Overlays

Fun is still suspended though

.gitignore

@@ -1,6 +1,7 @@
 # User-specific stuff
 .idea/
 urlaub/
+.kotlin/
 
 *.iml
 *.ipr

src/main/java/io/github/skippyall/minions/MinionMixinConfigPlugin.java

@@ -1,6 +1,7 @@
 package io.github.skippyall.minions;
 
 import net.fabricmc.loader.api.FabricLoader;
+import org.jspecify.annotations.Nullable;
 import org.objectweb.asm.tree.ClassNode;
 import org.spongepowered.asm.mixin.extensibility.IMixinConfigPlugin;
 import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
@@ -15,6 +16,7 @@ public class MinionMixinConfigPlugin implements IMixinConfigPlugin {
     }
 
     @Override
+    @Nullable
     public String getRefMapperConfig() {
         return null;
     }
@@ -34,6 +36,7 @@ public class MinionMixinConfigPlugin implements IMixinConfigPlugin {
     public void acceptTargets(Set<String> myTargets, Set<String> otherTargets) {}
 
     @Override
+    @Nullable
     public List<String> getMixins() {
         return null;
     }

src/main/java/io/github/skippyall/minions/Minions.java

@@ -1,16 +1,16 @@
 package io.github.skippyall.minions;
 
-import eu.pb4.polymer.resourcepack.api.PolymerResourcePackUtils;
 import io.github.skippyall.minions.command.MinionsCommand;
 import io.github.skippyall.minions.docs.DocsManager;
 import io.github.skippyall.minions.minion.MinionPersistentState;
 import io.github.skippyall.minions.minion.fakeplayer.MinionFakePlayer;
-import io.github.skippyall.minions.polymer.VersionSync;
+import io.github.skippyall.minions.polymer.PolymerRegistration;
 import io.github.skippyall.minions.registration.MinionRegistration;
 import net.fabricmc.api.ModInitializer;
 import net.fabricmc.fabric.api.command.v2.CommandRegistrationCallback;
 import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents;
-import net.fabricmc.fabric.api.resource.ResourceManagerHelper;
+import net.fabricmc.fabric.api.resource.v1.ResourceLoader;
+import net.minecraft.resources.Identifier;
 import net.minecraft.server.packs.PackType;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -26,8 +26,6 @@ public class Minions implements ModInitializer {
 
         MinionRegistration.register();
 
-        VersionSync.register();
-
         ServerLifecycleEvents.SERVER_STARTED.register(server -> {
             MinionPersistentState.get(server).getMinionData().forEach((uuid, data) -> {
                 if(data.isSpawned()) {
@@ -38,8 +36,8 @@ public class Minions implements ModInitializer {
 
         CommandRegistrationCallback.EVENT.register(MinionsCommand::register);
 
-        PolymerResourcePackUtils.addModAssets(Minions.MOD_ID);
+        PolymerRegistration.register();
 
-        ResourceManagerHelper.get(PackType.SERVER_DATA).registerReloadListener(new DocsManager());
+        ResourceLoader.get(PackType.SERVER_DATA).registerReloadListener(Identifier.fromNamespaceAndPath(Minions.MOD_ID, "docs"), new DocsManager());
     }
 }

src/main/java/io/github/skippyall/minions/MinionsConfig.java

@@ -11,13 +11,14 @@ import com.electronwill.nightconfig.core.serde.annotations.SerdeComment;
 import com.electronwill.nightconfig.toml.TomlFormat;
 import com.electronwill.nightconfig.toml.TomlParser;
 import net.fabricmc.loader.api.FabricLoader;
+import org.jspecify.annotations.Nullable;
 
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 
 public class MinionsConfig {
-    private static MinionsConfig INSTANCE;
+    private static @Nullable MinionsConfig INSTANCE;
 
     public Minion minion = new Minion();
 

src/main/java/io/github/skippyall/minions/block/input/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.block.input;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/block/instruction_bound/InstructionBoundBlock.java

