Initial code for the server-side enchanting

src/main/java/cn/nukkit/Player.java

@@ -109,6 +109,7 @@
 import java.util.*;
 import java.util.Map.Entry;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
@@ -265,6 +266,7 @@ public class Player extends EntityHuman implements CommandSender, InventoryHolde
 
     private int exp = 0;
     private int expLevel = 0;
+    private int expSeed;
 
     protected PlayerFood foodData = null;
 
@@ -2390,6 +2392,18 @@ private static EntityInteractable getEntityAtPosition(Entity[] nearbyEntities, i
         return null;
     }
 
+    public int getEnchantmentSeed() {
+        return this.expSeed;
+    }
+
+    public void setEnchantmentSeed(int seed) {
+        this.expSeed = seed;
+    }
+
+    public int generateEnchantmentSeed() {
+        return ThreadLocalRandom.current().nextInt(Integer.MAX_VALUE);
+    }
+
     public void checkNetwork() {
         if (this.protocol < ProtocolInfo.v1_16_100 && !this.isOnline()) {
             return;
@@ -2442,11 +2456,15 @@ protected void processLogin() {
         if (!this.server.isWhitelisted(lowerName)) {
             this.kick(PlayerKickEvent.Reason.NOT_WHITELISTED, server.whitelistReason);
             return;
-        } else if (this.isBanned()) {
+        }
+
+        if (this.isBanned()) {
             String reason = this.server.getNameBans().getEntires().get(lowerName).getReason();
             this.kick(PlayerKickEvent.Reason.NAME_BANNED, "You are banned!" + (reason.isEmpty() ? "" : (" Reason: " + reason)));
             return;
-        } else if (!server.strongIPBans && this.server.getIPBans().isBanned(this.getAddress())) {
+        }
+
+        if (!server.strongIPBans && this.server.getIPBans().isBanned(this.getAddress())) {
             this.kick(PlayerKickEvent.Reason.IP_BANNED, "Your IP is banned!");
             return;
         }
@@ -2554,7 +2572,6 @@ protected void processLogin() {
             this.fogStack.add(i, new PlayerFogPacket.Fog(Identifier.tryParse(fogIdentifiers.get(i).data), userProvidedFogIds.get(i).data));
         }
 
-
         for (Tag achievement : nbt.getCompound("Achievements").getAllTags()) {
             if (!(achievement instanceof ByteTag)) {
                 continue;
@@ -2593,6 +2610,13 @@ protected void processLogin() {
             this.namedTag.putFloat("foodSaturationLevel", 20);
         }
 
+        if (this.namedTag.contains("xpSeed")) {
+            this.expSeed = this.namedTag.getInt("xpSeed");
+        } else {
+            this.expSeed = this.generateEnchantmentSeed();
+            this.namedTag.putInt("xpSeed", this.expSeed);
+        }
+
         this.foodData = new PlayerFood(this, this.namedTag.getInt("foodLevel"), this.namedTag.getFloat("foodSaturationLevel"));
 
         if (this.isSpectator()) {
@@ -5316,9 +5340,9 @@ public void save(boolean async) {
                 namedTag.remove("SpawnBlockPositionX").remove("SpawnBlockPositionY").remove("SpawnBlockPositionZ").remove("SpawnBlockLevel");
             } else if (spawnBlockPosition.isValid()) {
                 namedTag.putInt("SpawnBlockPositionX", spawnBlockPosition.getFloorX())
-                        .putInt("SpawnBlockPositionY", spawnBlockPosition.getFloorY())
-                        .putInt("SpawnBlockPositionZ", spawnBlockPosition.getFloorZ())
-                        .putString("SpawnBlockLevel", this.spawnBlockPosition.getLevel().getFolderName());
+                    .putInt("SpawnBlockPositionY", spawnBlockPosition.getFloorY())
+                    .putInt("SpawnBlockPositionZ", spawnBlockPosition.getFloorZ())
+                    .putString("SpawnBlockLevel", this.spawnBlockPosition.getLevel().getFolderName());
             }
 
             CompoundTag achievements = new CompoundTag();
@@ -5339,6 +5363,7 @@ public void save(boolean async) {
             this.namedTag.putInt("foodLevel", this.foodData.getLevel());
             this.namedTag.putFloat("foodSaturationLevel", this.foodData.getFoodSaturationLevel());
 
+            this.namedTag.putInt("xpSeed", this.expSeed);
             this.namedTag.putInt("TimeSinceRest", this.timeSinceRest);
 
