improve placeholders & add group requirement

removed:
%rankup_rank_requirement_<rank>_<requirement>_left%
%rankup_rank_requirement_<rank>_<requirement>_percent_left%
%rankup_rank_requirement_<rank>_<requirement>_percent_done%

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

@@ -9,6 +9,7 @@ import org.bukkit.entity.Player;
 import sh.okx.rankup.Rankup;
 import sh.okx.rankup.messages.MessageBuilder;
 import sh.okx.rankup.messages.Variable;
+import sh.okx.rankup.ranks.requirements.DeductibleRequirement;
 import sh.okx.rankup.ranks.requirements.Requirement;
 
 import java.util.HashSet;
@@ -40,9 +41,8 @@ public class Rank {
     if(requirementsSection != null) {
       for (Map.Entry<String, Object> entry : requirementsSection.getValues(false).entrySet()) {
         String name = entry.getKey();
-        double amount = Double.parseDouble(String.valueOf(entry.getValue()).replace(",", ""));
-
-        Requirement requirement = plugin.getRequirementRegistry().newRequirement(name, amount);
+        String value = String.valueOf(entry.getValue());
+        Requirement requirement = plugin.getRequirementRegistry().newRequirement(name, value);
         if (requirement == null) {
           plugin.getLogger().warning("Unknown requirement " + name);
         } else {
@@ -113,7 +113,9 @@ public class Rank {
 
   public void applyRequirements(Player player) {
     for(Requirement requirement : requirements) {
-      requirement.apply(player);
+      if(requirement instanceof DeductibleRequirement) {
+        ((DeductibleRequirement) requirement).apply(player);
+      }
     }
   }
 

src/main/java/sh/okx/rankup/ranks/requirements/DeductibleRequirement.java

@@ -0,0 +1,23 @@
+package sh.okx.rankup.ranks.requirements;
+
+import org.bukkit.entity.Player;
+import sh.okx.rankup.Rankup;
+
+public abstract class DeductibleRequirement extends Requirement {
+  public DeductibleRequirement(Rankup plugin, String name) {
+    super(plugin, name);
+  }
+
+  protected DeductibleRequirement(Requirement clone) {
+    super(clone);
+  }
+
+  /**
+   * Apply the effect of this requirement to the player.
+   * For money, this could be taking money away from the player.
+   * You can assume that <code>Requirement#check(Player)</code> has been called,
+   * and has returned true immediately prior to this.
+   * @param player the player to take from
+   */
+  public abstract void apply(Player player);
+}

src/main/java/sh/okx/rankup/ranks/requirements/GroupRequirement.java

@@ -0,0 +1,33 @@
+package sh.okx.rankup.ranks.requirements;
+
+import org.bukkit.entity.Player;
+import sh.okx.rankup.Rankup;
+
+public class GroupRequirement extends Requirement {
+  public GroupRequirement(Rankup plugin, String name) {
+    super(plugin, name);
+  }
+
+  protected GroupRequirement(Requirement clone) {
+    super(clone);
+  }
+
+  @Override
+  public boolean check(Player player) {
+    OUTER:
+    for(String requiredGroup : getValueString().split(" ")) {
+      for(String group : plugin.getPermissions().getPlayerGroups(player)) {
+        if(group.equalsIgnoreCase(requiredGroup)) {
+          continue OUTER;
+        }
+      }
+      return false;
+    }
+    return true;
+  }
+
+  @Override
+  public Requirement clone() {
+    return new GroupRequirement(this);
+  }
+}

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

@@ -4,7 +4,7 @@ import net.milkbowl.vault.economy.Economy;
 import org.bukkit.entity.Player;
 import sh.okx.rankup.Rankup;
 
-public class MoneyRequirement extends Requirement {
+public class MoneyRequirement extends DeductibleRequirement {
   public MoneyRequirement(Rankup plugin, String name) {
     super(plugin, name);
   }
@@ -17,18 +17,18 @@ public class MoneyRequirement extends Requirement {
   public boolean check(Player player) {
     Economy economy = plugin.getEconomy();
     double balance = economy.getBalance(player);
-    return balance >= amount;
+    return balance >= getValueDouble();
   }
 
   @Override
   public void apply(Player player) {
     Economy economy = plugin.getEconomy();
-    economy.withdrawPlayer(player, amount);
+    economy.withdrawPlayer(player, getValueDouble());
   }
 
   @Override
   public double getRemaining(Player player) {
-    return Math.max(0, amount - plugin.getEconomy().getBalance(player));
+    return Math.max(0, getValueDouble() - plugin.getEconomy().getBalance(player));
   }
 
