refactoring

src/main/java/sh/okx/rankup/AutoRankup.java

@@ -11,12 +11,13 @@ public class AutoRankup extends BukkitRunnable {
 
   @Override
   public void run() {
+    RankupHelper helper = rankup.getHelper();
     for (Player player : Bukkit.getOnlinePlayers()) {
       if (player.hasPermission("rankup.auto")) {
-        if (rankup.checkRankup(player, false)) {
-          rankup.rankup(player);
-        } else if (rankup.getPrestiges() != null && rankup.checkPrestige(player, false)) {
-          rankup.prestige(player);
+        if (helper.checkRankup(player, false)) {
+          helper.rankup(player);
+        } else if (rankup.getPrestiges() != null && helper.checkPrestige(player, false)) {
+          helper.prestige(player);
         }
       }
     }

src/main/java/sh/okx/rankup/Rankup.java

@@ -4,6 +4,7 @@ import lombok.Getter;
 import net.milkbowl.vault.economy.Economy;
 import net.milkbowl.vault.permission.Permission;
 import org.bukkit.Bukkit;
+import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.configuration.ConfigurationSection;
 import org.bukkit.configuration.file.FileConfiguration;
@@ -11,6 +12,7 @@ import org.bukkit.configuration.file.YamlConfiguration;
 import org.bukkit.entity.Player;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.InventoryView;
+import org.bukkit.plugin.PluginManager;
 import org.bukkit.plugin.RegisteredServiceProvider;
 import org.bukkit.plugin.java.JavaPlugin;
 import sh.okx.rankup.commands.InfoCommand;
@@ -20,7 +22,7 @@ import sh.okx.rankup.commands.RanksCommand;
 import sh.okx.rankup.commands.RankupCommand;
 import sh.okx.rankup.gui.Gui;
 import sh.okx.rankup.gui.GuiListener;
-import sh.okx.rankup.messages.EmptyMessageBuilder;
+import sh.okx.rankup.messages.NullMessageBuilder;
 import sh.okx.rankup.messages.Message;
 import sh.okx.rankup.messages.MessageBuilder;
 import sh.okx.rankup.messages.Variable;
@@ -44,7 +46,6 @@ import java.text.DecimalFormat;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.WeakHashMap;
 import java.util.function.Supplier;
 
 public class Rankup extends JavaPlugin {
@@ -56,7 +57,7 @@ public class Rankup extends JavaPlugin {
    * The registry for listing the requirements to /rankup.
    */
   @Getter
-  private RequirementRegistry requirementRegistry;
+  private RequirementRegistry requirements;
   @Getter
   private FileConfiguration messages;
   @Getter
@@ -67,10 +68,8 @@ public class Rankup extends JavaPlugin {
   private Prestiges prestiges;
   @Getter
   private Placeholders placeholders;
-  /**
-   * Players who cannot rankup/prestige for a certain amount of time.
-   */
-  private Map<Player, Long> cooldowns;
+  @Getter
+  private RankupHelper helper;
   private AutoRankup autoRankup;
 
   @Override
@@ -117,7 +116,6 @@ public class Rankup extends JavaPlugin {
   }
 
   public void reload() {
-    cooldowns = new WeakHashMap<>();
     closeInventories();
     loadConfigs();
 
@@ -139,6 +137,8 @@ public class Rankup extends JavaPlugin {
       getLogger().severe("You may then copy in your config values from the old config.");
       getLogger().severe("Check the changelog on the Rankup spigot page to see the changes.");
     }
+
+    helper = new RankupHelper(this);
   }
 
   private void addAll(Map<String, Integer> map, RankList<? extends Rank> ranks) {
@@ -191,6 +191,7 @@ public class Rankup extends JavaPlugin {
       e.printStackTrace();
       Bukkit.getPluginManager().disablePlugin(this);
       getLogger().severe("Could not finish enabling Rankup");
+      Bukkit.broadcast(ChatColor.RED + "Could not reload rankup successfully, please check console for more information.", "rankup.reload");
     }
   }
 
