3.6-beta

add force rankup and prestige
add update notification on join
more reliable legacy server version check

added permissions: rankup.admin (grants rankup.checkversion, rankup.reload, rankup.force, and rankup.notify), rankup.notify (receive update notiifications on login), rankup.force (force a player to rankup or prestige)

build.gradle

@@ -1,11 +1,11 @@
 plugins {
     id 'java'
-    id "io.freefair.lombok" version "3.8.0"
+    id "io.freefair.lombok" version "4.1.6"
     id 'maven'
 }
 
 group 'sh.okx'
-version '3.5.8'
+version '3.6-beta'
 
 repositories {
     mavenCentral()
@@ -29,7 +29,7 @@ repositories {
 
 dependencies {
     testCompile group: 'junit', name: 'junit', version: '4.12'
-    compile 'org.spigotmc:spigot-api:1.14.4-R0.1-SNAPSHOT'
+    compile 'org.spigotmc:spigot-api:1.15.1-R0.1-SNAPSHOT'
     compile('com.github.Realizedd:TokenManager:3.2.4') {
         transitive = false
     }
@@ -39,7 +39,7 @@ dependencies {
     }
     compile 'me.clip:placeholderapi:2.9.2'
     compile 'com.hm.achievement:advanced-achievements-api:1.1.0'
-    compile ('com.github.mcMMO-Dev:mcMMO:ac8042f') {
+    compile ('com.github.mcMMO-Dev:mcMMO:601297') {
         exclude group: 'com.sk89q.worldguard'
     }
     compile 'com.github.Ben12345rocks:VotingPlugin:5.18.2'

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

@@ -0,0 +1,29 @@
+package sh.okx.rankup;
+
+import java.util.function.Supplier;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+import sh.okx.rankup.util.UpdateNotifier;
+
+public class JoinUpdateNotifier implements Listener {
+  private final UpdateNotifier notifier;
+  private final Supplier<Boolean> enabledSupplier;
+
+  public JoinUpdateNotifier(UpdateNotifier notifier,
+      Supplier<Boolean> enabledSupplier) {
+    this.notifier = notifier;
+    this.enabledSupplier = enabledSupplier;
+  }
+
+  @EventHandler
+  public void on(PlayerJoinEvent e) {
+    if (enabledSupplier.get()) {
+      Player player = e.getPlayer();
+      if (player.hasPermission("rankup.notify")) {
+        notifier.notify(player, true);
+      }
+    }
+  }
+}

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

@@ -1,5 +1,11 @@
 package sh.okx.rankup;
 
+import java.io.File;
+import java.text.DecimalFormat;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Supplier;
 import lombok.Getter;
 import net.milkbowl.vault.economy.Economy;
 import net.milkbowl.vault.permission.Permission;
@@ -22,38 +28,52 @@ 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.NullMessageBuilder;
 import sh.okx.rankup.messages.Message;
 import sh.okx.rankup.messages.MessageBuilder;
+import sh.okx.rankup.messages.NullMessageBuilder;
 import sh.okx.rankup.messages.Variable;
 import sh.okx.rankup.placeholders.Placeholders;
 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 sh.okx.rankup.requirements.DeductibleRequirement;
-import sh.okx.rankup.requirements.NonDeductibleRequirement;
-import sh.okx.rankup.requirements.ProgressiveRequirement;
 import sh.okx.rankup.requirements.Requirement;
 import sh.okx.rankup.requirements.RequirementRegistry;
-import sh.okx.rankup.requirements.requirement.*;
+import sh.okx.rankup.requirements.XpLevelDeductibleRequirement;
+import sh.okx.rankup.requirements.requirement.BlockBreakRequirement;
+import sh.okx.rankup.requirements.requirement.CraftItemRequirement;
+import sh.okx.rankup.requirements.requirement.GroupRequirement;
+import sh.okx.rankup.requirements.requirement.ItemDeductibleRequirement;
+import sh.okx.rankup.requirements.requirement.ItemRequirement;
+import sh.okx.rankup.requirements.requirement.MobKillsRequirement;
+import sh.okx.rankup.requirements.requirement.MoneyDeductibleRequirement;
+import sh.okx.rankup.requirements.requirement.MoneyRequirement;
+import sh.okx.rankup.requirements.requirement.PermissionRequirement;
+import sh.okx.rankup.requirements.requirement.PlaceholderRequirement;
+import sh.okx.rankup.requirements.requirement.PlayerKillsRequirement;
+import sh.okx.rankup.requirements.requirement.PlaytimeMinutesRequirement;
+import sh.okx.rankup.requirements.requirement.TokensDeductibleRequirement;
+import sh.okx.rankup.requirements.requirement.TotalMobKillsRequirement;
+import sh.okx.rankup.requirements.requirement.UseItemRequirement;
+import sh.okx.rankup.requirements.requirement.WorldRequirement;
 import sh.okx.rankup.requirements.requirement.XpLevelRequirement;
 import sh.okx.rankup.requirements.requirement.advancedachievements.AdvancedAchievementsAchievementRequirement;
 import sh.okx.rankup.requirements.requirement.advancedachievements.AdvancedAchievementsTotalRequirement;
 import sh.okx.rankup.requirements.requirement.mcmmo.McMMOPowerLevelRequirement;
 import sh.okx.rankup.requirements.requirement.mcmmo.McMMOSkillRequirement;
 import sh.okx.rankup.requirements.requirement.tokenmanager.TokensRequirement;
-import sh.okx.rankup.requirements.requirement.towny.*;
+import sh.okx.rankup.requirements.requirement.towny.TownyKingNumberResidentsRequirement;
+import sh.okx.rankup.requirements.requirement.towny.TownyKingNumberTownsRequirement;
+import sh.okx.rankup.requirements.requirement.towny.TownyKingRequirement;
+import sh.okx.rankup.requirements.requirement.towny.TownyMayorNumberResidentsRequirement;
+import sh.okx.rankup.requirements.requirement.towny.TownyMayorRequirement;
+import sh.okx.rankup.requirements.requirement.towny.TownyResidentRequirement;
 import sh.okx.rankup.requirements.requirement.votingplugin.VotingPluginVotesRequirement;
-
-import java.io.File;
-import java.text.DecimalFormat;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.function.Supplier;
+import sh.okx.rankup.util.UpdateNotifier;
+import sh.okx.rankup.util.VersionChecker;
 
 public class Rankup extends JavaPlugin {
+
   @Getter
   private Permission permissions;
   @Getter
@@ -77,9 +97,12 @@ public class Rankup extends JavaPlugin {
   private RankupHelper helper;
   private AutoRankup autoRankup;
   private String errorMessage;
+  private UpdateNotifier notifier;
 