@@ -51,7 +51,7 @@ public abstract class InstructionBoundBlock extends Block implements EntityBlock
         }
 
         world.getBlockEntity(pos, getBlockEntityType()).ifPresent(be -> {
-            String name = MinionPersistentState.get(world.getServer()).getMinionData(be.getMinionUuid()).name();
+            String name = MinionPersistentState.get(world.getServer()).getMinionData(be.getMinionUuid()).getName();
             player.sendSystemMessage(Component.translatable("minions.reference.instruction.tooltip", be.getInstructionName(), name));
         });
         return InteractionResult.SUCCESS;

src/main/java/io/github/skippyall/minions/block/instruction_bound/InstructionBoundBlockEntity.java

@@ -9,12 +9,13 @@ import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
 import net.minecraft.world.level.block.state.BlockState;
+import org.jspecify.annotations.Nullable;
 
 import java.util.Optional;
 import java.util.UUID;
 
 public abstract class InstructionBoundBlockEntity<L extends BlockEntityMinionListener<?>> extends BlockEntity {
-    protected UUID minionUuid;
+    protected @Nullable UUID minionUuid;
     protected String instructionName = "";
 
     public InstructionBoundBlockEntity(BlockEntityType<?> type, BlockPos pos, BlockState state) {
@@ -56,7 +57,7 @@ public abstract class InstructionBoundBlockEntity<L extends BlockEntityMinionLis
         return Optional.empty();
     }
 
-    public UUID getMinionUuid() {
+    public @Nullable UUID getMinionUuid() {
         return minionUuid;
     }
 
@@ -72,7 +73,7 @@ public abstract class InstructionBoundBlockEntity<L extends BlockEntityMinionLis
         return getMinion().flatMap(this::getInstruction);
     }
 
-    public L getListener() {
+    public @Nullable L getListener() {
         return BlockEntityMinionListener.getListener(level, worldPosition, minionUuid, getListenerClass());
     }
 }

src/main/java/io/github/skippyall/minions/block/instruction_bound/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.block.instruction_bound;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/block/miniontrigger/MinionTriggerBlock.java

@@ -1,32 +1,14 @@
 package io.github.skippyall.minions.block.miniontrigger;
 
 import com.mojang.serialization.MapCodec;
-import eu.pb4.polymer.core.api.block.PolymerBlock;
-import eu.pb4.polymer.core.api.utils.PolymerClientDecoded;
-import eu.pb4.polymer.resourcepack.api.PolymerResourcePackUtils;
-import eu.pb4.polymer.virtualentity.api.BlockWithElementHolder;
-import eu.pb4.polymer.virtualentity.api.ElementHolder;
-import eu.pb4.polymer.virtualentity.api.elements.ItemDisplayElement;
-import io.github.skippyall.minions.Minions;
 import io.github.skippyall.minions.block.instruction_bound.InstructionBoundBlock;
-import io.github.skippyall.minions.polymer.VersionSync;
 import io.github.skippyall.minions.registration.MinionBlocks;
-import net.fabricmc.fabric.api.networking.v1.context.PacketContext;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
-import net.minecraft.core.component.DataComponents;
-import net.minecraft.resources.Identifier;
-import net.minecraft.server.level.ServerLevel;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.server.network.ServerGamePacketListenerImpl;
-import net.minecraft.world.item.ItemDisplayContext;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.Items;
 import net.minecraft.world.level.BlockGetter;
 import net.minecraft.world.level.Level;
 import net.minecraft.world.level.LevelReader;
 import net.minecraft.world.level.block.Block;
-import net.minecraft.world.level.block.DiodeBlock;
 import net.minecraft.world.level.block.SupportType;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
@@ -36,9 +18,10 @@ import net.minecraft.world.level.block.state.properties.BooleanProperty;
 import net.minecraft.world.level.redstone.Orientation;
 import net.minecraft.world.phys.shapes.CollisionContext;
 import net.minecraft.world.phys.shapes.VoxelShape;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
-public class MinionTriggerBlock extends InstructionBoundBlock implements PolymerBlock, PolymerClientDecoded, BlockWithElementHolder {
+public class MinionTriggerBlock extends InstructionBoundBlock {
     public static final MapCodec<MinionTriggerBlock> CODEC = simpleCodec(MinionTriggerBlock::new);
 
     public static final BooleanProperty POWERED = BooleanProperty.create("powered");
@@ -70,6 +53,7 @@ public class MinionTriggerBlock extends InstructionBoundBlock implements Polymer
     }
 