             ListTag<StringTag> fogIdentifiers = new ListTag<>("fogIdentifiers");

src/main/java/cn/nukkit/block/Block.java

@@ -784,7 +784,7 @@ public int getItemId() {
         }
 
         return id;
-	}
+    }
 
     /**
      * The full id is a combination of the id and data.

src/main/java/cn/nukkit/event/player/PlayerEnchantOptionsRequestEvent.java

@@ -0,0 +1,26 @@
+package cn.nukkit.event.player;
+
+import cn.nukkit.Player;
+import cn.nukkit.event.Cancellable;
+import cn.nukkit.event.HandlerList;
+import cn.nukkit.inventory.EnchantInventory;
+import cn.nukkit.network.protocol.PlayerEnchantOptionsPacket;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+import java.util.List;
+
+@EqualsAndHashCode(callSuper = true)
+@Data
+public class PlayerEnchantOptionsRequestEvent extends PlayerEvent implements Cancellable {
+    private static final HandlerList handlers = new HandlerList();
+
+    private EnchantInventory table;
+    private List<PlayerEnchantOptionsPacket.EnchantOptionData> options;
+
+    public PlayerEnchantOptionsRequestEvent(Player player, EnchantInventory table, List<PlayerEnchantOptionsPacket.EnchantOptionData> options) {
+        this.player = player;
+        this.table = table;
+        this.options = options;
+    }
+}

src/main/java/cn/nukkit/inventory/EnchantInventory.java

@@ -1,18 +1,27 @@
 package cn.nukkit.inventory;
 
 import cn.nukkit.Player;
+import cn.nukkit.event.player.PlayerEnchantOptionsRequestEvent;
 import cn.nukkit.item.Item;
+import cn.nukkit.item.enchantment.EnchantmentHelper;
 import cn.nukkit.level.Position;
+import cn.nukkit.network.protocol.PlayerEnchantOptionsPacket;
+import lombok.Getter;
+
+import java.util.Collections;
+import java.util.List;
 
 /**
  * @author MagicDroidX
  * Nukkit Project
  */
 public class EnchantInventory extends FakeBlockUIComponent {
-
     public static final int ENCHANT_INPUT_ITEM_UI_SLOT = 14;
     public static final int ENCHANT_REAGENT_UI_SLOT = 15;
 
+    @Getter
+    private List<PlayerEnchantOptionsPacket.EnchantOptionData> options = Collections.emptyList();
+
     public EnchantInventory(PlayerUIInventory playerUI, Position position) {
         super(playerUI, InventoryType.ENCHANT_TABLE, 14, position);
     }
@@ -36,6 +45,26 @@ public void onClose(Player who) {
         who.resetCraftingGridType();
     }
 
+    @Override
+    public void onSlotChange(int index, Item before, boolean send) {
+        if (index == 0) {
+            for (final Player viewer : this.getViewers()) {
+                List<PlayerEnchantOptionsPacket.EnchantOptionData> options = EnchantmentHelper.getEnchantOptions(this.getHolder(), this.getInputSlot(), viewer.getEnchantmentSeed());
+                PlayerEnchantOptionsRequestEvent event = new PlayerEnchantOptionsRequestEvent(viewer, this, options);
+
+                if (!event.isCancelled() && !event.getOptions().isEmpty()) {
+                    this.options = event.getOptions();
+
+                    PlayerEnchantOptionsPacket pk = new PlayerEnchantOptionsPacket();
+                    pk.options = event.getOptions();
+                    viewer.dataPacket(pk);
+                }
+            }
+        }
+
+        super.onSlotChange(index, before, false);
+    }
+
     public Item getInputSlot() {
         return this.getItem(0);
     }

src/main/java/cn/nukkit/inventory/transaction/EnchantTransaction.java

@@ -3,11 +3,12 @@
 import cn.nukkit.Player;
 import cn.nukkit.event.inventory.EnchantItemEvent;
 import cn.nukkit.inventory.EnchantInventory;
-import cn.nukkit.inventory.Inventory;
 import cn.nukkit.inventory.transaction.action.EnchantingAction;
 import cn.nukkit.inventory.transaction.action.InventoryAction;
 import cn.nukkit.inventory.transaction.action.SlotChangeAction;
 import cn.nukkit.item.Item;
+import cn.nukkit.item.enchantment.Enchantment;
+import cn.nukkit.network.protocol.PlayerEnchantOptionsPacket;
 import cn.nukkit.network.protocol.types.NetworkInventoryAction;
 import lombok.Getter;
 import lombok.Setter;
@@ -17,7 +18,7 @@
 @Getter
 @Setter
 public class EnchantTransaction extends InventoryTransaction {
-
+    private EnchantInventory inv;
     private Item inputItem;
     private Item outputItem;
     private int cost = -1;
@@ -35,16 +36,19 @@ public EnchantTransaction(Player source, List<InventoryAction> actions) {
 
