());

         }

         catch(StorageBackendException ex)

         {

           ex.printStackTrace();

         }

       }

       else

       {

         Log.get().info("Group " + groupname + " does not exist.");

       }

     }

   }

   public void clientConnect()

   {

     this.connectedClients++;

   }

   public void clientDisconnect()

   {

     this.connectedClients--;

   }

   public int connectedClients()

   {

     return this.connectedClients;

   }

   public int getNumberOfGroups()

   {

     try

     {

       return StorageManager.current().countGroups();

     }

     catch(StorageBackendException ex)

     {

       ex.printStackTrace();

       return -1;

     }

   }

   public int getNumberOfNews()

   {

     try

     {

       return StorageManager.current().countArticles();

     }

     catch(StorageBackendException ex)

     {

       ex.printStackTrace();

       return -1;

     }

   }

   public int getYesterdaysEvents(final byte eventType, final int hour,

     final Channel group)

   {

     // Determine the timestamp values for yesterday and the given hour

     Calendar cal = Calendar.getInstance();

     int year  = cal.get(Calendar.YEAR);

     int month = cal.get(Calendar.MONTH);

     int dayom = cal.get(Calendar.DAY_OF_MONTH) - 1; // Yesterday

     cal.set(year, month, dayom, hour, 0, 0);

     long startTimestamp = cal.getTimeInMillis();

     cal.set(year, month, dayom, hour + 1, 0, 0);

     long endTimestamp = cal.getTimeInMillis();

     try

     {

       return StorageManager.current()

         .getEventsCount(eventType, startTimestamp, endTimestamp, group);

     }

     catch(StorageBackendException ex)

     {

       ex.printStackTrace();

       return -1;

     }

   }

   public void mailPosted(String groupname)

   {

     addEvent(POSTED_NEWS, groupname);

   }

   public void mailGatewayed(String groupname)

   {

     addEvent(GATEWAYED_NEWS, groupname);

   }

   public void mailFeeded(String groupname)

   {

     addEvent(FEEDED_NEWS, groupname);

   }

   public void mlgwRunStart()

   {

     addEvent(MLGW_RUNSTART, "control");

   }

   public void mlgwRunEnd()

   {

     addEvent(MLGW_RUNEND, "control");

   }

   private double perHour(int key, long gid)

   {

     try

     {

       return StorageManager.current().getEventsPerHour(key, gid);

     }

     catch(StorageBackendException ex)

     {

       ex.printStackTrace();

       return -1;

     }

   }

   public double postedPerHour(long gid)

   {

     return perHour(POSTED_NEWS, gid);

   }

   public double gatewayedPerHour(long gid)

   {

     return perHour(GATEWAYED_NEWS, gid);

   }

   public double feededPerHour(long gid)

   {

     return perHour(FEEDED_NEWS, gid);

   }

 }