2 files changed, 21 insertions, 1 deletions
diff --git a/src/main/java/world/anhgelus/lifesteal/LifeSteal.java b/src/main/java/world/anhgelus/lifesteal/LifeSteal.java
index 419480c..b237e6c 100644
--- a/src/main/java/world/anhgelus/lifesteal/LifeSteal.java
+++ b/src/main/java/world/anhgelus/lifesteal/LifeSteal.java
@@ -6,6 +6,7 @@ import net.fabricmc.fabric.api.command.v2.CommandRegistrationCallback;
 import net.fabricmc.fabric.api.entity.event.v1.ServerLivingEntityEvents;
 import net.fabricmc.fabric.api.entity.event.v1.ServerPlayerEvents;
 import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents;
+import net.fabricmc.fabric.api.event.player.UseItemCallback;
 import net.fabricmc.fabric.api.gamerule.v1.GameRuleFactory;
 import net.fabricmc.fabric.api.gamerule.v1.GameRuleRegistry;
 import net.fabricmc.fabric.api.networking.v1.PacketSender;
@@ -18,6 +19,7 @@ import net.minecraft.server.command.CommandManager;
 import net.minecraft.server.command.ServerCommandSource;
 import net.minecraft.server.network.ServerPlayNetworkHandler;
 import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.util.ActionResult;
 import net.minecraft.world.GameRules;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -68,5 +70,13 @@ public class LifeSteal implements ModInitializer {
         ServerPlayerEvents.AFTER_RESPAWN.register((ServerPlayerEntity oldPlayer, ServerPlayerEntity newPlayer, boolean alive) -> {
             getLifeStealer(oldPlayer).respawn(newPlayer);
         });
+
+        UseItemCallback.EVENT.register((player, world, hand) -> {
+            if (!LifeStealer.Manager.validHeart(player.getMainHandStack())) return ActionResult.PASS;
+            // if the heart was not added
+            if (!getLifeStealer((ServerPlayerEntity) player).kill()) return ActionResult.PASS;
+            player.getMainHandStack().decrement(1);
+            return ActionResult.SUCCESS;
+        });
     }
 }
diff --git a/src/main/java/world/anhgelus/lifesteal/LifeStealer.java b/src/main/java/world/anhgelus/lifesteal/LifeStealer.java
index 390a957..9052515 100644
--- a/src/main/java/world/anhgelus/lifesteal/LifeStealer.java
+++ b/src/main/java/world/anhgelus/lifesteal/LifeStealer.java
@@ -64,9 +64,11 @@ public class LifeStealer {
         updateHealth();
     }
 
-    public void kill() {
+    public boolean kill() {
+        final var before = healthModifier;
         healthModifier = clamp(healthModifier + 2);
         updateHealth();
+        return before != healthModifier;
     }
 
     public void death() {
@@ -115,5 +117,13 @@ public class LifeStealer {
         public static void savePlayers(StateSaver state) {
             players.forEach((u, player) -> state.players.put(u, LifeStealer.Data.from(player)));
         }
+
+        public static boolean validHeart(ItemStack is) {
+            if (!is.isOf(Items.NETHER_STAR)) return false;
+            final var nbtComponent = is.get(DataComponentTypes.CUSTOM_DATA);
+            if (nbtComponent == null || nbtComponent.isEmpty()) return false;
+            final var nbt = nbtComponent.copyNbt();
+            return nbt.contains(PLAYER_KEY);
+        }
     }
 }