Adds Loot Tables (#7242)

* Add Loot Tables

* Optimize Imports

* Fix docs and add a registry class info

* Changes

* remove license thing

* Add converter for LootTables - LootTable,
Change toString for LootTable class info,
Change syntax

* add tests ? unsure if theyre correct and add expressions to get luck/killer/entity of context

* Replace current implementation to module, add NameSpacedUtils class from the Recipe pull request, and changes

* Add docs, optimize imports and changes

* Change syntax and add some tests

* Fix docs, fix tests, replace paper methods to bukkit ones and changes

* one silly thing hehe

* Add JUnit tests, fix tests and changes

* Fix JUnit test

* ok junit test

* fix tests

* Optimize imports and fix description of EffGenerateLoot and ExprLootItems

* Clean up LootTableUtils and update docs

* update tests

* add loot table type in the default.lang file

* Fix the seed expression not actually updating the state

* optimize imports

* change exampled for loot table seed

* Add default event value for LootTable in LootGenerate event

* Add escape character for colons

* Add LootContext event value in LootGenerateEvent

* Make cached loot context transient

* changes

* tests and fix docs

* alot of things

* fix toString

* remove consumer

* fix tests

* optimize imports

* Fix exception in Java 17

* hopefully one last thing

* move LootGenerateEvent and event values to module class because idk why i didn't have it there

* optimize imports and another one

* pickel era changes

* update tests

* more pickel era changes

* uh oh

* more uh ohs

* even more uh ohs

* we dont talk about it

* small changes

* optimize le importos

* even more pickel era changes

* wow pickel has alot of changes

* Move ExprLoot to module and clean it up

* changes

---------

Co-authored-by: Moderocky <admin@moderocky.com>
Co-authored-by: Efnilite <35348263+Efnilite@users.noreply.github.com>

src/main/java/ch/njol/skript/Skript.java

@@ -98,6 +98,7 @@
 import org.skriptlang.skript.bukkit.displays.DisplayModule;
 import org.skriptlang.skript.bukkit.fishing.FishingModule;
 import org.skriptlang.skript.bukkit.input.InputModule;
+import org.skriptlang.skript.bukkit.loottables.LootTableModule;
 import org.skriptlang.skript.lang.comparator.Comparator;
 import org.skriptlang.skript.lang.comparator.Comparators;
 import org.skriptlang.skript.lang.converter.Converter;
@@ -549,6 +550,7 @@ public void onEnable() {
 			BreedingModule.load();
 			DisplayModule.load();
 			InputModule.load();
+			LootTableModule.load();
 		} catch (final Exception e) {
 			exception(e, "Could not load required .class files: " + e.getLocalizedMessage());
 			setEnabled(false);

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

@@ -1629,24 +1629,6 @@ public ItemType get(PlayerStopUsingItemEvent event) {
 			}, EventValues.TIME_NOW);
 		}
 
-		// LootGenerateEvent
-		if (Skript.classExists("org.bukkit.event.world.LootGenerateEvent")) {
-			EventValues.registerEventValue(LootGenerateEvent.class, Entity.class, new Getter<Entity, LootGenerateEvent>() {
-				@Override
-				@Nullable
-				public Entity get(LootGenerateEvent event) {
-					return event.getEntity();
-				}
-			}, EventValues.TIME_NOW);
-			EventValues.registerEventValue(LootGenerateEvent.class, Location.class, new Getter<Location, LootGenerateEvent>() {
-				@Override
-				@Nullable
-				public Location get(LootGenerateEvent event) {
-					return event.getLootContext().getLocation();
-				}
-			}, EventValues.TIME_NOW);
-		}
-
 		// EntityResurrectEvent
 		EventValues.registerEventValue(EntityResurrectEvent.class, Slot.class, new Getter<Slot, EntityResurrectEvent>() {
 			@Override

