Fix shulker box selling: purple variant undetected, contents wiped on deposit failure

README.md

@@ -0,0 +1,106 @@
+# SellPlugin
+
+A Minecraft Paper plugin that lets players sell items for in-game currency through a polished GUI system with per-category multipliers, daily bonuses, and a leaderboard.
+
+## Features
+
+- **Category shop** (`/sell`) — browse categories, view prices, and sell items one category at a time.
+- **Quick sell-all** (`/sellall`) — sell every sellable item in your inventory (including shulker box contents) with a single confirm click.
+- **Shulker box support** — place a shulker box in the sell GUI or run `/sellall`; the sellable items inside are sold and the (now-emptied) shulker box is returned to you automatically.
+- **Per-category multipliers** — players unlock higher sell multipliers by earning money in each category. Multipliers are persistent across sessions.
+- **Daily category bonuses** — a configurable number of random categories receive a flat bonus multiplier each day, encouraging varied play.
+- **Top sellers leaderboard** (`/topsell`) — paginated GUI showing top earners per category.
+- **Economy support** — works with Vault (any Vault-compatible economy plugin) or CoinsEngine.
+- **Fully configurable** — GUI titles, item slots, filler materials, sounds, messages, category icons, and item prices are all driven by config files.
+
+## Requirements
+
+| Dependency | Version | Notes |
+|------------|---------|-------|
+| Paper | 1.21.1+ | Spigot is not supported |
+| Vault | any | For standard economy plugins |
+| CoinsEngine | any | Alternative economy (optional) |
+
+## Installation
+
+1. Drop `SellPlugin.jar` into your server's `plugins/` folder.
+2. Make sure at least one of Vault (+ an economy plugin such as EssentialsX) or CoinsEngine is installed.
+3. Restart the server — `plugins/SellPlugin/` will be created with default config files.
+4. Edit `config.yml` and `price.yml` to your liking.
+5. Run `/sell reload` or restart to apply changes.
+
+## Commands
+
+| Command | Permission | Description |
+|---------|-----------|-------------|
+| `/sell` | `sellplugin.use` | Opens the main category shop GUI |
+| `/sell reload` | `sellplugin.reload` | Reloads config and price files in-place |
+| `/sellall` | `sellplugin.use` | Opens the quick sell-all GUI |
+| `/topsell` | `sellplugin.topsell` | Opens the top sellers leaderboard |
+
+Aliases for `/sell`: `sellmenu`, `sellgui`, `shop`  
+Aliases for `/topsell`: `sellertop`, `leaderboard`
+
+## Permissions
+
+| Node | Default | Description |
+|------|---------|-------------|
+| `sellplugin.use` | everyone | Use `/sell` and `/sellall` |
+| `sellplugin.topsell` | everyone | Use `/topsell` |
+| `sellplugin.reload` | op | Use `/sell reload` |
+
+## Configuration
+
+### `config.yml` — key options
+
+```yaml
+# Economy backend: VAULT or COINSENGINE
+economy-mode: VAULT
+
+# Multiplier unlock thresholds
+start-multiplier: 1000.0   # cost of first tier (1.1×)
+multiplier: 1.6             # each tier costs (previous × this)
+max-multiplier: 3.0         # display cap for the progress bar
+
+# Daily bonus
+daily-bonus:
+  boosted-count: 2          # how many categories get the bonus each day
+  bonus-amount: 0.4         # flat bonus added to the multiplier
+```
+
+### `price.yml` — item prices
+
+Items are grouped by category. Each top-level key is a category ID that must also appear in `category-order` inside `config.yml`.
+
+```yaml
+ores:
+  DIAMOND: 50
+  EMERALD: 80
+  IRON_INGOT: 5
+  GOLD_INGOT: 10
+```
+
+Potion prices use a `MATERIAL:POTION_TYPE` key:
+
+```yaml
+potions:
+  POTION:NIGHT_VISION: 12
+  SPLASH_POTION:HEALING: 8
+```
+
+## Shulker Box Selling
+
+Any shulker box colour — including the default purple `SHULKER_BOX` and all sixteen dyed variants — is supported everywhere:
+
+- **`/sell` GUI** — place a shulker box in the item area and close the inventory. The sellable items inside are sold, and the now-emptied shulker box is returned to your inventory.
+- **`/sellall`** — shulker box contents are sold along with your regular inventory items. The box itself stays in your inventory.
+
+If the economy transaction fails, the shulker box is returned **with its original contents intact** (no items are lost).
+
+## Building from source
+
+```bash
+mvn clean package
+```
+
+The shaded jar is produced in `target/SellPlugin-<version>.jar`. The `libs/` directory must contain `NightCore.jar` and `CoinsEngine.jar` (provided separately) for the build to succeed.

