Entity Potion Effect Event

src/main/java/ch/njol/skript/classes/data/BukkitClasses.java

@@ -61,6 +61,7 @@
 import org.bukkit.entity.Projectile;
 import org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason;
 import org.bukkit.event.entity.EntityDamageEvent.DamageCause;
+import org.bukkit.event.entity.EntityPotionEffectEvent;
 import org.bukkit.event.entity.EntityRegainHealthEvent.RegainReason;
 import org.bukkit.event.entity.EntityTransformEvent.TransformReason;
 import org.bukkit.event.inventory.ClickType;
@@ -1526,6 +1527,11 @@ public String toVariableNameString(EnchantmentOffer eo) {
 				.name("Transform Reason")
 				.description("Represents a transform reason of an <a href='events.html#entity transform'>entity transform event</a>.")
 				.since("2.8.0"));
+		Classes.registerClass(new EnumClassInfo<>(EntityPotionEffectEvent.Cause.class, "entitypotioncause", "entity potion causes")
+				.user("(entity )?potion ?effect ?cause")
+				.name("Entity Potion Cause")
+				.description("Represents the cause of the action of a potion effect on an entity, e.g. arrow, command")
+				.since("INSERT VERSION"));
 	}
 
 }

src/main/java/ch/njol/skript/classes/data/BukkitEventValues.java

@@ -109,6 +109,7 @@
 import org.bukkit.event.entity.EntityTeleportEvent;
 import org.bukkit.event.entity.EntityTransformEvent;
 import org.bukkit.event.entity.EntityTransformEvent.TransformReason;
+import org.bukkit.event.entity.EntityPotionEffectEvent;
 import org.bukkit.event.entity.FireworkExplodeEvent;
 import org.bukkit.event.entity.HorseJumpEvent;
 import org.bukkit.event.entity.ItemDespawnEvent;
@@ -178,6 +179,7 @@
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.PlayerInventory;
 import org.bukkit.inventory.Recipe;
+import org.bukkit.potion.PotionEffect;
 import org.bukkit.potion.PotionData;
 import org.bukkit.potion.PotionEffectType;
 import org.bukkit.potion.PotionType;
@@ -548,6 +550,33 @@ public DamageCause get(final EntityDeathEvent e) {
 				return ldc == null ? null : ldc.getCause();
 			}
 		}, 0);
+
+		// Entity Potion Effect
+		EventValues.registerEventValue(EntityPotionEffectEvent.class, PotionEffect.class, new Getter<PotionEffect, EntityPotionEffectEvent>() {
+			@Override
+			public PotionEffect get(EntityPotionEffectEvent event) {
+				return event.getOldEffect();
+			}
+		}, EventValues.TIME_PAST);
+		EventValues.registerEventValue(EntityPotionEffectEvent.class, PotionEffect.class, new Getter<PotionEffect, EntityPotionEffectEvent>() {
+			@Override
+			public PotionEffect get(EntityPotionEffectEvent event) {
+				return event.getNewEffect();
+			}
+		}, EventValues.TIME_NOW);
+		EventValues.registerEventValue(EntityPotionEffectEvent.class, PotionEffectType.class, new Getter<PotionEffectType, EntityPotionEffectEvent>() {
+			@Override
+			public PotionEffectType get(EntityPotionEffectEvent event) {
+				return event.getModifiedType();
+			}
+		}, EventValues.TIME_NOW);
+		EventValues.registerEventValue(EntityPotionEffectEvent.class, EntityPotionEffectEvent.Cause.class, new Getter<EntityPotionEffectEvent.Cause, EntityPotionEffectEvent>() {
+			@Override
+			public EntityPotionEffectEvent.Cause get(EntityPotionEffectEvent event) {
+				return event.getCause();
+			}
+		}, EventValues.TIME_NOW);
+
 		// ProjectileHitEvent
 		// ProjectileHitEvent#getHitBlock was added in 1.11
 		if (Skript.methodExists(ProjectileHitEvent.class, "getHitBlock"))