@@ -217,34 +218,36 @@ public class Rankup extends JavaPlugin {
   }
 
   private void registerRequirements() {
-    requirementRegistry = new RequirementRegistry();
+    requirements = new RequirementRegistry();
+    requirements.addRequirement(new XpLevelRequirement(this));
+    requirements.addRequirement(new PlaytimeMinutesRequirement(this));
+    requirements.addRequirement(new GroupRequirement(this));
+    requirements.addRequirement(new PermissionRequirement(this));
+    requirements.addRequirement(new PlaceholderRequirement(this));
+    requirements.addRequirement(new WorldRequirement(this));
+    requirements.addRequirement(new BlockBreakRequirement(this));
+    requirements.addRequirement(new PlayerKillsRequirement(this));
+    requirements.addRequirement(new MobKillsRequirement(this));
+    requirements.addRequirement(new ItemRequirement(this));
+    requirements.addRequirement(new UseItemRequirement(this));
+    requirements.addRequirement(new TotalMobKillsRequirement(this));
+    requirements.addRequirement(new CraftItemRequirement(this));
     if (economy != null) {
-      requirementRegistry.addRequirement(new MoneyRequirement(this));
+      requirements.addRequirement(new MoneyRequirement(this));
     }
-    requirementRegistry.addRequirement(new XpLevelRequirement(this));
-    requirementRegistry.addRequirement(new PlaytimeMinutesRequirement(this));
-    requirementRegistry.addRequirement(new GroupRequirement(this));
-    requirementRegistry.addRequirement(new PermissionRequirement(this));
-    requirementRegistry.addRequirement(new PlaceholderRequirement(this));
-    requirementRegistry.addRequirement(new WorldRequirement(this));
-    requirementRegistry.addRequirement(new BlockBreakRequirement(this));
-    requirementRegistry.addRequirement(new PlayerKillsRequirement(this));
-    requirementRegistry.addRequirement(new MobKillsRequirement(this));
-    if (Bukkit.getPluginManager().isPluginEnabled("mcMMO")) {
-      requirementRegistry.addRequirement(new McMMOSkillRequirement(this));
-      requirementRegistry.addRequirement(new McMMOPowerLevelRequirement(this));
+
+    PluginManager pluginManager = Bukkit.getPluginManager();
+    if (pluginManager.isPluginEnabled("mcMMO")) {
+      requirements.addRequirement(new McMMOSkillRequirement(this));
+      requirements.addRequirement(new McMMOPowerLevelRequirement(this));
     }
-    if (Bukkit.getPluginManager().isPluginEnabled("AdvancedAchievements")) {
-      requirementRegistry.addRequirement(new AdvancedAchievementsAchievementRequirement(this));
-      requirementRegistry.addRequirement(new AdvancedAchievementsTotalRequirement(this));
+    if (pluginManager.isPluginEnabled("AdvancedAchievements")) {
+      requirements.addRequirement(new AdvancedAchievementsAchievementRequirement(this));
+      requirements.addRequirement(new AdvancedAchievementsTotalRequirement(this));
     }
-    if (Bukkit.getPluginManager().isPluginEnabled("VotingPlugin")) {
-      requirementRegistry.addRequirement(new VotingPluginVotesRequirement(this));
+    if (pluginManager.isPluginEnabled("VotingPlugin")) {
+      requirements.addRequirement(new VotingPluginVotesRequirement(this));
     }
-    requirementRegistry.addRequirement(new ItemRequirement(this));
-    requirementRegistry.addRequirement(new UseItemRequirement(this));
-    requirementRegistry.addRequirement(new TotalMobKillsRequirement(this));
-    requirementRegistry.addRequirement(new CraftItemRequirement(this));
   }
 
   private void setupPermissions() {
@@ -289,166 +292,8 @@ public class Rankup extends JavaPlugin {
     return MessageBuilder.of(messages, message);
   }
 
