/*

 *   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.Group;

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 volatile int connectedClients = 0;

	private Stats() {

	}

	/**

	 * 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) {

		try {

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

				Group group = StorageManager.current().getGroup(groupname);

				if (group != null) {

					StorageManager.current().addEvent(

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

				}

			} else {

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

			}

		} catch (StorageBackendException ex) {

			ex.printStackTrace();

		}

	}

	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 Group 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);

	}

}