/*
 * Copyright (C) 2005, 2006 Aelitis, All Rights Reserved.
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * AELITIS, SAS au capital de 46,603.30 euros
 * 8 Allee Lenotre, La Grille Royale, 78600 Le Mesnil le Roi, France.
 * 
 */
package com.aelitis.azureus.plugins.startstoprules.defaultplugin;

import org.gudy.azureus2.core3.config.COConfigurationListener;
import org.gudy.azureus2.core3.config.COConfigurationManager;
import org.gudy.azureus2.core3.util.AEMonitor;
import org.gudy.azureus2.core3.util.SystemTime;
import org.gudy.azureus2.plugins.PluginConfig;
import org.gudy.azureus2.plugins.download.Download;
import org.gudy.azureus2.plugins.download.DownloadScrapeResult;
import org.gudy.azureus2.plugins.download.DownloadStats;
import org.gudy.azureus2.plugins.logging.LoggerChannel;

/**
 * @author TuxPaper
 * @created Dec 13, 2005
 *
 */
public class DefaultRankCalculator implements Comparable {
	/** All of the First Priority rules must match */
	public static final int FIRSTPRIORITY_ALL = 0;

	/** Any of the First Priority rules must match */
	public static final int FIRSTPRIORITY_ANY = 1;

	/** 
	 * Force torrent to be "Actively Seeding/Downloading" for this many ms upon
	 * start of torrent.
	 */
	private static final int FORCE_ACTIVE_FOR = 30000;

	/** 
	 * Wait XX ms before really changing activity (DL or CDing) state when
	 * state changes via speed change
	 */
	private static final int ACTIVE_CHANGE_WAIT = 10000;

	/** Maximium ranking that a torrent can get using the SPRATIO ranking type */
	private static int SPRATIO_BASE_LIMIT = 99999;

	/** 
	 * Amount to shift over the rank of the SEEDONLY ranking type, to make room
	 * in case the user has fallback to SPRATIO set.
	 */
	private static int SEEDONLY_SHIFT = SPRATIO_BASE_LIMIT + 1;

	/**
	 * For loading config settings
	 */
	private static COConfigurationListener configListener = null;

	//
	// Seeding Rank (SR) Limits and Values

	/** Rank that complete starts at (and incomplete ends at + 1) */
	public static final int SR_COMPLETE_STARTS_AT = 1000000000; // billion

	/** Maximimum ranking for time queue mode. 1 unit is a second */
	public static final int SR_TIMED_QUEUED_ENDS_AT = 999999; // 11.57 days

	/** Ranks below this value are for torrents to be ignored (moved to bottom & queued) */
	public static final int SR_IGNORED_LESS_THAN = -1;

	/** Seeding Rank value when download is marked as not queued */
	public static final int SR_NOTQUEUED = -2;

	/** Seeding Rank value when download is marked as S:P Ratio Met for FP */
	public static final int SR_FP_SPRATIOMET = -3;

	/** Seeding Rank value when download is marked as P:1S Ratio Met */
	public static final int SR_RATIOMET = -4;

	/** Seeding Rank value when download is marked as # Seeds Met */
	public static final int SR_NUMSEEDSMET = -5;

	/** Seeding Rank value when download is marked as 0 Peers and FP */
	public static final int SR_FP0PEERS = -6;

	/** Seeding Rank value when download is marked as 0 Peers */
	public static final int SR_0PEERS = -7;

	/** Seeding Rank value when download is marked as Share Ratio Met */
	public static final int SR_SHARERATIOMET = -8;

	//
	// Static config values

	/** Ranking System to use */
	protected static int iRankType = -1;

	/** Min # of Peers needed before boosting the rank of downloads with no seeds */
	private static int minPeersToBoostNoSeeds;

	/** Min Speed needed to count a incomplete download as being actively downloading */
	private static int minSpeedForActiveDL;

	/** Min speed needed to count a complete download as being actively seeding */
	private static int minSpeedForActiveSeeding;

	// Ignore torrent if seed count is at least..
	private static int iIgnoreSeedCount;

	// Ignore even when First Priority
	private static boolean bIgnore0Peers;

	private static int iIgnoreShareRatio;

	private static int iIgnoreShareRatio_SeedStart;

	private static int iIgnoreRatioPeers;

	private static int iIgnoreRatioPeers_SeedStart;

	private static int iRankTypeSeedFallback;

	private static boolean bPreferLargerSwarms;

	private static int minQueueingShareRatio;

	// Ignore First Priority
	private static int iFirstPriorityIgnoreSPRatio;

	private static boolean bFirstPriorityIgnore0Peer;

	private static int iFirstPriorityType;

	private static int iFirstPrioritySeedingMinutes;

	private static int iFirstPriorityDLMinutes;

	private static long minTimeAlive;

	private static boolean bAutoStart0Peers;