-  private boolean checkCooldown(Player player, Rank rank) {
-    if (cooldowns.containsKey(player)) {
-      long time = System.currentTimeMillis() - cooldowns.get(player);
-      // if time passed is less than the cooldown
-      long cooldownSeconds = config.getInt("cooldown");
-      long timeLeft = (cooldownSeconds * 1000) - time;
-      if (timeLeft > 0) {
-        long secondsLeft = (long) Math.ceil(timeLeft / 1000f);
-        getMessage(rank, secondsLeft > 1 ? Message.COOLDOWN_PLURAL : Message.COOLDOWN_SINGULAR)
-            .failIfEmpty()
-            .replaceRanks(player, rank.getRank())
-            .replaceFromTo(rank)
-            .replace(Variable.SECONDS, cooldownSeconds)
-            .replace(Variable.SECONDS_LEFT, secondsLeft)
-            .send(player);
-        return true;
-      }
-      // cooldown has expired so remove it
-      cooldowns.remove(player);
-    }
-    return false;
-  }
-
-  private void applyCooldown(Player player) {
-    if (config.getInt("cooldown") > 0) {
-      cooldowns.put(player, System.currentTimeMillis());
-    }
-  }
-
-  public void rankup(Player player) {
-    if (!checkRankup(player)) {
-      return;
-    }
-
-    Rank oldRank = rankups.getByPlayer(player);
-    String next = oldRank.getNext();
-
-    oldRank.applyRequirements(player);
-
-    permissions.playerRemoveGroup(null, player, oldRank.getRank());
-    permissions.playerAddGroup(null, player, next);
-
-    getMessage(oldRank, Message.SUCCESS_PUBLIC)
-        .failIfEmpty()
-        .replaceRanks(player, oldRank, next)
-        .broadcast();
-    getMessage(oldRank, Message.SUCCESS_PRIVATE)
-        .failIfEmpty()
-        .replaceRanks(player, oldRank, next)
-        .send(player);
-
-    oldRank.runCommands(player, next);
-    applyCooldown(player);
-  }
-
-  public boolean checkRankup(Player player) {
-    return checkRankup(player, true);
-  }
-
-  /**
-   * Checks if a player can rankup,
-   * and if they can't, sends the player a message and returns false
-   *
-   * @param player the player to check if they can rankup
-   * @return true if the player can rankup, false otherwise
-   */
-  public boolean checkRankup(Player player, boolean message) {
-    Rank rank = rankups.getByPlayer(player);
-    if (rankups.isLast(permissions, player)) {
-      getMessage(prestiges == null ? Message.NO_RANKUP : prestiges.isLast(permissions, player) ? Message.NO_RANKUP : Message.MUST_PRESTIGE)
-          .failIf(!message)
-          .replaceRanks(player, rankups.getLast())
-          .send(player);
-      return false;
-    } else if (rank == null) { // check if in ladder
-      getMessage(Message.NOT_IN_LADDER)
-          .failIf(!message)
-          .replace(Variable.PLAYER, player.getName())
-          .send(player);
-      return false;
-    } else if (!rank.hasRequirements(player)) { // check if they can afford it
-      if (message) {
-        replaceMoneyRequirements(getMessage(rank, Message.REQUIREMENTS_NOT_MET)
-            .replaceRanks(player, rank, rank.getNext()), player, rank)
-            .send(player);
-      }
-      return false;
-    } else if (message && checkCooldown(player, rank)) {
-      return false;
-    }
-
-    return true;
-  }
-
-  public void prestige(Player player) {
-    if (!checkPrestige(player)) {
-      return;
-    }
-
-    Prestige oldPrestige = prestiges.getByPlayer(player);
-
-    oldPrestige.applyRequirements(player);
-
-    permissions.playerRemoveGroup(null, player, oldPrestige.getFrom());
-    permissions.playerAddGroup(null, player, oldPrestige.getTo());
-    if (oldPrestige.getRank() != null) {
-      permissions.playerRemoveGroup(null, player, oldPrestige.getRank());
-    }
-    permissions.playerAddGroup(null, player, oldPrestige.getNext());
-
-    getMessage(oldPrestige, Message.PRESTIGE_SUCCESS_PUBLIC)
-        .failIfEmpty()
-        .replaceRanks(player, oldPrestige,oldPrestige.getNext())
-        .replaceFromTo(oldPrestige)
-        .broadcast();
-    getMessage(oldPrestige, Message.PRESTIGE_SUCCESS_PRIVATE)
-        .failIfEmpty()
-        .replaceRanks(player, oldPrestige, oldPrestige.getNext())
-        .replaceFromTo(oldPrestige)
-        .send(player);
-
-    oldPrestige.runCommands(player, oldPrestige.getNext());
-    applyCooldown(player);
-  }
-
-  public boolean checkPrestige(Player player) {
-    return checkPrestige(player, true);
-  }
-
-  public boolean checkPrestige(Player player, boolean message) {
-    Prestige prestige = prestiges.getByPlayer(player);
-    if (prestige == null || !prestige.isEligable(player)) { // check if in ladder
-      getMessage(Message.NOT_HIGH_ENOUGH)
-          .failIf(!message)
-          .replace(Variable.PLAYER, player.getName())
-          .send(player);
-      return false;
-    } else if (prestiges.isLast(permissions, player)) { // check if they are at the highest rank
-      getMessage(prestige, Message.PRESTIGE_NO_PRESTIGE)
-          .failIf(!message)
-          .replaceRanks(player, prestige.getRank())
-          .replaceFromTo(prestige)
-          .send(player);
-      return false;
-    } else if (!prestige.hasRequirements(player)) { // check if they can afford it
-      replaceMoneyRequirements(getMessage(prestige, Message.PRESTIGE_REQUIREMENTS_NOT_MET)
-          .failIf(!message)
-          .replaceRanks(player, prestige, prestiges.next(prestige).getRank()), player, prestige)
-          .replaceFromTo(prestige)
-          .send(player);
-      return false;
-    } else if (checkCooldown(player, prestige)) {
-      return false;
-    }
-
-    return true;
-  }
-
   public MessageBuilder replaceMoneyRequirements(MessageBuilder builder, CommandSender sender, Rank rank) {
-    if (builder instanceof EmptyMessageBuilder) {
+    if (builder instanceof NullMessageBuilder) {
       return builder;
     }
 

