Implement mutual exclusives

src/main/java/net/fretux/skillengine/skilltree/AbilityNode.java

@@ -0,0 +1,48 @@
+package net.fretux.skillengine.skilltree;
+
+import net.minecraft.network.chat.Component;
+import net.minecraft.resources.ResourceLocation;
+
+import java.util.List;
+
+public class AbilityNode {
+
+    private final ResourceLocation id;
+    private final Component title;
+    private final Component description;
+    private final float x, y;
+    private final List<ResourceLocation> links;
+    private final List<ResourceLocation> tags;
+    private final ResourceLocation icon;
+    private final int cooldown;
+
+    public AbilityNode(ResourceLocation id,
+                       Component title,
+                       Component description,
+                       float x, float y,
+                       List<ResourceLocation> links,
+                       List<ResourceLocation> tags,
+                       ResourceLocation icon,
+                       int cooldown) {
+
+        this.id = id;
+        this.title = title;
+        this.description = description;
+        this.x = x;
+        this.y = y;
+        this.links = List.copyOf(links);
+        this.tags = List.copyOf(tags);
+        this.icon = icon;
+        this.cooldown = cooldown;
+    }
+
+    public ResourceLocation getId() { return id; }
+    public Component getTitle() { return title; }
+    public Component getDescription() { return description; }
+    public float getX() { return x; }
+    public float getY() { return y; }
+    public List<ResourceLocation> getLinks() { return links; }
+    public List<ResourceLocation> getTags() { return tags; }
+    public ResourceLocation getIcon() { return icon; }
+    public int getCooldown() { return cooldown; }
+}

src/main/java/net/fretux/skillengine/skilltree/AbilityNodeLoader.java

@@ -0,0 +1,71 @@
+package net.fretux.skillengine.skilltree;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import net.fretux.skillengine.SkillEngine;
+import net.minecraft.network.chat.Component;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.packs.resources.ResourceManager;
+import net.minecraft.server.packs.resources.SimpleJsonResourceReloadListener;
+import net.minecraft.util.profiling.ProfilerFiller;
+import net.minecraftforge.event.AddReloadListenerEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.common.Mod;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+@Mod.EventBusSubscriber(modid = SkillEngine.MODID, bus = Mod.EventBusSubscriber.Bus.FORGE)
+public class AbilityNodeLoader extends SimpleJsonResourceReloadListener {
+
+    private static final Gson GSON = new GsonBuilder().create();
+
+    public AbilityNodeLoader() {
+        super(GSON, "abilitynodes");
+    }
+
+    @SubscribeEvent
+    public static void onAddReloadListeners(AddReloadListenerEvent event) {
+        event.addListener(new AbilityNodeLoader());
+    }
+
+    @Override
+    protected void apply(Map<ResourceLocation, JsonElement> jsons,
+                         ResourceManager resourceManager,
+                         ProfilerFiller profiler) {
+
+        SkillEngine.LOGGER.info("Loading ability nodes...");
+
+        AbilityNodeRegistry.clear();
+
+        jsons.forEach((id, json) -> {
+            JsonObject obj = json.getAsJsonObject();
+
+            Component title = Component.literal(obj.get("title").getAsString());
+            Component description = Component.literal(obj.get("description").getAsString());
+            JsonObject pos = obj.getAsJsonObject("position");
+            float x = pos.get("x").getAsFloat();
+            float y = pos.get("y").getAsFloat();
+
+            List<ResourceLocation> links = new ArrayList<>();
+            obj.getAsJsonArray("links").forEach(e ->
+                    links.add(new ResourceLocation(e.getAsString())));
+
+            List<ResourceLocation> tags = new ArrayList<>();
+            obj.getAsJsonArray("tags").forEach(e ->
+                    tags.add(new ResourceLocation(e.getAsString())));
+
+            ResourceLocation icon = new ResourceLocation(obj.get("icon").getAsString());
+
+            int cooldown = obj.has("cooldown") ? obj.get("cooldown").getAsInt() : 0;
+
+            AbilityNode node = new AbilityNode(id, title, description, x, y, links, tags, icon, cooldown);
+            AbilityNodeRegistry.put(node);
+        });
+
+        SkillEngine.LOGGER.info("Loaded {} active ability nodes", AbilityNodeRegistry.all().size());
+    }
+}

src/main/java/net/fretux/skillengine/skilltree/AbilityNodeRegistry.java

@@ -0,0 +1,28 @@
+package net.fretux.skillengine.skilltree;
+
+import net.minecraft.resources.ResourceLocation;
+
+import java.util.Collection;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+public class AbilityNodeRegistry {
+
+    private static final Map<ResourceLocation, AbilityNode> ABILITIES = new LinkedHashMap<>();
+
+    public static void clear() {
+        ABILITIES.clear();
+    }
+
+    public static void put(AbilityNode node) {
+        ABILITIES.put(node.getId(), node);
+    }
+
+    public static AbilityNode get(ResourceLocation id) {
+        return ABILITIES.get(id);
+    }
+
+    public static Collection<AbilityNode> all() {
+        return ABILITIES.values();
+    }
+}