Add new child.yml config for picking parents of child skills

src/main/java/com/gmail/nossr50/skills/child/ChildConfig.java

@@ -0,0 +1,60 @@
+package com.gmail.nossr50.skills.child;
+
+import java.util.EnumSet;
+import java.util.List;
+
+import org.bukkit.configuration.file.YamlConfiguration;
+
+import com.gmail.nossr50.config.AutoUpdateConfigLoader;
+import com.gmail.nossr50.skills.utilities.SkillType;
+import com.gmail.nossr50.util.StringUtils;
+
+public class ChildConfig extends AutoUpdateConfigLoader {
+    public ChildConfig() {
+        super("child.yml");
+        loadKeys();
+    }
+
+    @Override
+    protected void loadKeys() {
+        config.setDefaults(YamlConfiguration.loadConfiguration(plugin.getResource("child.yml")));
+
+        for (SkillType skill : SkillType.values()) {
+            if (skill.isChildSkill()) {
+                plugin.debug("Finding parents of " + skill.name());
+                List<String> parentNames = config.getStringList(StringUtils.getCapitalized(skill.name()));
+                EnumSet<SkillType> parentSkills = EnumSet.noneOf(SkillType.class);
+                boolean useDefaults = false; // If we had an error we back out and use defaults
+                for (String name : parentNames) {
+                    try {
+                        SkillType parentSkill = Enum.valueOf(SkillType.class, name.toUpperCase());
+                        FamilyTree.enforceNotChildSkill(parentSkill);
+                        parentSkills.add(parentSkill);
+                    } catch (IllegalArgumentException ex) {
+                        plugin.getLogger().warning(name + " is not a valid skill type, or is a child skill!");
+                        useDefaults = true;
+                        break;
+                    }
+                }
+
+                if (useDefaults) {
+                    parentSkills.clear();
+                    for (String name : config.getDefaults().getStringList(StringUtils.getCapitalized(skill.name()))) {
+                        /* We do less checks in here because it's from inside our jar.
+                         * If they're dedicated enough to have modified it, they can have the errors it may produce.
+                         * Alternatively, this can be used to allow child skills to be parent skills, provided there are no circular dependencies this is an advanced sort of configuration.
+                         */
+                        parentSkills.add(SkillType.valueOf(name.toUpperCase()));
+                    }
+                }
+
+                // Register them
+                for (SkillType parentSkill : parentSkills) {
+                    plugin.debug("Registering " + parentSkill.name() + " as parent of " + skill.name());
+                    FamilyTree.registerParent(skill, parentSkill);
+                }
+            }
+        }
+        FamilyTree.closeRegistration();
+    }
+}

src/main/java/com/gmail/nossr50/skills/child/FamilyTree.java

@@ -0,0 +1,49 @@
+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.skills.utilities.SkillType;
+
+public class FamilyTree {
+    private static HashMap<SkillType, Set<SkillType>> tree = new HashMap<SkillType, Set<SkillType>>();
+
+    public static Set<SkillType> 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<SkillType> 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!");
+        }
+    }
+}