fix: clear a plate's sauce once its last food is taken off (#48)

The sauce visual stayed on a plate after its food was taken off, so hasSauce rejected sauce for every later dish on that plate. Remove the sauce slot when the last food leaves, clear leftover sauce on plates saved before this fix, and keep the ladle full when no food on the plate can take the sauce.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Author: XxFran10xX

src/main/java/net/tfminecraft/cooking/manager/PlateManager.java

@@ -10,6 +10,7 @@
 import org.bukkit.Sound;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
 import org.bukkit.event.Listener;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ItemMeta;
@@ -31,6 +32,7 @@
 import net.tfminecraft.interactiblefurniture.events.FurnitureBreakEvent;
 import net.tfminecraft.interactiblefurniture.events.FurnitureInteractEvent;
 import net.tfminecraft.interactiblefurniture.events.FurnitureSlotItemAddEvent;
+import net.tfminecraft.interactiblefurniture.events.FurnitureSlotItemTakeEvent;
 import net.tfminecraft.interactiblefurniture.furniture.Furniture;
 import net.tfminecraft.interactiblefurniture.furniture.PlacedSlot;
 import net.tfminecraft.interactiblefurniture.furniture.data.DisplayData;
@@ -56,6 +58,11 @@ public void run() {
     }
 
     public void update(Furniture f) {
+        // Also clears plates saved with leftover sauce before the take handler existed.
+        if(hasLeftoverSauce(f, null)) {
+            f.removeActiveSlot("sauce");
+            InteractibleFurniture.getInstance().getFurnitureManager().persistFurniture(f);
+        }
         for(PlacedSlot slot : f.getActiveSlots().values()) {
             if(slot.getId().contains("display")) continue;
             ItemStack item = slot.getCurrentItem();
@@ -99,10 +106,51 @@ public boolean hasSauce(Furniture f) {
         return false;
     }
 
+    /**
+     * True when the plate shows a sauce visual but no food would remain once {@code leavingSlot}
+     * is gone. A leftover sauce visual makes hasSauce reject the next dish on the plate.
+     */
+    boolean hasLeftoverSauce(Furniture f, String leavingSlot) {
+        if(!f.hasActiveSlot("sauce")) return false;
+        return !hasFood(f, leavingSlot);
+    }
+
+    // An active food slot counts even without a loaded item: restore can leave the item unset
+    // while the display still shows the food.
+    private boolean hasFood(Furniture f, String ignoredSlot) {
+        for(String id : f.getActiveSlots().keySet()) {
+            if(id.equals("sauce") || id.contains("display") || id.equals(ignoredSlot)) continue;
+            return true;
+        }
+        return false;
+    }
+
+    // Food addSauce can actually apply the sauce to.
+    private boolean hasSauceableFood(Furniture f) {
+        for(PlacedSlot slot : f.getActiveSlots().values()) {
+            if(slot.getId().equals("sauce") || slot.getId().contains("display")) continue;
+            ItemStack item = slot.getCurrentItem();
+            if(item != null && FoodItem.fromItem(item) != null) return true;
+        }
+        return false;
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
+    public void takeItem(FurnitureSlotItemTakeEvent e) {
+        Furniture f = e.getFurniture();
+        if(!FurnitureCache.isPlate(f)) return;
+        // The taken slot is still active here; InteractibleFurniture removes it and saves the plate next.
+        if(hasLeftoverSauce(f, e.getSlot().getId())) {
+            f.removeActiveSlot("sauce");
+        }
+    }
+
     // Keep the existing legacy text representation, formatting, and exact-string comparisons.
     @SuppressWarnings("deprecation")
     public void addSauce(Player p, Furniture f, FoodItem sauce, ItemStack base) {
         if (hasSauce(f)) return;
+        // Sauce with no food to take it would never reach food added later, so keep the ladle full.
+        if (!hasSauceableFood(f)) return;
 
         // Replace player ladle with empty ladle
         p.getInventory().setItemInMainHand(

src/test/java/net/tfminecraft/cooking/manager/PlateManagerTest.java

@@ -116,4 +116,79 @@ public boolean hasItemMeta() {
 
         assertFalse(new PlateManager().hasSauce(plate));
     }
+
+    @Test
+    void sauceIsLeftoverOnceTheLastFoodLeaves() {
+        Furniture plate = plateWithSauceVisual();
+        plate.getActiveSlots().put("item_1", new PlacedSlot(plate, "item_1"));
+
+        assertFalse(new PlateManager().hasLeftoverSauce(plate, null));
+        assertTrue(new PlateManager().hasLeftoverSauce(plate, "item_1"));
+    }
+
+    @Test
+    void sauceStaysWhileOtherFoodRemains() {
+        Furniture plate = plateWithSauceVisual();
+        plate.getActiveSlots().put("item_1", new PlacedSlot(plate, "item_1"));
+        plate.getActiveSlots().put("item_2", new PlacedSlot(plate, "item_2"));
+
+        assertFalse(new PlateManager().hasLeftoverSauce(plate, "item_1"));
+    }
+
+    @Test
+    void sauceAloneOnAPlateIsLeftover() {
+        assertTrue(new PlateManager().hasLeftoverSauce(plateWithSauceVisual(), null));
+    }
+
+    @Test
+    void plateWithoutSauceHasNoLeftover() {
+        Furniture plate = new Furniture("plate", null, UUID.randomUUID());
+        plate.getActiveSlots().put("item_1", new PlacedSlot(plate, "item_1"));
+
+        assertFalse(new PlateManager().hasLeftoverSauce(plate, null));
+        assertFalse(new PlateManager().hasLeftoverSauce(plate, "item_1"));
+    }
+
+    @Test
+    void sauceOnAnEmptyPlateReturnsBeforeTouchingThePlayerOrLadle() {
+        Furniture plate = new Furniture("plate", null, UUID.randomUUID());
+
+        // Null interaction arguments ensure the empty-plate attempt exits before using them.
+        assertDoesNotThrow(() -> new PlateManager().addSauce(null, plate, null, null));
+        assertTrue(plate.getActiveSlots().isEmpty());
+    }
+
+    @Test
+    void sauceOnAPlateWithoutLoadedFoodReturnsBeforeTouchingThePlayerOrLadle() {
+        Furniture plate = new Furniture("plate", null, UUID.randomUUID());
+        plate.getActiveSlots().put("item_1", new PlacedSlot(plate, "item_1"));
+        PlacedSlot unrecognized = new PlacedSlot(plate, "item_2");
+        unrecognized.setModel(new ItemStack() {
+            @Override
+            public boolean hasItemMeta() {
+                return false;
+            }
+        });
+        plate.getActiveSlots().put("item_2", unrecognized);
+
+        assertDoesNotThrow(() -> new PlateManager().addSauce(null, plate, null, null));
+        assertFalse(plate.hasActiveSlot("sauce"));
+    }
+
+    @Test
+    void displaySlotsDoNotCountAsFood() {
+        Furniture plate = plateWithSauceVisual();
+        plate.getActiveSlots().put("display_1", new PlacedSlot(plate, "display_1"));
+
+        assertTrue(new PlateManager().hasLeftoverSauce(plate, null));
+    }
+
+    @Test
+    void sauceOnADisplayOnlyPlateReturnsBeforeTouchingThePlayerOrLadle() {
+        Furniture plate = new Furniture("plate", null, UUID.randomUUID());
+        plate.getActiveSlots().put("display_1", new PlacedSlot(plate, "display_1"));
+
+        assertDoesNotThrow(() -> new PlateManager().addSauce(null, plate, null, null));
+        assertFalse(plate.hasActiveSlot("sauce"));
+    }
 }