src/main/java/sh/okx/rankup/RankupHelper.java

@@ -0,0 +1,188 @@
+package sh.okx.rankup;
+
+import lombok.RequiredArgsConstructor;
+import net.milkbowl.vault.permission.Permission;
+import org.bukkit.configuration.ConfigurationSection;
+import org.bukkit.entity.Player;
+import sh.okx.rankup.messages.Message;
+import sh.okx.rankup.messages.Variable;
+import sh.okx.rankup.prestige.Prestige;
+import sh.okx.rankup.prestige.Prestiges;
+import sh.okx.rankup.ranks.Rank;
+import sh.okx.rankup.ranks.Rankups;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class RankupHelper {
+  private final Rankup plugin;
+  private final ConfigurationSection config;
+  private final Permission permissions;
+  /**
+   * Players who cannot rankup/prestige for a certain amount of time.
+   */
+  private Map<Player, Long> cooldowns = new HashMap<>();
+
+  public RankupHelper(Rankup plugin) {
+    this.plugin = plugin;
+    this.config = plugin.getConfig();
+    this.permissions = plugin.getPermissions();
+  }
+
+  private void doRankup(Player player, Rank rank) {
+    rank.runCommands(player);
+    applyCooldown(player);
+
+    permissions.playerRemoveGroup(null, player, rank.getRank());
+    permissions.playerAddGroup(null, player, rank.getNext());
+  }
+
+  private boolean checkCooldown(Player player, Rank rank) {
+    if (cooldowns.containsKey(player)) {
+      long time = System.currentTimeMillis() - cooldowns.get(player);
+      // if time passed is less than the cooldown
+      long cooldownSeconds = config.getInt("cooldown");
+      long timeLeft = (cooldownSeconds * 1000) - time;
+      if (timeLeft > 0) {
+        long secondsLeft = (long) Math.ceil(timeLeft / 1000f);
+        plugin.getMessage(rank, secondsLeft > 1 ? Message.COOLDOWN_PLURAL : Message.COOLDOWN_SINGULAR)
+            .failIfEmpty()
+            .replaceRanks(player, rank.getRank())
+            .replaceFromTo(rank)
+            .replace(Variable.SECONDS, cooldownSeconds)
+            .replace(Variable.SECONDS_LEFT, secondsLeft)
+            .send(player);
+        return true;
+      }
+      // cooldown has expired so remove it
+      cooldowns.remove(player);
+    }
+    return false;
+  }
+
+  private void applyCooldown(Player player) {
+    if (config.getInt("cooldown") > 0) {
+      cooldowns.put(player, System.currentTimeMillis());
+    }
+  }
+
+  public void rankup(Player player) {
+    if (!checkRankup(player)) {
+      return;
+    }
+
+    Rank rank = plugin.getRankups().getByPlayer(player);
+    rank.applyRequirements(player);
+    doRankup(player, rank);
+
+    plugin.getMessage(rank, Message.SUCCESS_PUBLIC)
+        .failIfEmpty()
+        .replaceRanks(player, rank, rank.getNext())
+        .broadcast();
+    plugin.getMessage(rank, Message.SUCCESS_PRIVATE)
+        .failIfEmpty()
+        .replaceRanks(player, rank, rank.getNext())
+        .send(player);
+  }
+
+  public boolean checkRankup(Player player) {
+    return checkRankup(player, true);
+  }
+
+  /**
+   * Checks if a player can rankup,
+   * and if they can't, sends the player a message and returns false
+   *
+   * @param player the player to check if they can rankup
+   * @return true if the player can rankup, false otherwise
+   */
+  public boolean checkRankup(Player player, boolean message) {
+    Rankups rankups = plugin.getRankups();
+    Rank rank = rankups.getByPlayer(player);
+    if (rankups.isLast(permissions, player)) {
+      Prestiges prestiges = plugin.getPrestiges();
+      plugin.getMessage(prestiges == null ? Message.NO_RANKUP : prestiges.isLast(permissions, player) ? Message.NO_RANKUP : Message.MUST_PRESTIGE)
