Added API to ExperienceAPI to get the amount of XP needed for a level

Changelog.txt

@@ -18,6 +18,7 @@ Version 1.5.01-dev
  + Added support for `MATERIAL|data` format in treasures.yml
  + Added API to experience events to get XP gain reason
  + Added API to check if an entity is bleeding
+ + Added API to ExperienceAPI to get the amount of XP needed for a level
  + Added options to tools.yml and armor.yml config files to set a pretty repair material name
  + Added full support for repairables in tools.yml and armor.yml config files
  + Added new API class SkillAPI used to get a list of valid skill names

src/main/java/com/gmail/nossr50/api/ExperienceAPI.java

@@ -5,6 +5,8 @@ import java.util.UUID;
 
 import org.bukkit.entity.Player;
 
+import com.gmail.nossr50.api.exceptions.InvalidFormulaTypeException;
+import com.gmail.nossr50.datatypes.experience.FormulaType;
 import com.gmail.nossr50.mcMMO;
 import com.gmail.nossr50.api.exceptions.InvalidPlayerException;
 import com.gmail.nossr50.api.exceptions.InvalidSkillException;
@@ -913,6 +915,33 @@ public final class ExperienceAPI {
         getOfflineProfile(uuid).removeXp(getNonChildSkillType(skillType), xp);
     }
 
+    /**
+     * Check how much XP is needed for a specific level with the selected level curve.
+     * </br>
+     * This function is designed for API usage.
+     *
+     * @param level The level to get the amount of XP for
+     *
+     * @throws InvalidFormulaTypeException if the given formulaType is not valid
+     */
+    public static int getXpNeededToLevel(int level) {
+        return mcMMO.getFormulaManager().getCachedXpToLevel(level, ExperienceConfig.getInstance().getFormulaType());
+    }
+
+    /**
+     * Check how much XP is needed for a specific level with the provided level curve.
+     * </br>
+     * This function is designed for API usage.
+     *
+     * @param level The level to get the amount of XP for
+     * @param formulaType The formula type to get the amount of XP for
+     *
+     * @throws InvalidFormulaTypeException if the given formulaType is not valid
+     */
+    public static int getXpNeededToLevel(int level, String formulaType) {
+        return mcMMO.getFormulaManager().getCachedXpToLevel(level, getFormulaType(formulaType));
+    }
+
     // Utility methods follow.
     private static void addOfflineXP(UUID playerUniqueId, SkillType skill, int XP) {
         PlayerProfile profile = getOfflineProfile(playerUniqueId);
@@ -980,4 +1009,14 @@ public final class ExperienceAPI {
 
         return xpGainReason;
     }
+
+    private static FormulaType getFormulaType(String formula) throws InvalidFormulaTypeException {
+        FormulaType formulaType = FormulaType.getFormulaType(formula);
+
+        if (formulaType == null) {
+            throw new InvalidFormulaTypeException();
+        }
+
+        return formulaType;
+    }
 }

src/main/java/com/gmail/nossr50/api/exceptions/InvalidFormulaTypeException.java

@@ -0,0 +1,9 @@
+package com.gmail.nossr50.api.exceptions;
+
+public class InvalidFormulaTypeException extends RuntimeException {
+    private static final long serialVersionUID = 3368670229490121886L;
+
+    public InvalidFormulaTypeException() {
+        super("That is not a valid FormulaType.");
+    }
+}