Add auto armor equip for kits (#3629)

Adds a config option to have player auto-equip armor from kits.

Also adds a performance improvement for all uses of EnumUtil#getAllMatching by switching it to an EnumSet.

Closes #347, closes #3452.

Essentials/src/main/java/com/earth2me/essentials/ISettings.java

@@ -331,6 +331,8 @@ public interface ISettings extends IConf {
 
     List<EssentialsSign> getUnprotectedSignNames();
 
+    boolean isKitAutoEquip();
+
     boolean isPastebinCreateKit();
 
     boolean isAllowBulkBuySell();

Essentials/src/main/java/com/earth2me/essentials/Kit.java

@@ -7,12 +7,14 @@ import com.earth2me.essentials.textreader.IText;
 import com.earth2me.essentials.textreader.KeywordReplacer;
 import com.earth2me.essentials.textreader.SimpleTextInput;
 import com.earth2me.essentials.utils.DateUtil;
+import com.earth2me.essentials.utils.MaterialUtil;
 import com.earth2me.essentials.utils.NumberUtil;
 import net.ess3.api.IEssentials;
 import net.ess3.api.events.KitClaimEvent;
 import org.bukkit.Bukkit;
 import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
 
 import java.math.BigDecimal;
 import java.util.ArrayList;
@@ -162,6 +164,7 @@ public class Kit {
 
             boolean spew = false;
             final boolean allowUnsafe = ess.getSettings().allowUnsafeEnchantments();
+            final boolean autoEquip = ess.getSettings().isKitAutoEquip();
             final List<ItemStack> itemList = new ArrayList<>();
             final List<String> commandQueue = new ArrayList<>();
             final List<String> moneyQueue = new ArrayList<>();
@@ -194,6 +197,25 @@ public class Kit {
                     metaStack.parseStringMeta(null, allowUnsafe, parts, 2, ess);
                 }
 
+                if (autoEquip) {
+                    final ItemStack stack = metaStack.getItemStack();
+                    final Material material = stack.getType();
+                    final PlayerInventory inventory = user.getBase().getInventory();
+                    if (MaterialUtil.isHelmet(material) && isEmptyStack(inventory.getHelmet())) {
+                        inventory.setHelmet(stack);
+                        continue;
+                    } else if (MaterialUtil.isChestplate(material) && isEmptyStack(inventory.getChestplate())) {
+                        inventory.setChestplate(stack);
+                        continue;
+                    } else if (MaterialUtil.isLeggings(material) && isEmptyStack(inventory.getLeggings())) {
+                        inventory.setLeggings(stack);
+                        continue;
+                    } else if (MaterialUtil.isBoots(material) && isEmptyStack(inventory.getBoots())) {
+                        inventory.setBoots(stack);
+                        continue;
+                    }
+                }
+
                 itemList.add(metaStack.getItemStack());
             }
 
@@ -253,4 +275,8 @@ public class Kit {
         }
         return true;
     }
+
+    private boolean isEmptyStack(ItemStack stack) {
+        return stack == null || stack.getType().isAir();
+    }
 }

Essentials/src/main/java/com/earth2me/essentials/Settings.java

@@ -1528,6 +1528,11 @@ public class Settings implements net.ess3.api.ISettings {
         return newSigns;
     }
 
+    @Override
+    public boolean isKitAutoEquip() {
+        return config.getBoolean("kit-auto-equip", false);
+    }
+
     @Override
     public boolean isPastebinCreateKit() {
         return config.getBoolean("pastebin-createkit", false);