+          .failIf(!message)
+          .replaceRanks(player, rankups.getLast())
+          .send(player);
+      return false;
+    } else if (rank == null) { // check if in ladder
+      plugin.getMessage(Message.NOT_IN_LADDER)
+          .failIf(!message)
+          .replace(Variable.PLAYER, player.getName())
+          .send(player);
+      return false;
+    } else if (!rank.hasRequirements(player)) { // check if they can afford it
+      if (message) {
+        plugin.replaceMoneyRequirements(plugin.getMessage(rank, Message.REQUIREMENTS_NOT_MET)
+            .replaceRanks(player, rank, rank.getNext()), player, rank)
+            .send(player);
+      }
+      return false;
+    } else if (message && checkCooldown(player, rank)) {
+      return false;
+    }
+
+    return true;
+  }
+
+  public void prestige(Player player) {
+    if (!checkPrestige(player)) {
+      return;
+    }
+
+    Prestige prestige = plugin.getPrestiges().getByPlayer(player);
+    prestige.applyRequirements(player);
+    doRankup(player, prestige);
+
+    if (prestige.getRank() != null) {
+      permissions.playerRemoveGroup(null, player, prestige.getRank());
+    }
+    permissions.playerAddGroup(null, player, prestige.getNext());
+
+    plugin.getMessage(prestige, Message.PRESTIGE_SUCCESS_PUBLIC)
+        .failIfEmpty()
+        .replaceRanks(player, prestige,prestige.getNext())
+        .replaceFromTo(prestige)
+        .broadcast();
+    plugin.getMessage(prestige, Message.PRESTIGE_SUCCESS_PRIVATE)
+        .failIfEmpty()
+        .replaceRanks(player, prestige, prestige.getNext())
+        .replaceFromTo(prestige)
+        .send(player);
+  }
+
+  public boolean checkPrestige(Player player) {
+    return checkPrestige(player, true);
+  }
+
+  public boolean checkPrestige(Player player, boolean message) {
+    Prestiges prestiges = plugin.getPrestiges();
+    Prestige prestige = prestiges.getByPlayer(player);
+    if (prestige == null || !prestige.isEligable(player)) { // check if in ladder
+      plugin.getMessage(Message.NOT_HIGH_ENOUGH)
+          .failIf(!message)
+          .replace(Variable.PLAYER, player.getName())
+          .send(player);
+      return false;
+    } else if (prestiges.isLast(plugin.getPermissions(), player)) { // check if they are at the highest rank
+      plugin.getMessage(prestige, Message.PRESTIGE_NO_PRESTIGE)
+          .failIf(!message)
+          .replaceRanks(player, prestige.getRank())
+          .replaceFromTo(prestige)
+          .send(player);
+      return false;
+    } else if (!prestige.hasRequirements(player)) { // check if they can afford it
+      plugin.replaceMoneyRequirements(plugin.getMessage(prestige, Message.PRESTIGE_REQUIREMENTS_NOT_MET)
+          .failIf(!message)
+          .replaceRanks(player, prestige, prestiges.next(prestige).getRank()), player, prestige)
+          .replaceFromTo(prestige)
+          .send(player);
+      return false;
+    } else if (checkCooldown(player, prestige)) {
+      return false;
+    }
+
+    return true;
+  }
+}

src/main/java/sh/okx/rankup/RankupRegisterEvent.java

@@ -24,11 +24,11 @@ public class RankupRegisterEvent extends Event {
   }
 
   public RequirementRegistry getRequirementRegistry() {
-    return plugin.getRequirementRegistry();
+    return plugin.getRequirements();
   }
 
   public void addRequirement(Requirement requirement) {
-    plugin.getRequirementRegistry().addRequirement(requirement);
+    plugin.getRequirements().addRequirement(requirement);
   }
 