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

@@ -602,21 +602,7 @@ public class SimpleEvents {
 				"\t\tset chat format to \"<orange>[player]<light gray>: <white>[message]\""
 			)
 			.since("1.4.1");
-		if (Skript.classExists("org.bukkit.event.world.LootGenerateEvent")) {
-			Skript.registerEvent("Loot Generate", SimpleEvent.class, LootGenerateEvent.class, "loot generat(e|ing)")
-					.description(
-						"Called when a loot table of an inventory is generated in the world.",
-						"For example, when opening a shipwreck chest."
-					)
-					.examples(
-						"on loot generate:",
-						"\tchance of 10%",
-						"\tadd 64 diamonds to the loot",
-						"\tsend \"You hit the jackpot at %event-location%!\""
-					)
-					.since("2.7")
-					.requiredPlugins("MC 1.16+");
-		}
+
 		if (Skript.classExists("io.papermc.paper.event.player.PlayerDeepSleepEvent")) {
 			Skript.registerEvent("Player Deep Sleep", SimpleEvent.class, PlayerDeepSleepEvent.class, "[player] deep sleep[ing]")
 					.description(

src/main/java/org/skriptlang/skript/bukkit/loottables/LootContextCreateEvent.java

@@ -0,0 +1,27 @@
+package org.skriptlang.skript.bukkit.loottables;
+
+import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
+import org.skriptlang.skript.bukkit.loottables.elements.expressions.ExprSecCreateLootContext;
+
+/**
+ * The event used in the {@link ExprSecCreateLootContext} section.
+ */
+public class LootContextCreateEvent extends Event {
+
+	private final LootContextWrapper contextWrapper;
+
+	public LootContextCreateEvent(LootContextWrapper context) {
+		this.contextWrapper = context;
+	}
+
+	public LootContextWrapper getContextWrapper() {
+		return contextWrapper;
+	}
+
+	@Override
+	public HandlerList getHandlers() {
+		throw new UnsupportedOperationException();
+	}
+
+}

src/main/java/org/skriptlang/skript/bukkit/loottables/LootContextWrapper.java

@@ -0,0 +1,112 @@
+package org.skriptlang.skript.bukkit.loottables;
+
+import org.bukkit.Location;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Player;
+import org.bukkit.loot.LootContext;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Wrapper for a LootContext.Builder to allow easier creation of LootContexts.
+ */
+public class LootContextWrapper {
+
+	private @NotNull Location location;
+	private transient @Nullable LootContext cachedLootContext;
+	private @Nullable Player killer;
+	private @Nullable Entity entity;
+	private float luck;
+
+	/**
+	 * Creates a new LootContextWrapper at the given location.
+	 * @param location the location of the LootContext.
+	 */
+	public LootContextWrapper(@NotNull Location location) {
+        this.location = location;
+	}
+
+	/**
+	 * Gets the LootContext from the wrapper.
+	 * @return the LootContext.
+	 */
+	public LootContext getContext() {
+		if (cachedLootContext == null)
+			cachedLootContext = new LootContext.Builder(location)
+				.killer(killer)
+				.lootedEntity(entity)
+				.luck(luck)
+				.build();
+
+		return cachedLootContext;
+	}
+
+	/**
+	 * Sets the location of the LootContext.
+	 * @param location the location.
+	 */
+	public void setLocation(@NotNull Location location) {
+		this.location = location;
+		cachedLootContext = null;
+	}
+
+	/**
+	 * Sets the killer of the LootContext.
+	 * @param killer the killer.
+	 */
+	public void setKiller(@Nullable Player killer) {
+		this.killer = killer;
+		cachedLootContext = null;
+	}
+
+	/**
+	 * Sets the entity of the LootContext.
+	 * @param entity the entity.
+	 */
+	public void setEntity(@Nullable Entity entity) {
+		this.entity = entity;
+		cachedLootContext = null;
+	}
+
+	/**
+	 * Sets the luck of the LootContext.
+	 * @param luck the luck value.
+	 */
+	public void setLuck(float luck) {
+		this.luck = luck;
+		cachedLootContext = null;
+	}
+
+	/**
+	 * Gets the location of the LootContext.
+	 * @return the location.
+	 */
+	public Location getLocation() {
+		return location;
+	}
+
+	/**
+	 * Gets the killer of the LootContext.
+	 * @return the killer.
+	 */
+	public @Nullable Player getKiller() {
+		return killer;
+	}
+
+	/**
+	 * Gets the entity of the LootContext.
+	 * @return the entity.
+	 */
+	public @Nullable Entity getEntity() {
+		return entity;
+	}
+
+	/**
+	 * Gets the luck of the LootContext.
+	 * @return the luck value.
+	 */
+	public float getLuck() {
+		return luck;
+	}
+
+}

