add item model support

src/main/java/org/skriptlang/skript/bukkit/item/ItemModule.java

@@ -24,7 +24,9 @@ public Iterable<AddonModule> children() {
 	@Override
 	public void loadSelf(SkriptAddon addon) {
 		register(addon,
+			ExprItemModel::register,
 			ExprItemWithLore::register,
+			ExprItemWithModel::register,
 			ExprLore::register
 		);
 	}

src/main/java/org/skriptlang/skript/bukkit/item/elements/ExprItemModel.java

@@ -0,0 +1,83 @@
+package org.skriptlang.skript.bukkit.item.elements;
+
+import ch.njol.skript.aliases.ItemType;
+import ch.njol.skript.bukkitutil.NamespacedUtils;
+import ch.njol.skript.classes.Changer.ChangeMode;
+import ch.njol.skript.doc.Description;
+import ch.njol.skript.doc.Example;
+import ch.njol.skript.doc.Name;
+import ch.njol.skript.doc.Since;
+import ch.njol.skript.expressions.base.SimplePropertyExpression;
+import ch.njol.util.coll.CollectionUtils;
+import org.bukkit.NamespacedKey;
+import org.bukkit.event.Event;
+import org.bukkit.inventory.meta.ItemMeta;
+import org.jetbrains.annotations.Nullable;
+import org.skriptlang.skript.registration.SyntaxRegistry;
+
+import static ch.njol.skript.classes.Changer.ChangeMode.SET;
+
+@Name("Item Model")
+@Description("The item model of an item. Accepts a Namespaced Key (e.g. 'minecraft:emerald').")
+@Example("""
+	set the item model of player's held item to "diamond"
+	set the item model of {_item} to "minecraft:dirt"
+	""")
+@Since("INSERT VERSION")
+public class ExprItemModel extends SimplePropertyExpression<ItemType, String> {
+
+	public static void register(SyntaxRegistry syntaxRegistry) {
+		syntaxRegistry.register(
+			SyntaxRegistry.EXPRESSION,
+			infoBuilder(ExprItemModel.class, String.class, "item model", "itemtypes", true)
+				.supplier(ExprItemModel::new)
+				.build()
+		);
+	}
+
+	@Override
+	public @Nullable String convert(ItemType from) {
+		NamespacedKey key = from.getItemMeta().getItemModel();
+		if (key == null)
+			return null;
+
+		return key.asString();
+	}
+
+	@Override
+	public Class<?> @Nullable [] acceptChange(ChangeMode mode) {
+		return switch (mode) {
+			case SET, DELETE, RESET -> CollectionUtils.array(String.class);
+			default -> null;
+		};
+	}
+
+	@Override
+	public void change(Event event, Object @Nullable [] delta, ChangeMode mode) {
+		NamespacedKey key = null;
+		if (mode == SET) {
+			//noinspection DataFlowIssue
+			key = NamespacedUtils.checkValidationAndSend((String) delta[0], this);
+			if (key == null) {
+				return;
+			}
+		}
+
+		for (ItemType item : getExpr().getArray(event)) {
+			ItemMeta meta = item.getItemMeta();
+			meta.setItemModel(key);
+			item.setItemMeta(meta);
+		}
+	}
+
+	@Override
+	public Class<? extends String> getReturnType() {
+		return String.class;
+	}
+
+	@Override
+	protected String getPropertyName() {
+		return "item model";
+	}
+
+}