   @Override
   public void onEnable() {
+    notifier = new UpdateNotifier(new VersionChecker(this));
+
     reload(true);
 
     Metrics metrics = new Metrics(this);
@@ -105,8 +128,10 @@ public class Rankup extends JavaPlugin {
     }
 
     getCommand("rankup").setExecutor(new RankupCommand(this));
-    getCommand("rankup3").setExecutor(new InfoCommand(this));
+    getCommand("rankup3").setExecutor(new InfoCommand(this, notifier));
     getServer().getPluginManager().registerEvents(new GuiListener(this), this);
+    getServer().getPluginManager().registerEvents(
+        new JoinUpdateNotifier(notifier, () -> getConfig().getBoolean("notify-update")), this);
 
     placeholders = new Placeholders(this);
     placeholders.register();
@@ -123,7 +148,7 @@ public class Rankup extends JavaPlugin {
 
   public void reload(boolean init) {
     errorMessage = null;
-    if(!setupPermissions()) {
+    if (!setupPermissions()) {
       errorMessage = "No permission plugin found";
     }
     setupEconomy();
@@ -140,7 +165,7 @@ public class Rankup extends JavaPlugin {
       autoRankup.runTaskTimer(this, time, time);
     }
 
-    if (config.getInt("version") < 4) {
+    if (config.getInt("version") < 5) {
       getLogger().severe("You are using an outdated config!");
       getLogger().severe("This means that some things might not work!");
       getLogger().severe("To update, please rename ALL your config files (or the folder they are in),");
@@ -159,6 +184,7 @@ public class Rankup extends JavaPlugin {
 
   /**
    * Notify the player of an error if there is one
+   *
    * @return true if there was an error and action was taken
    */
   public boolean error(CommandSender sender) {
@@ -187,9 +213,8 @@ public class Rankup extends JavaPlugin {
   }
 
   /**
-   * Closes all rankup inventories on disable
-   * so players cannot grab items from the inventory
-   * on a plugin reload.
+   * Closes all rankup inventories on disable so players cannot grab items from the inventory on a
+   * plugin reload.
    */
   private void closeInventories() {
     for (Player player : Bukkit.getOnlinePlayers()) {
@@ -267,58 +292,62 @@ public class Rankup extends JavaPlugin {
 
   private void registerRequirements() {
     requirements = new RequirementRegistry();
-    registerDeductible(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));
-    registerDeductible(new ItemRequirement(this));
-    requirements.addRequirement(new UseItemRequirement(this));
-    requirements.addRequirement(new TotalMobKillsRequirement(this));
-    requirements.addRequirement(new CraftItemRequirement(this));
+    requirements.addRequirements(
+        new XpLevelRequirement(this, "xp-levelh"),
+        new XpLevelDeductibleRequirement(this, "xp-level"),
+        new PlaytimeMinutesRequirement(this),
+        new GroupRequirement(this),
+        new PermissionRequirement(this),
+        new PlaceholderRequirement(this),
+        new WorldRequirement(this),
+        new BlockBreakRequirement(this),
+        new PlayerKillsRequirement(this),
+        new MobKillsRequirement(this),
+        new ItemRequirement(this, "itemh"),
+        new ItemDeductibleRequirement(this, "item"),
+        new UseItemRequirement(this),
+        new TotalMobKillsRequirement(this),
+        new CraftItemRequirement(this));
     if (economy != null) {
-      registerDeductible(new MoneyRequirement(this));
+      requirements.addRequirements(
+          new MoneyRequirement(this, "moneyh"),
+          new MoneyDeductibleRequirement(this, "money"));
     }
 
     PluginManager pluginManager = Bukkit.getPluginManager();
     if (pluginManager.isPluginEnabled("mcMMO")) {
-      requirements.addRequirement(new McMMOSkillRequirement(this));
-      requirements.addRequirement(new McMMOPowerLevelRequirement(this));
+      requirements.addRequirements(
+          new McMMOSkillRequirement(this),
+          new McMMOPowerLevelRequirement(this));
     }
     if (pluginManager.isPluginEnabled("AdvancedAchievements")) {
-      requirements.addRequirement(new AdvancedAchievementsAchievementRequirement(this));
-      requirements.addRequirement(new AdvancedAchievementsTotalRequirement(this));
+      requirements.addRequirements(
+          new AdvancedAchievementsAchievementRequirement(this),
+          new AdvancedAchievementsTotalRequirement(this));
     }
     if (pluginManager.isPluginEnabled("VotingPlugin")) {
-      requirements.addRequirement(new VotingPluginVotesRequirement(this));
+      requirements.addRequirements(
+          new VotingPluginVotesRequirement(this));
     }
     if (Bukkit.getPluginManager().isPluginEnabled("Towny")) {
-      requirements.addRequirement(new TownyResidentRequirement(this));
-      requirements.addRequirement(new TownyMayorRequirement(this));
-      requirements.addRequirement(new TownyMayorNumberResidentsRequirement(this));
-      requirements.addRequirement(new TownyKingRequirement(this));
-      requirements.addRequirement(new TownyKingNumberResidentsRequirement(this));
-      requirements.addRequirement(new TownyKingNumberTownsRequirement(this));
+      requirements.addRequirements(
+          new TownyResidentRequirement(this),
+          new TownyMayorRequirement(this),
+          new TownyMayorNumberResidentsRequirement(this),
+          new TownyKingRequirement(this),
+          new TownyKingNumberResidentsRequirement(this),
+          new TownyKingNumberTownsRequirement(this));
     }
     if (Bukkit.getPluginManager().isPluginEnabled("TokenManager")) {
-      registerDeductible(new TokensRequirement(this));
+      requirements.addRequirements(
+          new TokensRequirement(this, "tokenmanager-tokensh"),
+          new TokensDeductibleRequirement(this, "tokenmanager-tokens"));
     }
   }
 
