From 296d0cbdb2cceea190499ac7717ee005418ad5b6 Mon Sep 17 00:00:00 2001
From: Olof Larsson <olof@sylt.nu>
Date: Tue, 27 Aug 2013 10:56:11 +0200
Subject: [PATCH] Add in a system to detect if a PlayerDeathEvent is an invalid
 duplicate event.

---
 src/com/massivecraft/mcore/MCore.java         |  2 +-
 .../massivecraft/mcore/util/PlayerUtil.java   | 74 ++++++++++++++++---
 2 files changed, 65 insertions(+), 11 deletions(-)

diff --git a/src/com/massivecraft/mcore/MCore.java b/src/com/massivecraft/mcore/MCore.java
index caadb922..a5d1d0a2 100644
--- a/src/com/massivecraft/mcore/MCore.java
+++ b/src/com/massivecraft/mcore/MCore.java
@@ -135,7 +135,6 @@ public class MCore extends MPlugin
 		//db = MStore.getDb(ConfServer.dburi);
 		
 		// Setup PlayerUtil and it's events
-		new PlayerUtil(this);
 		SenderIdMixinDefault.get().setup();
 		
 		// Register events
@@ -144,6 +143,7 @@ public class MCore extends MPlugin
 		TeleportMixinCauseEngine.get().setup();
 		EngineWorldNameSet.get().setup();
 		EngineOfflineCase.get().setup();
+		PlayerUtil.get().setup();
 		
 		// Schedule the collection ticker.
 		Bukkit.getScheduler().scheduleSyncRepeatingTask(this, this.collTickTask, 1, 1);
diff --git a/src/com/massivecraft/mcore/util/PlayerUtil.java b/src/com/massivecraft/mcore/util/PlayerUtil.java
index 51fe9b18..7202fa83 100644
--- a/src/com/massivecraft/mcore/util/PlayerUtil.java
+++ b/src/com/massivecraft/mcore/util/PlayerUtil.java
@@ -1,5 +1,7 @@
 package com.massivecraft.mcore.util;
 
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentSkipListSet;
 
@@ -12,35 +14,87 @@ import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.EventPriority;
 import org.bukkit.event.Listener;
+import org.bukkit.event.entity.PlayerDeathEvent;
 import org.bukkit.event.player.PlayerJoinEvent;
 import org.bukkit.event.player.PlayerQuitEvent;
-import org.bukkit.plugin.Plugin;
 
 import com.massivecraft.mcore.MCore;
 
 public class PlayerUtil implements Listener
 {
+	// -------------------------------------------- //
+	// INSTANCE & CONSTRUCT
+	// -------------------------------------------- //
+	
+	private static PlayerUtil i = new PlayerUtil();
+	public static PlayerUtil get() { return i; }
+	
 	// -------------------------------------------- //
 	// FIELDS
 	// -------------------------------------------- //
 	
-	protected static Set<String> joinedPlayerNames = new ConcurrentSkipListSet<String>(String.CASE_INSENSITIVE_ORDER);
+	private static Set<String> joinedPlayerNames = new ConcurrentSkipListSet<String>(String.CASE_INSENSITIVE_ORDER);
+	
+	private static Map<String, PlayerDeathEvent> lowercaseToDeath = new HashMap<String, PlayerDeathEvent>();
 	
 	// -------------------------------------------- //
-	// CONSTRUCTOR AND EVENT LISTENER
+	// SETUP
 	// -------------------------------------------- //
 	
-	public PlayerUtil(Plugin plugin)
+	public void setup()
 	{
-		Bukkit.getPluginManager().registerEvents(this, plugin);
-		
 		joinedPlayerNames.clear();
 		for (Player player : Bukkit.getOnlinePlayers())
 		{
 			joinedPlayerNames.add(player.getName());
 		}
+		
+		Bukkit.getPluginManager().registerEvents(this, MCore.get());
 	}
 	
+	// -------------------------------------------- //
+	// IS DUPLICATE DEATH EVENT
+	// -------------------------------------------- //
+	// Some times when players die the PlayerDeathEvent is fired twice.
+	// We want to ignore the extra calls.
+	
+	public static boolean isDuplicateDeathEvent(PlayerDeathEvent event)
+	{
+		// Prepare the lowercase name ...
+		final String lowercase = event.getEntity().getName().toLowerCase();
+		
+		// ... take a look at the currently stored event ...
+		PlayerDeathEvent current = lowercaseToDeath.get(lowercase);
+		
+		if (current != null) return !current.equals(event);
+		
+		// ... otherwise store ... 
+		lowercaseToDeath.put(lowercase, event);
+		
+		// ... schedule removal ...
+		Bukkit.getScheduler().scheduleSyncDelayedTask(MCore.get(), new Runnable()
+		{
+			@Override
+			public void run()
+			{
+				lowercaseToDeath.remove(lowercase);
+			}
+		});
+		
+		// ... and return the fact that it was not a duplicate.
+		return false;
+	}
+	
+	@EventHandler(priority = EventPriority.LOWEST)
+	public void isDuplicateDeathEventLowest(PlayerDeathEvent event)
+	{
+		isDuplicateDeathEvent(event);
+	}
+	
+	// -------------------------------------------- //
+	// IS JOINED
+	// -------------------------------------------- //
+	
 	@EventHandler(priority = EventPriority.MONITOR)
 	public void joinMonitor(PlayerJoinEvent event)
 	{
@@ -62,16 +116,16 @@ public class PlayerUtil implements Listener
 		joinedPlayerNames.remove(playerName);
 	}
 	
-	// -------------------------------------------- //
-	// PUBLIC METHODS
-	// -------------------------------------------- //
-	
 	public static boolean isJoined(Player player)
 	{
 		if (player == null) throw new NullPointerException("player was null");
 		return joinedPlayerNames.contains(player.getName());
 	}
 	
+	// -------------------------------------------- //
+	// PACKET
+	// -------------------------------------------- //
+	
 	/**
 	 * Updates the players food and health information.
 	 */