   @Override

src/main/java/sh/okx/rankup/ranks/requirements/PlaytimeMinutesRequirement.java

@@ -25,17 +25,12 @@ public class PlaytimeMinutesRequirement extends Requirement {
 
   @Override
   public boolean check(Player player) {
-    return player.getStatistic(playOneTick) * TICKS_PER_MINUTE >= amount;
-  }
-
-  @Override
-  public void apply(Player player) {
-    // well, we can't really take hours of playtime away, can we?
+    return player.getStatistic(playOneTick) * TICKS_PER_MINUTE >= getValueDouble();
   }
 
   @Override
   public double getRemaining(Player player) {
-    return Math.max(0, amount - (player.getStatistic(playOneTick) * TICKS_PER_MINUTE));
+    return Math.max(0, getValueDouble() - (player.getStatistic(playOneTick) * TICKS_PER_MINUTE));
   }
 
   @Override

src/main/java/sh/okx/rankup/ranks/requirements/Requirement.java

@@ -9,9 +9,7 @@ public abstract class Requirement implements Cloneable {
   protected Rankup plugin;
   @Getter
   protected String name;
-  @Getter
-  @Setter
-  protected double amount;
+  private String value;
 
   public Requirement(Rankup plugin, String name) {
     this.plugin = plugin;
@@ -19,13 +17,30 @@ public abstract class Requirement implements Cloneable {
   }
 
   protected Requirement(Requirement clone) {
-    if(clone != null) {
+    if (clone != null) {
       this.plugin = clone.plugin;
       this.name = clone.name;
-      this.amount = clone.amount;
+      this.value = clone.value;
     }
   }
 
+  public void setValue(String value) {
+    this.value = value;
+  }
+
+  public String getValueString() {
+    return value;
+  }
+
+  public double getValueDouble() {
+    return Double.parseDouble(value);
+  }
+
+  public int getValueInt() {
+    return Integer.parseInt(value);
+  }
+
+
   /**
    * Check if a player meets this requirement
    * @param player the player to check
@@ -33,15 +48,6 @@ public abstract class Requirement implements Cloneable {
    */
   public abstract boolean check(Player player);
 
-  /**
-   * Apply the effect of this requirement to the player.
-   * For money, this could be taking money away from the player.
-   * You can assume that <code>Requirement#check(Player)</code> has been called,
-   * and has returned true immediately prior to this.
-   * @param player the player to take from
-   */
-  public abstract void apply(Player player);
-
   /**
    * Get the remaining amount needed for <code>Requirement#check(Player)</code> to yield true.
    * This is not required and is only used in placeholders.
@@ -49,7 +55,7 @@ public abstract class Requirement implements Cloneable {
    * @return the remaining amount needed. Should be non-negative.
    */
   public double getRemaining(Player player) {
-    return amount;
+    return getValueDouble();
   }
   public abstract Requirement clone();
 }

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

@@ -10,11 +10,11 @@ public class RequirementRegistry {
     requirements.add(requirement);
   }
 
-  public Requirement newRequirement(String name, double amount) {
+  public Requirement newRequirement(String name, String value) {
     for(Requirement requirement : requirements) {
       if(requirement.getName().equalsIgnoreCase(name)) {
         Requirement newRequirement = requirement.clone();
-        newRequirement.setAmount(amount);
+        newRequirement.setValue(value);
         return newRequirement;
       }
     }

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

@@ -3,7 +3,7 @@ package sh.okx.rankup.ranks.requirements;
 import org.bukkit.entity.Player;
 import sh.okx.rankup.Rankup;
 
-public class XpLevelRequirement extends Requirement {
+public class XpLevelRequirement extends DeductibleRequirement {
   public XpLevelRequirement(Rankup plugin, String name) {
     super(plugin, name);
   }
@@ -12,25 +12,19 @@ public class XpLevelRequirement extends Requirement {
     super(clone);
   }
 
-  @Override
-  public void setAmount(double amount) {
-    // experience level should be a whole number
-    super.setAmount(Math.round(amount));
-  }
-
   @Override
   public boolean check(Player player) {
-    return player.getLevel() >= amount;
+    return player.getLevel() >= getValueInt();
   }
 
   @Override
   public void apply(Player player) {
-    player.setLevel(player.getLevel() - (int) amount);
+    player.setLevel(player.getLevel() - getValueInt());
   }
 
   @Override
   public double getRemaining(Player player) {
-    return Math.max(0, amount - player.getLevel());
+    return Math.max(0, getValueInt() - player.getLevel());
   }
 
   @Override