     @Override
+    @NullMarked
     protected void neighborChanged(BlockState state, Level world, BlockPos pos, Block sourceBlock, @Nullable Orientation wireOrientation, boolean notify) {
         if(!canSurvive(state, world, pos)) {
             dropResources(state, world, pos);
@@ -103,35 +87,4 @@ public class MinionTriggerBlock extends InstructionBoundBlock implements Polymer
     protected BlockEntityType<MinionTriggerBlockEntity> getBlockEntityType() {
         return MinionBlocks.MINION_TRIGGER_BE_TYPE;
     }
-
-    @Override
-    public BlockState getPolymerBlockState(BlockState state, PacketContext context) {
-        return VersionSync.isOnClient(context) ? state : net.minecraft.world.level.block.Blocks.COMPARATOR.defaultBlockState().setValue(DiodeBlock.POWERED, state.getValue(POWERED));
-    }
-
-    @Override
-    public boolean handleMiningOnServer(ItemStack tool, BlockState state, BlockPos pos, ServerPlayer player) {
-        return false;
-    }
-
-    @Override
-    public @Nullable ElementHolder createElementHolder(ServerLevel world, BlockPos pos, BlockState initialBlockState) {
-        ElementHolder holder = new ElementHolder() {
-            @Override
-            public boolean startWatching(ServerGamePacketListenerImpl player) {
-                if(PolymerResourcePackUtils.hasMainPack(player) && !VersionSync.isOnClient(player)) {
-                    return super.startWatching(player);
-                } else {
-                    return false;
-                }
-            }
-        };
-        ItemStack stack = new ItemStack(Items.BARRIER);
-        stack.set(DataComponents.ITEM_MODEL, Identifier.fromNamespaceAndPath(Minions.MOD_ID, "minion_trigger_no_plate_" + (initialBlockState.getValue(MinionTriggerBlock.POWERED) ? "active" : "inactive")));
-
-        ItemDisplayElement element = new ItemDisplayElement(stack);
-        element.setItemDisplayContext(ItemDisplayContext.NONE);
-        holder.addElement(element);
-        return holder;
-    }
 }

src/main/java/io/github/skippyall/minions/block/miniontrigger/MinionTriggerBlockItem.java

@@ -1,26 +0,0 @@
-package io.github.skippyall.minions.block.miniontrigger;
-
-import eu.pb4.polymer.core.api.item.PolymerBlockItem;
-import eu.pb4.polymer.resourcepack.api.PolymerResourcePackUtils;
-import net.fabricmc.fabric.api.networking.v1.context.PacketContext;
-import net.minecraft.core.HolderLookup;
-import net.minecraft.resources.Identifier;
-import net.minecraft.world.item.Item;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.level.block.Block;
-import org.jetbrains.annotations.Nullable;
-
-public class MinionTriggerBlockItem extends PolymerBlockItem {
-    public MinionTriggerBlockItem(Block block, Properties settings, Item polymerItem) {
-        super(block, settings, polymerItem, true);
-    }
-
-    @Override
-    public @Nullable Identifier getPolymerItemModel(ItemStack stack, PacketContext context, HolderLookup.Provider lookup) {
-        if(PolymerResourcePackUtils.hasMainPack(context)) {
-            return super.getPolymerItemModel(stack, context, lookup);
-        } else {
-            return null;
-        }
-    }
-}

src/main/java/io/github/skippyall/minions/block/miniontrigger/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.block.miniontrigger;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/block/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.block;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/clipboard/ClipboardItem.java