-  private void registerDeductible(ProgressiveRequirement requirement) {
-    if (!(requirement instanceof DeductibleRequirement)) {
-      throw new IllegalArgumentException("Requirement is not DeductibleRequirement");
-    }
-    requirements.addRequirement(requirement);
-    requirements.addRequirement(new NonDeductibleRequirement(requirement, requirement.getName() + "h"));
-  }
-
   private boolean setupPermissions() {
-    RegisteredServiceProvider<Permission> rsp = getServer().getServicesManager().getRegistration(Permission.class);
+    RegisteredServiceProvider<Permission> rsp = getServer().getServicesManager()
+        .getRegistration(Permission.class);
     if (rsp == null) {
       return false;
     }
@@ -327,7 +356,8 @@ public class Rankup extends JavaPlugin {
   }
 
   private void setupEconomy() {
-    RegisteredServiceProvider<Economy> rsp = getServer().getServicesManager().getRegistration(Economy.class);
+    RegisteredServiceProvider<Economy> rsp = getServer().getServicesManager()
+        .getRegistration(Economy.class);
     if (rsp != null) {
       economy = rsp.getProvider();
     } else {
@@ -363,7 +393,8 @@ public class Rankup extends JavaPlugin {
     return MessageBuilder.of(messages, message);
   }
 
-  public MessageBuilder replaceMoneyRequirements(MessageBuilder builder, CommandSender sender, Rank rank) {
+  public MessageBuilder replaceMoneyRequirements(MessageBuilder builder, CommandSender sender,
+      Rank rank) {
     if (builder instanceof NullMessageBuilder) {
       return builder;
     }
@@ -394,15 +425,20 @@ public class Rankup extends JavaPlugin {
     DecimalFormat percentFormat = placeholders.getPercentFormat();
     for (Requirement requirement : rank.getRequirements()) {
       try {
-        replaceRequirements(builder, Variable.AMOUNT, requirement, () -> simpleFormat.format(requirement.getTotal(player)));
+        replaceRequirements(builder, Variable.AMOUNT, requirement,
+            () -> simpleFormat.format(requirement.getTotal(player)));
         if (rank.isIn(player)) {
-          replaceRequirements(builder, Variable.AMOUNT_NEEDED, requirement, () -> simpleFormat.format(requirement.getRemaining(player)));
+          replaceRequirements(builder, Variable.AMOUNT_NEEDED, requirement,
+              () -> simpleFormat.format(requirement.getRemaining(player)));
           replaceRequirements(builder, Variable.PERCENT_LEFT, requirement,
-              () -> percentFormat.format(Math.max(0, (requirement.getRemaining(player) / requirement.getTotal(player)) * 100)));
+              () -> percentFormat.format(Math.max(0,
+                  (requirement.getRemaining(player) / requirement.getTotal(player)) * 100)));
           replaceRequirements(builder, Variable.PERCENT_DONE, requirement,
-              () -> percentFormat.format(Math.min(100, (1 - (requirement.getRemaining(player) / requirement.getTotal(player))) * 100)));
+              () -> percentFormat.format(Math.min(100,
+                  (1 - (requirement.getRemaining(player) / requirement.getTotal(player))) * 100)));
           replaceRequirements(builder, Variable.AMOUNT_DONE, requirement,
-              () -> simpleFormat.format(requirement.getTotal(player) - requirement.getRemaining(player)));
+              () -> simpleFormat
+                  .format(requirement.getTotal(player) - requirement.getRemaining(player)));
         }
       } catch (NumberFormatException ignored) {
       }
@@ -410,7 +446,8 @@ public class Rankup extends JavaPlugin {
     return builder;
   }
 
-  private void replaceRequirements(MessageBuilder builder, Variable variable, Requirement requirement, Supplier<Object> value) {
+  private void replaceRequirements(MessageBuilder builder, Variable variable,
+      Requirement requirement, Supplier<Object> value) {
     Object get;
     try {
       get = value.get();
@@ -420,7 +457,8 @@ public class Rankup extends JavaPlugin {
     }
   }
 
-  public MessageBuilder getMessage(CommandSender player, Message message, Rank oldRank, String rankName) {
+  public MessageBuilder getMessage(CommandSender player, Message message, Rank oldRank,
+      String rankName) {
     String oldRankName;
     if (oldRank instanceof Prestige && oldRank.getRank() == null) {
       oldRankName = ((Prestige) oldRank).getFrom();
@@ -448,9 +486,4 @@ public class Rankup extends JavaPlugin {
     }
     builder.send(sender);
   }
-
-  public boolean isLegacy() {
-    String version = Bukkit.getVersion();
-    return !(version.contains("1.13") || version.contains("1.14") || version.contains("1.15"));
-  }
 }

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

@@ -13,7 +13,12 @@ import sh.okx.rankup.ranks.Rankups;
 import java.util.HashMap;
 import java.util.Map;
 
+/**
+ * Actually performs the ranking up and prestiging for the plugin and also manages the cooldowns
+ * between ranking up.
+ */
 public class RankupHelper {
+
   private final Rankup plugin;
   private final ConfigurationSection config;
   private final Permission permissions;
@@ -28,9 +33,8 @@ public class RankupHelper {
     this.permissions = plugin.getPermissions();
   }
 
-  private void doRankup(Player player, Rank rank) {
+  public void doRankup(Player player, Rank rank) {
     rank.runCommands(player);
-    applyCooldown(player);
 
     if (rank.getRank() != null) {
       permissions.playerRemoveGroup(null, player, rank.getRank());
@@ -38,6 +42,42 @@ public class RankupHelper {
     permissions.playerAddGroup(null, player, rank.getNext());
   }
 
+  public void sendRankupMessages(Player player, Rank 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 void doPrestige(Player player, Prestige prestige) {
+    prestige.runCommands(player);
+
+    permissions.playerRemoveGroup(null, player, prestige.getFrom());
+    permissions.playerAddGroup(null, player, prestige.getTo());
+
+    if (prestige.getRank() != null) {
+      permissions.playerRemoveGroup(null, player, prestige.getRank());
+    }
+    permissions.playerAddGroup(null, player, prestige.getNext());
+  }
+
+  public void sendPrestigeMessages(Player player, Prestige prestige) {
+    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);
+  }
+
   private boolean checkCooldown(Player player, Rank rank) {
     if (cooldowns.containsKey(player)) {
       long time = System.currentTimeMillis() - cooldowns.get(player);
@@ -46,7 +86,8 @@ public class RankupHelper {
       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)
+        plugin
+            .getMessage(rank, secondsLeft > 1 ? Message.COOLDOWN_PLURAL : Message.COOLDOWN_SINGULAR)
             .failIfEmpty()
             .replaceRanks(player, rank.getRank())
             .replaceFromTo(rank)
@@ -74,16 +115,10 @@ public class RankupHelper {
 
