Rewrite enchantment window properties in 1.8->1.9

Closes #485

common/src/main/java/com/viaversion/viarewind/protocol/protocol1_8to1_9/packets/BlockItemPackets1_9.java

@@ -163,6 +163,27 @@ public void register() {
 				});
 			}
 		});
+
+		protocol.registerClientbound(ClientboundPackets1_9.WINDOW_PROPERTY, wrapper -> {
+			final short windowId = wrapper.passthrough(Type.UNSIGNED_BYTE);
+			short key = wrapper.read(Type.SHORT);
+			short value = wrapper.read(Type.SHORT);
+
+			final WindowTracker tracker = wrapper.user().get(WindowTracker.class);
+			final String windowType = tracker.get(windowId);
+			if (windowType != null && windowType.equalsIgnoreCase("minecraft:enchanting_table")) {
+				if (key >= 4 && key <= 6) { // Store enchantment ids
+					tracker.storeEnchantmentTableProperty(windowId, key, value);
+					wrapper.cancel();
+				} else if (key >= 7 && key <= 9) { // Mix levels with tracked ids
+					key -= 3;
+					final short property = tracker.getEnchantmentTableProperty(windowId, key);
+					value = (short) (property | (value << 8));
+				}
+			}
+			wrapper.write(Type.SHORT, key);
+			wrapper.write(Type.SHORT, value);
+		});
 	}
 
 	@Override

common/src/main/java/com/viaversion/viarewind/protocol/protocol1_8to1_9/storage/WindowTracker.java

@@ -32,10 +32,12 @@
 import com.viaversion.viaversion.protocols.protocol1_8.ClientboundPackets1_8;
 
 import java.util.HashMap;
+import java.util.Map;
 
 public class WindowTracker extends StoredObject {
 	private final HashMap<Short, String> types = new HashMap<>();
 	private final HashMap<Short, Item[]> brewingItems = new HashMap<>();
+	private final Map<Short, WindowProperties> enchantmentProperties = new HashMap<>();
 
 	public WindowTracker(UserConnection user) {
 		super(user);
@@ -63,6 +65,21 @@ public Item[] getBrewingItems(short windowId) {
 		});
 	}
 
+	public void storeEnchantmentTableProperty(short windowId, int key, int value) {
+		enchantmentProperties.computeIfAbsent(windowId, aShort -> new WindowProperties()).put(key, value);
+	}
+
+	public short getEnchantmentTableProperty(short windowId, int key) {
+		final Integer value = enchantmentProperties.get(windowId).get(key);
+		if (value == null) {
+			return 0; // Assume default value, nothing we can do about
+		}
+		if (enchantmentProperties.get(windowId).properties.isEmpty()) { // Remove from list if nothing to track
+			enchantmentProperties.remove(windowId);
+		}
+		return value.shortValue();
+	}
+
 	public static void updateBrewingStand(UserConnection user, Item blazePowder, short windowId) throws Exception {
 		if (blazePowder != null && blazePowder.identifier() != 377) {
 			return;
@@ -92,4 +109,20 @@ public static void updateBrewingStand(UserConnection user, Item blazePowder, sho
 			setSlot.scheduleSend(Protocol1_8To1_9.class);
 		}
 	}
+
+	public static class WindowProperties {
+
+		private final Map<Integer, Integer> properties = new HashMap<>();
+
+		public Integer get(int key) {
+			if (!properties.containsKey(key)) {
+				return null;
+			}
+			return properties.remove(key);
+		}
+
+		public void put(int key, int value) {
+			properties.put(key, value);
+		}
+	}
 }