@@ -1,42 +1,13 @@
 package io.github.skippyall.minions.clipboard;
 
-import eu.pb4.polymer.core.api.item.PolymerItem;
 import io.github.skippyall.minions.minion.fakeplayer.MinionFakePlayer;
 import io.github.skippyall.minions.registration.MinionComponentTypes;
 import io.github.skippyall.minions.registration.MinionItems;
-import net.fabricmc.fabric.api.networking.v1.context.PacketContext;
 import net.minecraft.core.BlockPos;
-import net.minecraft.core.HolderLookup;
-import net.minecraft.core.component.DataComponents;
-import net.minecraft.resources.Identifier;
-import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.Items;
-import net.minecraft.world.item.TooltipFlag;
 import net.minecraft.world.level.Level;
-import org.jetbrains.annotations.Nullable;
 
-public class ClipboardItem extends Item implements PolymerItem {
-    public ClipboardItem(Properties settings) {
-        super(settings);
-    }
-
-    @Override
-    public Item getPolymerItem(ItemStack itemStack, PacketContext context) {
-        return /*VersionSync.isOnClient(context) ? this : */Items.PAPER;
-    }
-
-    @Override
-    public @Nullable Identifier getPolymerItemModel(ItemStack stack, PacketContext context, HolderLookup.Provider lookup) {
-        return null;
-    }
-
-    @Override
-    public ItemStack getPolymerItemStack(ItemStack itemStack, TooltipFlag tooltipType, PacketContext context, HolderLookup.Provider lookup) {
-        ItemStack stack = PolymerItem.super.getPolymerItemStack(itemStack, tooltipType, context, lookup);
-        stack.set(DataComponents.ENCHANTMENT_GLINT_OVERRIDE, true);
-        return stack;
-    }
+public class ClipboardItem {
 
     public static ItemStack createInstructionReference(MinionFakePlayer minion, String instructionName) {
         ItemStack stack = new ItemStack(MinionItems.REFERENCE_ITEM);

src/main/java/io/github/skippyall/minions/clipboard/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.clipboard;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/command/ListSubcommand.java

@@ -18,7 +18,7 @@ public class ListSubcommand {
     public static int list(CommandContext<CommandSourceStack> context) {
         Collection<MinionData> minions = MinionPersistentState.get(context.getSource().getServer()).getMinionData().values();
         for (MinionData minion : minions) {
-            context.getSource().sendSuccess(() -> Component.literal(minion.name() + "(" + minion.uuid() + "):" + minion.isSpawned()), false);
+            context.getSource().sendSuccess(() -> Component.literal(minion.getName() + "(" + minion.getUuid() + "):" + minion.isSpawned()), false);
         }
         return 0;
     }

src/main/java/io/github/skippyall/minions/command/MinionArgument.java

@@ -41,7 +41,7 @@ public class MinionArgument {
         @Override
         public CompletableFuture<Suggestions> getSuggestions(CommandContext<CommandSourceStack> context, SuggestionsBuilder builder) throws CommandSyntaxException {
             for (MinionData data : MinionPersistentState.get(context.getSource().getServer()).getMinionDataList()) {
-                builder.suggest(data.name());
+                builder.suggest(data.getName());
             }
 
             return builder.buildFuture();

src/main/java/io/github/skippyall/minions/command/SpawnSubcommand.java

@@ -10,6 +10,7 @@ import net.minecraft.commands.CommandSourceStack;
 import net.minecraft.commands.arguments.coordinates.Coordinates;
 import net.minecraft.commands.arguments.coordinates.Vec3Argument;
 import net.minecraft.server.permissions.Permissions;
+import org.jspecify.annotations.Nullable;
 
 import static net.minecraft.commands.Commands.argument;
 import static net.minecraft.commands.Commands.literal;
@@ -48,7 +49,7 @@ public class SpawnSubcommand {
                             ))
             );
 