   @Override

src/main/java/sh/okx/rankup/commands/PrestigeCommand.java

@@ -30,7 +30,7 @@ public class PrestigeCommand implements CommandExecutor {
 
     Prestiges prestiges = plugin.getPrestiges();
     Prestige prestige = prestiges.getByPlayer(player);
-    if (!plugin.checkPrestige(player)) {
+    if (!plugin.getHelper().checkPrestige(player)) {
       return true;
     }
 
@@ -39,7 +39,7 @@ public class PrestigeCommand implements CommandExecutor {
     if (confirmationType.equals("text") && confirming.containsKey(player)) {
       long time = System.currentTimeMillis() - confirming.remove(player);
       if (time < config.getInt("text.timeout") * 1000) {
-        plugin.prestige(player);
+        plugin.getHelper().prestige(player);
         return true;
       }
     }
@@ -59,7 +59,7 @@ public class PrestigeCommand implements CommandExecutor {
         Gui.of(player, prestige, prestige.getNext(), plugin).open(player);
         break;
       case "none":
-        plugin.prestige(player);
+        plugin.getHelper().prestige(player);
         break;
       default:
         throw new IllegalArgumentException("Invalid confirmation type " + confirmationType);

src/main/java/sh/okx/rankup/commands/RankupCommand.java

@@ -32,7 +32,7 @@ public class RankupCommand implements CommandExecutor {
 
     Rankups rankups = plugin.getRankups();
     Rank rank = rankups.getByPlayer(player);
-    if (!plugin.checkRankup(player)) {
+    if (!plugin.getHelper().checkRankup(player)) {
       return true;
     }
     /*Rank next = rankups.next(rank);
@@ -51,7 +51,7 @@ public class RankupCommand implements CommandExecutor {
     if (confirmationType.equals("text") && confirming.containsKey(player)) {
       long time = System.currentTimeMillis() - confirming.remove(player);
       if (time < config.getInt("text.timeout") * 1000) {
-        plugin.rankup(player);
+        plugin.getHelper().rankup(player);
         return true;
       }
     }
@@ -67,7 +67,7 @@ public class RankupCommand implements CommandExecutor {
         Gui.of(player, rank, next, plugin).open(player);
         break;
       case "none":
-        plugin.rankup(player);
+        plugin.getHelper().rankup(player);
         break;
       default:
         throw new IllegalArgumentException("Invalid confirmation type " + confirmationType);

src/main/java/sh/okx/rankup/gui/GuiListener.java

@@ -18,7 +18,7 @@ public class GuiListener implements Listener {
     Inventory inventory = e.getInventory();
     if (inventory == null
         || !(inventory.getHolder() instanceof Gui)
-        || !e.getInventory().equals(e.getClickedInventory())) {
+        || !inventory.equals(e.getClickedInventory())) {
       return;
     }
     e.setCancelled(true);
@@ -29,9 +29,9 @@ public class GuiListener implements Listener {
     if (gui.getRankup().isSimilar(e.getCurrentItem())) {
       Bukkit.getScheduler().runTask(plugin, player::closeInventory);
       if (gui.isPrestige()) {
-        plugin.prestige(player);
+        plugin.getHelper().prestige(player);
       } else {
-        plugin.rankup(player);
+        plugin.getHelper().rankup(player);
       }
     } else if (gui.getCancel().isSimilar(e.getCurrentItem())) {
       Bukkit.getScheduler().runTask(plugin, player::closeInventory);

src/main/java/sh/okx/rankup/messages/MessageBuilder.java

@@ -84,8 +84,7 @@ public class MessageBuilder {
   /**
    * Fails the MessageBuilder if the message is empty.
    * if this fails, all subsequent calls to that MessageBuilder will do nothing
-   *
-   * @return an EmptyMessageBuilder if the message is empty, itself otherwise
+   * @return a NullMessageBuilder if the message is empty, itself otherwise
    */
   public MessageBuilder failIfEmpty() {
     return failIf(message.isEmpty());
@@ -93,7 +92,7 @@ public class MessageBuilder {
 
   public MessageBuilder failIf(boolean value) {
     if (value) {
-      return new EmptyMessageBuilder();
+      return new NullMessageBuilder();
     } else {
       return this;
     }

src/main/java/sh/okx/rankup/messages/NullMessageBuilder.java

@@ -2,13 +2,13 @@ package sh.okx.rankup.messages;
 
 import org.bukkit.command.CommandSender;
 