	//
	// Class variables

	protected Download dl;

	private boolean bActivelyDownloading;

	private long lDLActivelyChangedOn;

	private boolean bActivelySeeding;

	private long lCDActivelyChangedOn;

	private boolean bIsFirstPriority;

	/** Public for tooltip to access it */
	public String sExplainFP = "";

	/** Public for tooltip to access it */
	public String sExplainSR = "";

	/** Public for tooltip to access it */
	public String sTrace = "";

	private AEMonitor downloadData_this_mon = new AEMonitor(
			"StartStopRules:downloadData");

	private final StartStopRulesDefaultPlugin rules;

	/**
	 * Default Initializer
	 * 
	 * @param _rules
	 * @param _dl
	 */
	public DefaultRankCalculator(StartStopRulesDefaultPlugin _rules, Download _dl) {
		rules = _rules;
		dl = _dl;

		try {
			downloadData_this_mon.enter();

			if (configListener == null) {

				configListener = new COConfigurationListener() {
					public void configurationSaved() {
						reloadConfigParams(rules.plugin_config);
					}
				};

				COConfigurationManager.addListener(configListener);
				configListener.configurationSaved();
			}
		} finally {
			downloadData_this_mon.exit();
		}
	}

	/**
	 * Load config values into the static variables
	 * 
	 * @param cfg
	 */
	public static void reloadConfigParams(PluginConfig cfg) {
		final String PREFIX = "StartStopManager_";

		iRankType = cfg.getIntParameter(PREFIX + "iRankType");

		minPeersToBoostNoSeeds = cfg.getIntParameter(PREFIX
				+ "iMinPeersToBoostNoSeeds");
		minSpeedForActiveDL = cfg.getIntParameter(PREFIX + "iMinSpeedForActiveDL");
		minSpeedForActiveSeeding = cfg.getIntParameter(PREFIX
				+ "iMinSpeedForActiveSeeding");

		iRankTypeSeedFallback = cfg.getIntParameter(PREFIX
				+ "iRankTypeSeedFallback");
		bPreferLargerSwarms = cfg.getBooleanParameter(PREFIX
				+ "bPreferLargerSwarms");
		minTimeAlive = cfg.getIntParameter(PREFIX + "iMinSeedingTime") * 1000;
		bAutoStart0Peers = cfg.getBooleanParameter(PREFIX + "bAutoStart0Peers");

		// Ignore torrent if seed count is at least..
		iIgnoreSeedCount = cfg.getIntParameter(PREFIX + "iIgnoreSeedCount");
		bIgnore0Peers = cfg.getBooleanParameter(PREFIX + "bIgnore0Peers");
		iIgnoreShareRatio = (int) (1000 * cfg.getFloatParameter("Stop Ratio"));
		iIgnoreShareRatio_SeedStart = cfg.getIntParameter(PREFIX
				+ "iIgnoreShareRatioSeedStart");
		iIgnoreRatioPeers = cfg.getIntParameter("Stop Peers Ratio", 0);
		iIgnoreRatioPeers_SeedStart = cfg.getIntParameter(PREFIX
				+ "iIgnoreRatioPeersSeedStart", 0);

		minQueueingShareRatio = cfg.getIntParameter(PREFIX
				+ "iFirstPriority_ShareRatio");
		iFirstPriorityType = cfg.getIntParameter(PREFIX + "iFirstPriority_Type");
		iFirstPrioritySeedingMinutes = cfg.getIntParameter(PREFIX
				+ "iFirstPriority_SeedingMinutes");
		iFirstPriorityDLMinutes = cfg.getIntParameter(PREFIX
				+ "iFirstPriority_DLMinutes");
		// Ignore FP
		iFirstPriorityIgnoreSPRatio = cfg.getIntParameter(PREFIX
				+ "iFirstPriority_ignoreSPRatio");
		bFirstPriorityIgnore0Peer = cfg.getBooleanParameter(PREFIX
				+ "bFirstPriority_ignore0Peer");
	}

	/** Sort first by SeedingRank Descending, then by Position Ascending.
	 */
	public int compareTo(Object obj) {
		DefaultRankCalculator dlData = (DefaultRankCalculator) obj;
		// Test Completeness
		boolean aIsComplete = dlData.dl.getStats().getDownloadCompleted(false) == 1000;
		boolean bIsComplete = dl.getStats().getDownloadCompleted(false) == 1000;
		if (aIsComplete && !bIsComplete)
			return 1;
		if (!aIsComplete && bIsComplete)
			return -1;

		// Test FP
		if (dlData.bIsFirstPriority && !bIsFirstPriority)
			return 1;
		if (!dlData.bIsFirstPriority && bIsFirstPriority)
			return -1;

		if (iRankType == StartStopRulesDefaultPlugin.RANK_NONE) {
			return dl.getPosition() - dlData.dl.getPosition();
		}