     Rank rank = plugin.getRankups().getByPlayer(player);
     rank.applyRequirements(player);
-    doRankup(player, rank);
+    applyCooldown(player);
 
-    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);
+    doRankup(player, rank);
+    sendRankupMessages(player, rank);
   }
 
   public boolean checkRankup(Player player) {
@@ -91,8 +126,7 @@ public class RankupHelper {
   }
 
   /**
-   * Checks if a player can rankup,
-   * and if they can't, sends the player a message and returns false
+   * 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
@@ -102,7 +136,8 @@ public class RankupHelper {
     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)
+      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);
@@ -135,27 +170,9 @@ public class RankupHelper {
     Prestige prestige = plugin.getPrestiges().getByPlayer(player);
     prestige.applyRequirements(player);
 
-    prestige.runCommands(player);
     applyCooldown(player);
-
-    permissions.playerRemoveGroup(null, player, prestige.getFrom());
-    permissions.playerAddGroup(null, player, prestige.getTo());
-
-    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);
+    doPrestige(player, prestige);
+    sendPrestigeMessages(player, prestige);
   }
 
   public boolean checkPrestige(Player player) {
@@ -171,7 +188,8 @@ public class RankupHelper {
           .replace(Variable.PLAYER, player.getName())
           .send(player);
       return false;
-    } else if (prestiges.isLast(plugin.getPermissions(), player)) { // check if they are at the highest rank
+    } 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())
@@ -179,9 +197,10 @@ public class RankupHelper {
           .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)
+      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;

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

@@ -1,24 +1,29 @@
 package sh.okx.rankup.commands;
 
-import com.google.common.base.Charsets;
-import com.google.common.io.CharStreams;
-import lombok.RequiredArgsConstructor;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
 import org.bukkit.plugin.PluginDescriptionFile;
 import sh.okx.rankup.Rankup;
 
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.net.URL;
+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 sh.okx.rankup.util.UpdateNotifier;
 
-@RequiredArgsConstructor
 public class InfoCommand implements CommandExecutor {
   private final Rankup plugin;
-  private String versionMessage;
+
+  private final UpdateNotifier notifier;
+
+  public InfoCommand(Rankup plugin, UpdateNotifier notifier) {
+    this.plugin = plugin;
+    this.notifier = notifier;
+  }
 
   @Override
   public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
@@ -29,6 +34,75 @@ public class InfoCommand implements CommandExecutor {
           sender.sendMessage(ChatColor.GREEN + "" + ChatColor.BOLD + "Rankup " + ChatColor.YELLOW + "Reloaded configuration files.");
         }
         return true;
+      } else if (args[0].equalsIgnoreCase("forcerankup") && sender.hasPermission("rankup.force")) {
+        if (args.length < 2) {
+          sender.sendMessage(ChatColor.YELLOW + "Usage: /" + label + " forcerankup <player>");
+          return true;
+        }
+
+        Player player = Bukkit.getPlayer(args[1]);
+        if (player == null) {
+          sender.sendMessage(ChatColor.YELLOW + "Player not found.");
+          return true;
+        }
+
+        Rankups rankups = plugin.getRankups();
+        if (rankups.isLast(plugin.getPermissions(), player)) {
+          sender.sendMessage(ChatColor.YELLOW + "That player is at the last rank.");
+          return true;
+        }
+
+        Rank rank = rankups.getByPlayer(player);
+        if (rank == null) {
+          sender.sendMessage(ChatColor.YELLOW + "That player is not in any rankup groups.");
+          return true;
+        }
+
+        plugin.getHelper().doRankup(player, rank);
+        plugin.getHelper().sendRankupMessages(player, rank);
+        sender.sendMessage(ChatColor.GREEN + "Successfully forced "
+            + ChatColor.GOLD + player.getName()
+            + ChatColor.GREEN + " to rankup from " + ChatColor.GOLD + rank.getRank()
+            + ChatColor.GREEN + " to " + ChatColor.GOLD + rank.getNext());
+        return true;
+      } else if (args[0].equalsIgnoreCase("forceprestige") && sender.hasPermission("rankup.force")) {
+        if (plugin.getPrestiges() == null) {
+          sender.sendMessage(ChatColor.RED + "Prestige is disabled.");
+          return true;
+        }
+
+        if (args.length < 2) {
+          sender.sendMessage(ChatColor.YELLOW + "Usage: /" + label + " forceprestige <player>");
+          return true;
+        }
+
+        Player player = Bukkit.getPlayer(args[1]);
+        if (player == null) {
+          sender.sendMessage(ChatColor.YELLOW + "Player not found.");
+          return true;
+        }
+
+        Prestiges prestiges = plugin.getPrestiges();
+        if (prestiges.isLast(plugin.getPermissions(), player)) {
+          sender.sendMessage(ChatColor.YELLOW + "That player is at the last prestige.");
+          return true;
+        }
+
+        Prestige prestige = prestiges.getByPlayer(player);
+        if (prestige == null) {
+          sender.sendMessage(ChatColor.YELLOW + "That player is not in any prestige groups.");
+          return true;
+        }
+
+        plugin.getHelper().doPrestige(player, prestige);
+        plugin.getHelper().sendPrestigeMessages(player, prestige);
+        sender.sendMessage(ChatColor.GREEN + "Successfully forced "
+            + ChatColor.GOLD + player.getName()
+            + ChatColor.GREEN + " to prestige "
+            + ChatColor.GOLD + prestige.getRank()
+            + ChatColor.GREEN + " from " + ChatColor.GOLD + prestige.getFrom()
+            + ChatColor.GREEN + " to " + ChatColor.GOLD + prestige.getTo());
+        return true;
       }
     }
     