-public class EmptyMessageBuilder extends MessageBuilder {
-  EmptyMessageBuilder() {
+public class NullMessageBuilder extends MessageBuilder {
+  NullMessageBuilder() {
     super(null);
   }
 
   @Override
-  public MessageBuilder failIfEmpty() {
+  public MessageBuilder failIf(boolean value) {
     return this;
   }
 

src/main/java/sh/okx/rankup/placeholders/RankupExpansion.java

@@ -185,4 +185,9 @@ public class RankupExpansion extends PlaceholderExpansion {
   public String getVersion() {
     return plugin.getDescription().getVersion();
   }
+
+  @Override
+  public boolean persist() {
+    return true;
+  }
 }

src/main/java/sh/okx/rankup/prestige/Prestige.java

@@ -28,7 +28,7 @@ public class Prestige extends Rank {
 
   public static Prestige deserialize(Rankup plugin, ConfigurationSection section) {
     List<String> requirementsList = section.getStringList("requirements");
-    Set<Requirement> requirements = plugin.getRequirementRegistry().getRequirements(requirementsList);
+    Set<Requirement> requirements = plugin.getRequirements().getRequirements(requirementsList);
 
     return new Prestige(section, plugin,
         section.getString("next"),

src/main/java/sh/okx/rankup/ranks/Rank.java

@@ -34,7 +34,7 @@ public class Rank {
 
   public static Rank deserialize(Rankup plugin, ConfigurationSection section) {
     List<String> requirementsList = section.getStringList("requirements");
-    Set<Requirement> requirements = plugin.getRequirementRegistry().getRequirements(requirementsList);
+    Set<Requirement> requirements = plugin.getRequirements().getRequirements(requirementsList);
 
     return new Rank(section, plugin,
         section.getString("next"),
@@ -87,11 +87,13 @@ public class Rank {
     }
   }
 
-  public void runCommands(Player player, String next) {
+  public void runCommands(Player player) {
     for (String command : commands) {
       String string = new MessageBuilder(command).replaceRanks(player, this, next).toString();
-      Bukkit.dispatchCommand(Bukkit.getConsoleSender(),
-          PlaceholderAPI.setPlaceholders(player, string));
+      if (Bukkit.getPluginManager().isPluginEnabled("PlaceholderAPI")) {
+        string = PlaceholderAPI.setPlaceholders(player, string);
+      }
+      Bukkit.dispatchCommand(Bukkit.getConsoleSender(), string);
     }
   }
 }

src/main/java/sh/okx/rankup/requirements/requirement/MobKillsRequirement.java

@@ -18,6 +18,7 @@ public class MobKillsRequirement extends ProgressiveRequirement {
     super(clone);
   }
 
+  @SuppressWarnings("deprecation")
   @Override
   public double getProgress(Player player) {
     EntityType entity = Objects.requireNonNull(EntityType.fromName(getSub()), "Invalid entity type '" + getSub() + "' in mob-kills requirement.");

src/main/resources/plugin.yml

@@ -1,10 +1,10 @@
 name: Rankup
-version: 3.5.4
+version: 3.5.6
 main: sh.okx.rankup.Rankup
 author: Okx
 depend: [Vault]
 softdepend: [PlaceholderAPI, mcMMO, AdvancedAchievements]
-api-version: 1.13
+api-version: '1.13'
 
 commands:
   rankup:

src/test/java/sh/okx/rankup/messages/MessageBuilderTest.java

@@ -9,6 +9,6 @@ import static org.junit.Assert.assertThat;
 public class MessageBuilderTest {
   @Test
   public void testFailIfEmpty() {
-    assertThat(new MessageBuilder("").failIfEmpty(), instanceOf(EmptyMessageBuilder.class));
+    assertThat(new MessageBuilder("").failIfEmpty(), instanceOf(NullMessageBuilder.class));
   }
 }