		// Check Rank
		int value = dlData.dl.getSeedingRank() - dl.getSeedingRank();
		if (value != 0)
			return value;

		if (iRankType != StartStopRulesDefaultPlugin.RANK_TIMED) {
			// Test Large/Small Swarm pref
			int numPeersThem = rules.calcPeersNoUs(dlData.dl);
			int numPeersUs = rules.calcPeersNoUs(dl);
			if (bPreferLargerSwarms)
				value = numPeersThem - numPeersUs;
			else
				value = numPeersUs - numPeersThem;
			if (value != 0)
				return value;

			// Test Share Ratio
			int shareRatioUs = dl.getStats().getShareRatio();
			int shareRatioThem = dlData.dl.getStats().getShareRatio();
			value = shareRatioUs - shareRatioThem;
			if (value != 0)
				return value;
		}

		// Test Position
		return dl.getPosition() - dlData.dl.getPosition();
	}

	public Download getDownloadObject() {
		return dl;
	}

	/**
	 * Retrieves whether the torrent is "actively" downloading
	 * 
	 * @return true: actively downloading
	 */
	public boolean getActivelyDownloading() {
		boolean bIsActive = false;
		DownloadStats stats = dl.getStats();
		int state = dl.getState();

		// In order to be active,
		// - Must be downloading (and thus incomplete)
		// - Must be above speed threshold, or started less than 30s ago
		if (state != Download.ST_DOWNLOADING) {
			bIsActive = false;
		} else if (System.currentTimeMillis() - stats.getTimeStarted() <= FORCE_ACTIVE_FOR) {
			bIsActive = true;
		} else {
			// activity based on DL Average
			bIsActive = (stats.getDownloadAverage() >= minSpeedForActiveDL);

			if (bActivelyDownloading != bIsActive) {
				long now = System.currentTimeMillis();
				// Change
				if (lDLActivelyChangedOn == -1) {
					// Start Timer
					lDLActivelyChangedOn = now;
					bIsActive = !bIsActive;
				} else if (now - lDLActivelyChangedOn < ACTIVE_CHANGE_WAIT) {
					// Continue as old state until timer finishes
					bIsActive = !bIsActive;
				}
			} else {
				// no change, reset timer
				lDLActivelyChangedOn = -1;
			}
		}

		if (bActivelyDownloading != bIsActive) {
			bActivelyDownloading = bIsActive;
			if (rules != null) {
				rules.requestProcessCycle();
				if (rules.bDebugLog)
					rules.log.log(dl.getTorrent(), LoggerChannel.LT_INFORMATION,
							"somethingChanged: ActivelyDownloading changed");
			}
		}
		return bActivelyDownloading;
	}

	/**
	 * Retrieves whether the torrent is "actively" seeding
	 * 
	 * @return true: actively seeding
	 */
	public boolean getActivelySeeding() {
		boolean bIsActive = false;
		DownloadStats stats = dl.getStats();
		int state = dl.getState();
		// Timed torrents don't use a speed threshold, since they are based on time!
		// However, First Priorities need to be checked for activity so that 
		// timed ones can start when FPs are below threshold.  Ditto for 0 Peers
		// when bAutoStart0Peers
		if (iRankType == StartStopRulesDefaultPlugin.RANK_TIMED
				&& !isFirstPriority()
				&& !(bAutoStart0Peers && rules.calcPeersNoUs(dl) == 0 && scrapeResultOk(dl))) {
			bIsActive = (state == Download.ST_SEEDING);

		} else if (state != Download.ST_SEEDING
				|| (bAutoStart0Peers && rules.calcPeersNoUs(dl) == 0)) {
			// Not active if we aren't seeding
			// Not active if we are AutoStarting 0 Peers, and peer count == 0
			bIsActive = false;
		} else if (System.currentTimeMillis() - stats.getTimeStarted() <= FORCE_ACTIVE_FOR) {
			bIsActive = true;
		} else {
			bIsActive = (stats.getUploadAverage() >= minSpeedForActiveSeeding);

			if (bActivelySeeding != bIsActive) {
				long now = System.currentTimeMillis();
				// Change
				if (lCDActivelyChangedOn == -1) {
					// Start Timer
					lCDActivelyChangedOn = now;
					bIsActive = !bIsActive;
				} else if (now - lCDActivelyChangedOn < ACTIVE_CHANGE_WAIT) {
					// Continue as old state until timer finishes
					bIsActive = !bIsActive;
				}
			} else {
				// no change, reset timer
				lCDActivelyChangedOn = -1;
			}
		}

		if (bActivelySeeding != bIsActive) {
			bActivelySeeding = bIsActive;
			if (rules != null) {
				rules.requestProcessCycle();
				if (rules.bDebugLog)
					rules.log.log(dl.getTorrent(), LoggerChannel.LT_INFORMATION,
							"somethingChanged: ActivelySeeding changed");