@@ -39,41 +113,18 @@ public class InfoCommand implements CommandExecutor {
             ChatColor.YELLOW + " by " + ChatColor.BLUE + ChatColor.BOLD + String.join(", ", description.getAuthors()));
     if (sender.hasPermission("rankup.reload")) {
       sender.sendMessage(ChatColor.GREEN + "/" + label + " reload " + ChatColor.YELLOW + "Reloads configuration files.");
-    }
-    if (sender.hasPermission("rankup.checkversion")) {
-      if (versionMessage == null) {
-        if (version.contains("alpha") || version.contains("beta") || version.contains("rc")) {
-          versionMessage = ChatColor.YELLOW + "You are on a pre-release version.";
-          sender.sendMessage(versionMessage);
-          return true;
-        }
-        sender.sendMessage(ChatColor.YELLOW + "Checking version...");
-        Bukkit.getScheduler().runTaskAsynchronously(plugin, () -> {
-          String message;
-          try {
-            String latest = getLatestVersion();
-            if (version.equals(latest)) {
-              message = ChatColor.GREEN + "You are on the latest version.";
-            } else {
-              message = ChatColor.YELLOW + "A new version is available: " + ChatColor.GOLD + latest
-                  + "\nhttps://www.spigotmc.org/resources/rankup.17933/";
-            }
-          } catch (IOException e) {
-            message = ChatColor.RED + "Error while checking version.";
-          }
-          versionMessage = message;
-          Bukkit.getScheduler().runTask(plugin, () -> sender.sendMessage(versionMessage));
-        });
-      } else {
-        sender.sendMessage(versionMessage);
+      sender.sendMessage(ChatColor.GREEN + "/" + label + " forcerankup <player> " + ChatColor.YELLOW + "Force a player to rankup, bypassing requirements.");
+      if (plugin.getPrestiges() != null) {
+        sender.sendMessage(
+            ChatColor.GREEN + "/" + label + " forceprestige <player> " + ChatColor.YELLOW
+                + "Force a player to prestige, bypassing requirements.");
       }
     }
 
+    if (sender.hasPermission("rankup.checkversion")) {
+      notifier.notify(sender, false);
+    }
+
     return true;
   }
-
-  private String getLatestVersion() throws IOException {
-    URL url = new URL("https://api.spigotmc.org/legacy/update.php?resource=17933");
-    return CharStreams.toString(new InputStreamReader(url.openStream(), Charsets.UTF_8));
-  }
 }

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

@@ -18,7 +18,7 @@ import java.util.WeakHashMap;
 @RequiredArgsConstructor
 public class RankupCommand implements CommandExecutor {
   // weak hash maps so players going offline are automatically removed.
-  // otherwise there is a potential (but small) memory leak.
+  // otherwise there is a potential (albeit small) memory leak.
   private final Map<Player, Long> confirming = new WeakHashMap<>();
   private final Rankup plugin;
 

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

@@ -21,6 +21,7 @@ import sh.okx.rankup.ranks.Rank;
 import java.util.Arrays;
 import java.util.Objects;
 import java.util.stream.Collectors;
+import sh.okx.rankup.util.ItemUtil;
 
 @NoArgsConstructor(access = AccessLevel.PRIVATE)
 public class Gui implements InventoryHolder {
@@ -66,20 +67,20 @@ public class Gui implements InventoryHolder {
 
     String materialName = section.getString("material").toUpperCase();
     // handle default material correctly on older versions
-    if (plugin.isLegacy() && materialName.equals("BLACK_STAINED_GLASS_PANE")) {
+    if (!ItemUtil.isServerFlattened() && materialName.equals("BLACK_STAINED_GLASS_PANE")) {
       materialName = "STAINED_GLASS_PANE:15";
     }
 
     ItemStack item;
-    if (plugin.isLegacy()) {
+    if (ItemUtil.isServerFlattened()) {
+      Material material = Material.valueOf(materialName);
+      item = new ItemStack(material);
+    } else {
       String[] parts = materialName.split(":");
       Material material = Material.valueOf(parts[0]);
 
       short type = parts.length > 1 ? Short.parseShort(parts[1]) : 0;
       item = new ItemStack(material, 1, type);
-    } else {
-      Material material = Material.valueOf(materialName);
-      item = new ItemStack(material);
     }
 
     if (item.getType() == Material.AIR && section.getName().equalsIgnoreCase("fill")) {

src/main/java/sh/okx/rankup/requirements/NonDeductibleRequirement.java

@@ -1,30 +0,0 @@
-package sh.okx.rankup.requirements;
-
-import org.bukkit.entity.Player;
-
-/**
- * Proxy requirement for a deductible requirement that is exactly the same but is not deductible
- */
-public class NonDeductibleRequirement extends ProgressiveRequirement {
-  private final ProgressiveRequirement requirement;
-
-  public NonDeductibleRequirement(ProgressiveRequirement requirement, String name) {
-    super(requirement.plugin, name, requirement.hasSubRequirement());
-    this.requirement = requirement;
-  }
-
-  protected NonDeductibleRequirement(NonDeductibleRequirement clone) {
-    super(clone);
-    this.requirement = clone.requirement;
-  }
-
-  @Override
-  public double getProgress(Player player) {
-    return requirement.getProgress(player);
-  }
-
-  @Override
-  public Requirement clone() {
-    return new NonDeductibleRequirement(this);
-  }
-}

src/main/java/sh/okx/rankup/requirements/RequirementRegistry.java

@@ -1,5 +1,6 @@
 package sh.okx.rankup.requirements;
 
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Objects;
@@ -12,6 +13,10 @@ public class RequirementRegistry {
     requirements.add(requirement);
   }
 
+  public void addRequirements(Requirement... requirements) {
+    Collections.addAll(this.requirements, requirements);
+  }
+
   public Requirement newRequirement(String name, String value) {
     for (Requirement requirement : requirements) {
       if (requirement.getName().equalsIgnoreCase(name)) {

src/main/java/sh/okx/rankup/requirements/XpLevelDeductibleRequirement.java

@@ -0,0 +1,26 @@
+package sh.okx.rankup.requirements;
+
+import org.bukkit.entity.Player;
+import sh.okx.rankup.Rankup;
+import sh.okx.rankup.requirements.requirement.XpLevelRequirement;
+
+public class XpLevelDeductibleRequirement extends XpLevelRequirement implements DeductibleRequirement {
+
+  public XpLevelDeductibleRequirement(Rankup plugin, String name) {
+    super(plugin, name);
+  }
+
+  private XpLevelDeductibleRequirement(XpLevelDeductibleRequirement clone) {
+    super(clone);
+  }
+
+  @Override
+  public void apply(Player player, double multiplier) {
+    player.setLevel(player.getLevel() - (int) Math.round(getValueInt() * multiplier));
+  }
+
+  @Override
+  public Requirement clone() {
+    return new XpLevelDeductibleRequirement(this);
+  }
+}

