feat(xp-items): implement instant xp vacuum and spawned item consolidation listener

src/main/java/dev/marcospaulo/canalhandia/Canalhandia.java

@@ -161,6 +161,7 @@ public final class Canalhandia extends JavaPlugin implements Listener {
         getServer().getPluginManager().registerEvents(this, this);
         getServer().getPluginManager().registerEvents(new TitleChatListener(this), this);
         getServer().getPluginManager().registerEvents(new ChunkLoaderListener(this), this);
+        getServer().getPluginManager().registerEvents(new XpAndItemMergeListener(this), this);
         rescheduleTimer();
         rescheduleMilestones();
 

src/main/java/dev/marcospaulo/canalhandia/XpAndItemMergeListener.java

@@ -0,0 +1,109 @@
+package dev.marcospaulo.canalhandia;
+
+import com.destroystokyo.paper.event.player.PlayerPickupExperienceEvent;
+import org.bukkit.Location;
+import org.bukkit.Sound;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.ExperienceOrb;
+import org.bukkit.entity.Item;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.ItemSpawnEvent;
+import org.bukkit.inventory.ItemStack;
+
+/**
+ * Optimises XP and Item collection by instantly vacuuming nearby XP orbs into the player's
+ * XP bar (bypassing Vanilla's 2-tick per orb delay) and consolidating spawned item drops into
+ * full stacks.
+ */
+public final class XpAndItemMergeListener implements Listener {
+
+    private final Canalhandia plugin;
+
+    public XpAndItemMergeListener(Canalhandia plugin) {
+        this.plugin = plugin;
+    }
+
+    /**
+     * Vacuums all experience orbs within radius instantly on player contact.
+     */
+    @EventHandler(priority = EventPriority.HIGH, ignoreCancelled = true)
+    public void onPlayerPickupXp(PlayerPickupExperienceEvent event) {
+        Player player = event.getPlayer();
+        Location loc = player.getLocation();
+        if (loc.getWorld() == null) {
+            return;
+        }
+
+        int totalExp = 0;
+        try {
+            for (Entity entity : loc.getWorld().getNearbyEntities(loc, 6.0, 6.0, 6.0)) {
+                if (entity instanceof ExperienceOrb orb && orb.isValid()) {
+                    totalExp += orb.getExperience();
+                    orb.remove();
+                }
+            }
+        } catch (Exception ignored) {
+        }
+
+        if (totalExp > 0) {
+            player.giveExp(totalExp);
+            try {
+                player.playSound(loc, Sound.ENTITY_EXPERIENCE_ORB_PICKUP, 0.5f, 1.2f);
+            } catch (Exception ignored) {
+            }
+            event.setCancelled(true);
+        }
+    }
+
+    /**
+     * Consolidates spawned items of the same type in a 4-block radius into unified stacks.
+     */
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void onItemSpawn(ItemSpawnEvent event) {
+        Item item = event.getEntity();
+        ItemStack stack = item.getItemStack();
+        if (stack.getAmount() >= stack.getMaxStackSize() || item.getWorld() == null) {
+            return;
+        }
+
+        try {
+            for (Entity e : item.getWorld().getNearbyEntities(item.getLocation(), 4.0, 4.0, 4.0)) {
+                if (e instanceof Item other && other != item && other.isValid()) {
+                    ItemStack otherStack = other.getItemStack();
+                    if (otherStack.isSimilar(stack)) {
+                        int toTransfer = calculateTransfer(stack.getAmount(), stack.getMaxStackSize(), otherStack.getAmount());
+                        if (toTransfer > 0) {
+                            stack.setAmount(stack.getAmount() + toTransfer);
+                            otherStack.setAmount(otherStack.getAmount() - toTransfer);
+                            if (otherStack.getAmount() <= 0) {
+                                other.remove();
+                            } else {
+                                other.setItemStack(otherStack);
+                            }
+                            item.setItemStack(stack);
+                            if (stack.getAmount() >= stack.getMaxStackSize()) {
+                                break;
+                            }
+                        }
+                    }
+                }
+            }
+        } catch (Exception ignored) {
+        }
+    }
+
+    /** Pure transfer amount calculator for stack consolidation. */
+    public static int calculateTransfer(int targetAmount, int targetMax, int sourceAmount) {
+        if (targetAmount < 0 || targetMax <= 0 || sourceAmount <= 0) {
+            return 0;
+        }
+        int canAdd = targetMax - targetAmount;
+        if (canAdd <= 0) {
+            return 0;
+        }
+        return Math.min(canAdd, sourceAmount);
+    }
+}

src/test/java/dev/marcospaulo/canalhandia/XpAndItemMergeTest.java

@@ -0,0 +1,28 @@
+package dev.marcospaulo.canalhandia;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class XpAndItemMergeTest {
+
+    @Test
+    void handlesZeroOrNegativeAmountsGracefully() {
+        assertEquals(0, XpAndItemMergeListener.calculateTransfer(0, 0, 0));
+        assertEquals(0, XpAndItemMergeListener.calculateTransfer(-1, 16, 5));
+        assertEquals(0, XpAndItemMergeListener.calculateTransfer(16, 16, 5));
+        assertEquals(0, XpAndItemMergeListener.calculateTransfer(10, 16, 0));
+    }
+
+    @Test
+    void calculatesTransfersUpToMaxCapacity() {
+        // Target has 10, max is 16, source has 10 -> can transfer 6
+        assertEquals(6, XpAndItemMergeListener.calculateTransfer(10, 16, 10));
+
+        // Target has 5, max is 64, source has 20 -> can transfer all 20
+        assertEquals(20, XpAndItemMergeListener.calculateTransfer(5, 64, 20));
+
+        // Target has 63, max is 64, source has 10 -> can transfer 1
+        assertEquals(1, XpAndItemMergeListener.calculateTransfer(63, 64, 10));
+    }
+}