src/main/java/com/yourname/sellplugin/gui/GUIListener.java

@@ -248,18 +248,24 @@ public void onClose(InventoryCloseEvent e) {
         List<ItemStack> sellableItems = new ArrayList<>();
         List<ItemStack> nonSellableItems = new ArrayList<>();
 
+        // Track shulker boxes as [modifiedItem, originalClone] pairs so we can
+        // return the correct version depending on whether the deposit succeeds.
+        List<ItemStack[]> shulkerBoxPairs = new ArrayList<>();
+
         for (int i = 0; i < ShopMainGUI.BOTTOM_ROW_START; i++) {
             ItemStack item = top.getItem(i);
             if (item == null || item.getType() == Material.AIR) continue;
 
-            // Shulker box: sell its contents, return the (now empty/partially-empty) shulker
+            // Shulker box: sell its contents but defer returning the box until
+            // after the deposit so we can roll back properly on failure.
             if (SellManager.isShulkerBox(item)) {
+                ItemStack originalClone = item.clone();
                 SellManager.ShulkerSellData data = pl.getSellManager().sellShulkerContents(player, item, null, null);
                 totalEarned += data.earned;
                 totalItems += data.items;
                 data.categoryEarnings.forEach((cat, val) -> categoryEarnings.merge(cat, val, Double::sum));
-                // Return the shulker box (now with sold items removed) to the player
-                returnItem(player, item);
+                // [0] = modified item (contents removed), [1] = original clone
+                shulkerBoxPairs.add(new ItemStack[]{item, originalClone});
                 continue;
             }
 
@@ -280,6 +286,7 @@ public void onClose(InventoryCloseEvent e) {
             sellableItems.add(item);
         }
 
+        // Always return non-sellable items immediately.
         for (ItemStack item : nonSellableItems) {
             returnItem(player, item);
         }
@@ -290,12 +297,26 @@ public void onClose(InventoryCloseEvent e) {
                 for (Map.Entry<String, Double> entry : categoryEarnings.entrySet()) {
                     pl.getMultiplierManager().addEarnings(player, entry.getKey(), entry.getValue());
                 }
+                // Return the modified shulker boxes (sellable contents removed).
+                for (ItemStack[] pair : shulkerBoxPairs) {
+                    returnItem(player, pair[0]);
+                }
                 pl.getSellManager().sendSellNotification(player, totalEarned, totalItems);
             } else {
                 player.sendMessage(pl.getConfigManager().getMessage("economy-error"));
+                // Deposit failed – return everything in its original state.
                 for (ItemStack item : sellableItems) {
                     returnItem(player, item);
                 }
+                // Restore shulker boxes to their original state (undo content removal).
+                for (ItemStack[] pair : shulkerBoxPairs) {
+                    returnItem(player, pair[1]);
+                }
+            }
+        } else {
+            // Nothing was sold – return shulker boxes unchanged.
+            for (ItemStack[] pair : shulkerBoxPairs) {
+                returnItem(player, pair[0]);
             }
         }
     }

src/main/java/com/yourname/sellplugin/manager/SellManager.java

@@ -289,9 +289,11 @@ public void sendSellNotification(Player player, double amount, int itemCount) {
     // Shulker box helpers
     // ---------------------------------------------------------------
 
-    /** Returns true if the item is any colour of shulker box. */
+    /** Returns true if the item is any colour of shulker box (including the default purple one). */
     public static boolean isShulkerBox(ItemStack item) {
-        return item != null && item.getType().name().endsWith("_SHULKER_BOX");
+        if (item == null) return false;
+        String name = item.getType().name();
+        return name.equals("SHULKER_BOX") || name.endsWith("_SHULKER_BOX");
     }
 
     /**