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

@@ -0,0 +1,33 @@
+package sh.okx.rankup.requirements.requirement;
+
+import org.bukkit.Material;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import sh.okx.rankup.Rankup;
+import sh.okx.rankup.requirements.DeductibleRequirement;
+import sh.okx.rankup.requirements.Requirement;
+
+public class ItemDeductibleRequirement extends ItemRequirement implements DeductibleRequirement {
+
+  public ItemDeductibleRequirement(Rankup plugin, String name) {
+    super(plugin, name);
+  }
+
+  public ItemDeductibleRequirement(ItemDeductibleRequirement clone) {
+    super(clone);
+  }
+
+  @Override
+  public void apply(Player player, double multiplier) {
+    Material type = Material.matchMaterial(getSub());
+    if (type == null) {
+      throw new IllegalArgumentException("Invalid item " + getSub());
+    }
+    player.getInventory().removeItem(new ItemStack(type, (int) (getValueInt() * multiplier)));
+  }
+
+  @Override
+  public Requirement clone() {
+    return new ItemDeductibleRequirement(this);
+  }
+}

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

@@ -1,7 +1,6 @@
 package sh.okx.rankup.requirements.requirement;
 
 import org.bukkit.Material;
-import org.bukkit.Statistic;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 import sh.okx.rankup.Rankup;
@@ -11,24 +10,15 @@ import sh.okx.rankup.requirements.Requirement;
 
 import java.util.Arrays;
 
-public class ItemRequirement extends ProgressiveRequirement implements DeductibleRequirement {
-  public ItemRequirement(Rankup plugin) {
-    super(plugin, "item", true);
+public class ItemRequirement extends ProgressiveRequirement {
+  public ItemRequirement(Rankup plugin, String name) {
+    super(plugin, name, true);
   }
 
   protected ItemRequirement(ItemRequirement clone) {
     super(clone);
   }
 
-  @Override
-  public void apply(Player player, double multiplier) {
-    Material type = Material.matchMaterial(getSub());
-    if (type == null) {
-      throw new IllegalArgumentException("Invalid item " + getSub());
-    }
-    player.getInventory().removeItem(new ItemStack(type, (int) (getValueInt() * multiplier)));
-  }
-
   @Override
   public Requirement clone() {
     return new ItemRequirement(this);

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

@@ -0,0 +1,29 @@
+package sh.okx.rankup.requirements.requirement;
+
+import net.milkbowl.vault.economy.Economy;
+import org.bukkit.entity.Player;
+import sh.okx.rankup.Rankup;
+import sh.okx.rankup.requirements.DeductibleRequirement;
+import sh.okx.rankup.requirements.Requirement;
+
+public class MoneyDeductibleRequirement extends MoneyRequirement implements DeductibleRequirement {
+
+  public MoneyDeductibleRequirement(Rankup plugin, String name) {
+    super(plugin, name);
+  }
+
+  protected MoneyDeductibleRequirement(MoneyDeductibleRequirement clone) {
+    super(clone);
+  }
+
+  @Override
+  public void apply(Player player, double multiplier) {
+    Economy economy = plugin.getEconomy();
+    economy.withdrawPlayer(player, getValueDouble() * multiplier);
+  }
+
+  @Override
+  public Requirement clone() {
+    return new MoneyDeductibleRequirement(this);
+  }
+}

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

@@ -1,27 +1,19 @@
 package sh.okx.rankup.requirements.requirement;
 
-import net.milkbowl.vault.economy.Economy;
 import org.bukkit.entity.Player;
 import sh.okx.rankup.Rankup;
-import sh.okx.rankup.requirements.DeductibleRequirement;
 import sh.okx.rankup.requirements.ProgressiveRequirement;
 import sh.okx.rankup.requirements.Requirement;
 
-public class MoneyRequirement extends ProgressiveRequirement implements DeductibleRequirement {
-  public MoneyRequirement(Rankup plugin) {
-    super(plugin, "money");
+public class MoneyRequirement extends ProgressiveRequirement {
+  public MoneyRequirement(Rankup plugin, String name) {
+    super(plugin, name);
   }
 
-  protected MoneyRequirement(Requirement clone) {
+  protected MoneyRequirement(MoneyRequirement clone) {
     super(clone);
   }
 
-  @Override
-  public void apply(Player player, double multiplier) {
-    Economy economy = plugin.getEconomy();
-    economy.withdrawPlayer(player, getValueDouble() * multiplier);
-  }
-
   @Override
   public double getProgress(Player player) {
     return plugin.getEconomy().getBalance(player);

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

@@ -0,0 +1,26 @@
+package sh.okx.rankup.requirements.requirement;
+
+import org.bukkit.entity.Player;
+import sh.okx.rankup.Rankup;
+import sh.okx.rankup.requirements.DeductibleRequirement;
+import sh.okx.rankup.requirements.requirement.tokenmanager.TokensRequirement;
+
+public class TokensDeductibleRequirement extends TokensRequirement implements DeductibleRequirement {
+  public TokensDeductibleRequirement(Rankup plugin, String name) {
+    super(plugin, name);
+  }
+
+  protected TokensDeductibleRequirement(TokensDeductibleRequirement clone) {
+    super(clone);
+  }
+
+  @Override
+  public void apply(Player player, double multiplier) {
+    manager.removeTokens(player, (long) (getValueInt() * multiplier));
+  }
+
+  @Override
+  public TokensRequirement clone() {
+    return new TokensDeductibleRequirement(this);
+  }
+}

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

@@ -2,24 +2,18 @@ package sh.okx.rankup.requirements.requirement;
 
 import org.bukkit.entity.Player;
 import sh.okx.rankup.Rankup;
-import sh.okx.rankup.requirements.DeductibleRequirement;
 import sh.okx.rankup.requirements.ProgressiveRequirement;
 import sh.okx.rankup.requirements.Requirement;
 
-public class XpLevelRequirement extends ProgressiveRequirement implements DeductibleRequirement {
-  public XpLevelRequirement(Rankup plugin) {
-    super(plugin, "xp-level");
+public class XpLevelRequirement extends ProgressiveRequirement {
+  public XpLevelRequirement(Rankup plugin, String name) {
+    super(plugin, name);
   }
 
-  protected XpLevelRequirement(Requirement clone) {
+  protected XpLevelRequirement(XpLevelRequirement clone) {
     super(clone);
   }
 