src/main/java/ch/njol/skript/events/EvtEntityPotion.java

@@ -0,0 +1,74 @@
+/**
+ *   This file is part of Skript.
+ *
+ *  Skript 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.
+ *
+ *  Skript 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 Skript.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright Peter Güttinger, SkriptLang team and contributors
+ */
+package ch.njol.skript.events;
+
+import ch.njol.skript.Skript;
+import ch.njol.skript.lang.Expression;
+import ch.njol.skript.lang.Literal;
+import ch.njol.skript.lang.SkriptEvent;
+import ch.njol.skript.lang.SkriptParser.ParseResult;
+import org.bukkit.event.Event;
+import org.bukkit.event.entity.EntityPotionEffectEvent;
+import org.bukkit.potion.PotionEffectType;
+
+import javax.annotation.Nullable;
+
+public class EvtEntityPotion extends SkriptEvent {
+
+	static {
+		Skript.registerEvent("Entity Potion Effect", EvtEntityPotion.class, EntityPotionEffectEvent.class,
+				"entity potion effect [modif[y|ication]] [[of] %-potioneffecttypes%] [due to %-entitypotioncause%]")
+			.description("Called when an entity's potion effect is modified.", "This modification can include adding, removing or changing their potion effect.")
+			.examples(
+				"on entity potion effect modification:",
+					"\t\tbroadcast \"A potion effect was added to %event-entity%!\" ",
+				"",
+				"on entity potion effect modification of night vision:")
+			.since("INSERT VERSION");
+	}
+
+	@SuppressWarnings("unchecked")
+	private Expression<PotionEffectType> potionEffects;
+	private Expression<EntityPotionEffectEvent.Cause> cause;
+
+	@Override
+	public boolean init(Literal<?>[] args, int matchedPattern, ParseResult parseResult) {
+		potionEffects = (Expression<PotionEffectType>) args[0];
+		cause = (Expression<EntityPotionEffectEvent.Cause>) args[1];
+		return true;
+	}
+
+	@Override
+	public boolean check(Event event) {
+		EntityPotionEffectEvent potionEvent = (EntityPotionEffectEvent) event;
+		boolean effectMatches = potionEffects == null ||
+			(potionEvent.getOldEffect() != null && potionEffects.check(event, effectType -> effectType.equals(potionEvent.getOldEffect().getType()))) ||
+			(potionEvent.getNewEffect() != null && potionEffects.check(event, effectType -> effectType.equals(potionEvent.getNewEffect().getType())));
+
+		boolean causeMatches = cause == null || cause.check(event, cause -> cause.equals(potionEvent.getCause()));
+
+		return effectMatches && causeMatches;
+	}
+
+
+	@Override
+	public String toString(@Nullable Event event, boolean debug) {
+		return "on entity potion effect modification";
+	}
+}

src/main/resources/lang/default.lang

@@ -2244,6 +2244,32 @@ environments:
 	the_end: end, the end
 	custom: custom
 
+
+entity potion causes:
+	area_effect_cloud: enter area effect cloud
+	arrow: arrow infliction
+	attack: attack
+	beacon: beacon effect
+	command: command
+	conduit: conduit effect
+	conversion: conversion, converted
+	death: death
+	dolphin: dolphin boost
+	expiration: expiration, expired
+	food: food
+	illusion: illusion
+	milk: drinking milk
+	plugin: plugin
+	potion_drink: potion drunk, drinking potion
+	potion_splash: potion splash, splash potion
+	spider_spawn: spider spawn, spawned spider
+	totem: removal by resurrection
+	turtle_helmet: turtle helmet effect
+	unknown: unknown
+	villager_trade: villager trade
+	patrol_captain: pillager captain, patrol captain
+	wither_rose: wither rose infliction
+
 # -- Moon Phases --
 moon phases:
 	first_quarter: first quarter