Add EngineGank

src/com/massivecraft/massivecore/EngineGank.java

@@ -0,0 +1,145 @@
+package com.massivecraft.massivecore;
+
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+import java.util.WeakHashMap;
+
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.entity.EntityDamageByEntityEvent;
+import org.bukkit.plugin.Plugin;
+
+import com.massivecraft.massivecore.EngineAbstract;
+import com.massivecraft.massivecore.MassiveCore;
+import com.massivecraft.massivecore.collections.MassiveMap;
+import com.massivecraft.massivecore.util.MUtil;
+
+public class EngineGank extends EngineAbstract
+{
+	// -------------------------------------------- //
+	// INSTANCE & CONSTRUCT
+	// -------------------------------------------- //
+	
+	private static EngineGank i = new EngineGank();
+	public static EngineGank get() { return i; }
+	public EngineGank() {}
+	
+	// -------------------------------------------- //
+	// OVERRIDE
+	// -------------------------------------------- //
+	
+	@Override
+	public Plugin getPlugin()
+	{
+		return MassiveCore.get();
+	}
+	
+	// -------------------------------------------- //
+	// PROTECTED
+	// -------------------------------------------- //
+	
+	// NOTE: The usage of WeakHashMap here is important. We would create a memory leak otherwise. WeakHashMap works very well for meta data storage.
+	protected WeakHashMap<Entity, WeakHashMap<Player, Double>> entityToPlayerDamages = new WeakHashMap<Entity, WeakHashMap<Player, Double>>();
+	
+	protected Map<Player, Double> getPlayerDamages(Entity entity, boolean store)
+	{
+		WeakHashMap<Player, Double> ret = this.entityToPlayerDamages.get(entity);
+		
+		if (ret == null)
+		{
+			ret = new WeakHashMap<Player, Double>(4);
+			if (store)
+			{
+				this.entityToPlayerDamages.put(entity, ret);
+			}
+		}
+		
+		return ret;
+	}
+	
+	// -------------------------------------------- //
+	// PUBLIC
+	// -------------------------------------------- //
+	
+	public Map<Player, Double> getPlayerDamages(Entity entity)
+	{
+		return this.getPlayerDamages(entity, false);
+	}
+	
+	public Set<Player> getPlayers(Entity entity)
+	{
+		return this.getPlayerDamages(entity).keySet();
+	}
+	
+	public Map<Player, Double> getPlayerQuotients(Entity entity)
+	{
+		// Get PlayerDamages
+		Map<Player, Double> playerDamages = getPlayerDamages(entity);
+		
+		// Calculate Total
+		double total = 0;
+		for (Double damage : playerDamages.values())
+		{
+			total += damage;
+		}
+		
+		// Create Ret
+		Map<Player, Double> ret = new MassiveMap<Player, Double>(playerDamages.size());
+		
+		// Fill Ret
+		for (Entry<Player, Double> playerDamage : playerDamages.entrySet())
+		{
+			Player player = playerDamage.getKey();
+			Double damage = playerDamage.getValue();
+			ret.put(player, damage / total);
+		}
+		
+		// Return Ret
+		return ret;
+	}
+	
+	// -------------------------------------------- //
+	// LISTENER
+	// -------------------------------------------- //
+	
+	@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onEntityDamage(EntityDamageByEntityEvent event)
+    {
+		// If an entity ...
+		Entity entity = event.getEntity();
+		
+		// ... takes damage ...
+		double damage = event.getDamage();
+		if (damage <= 0.1) return;
+		
+		// ... and the damager ...
+		Entity edamager = MUtil.getLiableDamager(event);
+		
+		// ... is a player ...
+		if ( ! (edamager instanceof Player)) return;
+		Player player = (Player)edamager;
+		
+		// ... that is not an NPC ...
+		if (player.hasMetadata("NPC")) return;
+		
+		// ... that is someone else ...
+		if (player.equals(entity)) return;
+		
+		// ... then get player damages ...
+		Map<Player, Double> playerDamages = this.getPlayerDamages(entity, true);
+		
+		// ... get player damage ...
+		Double playerDamage = playerDamages.get(player);
+		if (playerDamage == null) playerDamage = 0D;
+		
+		// ... increment ...
+		playerDamage += damage;
+		
+		// ... and set.
+		playerDamages.put(player, playerDamage);
+    }
+	
+}

src/com/massivecraft/massivecore/MassiveCore.java

@@ -183,6 +183,7 @@ public class MassiveCore extends MassivePlugin
 		MassiveCoreEngineDestination.get().activate();
 		PlayerUtil.get().activate();
 		EngineChestGui.get().activate();
+		EngineGank.get().activate();
 		
 		// Collections
 		MultiverseColl.get().init();