src/main/java/org/skriptlang/skript/bukkit/loottables/LootTableModule.java

@@ -0,0 +1,127 @@
+package org.skriptlang.skript.bukkit.loottables;
+
+import ch.njol.skript.Skript;
+import ch.njol.skript.classes.ClassInfo;
+import ch.njol.skript.classes.Parser;
+import ch.njol.skript.expressions.base.EventValueExpression;
+import ch.njol.skript.lang.ParseContext;
+import ch.njol.skript.lang.util.SimpleEvent;
+import ch.njol.skript.registrations.Classes;
+import ch.njol.skript.registrations.EventValues;
+import org.bukkit.Bukkit;
+import org.bukkit.Location;
+import org.bukkit.NamespacedKey;
+import org.bukkit.entity.Entity;
+import org.bukkit.event.world.LootGenerateEvent;
+import org.bukkit.loot.LootContext;
+import org.bukkit.loot.LootTable;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.IOException;
+
+public class LootTableModule {
+
+	public static void load() throws IOException {
+
+		// --- CLASSES --- //
+
+		Classes.registerClass(new ClassInfo<>(LootTable.class, "loottable")
+			.user("loot ?tables?")
+			.name("Loot Table")
+			.description(
+				"Loot tables represent what items should be in naturally generated containers, "
+					+ "what items should be dropped when killing a mob, or what items can be fished.",
+				"You can find more information about this in https://minecraft.wiki/w/Loot_table"
+			)
+			.since("INSERT VERSION")
+			.parser(new Parser<>() {
+				@Override
+				public @Nullable LootTable parse(String key, ParseContext context) {
+					NamespacedKey namespacedKey = NamespacedKey.fromString(key);
+					if (namespacedKey == null)
+						return null;
+					return Bukkit.getLootTable(namespacedKey);
+				}
+
+				@Override
+				public String toString(LootTable o, int flags) {
+					return "loot table \"" + o.getKey() + '\"';
+				}
+
+				@Override
+				public String toVariableNameString(LootTable o) {
+					return "loot table:" + o.getKey();
+				}
+			})
+		);
+
+		Classes.registerClass(new ClassInfo<>(LootContext.class, "lootcontext")
+			.user("loot ?contexts?")
+			.name("Loot Context")
+			.description(
+				"Represents additional information a loot table can use to modify its generated loot.",
+				"",
+				"Some loot tables will require some values (i.e. looter, location, looted entity) "
+					+ "in a loot context when generating loot whereas others may not.",
+				"For example, the loot table of a simple dungeon chest will only require a location, "
+					+ "whereas the loot table of a cow will require a looting player, looted entity, and location.",
+				"You can find more information about this in https://minecraft.wiki/w/Loot_context"
+			)
+			.since("INSERT VERSION")
+			.defaultExpression(new EventValueExpression<>(LootContext.class))
+			.parser(new Parser<>() {
+				@Override
+				public boolean canParse(ParseContext context) {
+					return false;
+				}
+
+				@Override
+				public String toString(LootContext context, int flags) {
+					StringBuilder builder = new StringBuilder("loot context at ")
+						.append(Classes.toString(context.getLocation()));
+
+					if (context.getLootedEntity() != null)
+						builder.append(" with entity ").append(Classes.toString(context.getLootedEntity()));
+					if (context.getKiller() != null)
+						builder.append(" with killer ").append(Classes.toString(context.getKiller()));
+					if (context.getLuck() != 0)
+						builder.append(" with luck ").append(context.getLuck());
+
+					return builder.toString();
+				}
+
+				@Override
+				public String toVariableNameString(LootContext context) {
+					return "loot context:" + context.hashCode();
+				}
+			})
+		);
+
+		Skript.getAddonInstance().loadClasses("org.skriptlang.skript.bukkit.loottables", "elements");
+
+		// --- SIMPLE EVENTS --- //
+
+		Skript.registerEvent("Loot Generate", SimpleEvent.class, LootGenerateEvent.class, "loot generat(e|ing)")
+			.description(
+				"Called when a loot table of an inventory is generated in the world.",
+				"For example, when opening a shipwreck chest."
+			)
+			.examples(
+				"on loot generate:",
+					"\tchance of 10%",
+					"\tadd 64 diamonds to the loot",
+					"\tsend \"You hit the jackpot at %event-location%!\""
+			)
+			.since("2.7")
+			.requiredPlugins("MC 1.16+");
+
+		// --- EVENT VALUES --- //
+
+		// LootGenerateEvent
+		EventValues.registerEventValue(LootGenerateEvent.class, Entity.class, LootGenerateEvent::getEntity);
+		EventValues.registerEventValue(LootGenerateEvent.class, Location.class, event -> event.getLootContext().getLocation());
+		EventValues.registerEventValue(LootGenerateEvent.class, LootTable.class, LootGenerateEvent::getLootTable);
+		EventValues.registerEventValue(LootGenerateEvent.class, LootContext.class, LootGenerateEvent::getLootContext);
+	}
+
+}