-  @Override
-  public void apply(Player player, double multiplier) {
-    player.setLevel(player.getLevel() - (int) Math.round(getValueInt() * multiplier));
-  }
-
   @Override
   public double getProgress(Player player) {
     return player.getLevel();

src/main/java/sh/okx/rankup/requirements/requirement/tokenmanager/TokensRequirement.java

@@ -1,31 +1,23 @@
 package sh.okx.rankup.requirements.requirement.tokenmanager;
 
+import java.util.Objects;
 import me.realized.tokenmanager.api.TokenManager;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 import sh.okx.rankup.Rankup;
-import sh.okx.rankup.requirements.DeductibleRequirement;
 import sh.okx.rankup.requirements.ProgressiveRequirement;
-import sh.okx.rankup.requirements.Requirement;
 
-import java.util.Objects;
+public class TokensRequirement extends ProgressiveRequirement {
+  protected final TokenManager manager = (TokenManager) Objects.requireNonNull(Bukkit.getPluginManager().getPlugin("TokenManager"));
 
-public class TokensRequirement extends ProgressiveRequirement implements DeductibleRequirement {
-  private final TokenManager manager = (TokenManager) Objects.requireNonNull(Bukkit.getPluginManager().getPlugin("TokenManager"));
-
-  public TokensRequirement(Rankup plugin) {
-    super(plugin, "tokenmanager-tokens");
+  public TokensRequirement(Rankup plugin, String name) {
+    super(plugin, name);
   }
 
-  private TokensRequirement(Requirement clone) {
+  protected TokensRequirement(TokensRequirement clone) {
     super(clone);
   }
 
-  @Override
-  public void apply(Player player, double multiplier) {
-    manager.removeTokens(player, (long) (getValueInt() * multiplier));
-  }
-
   @Override
   public double getProgress(Player player) {
     return manager.getTokens(player).orElse(0);

src/main/java/sh/okx/rankup/requirements/requirement/towny/TownyKingNumberTownsRequirement.java

@@ -10,7 +10,7 @@ public class TownyKingNumberTownsRequirement extends ProgressiveRequirement {
     super(plugin, "towny-king-towns");
   }
 
-  protected TownyKingNumberTownsRequirement(Requirement clone) {
+  protected TownyKingNumberTownsRequirement(TownyKingNumberTownsRequirement clone) {
     super(clone);
   }
 

src/main/java/sh/okx/rankup/util/ItemUtil.java

@@ -0,0 +1,31 @@
+package sh.okx.rankup.util;
+
+import com.google.common.base.Suppliers;
+import java.util.function.Supplier;
+import org.bukkit.Material;
+
+public class ItemUtil {
+  private static Supplier<Boolean> flattenedSupplier = Suppliers.memoize(ItemUtil::isServerFlattenedPrivate);
+
+  private static boolean isServerFlattenedPrivate() {
+    try {
+      Material.valueOf("BLACK_STAINED_GLASS_PANE");
+      return true;
+    } catch (IllegalArgumentException e) {
+      return false;
+    }
+  }
+
+  /**
+   * Determines if a server is post-flattening or pre-flattening.
+   * The flattening is the name for a process where, instead of using durability to represent
+   * similar items, Mojang decided to use distinct item types for each item.
+   * This caused many {@link Material} names to change, making some things incompatible.
+   * The flattening happened in 1.13.
+   *
+   * @return true if the server is post-flattening (server versions 1.13, 1.14, 1.15) or false if it is pre-flattening (1.12, 1.11, 1.10 etc)
+   */
+  public static boolean isServerFlattened() {
+    return flattenedSupplier.get();
+  }
+}

src/main/java/sh/okx/rankup/util/UpdateNotifier.java

@@ -0,0 +1,56 @@
+package sh.okx.rankup.util;
+
+import org.bukkit.ChatColor;
+import org.bukkit.command.CommandSender;
+import sh.okx.rankup.util.VersionChecker.VersionCheckerCallback;
+
+public class UpdateNotifier {
+  private static final String PREFIX = ChatColor.GREEN + "" + ChatColor.BOLD + "Rankup " + ChatColor.RESET;
+
+  private final VersionChecker checker;
+
+  public UpdateNotifier(VersionChecker checker) {
+    this.checker = checker;
+  }
+
+  public void notify(CommandSender sender, boolean join) {
+    if (!checker.hasChecked() && !join) {
+      send(sender, false, ChatColor.YELLOW + "Checking version...");
+    }
+    checker.checkVersion(new VersionCheckerCallback() {
+      @Override
+      public void onLatestVersion(String version) {
+        if (!join) {
+          send(sender, false, ChatColor.GREEN + "You are on the latest version.");
+        }
+      }
+
+      @Override
+      public void onOutdatedVersion(String currentVersion, String latestVersion) {
+        send(sender, join, ChatColor.YELLOW + "A new version is available: " + ChatColor.GOLD + latestVersion
+            + ChatColor.YELLOW + ". You are on: " + ChatColor.GOLD + currentVersion
+            + ChatColor.GOLD + "\nhttps://www.spigotmc.org/resources/rankup.17933/");
+      }
+
+      @Override
+      public void onPreReleaseVersion(String version) {
+        send(sender, join, ChatColor.RED + "You are on a pre-release version.");
+      }
+
+      @Override
+      public void onFailure() {
+        if (!join) {
+          send(sender, join, ChatColor.RED + "Error while checking version.");
+        }
+      }
+    });
+  }
+
+  private void send(CommandSender sender, boolean prefix, String message) {
+    if (prefix) {
+      sender.sendMessage(PREFIX + message);
+    } else {
+      sender.sendMessage(message);
+    }
+  }
+}

