feat: custom menu items now support permissions

- Add permissions support to custom menu items
- If the player tries to use the item without the permission they will
  receive the no permission message and the item's actions won't run

Author: Fritx22

src/main/java/me/zetastormy/akropolis/inventory/InventoryItem.java

@@ -20,17 +20,21 @@
 package me.zetastormy.akropolis.inventory;
 
 import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.List;
 
 public class InventoryItem {
     public final ItemStack itemStack;
     public final List<ClickAction> clickActions;
+    public final @Nullable String permission;
 
-    public InventoryItem(ItemStack itemStack) {
+    public InventoryItem(@NotNull ItemStack itemStack, @Nullable String permission) {
         this.clickActions = new ArrayList<>();
         this.itemStack = itemStack;
+        this.permission = permission;
     }
 
     public InventoryItem addClickAction(ClickAction clickAction) {
@@ -45,4 +49,8 @@ public List<ClickAction> getClickActions() {
     public ItemStack getItemStack() {
         return this.itemStack;
     }
+
+    public @Nullable String getPermission() {
+        return this.permission;
+    }
 }

src/main/java/me/zetastormy/akropolis/inventory/InventoryListener.java

@@ -19,6 +19,7 @@
 
 package me.zetastormy.akropolis.inventory;
 
+import me.zetastormy.akropolis.config.Message;
 import org.bukkit.Material;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
@@ -46,6 +47,11 @@ public void onInventoryClick(InventoryClickEvent event) {
                 if (item == null)
                     return;
 
+                if (item.getPermission() != null && !player.hasPermission(item.getPermission())) {
+                    Message.NO_PERMISSION.send(player);
+                    return;
+                }
+
                 for (final ClickAction clickAction : item.getClickActions()) {
                     clickAction.execute(player);
                 }

src/main/java/me/zetastormy/akropolis/inventory/inventories/CustomGUI.java

@@ -27,6 +27,9 @@
 import org.bukkit.configuration.ConfigurationSection;
 import org.bukkit.configuration.file.FileConfiguration;
 import org.bukkit.inventory.Inventory;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Objects;
 
 public class CustomGUI extends AbstractInventory {
     private final FileConfiguration config;
@@ -66,16 +69,19 @@ public void onEnable() {
         inventory = inventoryBuilder;
     }
 
-    private InventoryItem build(String item) {
+    private InventoryItem build(final @NotNull String itemKey) {
+        // if the key exists then the section should exist too
+        final ConfigurationSection itemConfig = Objects.requireNonNull(itemsSection.getConfigurationSection(itemKey));
         ItemStackBuilder itemStackBuilder = ItemStackBuilder
-                .getItemStack(itemsSection.getConfigurationSection(item));
+                .getItemStack(itemConfig);
         InventoryItem inventoryItem;
 
-        if (!itemsSection.contains(item + ".actions")) {
-            inventoryItem = new InventoryItem(itemStackBuilder.build());
+        if (!itemsSection.contains(itemKey + ".actions")) {
+            inventoryItem = new InventoryItem(itemStackBuilder.build(), itemConfig.getString("permission"));
         } else {
-            inventoryItem = new InventoryItem(itemStackBuilder.build()).addClickAction(p -> getPlugin()
-                    .getActionManager().executeActions(p, itemsSection.getStringList(item + ".actions")));
+            inventoryItem = new InventoryItem(itemStackBuilder.build(), itemConfig.getString("permission"))
+                    .addClickAction(p -> getPlugin().getActionManager()
+                            .executeActions(p, itemsSection.getStringList(itemKey + ".actions")));
         }
 
         return inventoryItem;