-    public static int spawnCommand(CommandSourceStack source, String minion, Coordinates pos, boolean force) throws CommandSyntaxException {
+    public static int spawnCommand(CommandSourceStack source, String minion, @Nullable Coordinates pos, boolean force) throws CommandSyntaxException {
         MinionData data = MinionArgument.parse(source.getServer(), minion);
         MinionFakePlayer.spawnMinion(data, source.getLevel(), pos != null ? pos.getPosition(source) : null, pos != null ? pos.getRotation(source) : null, force);
         return 0;

src/main/java/io/github/skippyall/minions/command/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.command;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/docs/DocsManager.java

@@ -3,7 +3,7 @@ package io.github.skippyall.minions.docs;
 import com.google.gson.JsonParseException;
 import com.mojang.serialization.JsonOps;
 import io.github.skippyall.minions.Minions;
-import net.fabricmc.fabric.api.resource.SimpleResourceReloadListener;
+import net.fabricmc.fabric.api.resource.v1.reloader.SimpleReloadListener;
 import net.minecraft.core.Holder;
 import net.minecraft.network.chat.ClickEvent;
 import net.minecraft.network.chat.Component;
@@ -16,9 +16,10 @@ import net.minecraft.server.dialog.MultiActionDialog;
 import net.minecraft.server.dialog.action.StaticAction;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.server.packs.resources.Resource;
-import net.minecraft.server.packs.resources.ResourceManager;
 import net.minecraft.util.StrictJsonParser;
 import net.minecraft.util.Tuple;
+import org.jspecify.annotations.Nullable;
+
 import java.io.IOException;
 import java.io.Reader;
 import java.util.ArrayList;
@@ -27,14 +28,12 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.Executor;
 
-public class DocsManager implements SimpleResourceReloadListener<Tuple<Map<Identifier, DocsEntry>, DocsTree>> {
-    private static Map<Identifier, DocsEntry> docs;
-    private static DocsTree tree;
+public class DocsManager extends SimpleReloadListener<Tuple<Map<Identifier, DocsEntry>, DocsTree>> {
+    private static @Nullable Map<Identifier, DocsEntry> docs;
+    private static @Nullable DocsTree tree;
 
-    public static DocsTree getTree() {
+    public static @Nullable DocsTree getTree() {
         return tree;
     }
 
@@ -87,20 +86,27 @@ public class DocsManager implements SimpleResourceReloadListener<Tuple<Map<Ident
         );
     }
 
-    public static DocsEntry getDocsEntry(Identifier id) {
+    public static @Nullable DocsEntry getDocsEntry(Identifier id) {
+        if(docs != null) {
             return docs.get(id);
+        } else {
+            return null;
+        }
     }
 
-    public static Collection<Identifier> getDocsEntryIds() {
+    public static @Nullable Collection<Identifier> getDocsEntryIds() {
+        if (docs != null) {
             return docs.keySet();
+        } else {
+            return null;
+        }
     }
 
     @Override
-    public CompletableFuture<Tuple<Map<Identifier, DocsEntry>, DocsTree>> load(ResourceManager resourceManager, Executor executor) {
-        return CompletableFuture.supplyAsync(() -> {
-            Map<Identifier, Resource> resources = resourceManager.listResources("docs", id -> id.getNamespace().equals(Minions.MOD_ID) && id.getPath().endsWith(".json"));
+    public Tuple<Map<Identifier, DocsEntry>, DocsTree> prepare(SharedState state) {
+        Map<Identifier, Resource> resources = state.resourceManager().listResources("docs", id -> id.getNamespace().equals(Minions.MOD_ID) && id.getPath().endsWith(".json"));
 