src/main/java/sh/okx/rankup/util/VersionChecker.java

@@ -0,0 +1,144 @@
+package sh.okx.rankup.util;
+
+import com.google.common.base.Charsets;
+import com.google.common.io.CharStreams;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.URL;
+import org.bukkit.Bukkit;
+import org.bukkit.plugin.Plugin;
+
+public class VersionChecker {
+
+  private static final int RESOURCE_ID = 17933;
+
+  private final Plugin plugin; // used exclusively for scheduling
+  private final String currentVersion;
+  private String latestVersion;
+  private boolean checked = false;
+
+  public VersionChecker(Plugin plugin) {
+    this.currentVersion = plugin.getDescription().getVersion();
+    this.plugin = plugin;
+  }
+
+  /**
+   * Checks if the version checker has already made an asynchronous call to the web server to check
+   * the version, so future checks will run instantly.
+   * @return true if the version checker already knows the latest version, false otherwise
+   */
+  public boolean hasChecked() {
+    return checked;
+  }
+
+  public void checkVersion(VersionCheckerCallback callback) {
+    if (latestVersion != null) {
+      if (currentVersion.equals(latestVersion)) {
+        callback.onLatestVersion(currentVersion);
+      } else {
+        callback.onOutdatedVersion(currentVersion, latestVersion);
+      }
+    } else {
+      Bukkit.getScheduler().runTaskAsynchronously(plugin,
+          () -> checkVersionSync(new SyncVersionCheckerCallback(plugin, callback)));
+    }
+  }
+
+  private void checkVersionSync(VersionCheckerCallback callback) {
+    if (currentVersion.contains("alpha")
+        || currentVersion.contains("beta")
+        || currentVersion.contains("rc")) {
+      checked = true;
+      callback.onPreReleaseVersion(currentVersion);
+      return;
+    }
+
+    try {
+      latestVersion = getLatestVersion();
+      checked = true;
+      if (currentVersion.equals(latestVersion)) {
+        callback.onLatestVersion(currentVersion);
+      } else {
+        callback.onOutdatedVersion(currentVersion, latestVersion);
+      }
+
+    } catch (IOException e) {
+      callback.onFailure();
+    }
+  }
+
+  private String getLatestVersion() throws IOException {
+    URL url = new URL("https://api.spigotmc.org/legacy/update.php?resource=" + RESOURCE_ID);
+    return CharStreams.toString(new InputStreamReader(url.openStream(), Charsets.UTF_8));
+  }
+
+  /**
+   * A callback used when a version check runs
+   */
+  public interface VersionCheckerCallback {
+
+    /**
+     * Called when the plugin is already on the latest version
+     *
+     * @param version the current, and latest, version of the plugin
+     */
+    void onLatestVersion(String version);
+
+    /**
+     * Called when the plugin is on a version other than the latest on the SpigotMC plugin page.
+     *
+     * @param currentVersion the current version of the plugin specified in plugin.yml
+     * @param latestVersion the latest version of the plugin specified on SpigotMC.
+     */
+    void onOutdatedVersion(String currentVersion, String latestVersion);
+
+    /**
+     * Called when the plugin is on a pre-release version and is exempt to the usual update system.
+     * @param version the current version of the plugin
+     */
+    void onPreReleaseVersion(String version);
+
+    /**
+     * Called when the version checker was unable to retrieve the latest version
+     */
+    void onFailure();
+  }
+
+  /**
+   * An implementation of {@link VersionCheckerCallback} that is called asynchronously, and then
+   * forwards the calls an underlying VersionCheckerCallback synchronously on the main Bukkit thread.
+   */
+  class SyncVersionCheckerCallback implements VersionCheckerCallback {
+    private final Plugin plugin;
+    private final VersionCheckerCallback callback;
+
+    SyncVersionCheckerCallback(Plugin plugin, VersionCheckerCallback callback) {
+      this.plugin = plugin;
+      this.callback = callback;
+    }
+
+    @Override
+    public void onLatestVersion(String version) {
+      doSync(() -> callback.onLatestVersion(version));
+    }
+
+    @Override
+    public void onOutdatedVersion(String currentVersion, String latestVersion) {
+      doSync(() -> callback.onOutdatedVersion(currentVersion, latestVersion));
+    }
+
+    @Override
+    public void onPreReleaseVersion(String version) {
+      doSync(() -> callback.onPreReleaseVersion(version));
+    }
+
+    @Override
+    public void onFailure() {
+      doSync(callback::onFailure);
+    }
+
+    private void doSync(Runnable r) {
+      Bukkit.getScheduler().scheduleSyncDelayedTask(plugin, r);
+    }
+  }
+}

src/main/resources/config.yml

@@ -1,5 +1,5 @@
 # this is used for letting you know that you need to update/change your config file
-version: 4
+version: 5
 
 # the locale to use for messages
 # all messages can be customised but this allows you to
@@ -21,16 +21,23 @@ ranks: true
 prestiges: true
 
 # whether or not /prestige and /prestiges should be enabled.
-# you can alternatively negate the permission rankup.prestige
-# this will also make the command not autocomplete in 1.13
+# when a player reaches the top rank, they can do /prestige to return to the first rank,
+# but you will be able to grant them an additional "prestige" group or additional items.
+#
+# if you do not want this command to autocomplete, make sure
+# you negate the permission rankup.prestige with your permissions plugin.
 # if enabled, a prestiges.yml file will be generated with some example prestiges
 prestige: false
 
+# if true, players with the permission rankup.notify will receive notifications when they join
+# to update if they are on an older version of Rankup.
+notify-update: true
+
 # how people should confirm ranking up
 # options are: gui, text or none
 confirmation-type: 'gui'
 
-# how long, in seconds, people have to wait between a successful /rankup or a /prestige
+# how long, in seconds, people have to wait between a successful /rankup or /prestige
 # set to 0 to disable.
 cooldown: 1
 
@@ -81,6 +88,8 @@ placeholders:
 # what to shorten money by.
 # ie 1000 -> 1k
 # set to an empty list to disable
+# for each entry here, it counts as increasing by a factor of 1,000
+# the first represents thousands (1000, 1e3) then millions (1000000, 1e6) then billions (1000000000, 1e9) etc.
 shorten:
 - 'k'
 - 'M'

src/main/resources/plugin.yml

@@ -29,20 +29,26 @@ permissions:
     children:
       rankup.info: true
       rankup.rankup: true
-      rankup.checkversion: true
+      rankup.admin: true
       rankup.ranks: true
-      rankup.reload: true
       rankup.prestige: true
       rankup.prestiges: true
       rankup.auto: true
+  rankup.admin:
+    children:
+      # if a player can see if the plugin needs updating when they run /pru
+      rankup.checkversion: true
+      # if a player can run /pru reload
+      rankup.reload: true
+      # if a player can force rankup or prestige someone
+      rankup.force: true
+      # if a player receives notifications to update rankup when the log in.
+      rankup.notify: true
+    default: op
   rankup.info:
     default: true
   rankup.rankup:
     default: true
-  rankup.checkversion:
-    default: op
-  rankup.reload:
-    default: op
   rankup.ranks:
     default: true
   rankup.prestige:
@@ -50,4 +56,4 @@ permissions:
   rankup.prestiges:
     default: true
   rankup.auto:
-    default: true
+    default: true