src/main/java/org/skriptlang/skript/bukkit/loottables/LootTableUtils.java

@@ -0,0 +1,55 @@
+package org.skriptlang.skript.bukkit.loottables;
+
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockState;
+import org.bukkit.loot.LootTable;
+import org.bukkit.loot.Lootable;
+
+/**
+ * Utility class for loot tables.
+ */
+public class LootTableUtils {
+
+	/**
+	 * * Checks whether a block or entity is an instance of {@link Lootable}. This is done because a block is not an instance of Lootable, but a block state is.
+	 * @param object the object to check.
+	 * @return whether the object is lootable.
+	 */
+	public static boolean isLootable(Object object) {
+		if (object instanceof Block block)
+			object = block.getState();
+		return object instanceof Lootable;
+	}
+
+	/**
+	 * Gets the Lootable instance of an object. You should call {@link #isLootable(Object)} before calling this method.
+	 * @param object the object to get the Lootable instance of.
+	 * @return the Lootable instance of the object.
+	 */
+	public static Lootable getAsLootable(Object object) {
+		if (object instanceof Block block)
+			object = block.getState();
+		if (object instanceof Lootable lootable)
+			return lootable;
+		return null;
+	}
+
+	/**
+	 * Gets the loot table of an object. You should call {@link #isLootable(Object)} before calling this method.
+	 * @param object the object to get the loot table of.
+	 * @return returns the LootTable of the object.
+	 */
+	public static LootTable getLootTable(Object object) {
+		return getAsLootable(object).getLootTable();
+	}
+
+	/**
+	 * Updates the state of a Lootable. This is done because setting the LootTable or seed of a BlockState changes the NBT value, but is never updated.
+	 * @param lootable the Lootable to update the state of.
+	 */
+	public static void updateState(Lootable lootable) {
+		if (lootable instanceof BlockState blockState)
+			blockState.update(true, false);
+	}
+
+}