src/main/java/org/skriptlang/skript/bukkit/item/elements/ExprItemWithModel.java

@@ -0,0 +1,76 @@
+package org.skriptlang.skript.bukkit.item.elements;
+
+import ch.njol.skript.aliases.ItemType;
+import ch.njol.skript.bukkitutil.NamespacedUtils;
+import ch.njol.skript.doc.*;
+import ch.njol.skript.expressions.base.PropertyExpression;
+import ch.njol.skript.lang.Expression;
+import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.util.Kleenean;
+import org.bukkit.NamespacedKey;
+import org.bukkit.event.Event;
+import org.bukkit.inventory.meta.ItemMeta;
+import org.jetbrains.annotations.Nullable;
+import org.skriptlang.skript.registration.DefaultSyntaxInfos;
+import org.skriptlang.skript.registration.SyntaxRegistry;
+
+@Name("Item With Model")
+@Description("Returns a copy of an item with a custom item model. Accepts a Namespaced Key (e.g. 'minecraft:emerald').")
+@Example("""
+	set {_item} to emerald with model "minecraft:diamond" named "fake diamond"'
+	give {_item} to player
+	""")
+@Since("INSERT VERSION")
+@Keywords("item model")
+public class ExprItemWithModel extends PropertyExpression<ItemType, ItemType> {
+
+	public static void register(SyntaxRegistry syntaxRegistry) {
+		syntaxRegistry.register(
+			SyntaxRegistry.EXPRESSION,
+			DefaultSyntaxInfos.Expression.builder(ExprItemWithModel.class, ItemType.class)
+				.addPattern("%itemtype% with [the] [item] model %string%")
+				.supplier(ExprItemWithModel::new)
+				.build()
+		);
+	}
+
+	private Expression<String> key;
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
+		setExpr((Expression<ItemType>) exprs[0]);
+		key = (Expression<String>) exprs[1];
+		return true;
+	}
+
+	@Override
+	protected ItemType[] get(Event event, ItemType[] source) {
+		String key = this.key.getSingle(event);
+		if (key == null)
+			return source;
+
+		NamespacedKey namespacedKey = NamespacedUtils.checkValidationAndSend(key, this);
+		if (namespacedKey == null)
+			return source;
+
+		return get(source, itemType -> {
+			itemType = itemType.clone();
+			ItemMeta itemMeta = itemType.getItemMeta();
+			itemMeta.setItemModel(namespacedKey);
+			itemType.setItemMeta(itemMeta);
+			return itemType;
+		});
+	}
+
+	@Override
+	public Class<? extends ItemType> getReturnType() {
+		return ItemType.class;
+	}
+
+	@Override
+	public String toString(@Nullable Event event, boolean debug) {
+		return getExpr().toString(event, debug) + " with item model " + key.toString(event, debug);
+	}
+
+}

src/test/skript/tests/bukkit/item/ExprItemModel.sk

@@ -0,0 +1,46 @@
+using error catching
+
+test "ExprItemModel":
+	set {_item} to diamond
+
+	set item model of {_item} to "emerald"
+	assert item model of {_item} is "minecraft:emerald" with "Set item model of item"
+
+	set {_inv} to chest inventory with 1 row named "test slots"
+	set slot 1 of {_inv} to diamond
+
+	set item model of slot 1 of {_inv} to "emerald"
+
+	assert item model of slot 1 of {_inv} is "minecraft:emerald" with "Set item model of slot from container"
+
+	set {_item} to dirt with item model "diamond"
+	assert item model of {_item} is "minecraft:diamond" with "ItemType with item model"
+
+	reset item model of {_item}
+	assert item model of {_item} is not set with "Reset item model of item"
+
+	set item model of {_item} to "minecraft:redstone"
+	delete item model of {_item}
+	assert item model of {_item} is not set with "Delete item model of item"
+
+	set {_string} to "test_string"
+	set item model of {_item} to {_string}
+	assert item model of {_item} is "minecraft:test_string" with "Set item model from variable string"
+
+	set item model of {_item} to {_}
+	assert item model of {_item} is not set with "Set item model of item to null"
+
+	set {_item} to diamond with model {_}
+	assert item model of {_item} is not set with "Item with null item model"
+
+	set {_item} to emerald with model {_string}
+	assert item model of {_item} is "minecraft:test_string" with "Item with item model of variable string"
+
+	set {_item} to diamond
+	catch runtime errors:
+		set item model of {_item} to "with spaces"
+	assert last caught runtime errors are set with "Runtime errors produced for invalid key for item model"
+
+	catch runtime errors:
+		set {_item} to diamond with model "with spaces"
+	assert last caught runtime errors are set with "Runtime errors produced for invalid key for item with model"