Create ExprPDC.java

Author: sovdeeth

src/main/java/ch/njol/skript/expressions/ExprPDC.java

@@ -0,0 +1,160 @@
+package ch.njol.skript.expressions;
+
+import ch.njol.skript.aliases.ItemType;
+import ch.njol.skript.classes.Changer;
+import ch.njol.skript.expressions.base.PropertyExpression;
+import ch.njol.skript.lang.Expression;
+import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.skript.registrations.Classes;
+import ch.njol.skript.util.slot.Slot;
+import ch.njol.util.Kleenean;
+import org.bukkit.NamespacedKey;
+import org.bukkit.block.Block;
+import org.bukkit.block.TileState;
+import org.bukkit.event.Event;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.persistence.PersistentDataContainer;
+import org.bukkit.persistence.PersistentDataHolder;
+import org.bukkit.persistence.PersistentDataType;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+
+import static ch.njol.util.StringUtils.hexStringToByteArray;
+
+public class ExprPDC extends PropertyExpression<Object, Object> {
+
+	static {
+		register(ExprPDC.class, Object.class, "pdc tag %string%", "chunks/worlds/entities/blocks/itemtypes/offlineplayers");
+	}
+
+	private Expression<String> tag;
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public boolean init(Expression<?>[] expressions, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
+		tag = (Expression<String>) expressions[matchedPattern];
+		setExpr(expressions[matchedPattern == 0 ? 1 : 0]);
+		return true;
+	}
+
+	@Override
+	protected Object[] get(Event event, Object[] source) {
+		String tagName = tag.getSingle(event);
+		if (tagName == null)
+			return new Object[0];
+		var key = NamespacedKey.fromString(tagName);
+
+		List<Object> values = new ArrayList<>();
+		for (Object holder : source) {
+			if (holder == null)
+				continue;
+			editPersistentDataContainer(holder, container -> {
+				assert key != null;
+				if (!container.has(key, PersistentDataType.STRING)) {
+					// If the key does not exist, we skip this holder
+					return;
+				}
+				String stringValue = container.get(key, PersistentDataType.STRING);
+				Object object;
+				if (stringValue != null && (object = deserialize(stringValue)) != null) {
+					values.add(object);
+				}
+			});
+		}
+		return values.toArray(new Object[0]);
+	}
+
+	@Override
+	public Class<?> @Nullable [] acceptChange(Changer.ChangeMode mode) {
+		return switch (mode) {
+			case SET, DELETE -> new Class<?>[]{Object.class};
+			default -> null;
+		};
+	}
+
+	@Override
+	public void change(Event event, Object @Nullable [] delta, Changer.ChangeMode mode) {
+		var tagName = tag.getSingle(event);
+		if (tagName == null)
+			return;
+		var key = NamespacedKey.fromString(tagName);
+		if (key == null)
+			return; // Invalid key, cannot proceed
+
+		for (Object holder : getExpr().getArray(event)) {
+			editPersistentDataContainer(holder, container -> {
+				if (mode == Changer.ChangeMode.SET) {
+					assert delta != null;
+					container.set(key, PersistentDataType.STRING, serialize(delta[0]));
+				} else if (mode == Changer.ChangeMode.DELETE) {
+					container.remove(key);
+				}
+			});
+		}
+	}
+
+	private void editPersistentDataContainer(Object holder, Consumer<PersistentDataContainer> consumer) {
+		if (holder instanceof PersistentDataHolder dataHolder)
+			consumer.accept(dataHolder.getPersistentDataContainer());
+		else if (holder instanceof ItemType itemType) {
+			var meta = itemType.getItemMeta();
+			consumer.accept(meta.getPersistentDataContainer());
+			itemType.setItemMeta(meta);
+		} else if (holder instanceof ItemStack itemStack) {
+			if (!itemStack.hasItemMeta()) return;
+			var meta = itemStack.getItemMeta();
+			consumer.accept(meta.getPersistentDataContainer());
+			itemStack.setItemMeta(meta);
+		} else if (holder instanceof Slot slot) {
+			var item =  slot.getItem();
+			if (item == null || !item.hasItemMeta()) return;
+			var meta = item.getItemMeta();
+			consumer.accept(meta.getPersistentDataContainer());
+			item.setItemMeta(meta);
+			slot.setItem(item);
+		} else if (holder instanceof Block block && block.getState() instanceof TileState tileState) {
+			consumer.accept(tileState.getPersistentDataContainer());
+			tileState.update();
+		}
+	}
+
+	@Override
+	public Class<?> getReturnType() {
+		return Object.class;
+	}
+
+	@Override
+	public String toString(@Nullable Event event, boolean debug) {
+		return "pdc tag " + tag.toString(event, debug) + " of " + getExpr().toString(event, debug);
+	}
+
+	private @NotNull String serialize(Object object) {
+		var value = Classes.serialize(object);
+		assert value != null;
+		return value.type + ":" + bytesToHex(value.data);
+	}
+
+	private Object deserialize(@NotNull String input) {
+		var values = input.split(":", 2);
+		var type = values[0];
+		var data = values[1];
+		return Classes.deserialize(type, hexStringToByteArray(data));
+	}
+
+	private static final byte[] HEX_ARRAY = "0123456789ABCDEF".getBytes(StandardCharsets.US_ASCII);
+
+	private static String bytesToHex(byte[] bytes) {
+		byte[] hexChars = new byte[bytes.length * 2];
+		for (int j = 0; j < bytes.length; j++) {
+			int v = bytes[j] & 0xFF;
+			hexChars[j * 2] = HEX_ARRAY[v >>> 4];
+			hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];
+		}
+		return new String(hexChars, StandardCharsets.UTF_8);
+	}
+}