Add client-side ability cooldowns, sync, and GUI updates

src/main/java/net/fretux/skillengine/network/ClientboundSyncCooldownPacket.java

@@ -0,0 +1,32 @@
+package net.fretux.skillengine.network;
+
+import net.fretux.skillengine.client.SkilltreeClientState;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraftforge.network.NetworkEvent;
+
+import java.util.function.Supplier;
+
+public class ClientboundSyncCooldownPacket {
+
+    private final int slot;
+    private final int cooldown;
+
+    public ClientboundSyncCooldownPacket(int slot, int cooldown) {
+        this.slot = slot;
+        this.cooldown = cooldown;
+    }
+
+    public static void encode(ClientboundSyncCooldownPacket msg, FriendlyByteBuf buf) {
+        buf.writeInt(msg.slot);
+        buf.writeInt(msg.cooldown);
+    }
+
+    public static ClientboundSyncCooldownPacket decode(FriendlyByteBuf buf) {
+        return new ClientboundSyncCooldownPacket(buf.readInt(), buf.readInt());
+    }
+
+    public static void handle(ClientboundSyncCooldownPacket msg, Supplier<NetworkEvent.Context> ctx) {
+        ctx.get().enqueueWork(() -> SkilltreeClientState.updateCooldown(msg.slot, msg.cooldown));
+        ctx.get().setPacketHandled(true);
+    }
+}

src/main/java/net/fretux/skillengine/network/PacketHandler.java

@@ -42,6 +42,16 @@ public class PacketHandler {
                 .decoder(ServerboundBindAbilityPacket::decode)
                 .consumerMainThread(ServerboundBindAbilityPacket::handle)
                 .add();
+        CHANNEL.messageBuilder(ClientboundSyncCooldownPacket.class, id++, NetworkDirection.PLAY_TO_CLIENT)
+                .encoder(ClientboundSyncCooldownPacket::encode)
+                .decoder(ClientboundSyncCooldownPacket::decode)
+                .consumerMainThread(ClientboundSyncCooldownPacket::handle)
+                .add();
+        CHANNEL.messageBuilder(ServerboundActivateAbilityPacket.class, id++, NetworkDirection.PLAY_TO_SERVER)
+                .encoder(ServerboundActivateAbilityPacket::encode)
+                .decoder(ServerboundActivateAbilityPacket::decode)
+                .consumerMainThread(ServerboundActivateAbilityPacket::handle)
+                .add();
     }
 
     public static void syncSkillsTo(ServerPlayer player) {

src/main/java/net/fretux/skillengine/network/ServerboundActivateAbilityPacket.java

@@ -0,0 +1,56 @@
+package net.fretux.skillengine.network;
+
+import net.fretux.skillengine.capability.SkillEngineCapabilities;
+import net.fretux.skillengine.skilltree.AbilityNode;
+import net.fretux.skillengine.skilltree.AbilityNodeRegistry;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraftforge.network.NetworkEvent;
+import net.minecraftforge.network.PacketDistributor;
+
+import java.util.function.Supplier;
+
+public class ServerboundActivateAbilityPacket {
+
+    private final int slot;
+
+    public ServerboundActivateAbilityPacket(int slot) {
+        this.slot = slot;
+    }
+
+    public static void encode(ServerboundActivateAbilityPacket msg, FriendlyByteBuf buf) {
+        buf.writeInt(msg.slot);
+    }
+
+    public static ServerboundActivateAbilityPacket decode(FriendlyByteBuf buf) {
+        return new ServerboundActivateAbilityPacket(buf.readInt());
+    }
+
+    public static void handle(ServerboundActivateAbilityPacket msg, Supplier<NetworkEvent.Context> ctx) {
+        ctx.get().enqueueWork(() -> {
+
+            ServerPlayer player = ctx.get().getSender();
+            if (player == null) return;
+
+            player.getCapability(SkillEngineCapabilities.PLAYER_SKILLS).ifPresent(data -> {
+
+                ResourceLocation abilityId = data.getAbilityInSlot(msg.slot);
+                if (abilityId == null) return;
+
+                AbilityNode ability = AbilityNodeRegistry.get(abilityId);
+                if (ability == null) return;
+
+                int cd = data.getCooldown(msg.slot);
+                if (cd > 0) return;
+                ability.execute(player);
+                data.setCooldown(msg.slot, ability.getCooldown());
+                PacketHandler.CHANNEL.send(
+                        PacketDistributor.PLAYER.with(() -> player),
+                        new ClientboundSyncCooldownPacket(msg.slot, ability.getCooldown())
+                );
+            });
+        });
+        ctx.get().setPacketHandled(true);
+    }
+}