     @Override
     public boolean canExecute() {
-        Inventory inv = getSource().getWindowById(Player.ENCHANT_WINDOW_ID);
-        if (inv == null) return false;
-        EnchantInventory eInv = (EnchantInventory) inv;
-        if (!getSource().isCreative()) {
-            if (cost == -1 || !eInv.getReagentSlot().equals(Item.get(Item.DYE, 4), true, false) || eInv.getReagentSlot().count < cost)
+        if (!(this.getSource().getWindowById(Player.ENCHANT_WINDOW_ID) instanceof final EnchantInventory inv)) {
+            return false;
+        }
+
+        if (!this.getSource().isCreative()) {
+            if (cost == -1 || !inv.getReagentSlot().equals(Item.get(Item.DYE, 4), true, false) || inv.getReagentSlot().count < cost) {
                 return false;
+            }
         }
+
         return inputItem != null && outputItem != null
-                && inputItem.equals(eInv.getInputSlot(), true, true)
-                && this.checkEnchantValid();
+            && inputItem.equals(inv.getInputSlot(), true, true)
+            && this.checkEnchantValid(inv);
     }
 
     @Override
@@ -55,7 +59,7 @@ public boolean execute() {
             this.sendInventories();
             return false;
         }
-        EnchantInventory inv = (EnchantInventory) getSource().getWindowById(Player.ENCHANT_WINDOW_ID);
+        EnchantInventory inv = (EnchantInventory) this.getSource().getWindowById(Player.ENCHANT_WINDOW_ID);
         EnchantItemEvent ev = new EnchantItemEvent(inv, inputItem, outputItem, cost, source);
         source.getServer().getPluginManager().callEvent(ev);
         if (ev.isCancelled()) {
@@ -80,8 +84,10 @@ public boolean execute() {
         }
 
         if (!source.isCreative()) {
+            source.setEnchantmentSeed(source.generateEnchantmentSeed());
             source.setExperience(source.getExperience(), source.getExperienceLevel() - ev.getXpCost());
         }
+
         return true;
     }
 
@@ -90,21 +96,18 @@ public void addAction(InventoryAction action) {
         super.addAction(action);
         if (action instanceof EnchantingAction) {
             switch (((EnchantingAction) action).getType()) {
-                case NetworkInventoryAction.SOURCE_TYPE_ENCHANT_INPUT:
+                case NetworkInventoryAction.SOURCE_TYPE_ENCHANT_INPUT ->
                     this.inputItem = action.getTargetItem(); // Input sent as newItem
-                    break;
-                case NetworkInventoryAction.SOURCE_TYPE_ENCHANT_OUTPUT:
+                case NetworkInventoryAction.SOURCE_TYPE_ENCHANT_OUTPUT ->
                     this.outputItem = action.getSourceItem(); // Output sent as oldItem
-                    break;
-                case NetworkInventoryAction.SOURCE_TYPE_ENCHANT_MATERIAL:
+                case NetworkInventoryAction.SOURCE_TYPE_ENCHANT_MATERIAL -> {
                     if (action.getTargetItem().equals(Item.get(Item.AIR), false, false)) {
                         this.cost = action.getSourceItem().count;
                     } else {
                         this.cost = action.getSourceItem().count - action.getTargetItem().count;
                     }
-                    break;
+                }
             }
-
         }
     }
 
@@ -115,14 +118,17 @@ public boolean checkForEnchantPart(List<InventoryAction> actions) {
         return false;
     }
 
-    public boolean checkEnchantValid() {
-        if (this.inputItem.getId() != this.outputItem.getId()
-                || this.inputItem.getCount() != this.outputItem.getCount()) {
-            return false;
+    public boolean checkEnchantValid(EnchantInventory inv) {
+        for (final PlayerEnchantOptionsPacket.EnchantOptionData option : inv.getOptions()) {
+            for (final Enchantment ench : option.enchantments()) {
+                if (outputItem.hasEnchantment(ench.getId())) {
+                    return outputItem.getId() == inputItem.getId() && outputItem.getDamage() == inputItem.getDamage();
+                }
+            }
         }
 
-        //TODO 检查附魔
+        System.out.println(inv.getOptions());
 
-        return true;
+        return false;
     }
 }