Essentials/src/main/java/com/earth2me/essentials/utils/EnumUtil.java

@@ -5,7 +5,7 @@ import org.bukkit.Statistic;
 import org.bukkit.entity.EntityType;
 
 import java.lang.reflect.Field;
-import java.util.HashSet;
+import java.util.EnumSet;
 import java.util.Set;
 
 public final class EnumUtil {
@@ -22,7 +22,7 @@ public final class EnumUtil {
      * @param <T>       The enum to search through
      * @return The first matching enum field
      */
-    public static <T extends Enum> T valueOf(final Class<T> enumClass, final String... names) {
+    public static <T extends Enum<T>> T valueOf(final Class<T> enumClass, final String... names) {
         for (final String name : names) {
             try {
                 final Field enumField = enumClass.getDeclaredField(name);
@@ -46,8 +46,8 @@ public final class EnumUtil {
      * @param <T>       The enum to search through
      * @return All matching enum fields
      */
-    public static <T extends Enum> Set<T> getAllMatching(final Class<T> enumClass, final String... names) {
+    public static <T extends Enum<T>> Set<T> getAllMatching(final Class<T> enumClass, final String... names) {
-        final Set<T> set = new HashSet<>();
+        final Set<T> set = EnumSet.noneOf(enumClass);
 
         for (final String name : names) {
             try {

Essentials/src/main/java/com/earth2me/essentials/utils/MaterialUtil.java

@@ -25,7 +25,24 @@ public final class MaterialUtil {
     private static final Set<Material> SIGN_POSTS;
     private static final Set<Material> WALL_SIGNS;
 
+    private static final Set<Material> HELMETS;
+    private static final Set<Material> CHESTPLATES;
+    private static final Set<Material> LEGGINGS;
+    private static final Set<Material> BOOTS;
+
     static {
+        HELMETS = EnumUtil.getAllMatching(Material.class, "LEATHER_HELMET", "CHAINMAIL_HELMET", "IRON_HELMET",
+                "GOLD_HELMET", "GOLDEN_HELMET", "DIAMOND_HELMET", "NETHERITE_HELMET", "TURTLE_HELMET");
+
+        CHESTPLATES = EnumUtil.getAllMatching(Material.class, "LEATHER_CHESTPLATE", "CHAINMAIL_CHESTPLATE",
+                "IRON_CHESTPLATE", "GOLD_CHESTPLATE", "GOLDEN_CHESTPLATE", "DIAMOND_CHESTPLATE", "NETHERITE_CHESTPLATE",
+                "ELYTRA");
+
+        LEGGINGS = EnumUtil.getAllMatching(Material.class, "LEATHER_LEGGINGS", "CHAINMAIL_LEGGINGS",
+                "IRON_LEGGINGS", "GOLD_LEGGINGS", "GOLDEN_LEGGINGS", "DIAMOND_LEGGINGS", "NETHERITE_LEGGINGS");
+
+        BOOTS = EnumUtil.getAllMatching(Material.class, "LEATHER_BOOTS", "CHAINMAIL_BOOTS", "IRON_BOOTS",
+                "GOLD_BOOTS", "GOLDEN_BOOTS", "DIAMOND_BOOTS", "NETHERITE_BOOTS");
 
         BEDS = EnumUtil.getAllMatching(Material.class, "BED", "BED_BLOCK", "WHITE_BED", "ORANGE_BED",
             "MAGENTA_BED", "LIGHT_BLUE_BED", "YELLOW_BED", "LIME_BED", "PINK_BED", "GRAY_BED",
@@ -71,6 +88,22 @@ public final class MaterialUtil {
     private MaterialUtil() {
     }
 
+    public static boolean isHelmet(final Material material) {
+        return HELMETS.contains(material);
+    }
+
+    public static boolean isChestplate(final Material material) {
+        return CHESTPLATES.contains(material);
+    }
+
+    public static boolean isLeggings(final Material material) {
+        return LEGGINGS.contains(material);
+    }
+
+    public static boolean isBoots(final Material material) {
+        return BOOTS.contains(material);
+    }
+
     public static boolean isBed(final Material material) {
         return BEDS.contains(material);
     }

Essentials/src/main/resources/config.yml

@@ -321,6 +321,9 @@ use-bukkit-permissions: true
 # removed from the /kit list when a player can no longer use it
 skip-used-one-time-kits-from-kit-list: false
 
+# When enabled, armor from kits will automatically be equipped as long as the player's armor slots are empty.
+kit-auto-equip: false
+
 # Determines the functionality of the /createkit command.
 # If this is true, /createkit will give the user a link with the kit code.
 # If this is false, /createkit will add the kit to the kits.yml config file directly.