package com.gmail.nossr50.skills.child; import java.util.Collections; import java.util.EnumSet; import java.util.HashMap; import java.util.Set; import com.gmail.nossr50.datatypes.skills.SkillType; public class FamilyTree { private static HashMap> tree = new HashMap>(); public static Set getParents(SkillType childSkill) { enforceChildSkill(childSkill); // We do not check if we have the child skill in question, as not having it would mean we did something wrong, and an NPE is desired. return tree.get(childSkill); } protected static void registerParent(SkillType childSkill, SkillType parentSkill) { enforceChildSkill(childSkill); enforceNotChildSkill(parentSkill); if (!tree.containsKey(childSkill)) { tree.put(childSkill, EnumSet.noneOf(SkillType.class)); } tree.get(childSkill).add(parentSkill); } protected static void closeRegistration() { for (SkillType childSkill : tree.keySet()) { Set immutableSet = Collections.unmodifiableSet(tree.get(childSkill)); tree.put(childSkill, immutableSet); } } protected static void enforceChildSkill(SkillType skill) { if (!skill.isChildSkill()) { throw new IllegalArgumentException(skill.name() + " is not a child skill!"); } } protected static void enforceNotChildSkill(SkillType skill) { if (skill.isChildSkill()) { throw new IllegalArgumentException(skill.name() + " is a child skill!"); } } }