-            final DocsTree.BranchElement[] root = {null};
+        final DocsTree. @Nullable BranchElement[] root = {null};
         Map<Identifier, DocsEntry> docsEntries = new HashMap<>();
         resources.forEach((id, resource) -> {
             try(Reader reader = resource.openAsReader()) {
@@ -124,20 +130,11 @@ public class DocsManager implements SimpleResourceReloadListener<Tuple<Map<Ident
         } else {
             return new Tuple<>(docsEntries, null);
         }
-        }, executor);
     }
 
     @Override
-    public CompletableFuture<Void> apply(Tuple<Map<Identifier, DocsEntry>, DocsTree> o, ResourceManager resourceManager, Executor executor) {
-        return CompletableFuture.supplyAsync(() -> {
+    public void apply(Tuple<Map<Identifier, DocsEntry>, DocsTree> o, SharedState state) {
         docs = o.getA();
         tree = o.getB();
-            return null;
-        });
-    }
-
-    @Override
-    public Identifier getFabricId() {
-        return Identifier.fromNamespaceAndPath(Minions.MOD_ID, "docs");
     }
 }

src/main/java/io/github/skippyall/minions/docs/DocsTree.java

@@ -3,6 +3,7 @@ package io.github.skippyall.minions.docs;
 import com.mojang.datafixers.util.Either;
 import com.mojang.serialization.Codec;
 import net.minecraft.resources.Identifier;
+import org.jspecify.annotations.Nullable;
 
 import java.util.HashMap;
 import java.util.List;
@@ -35,9 +36,9 @@ public class DocsTree {
     }
 
     public static abstract sealed class Element {
-        private BranchElement parent;
+        private @Nullable BranchElement parent;
 
-        public BranchElement getParent() {
+        public @Nullable BranchElement getParent() {
             return parent;
         }
 
@@ -45,12 +46,20 @@ public class DocsTree {
             this.parent = parent;
         }
 
-        public DocElement next() {
+        public @Nullable DocElement next() {
+            if (parent != null) {
                 return parent.next(this);
+            } else {
+                return null;
+            }
         }
 
-        public DocElement previous() {
+        public @Nullable DocElement previous() {
+            if (parent != null) {
                 return parent.previous(this);
+            } else {
+                return null;
+            }
         }
     }
 
@@ -101,7 +110,7 @@ public class DocsTree {
             };
         }
 
-        public DocElement next(Element current) {
+        public @Nullable DocElement next(Element current) {
             int nextIndex = e.indexOf(current) + 1;
             if(nextIndex < e.size()) {
                 return switch (e.get(nextIndex)) {
@@ -117,7 +126,7 @@ public class DocsTree {
             }
         }
 
-        public DocElement previous(Element current) {
+        public @Nullable DocElement previous(Element current) {
             int previousIndex = e.indexOf(current) - 1;
             if(previousIndex >= 0) {
                 return switch (e.get(previousIndex)) {

src/main/java/io/github/skippyall/minions/docs/ReferenceEntry.java

@@ -15,6 +15,7 @@ import net.minecraft.server.dialog.body.DialogBody;
 import net.minecraft.server.dialog.body.ItemBody;
 import net.minecraft.server.dialog.body.PlainMessage;
 import net.minecraft.world.item.Item;
+import org.jspecify.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -55,7 +56,7 @@ public record ReferenceEntry(Metadata metadata, ResourceKey<?> object, Component
         return bodyElements;
     }
 
-    public GuiDisplay getObjectDisplay(RegistryAccess manager) {
+    public @Nullable GuiDisplay getObjectDisplay(RegistryAccess manager) {
         GuiDisplay display = GuiDisplay.DEFAULT_DISPLAY;
         if(object.isFor(Registries.ITEM) || object.isFor(Registries.BLOCK)) {
             Item item;

src/main/java/io/github/skippyall/minions/docs/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.docs;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/gui/GuiDisplay.java

@@ -27,9 +27,10 @@ import java.util.UUID;
 public interface GuiDisplay {
     Codec<GuiDisplay> CODEC = MinionRegistries.GUI_DISPLAY_TYPE.byNameCodec().dispatch(GuiDisplay::getCodec, codec -> codec.fieldOf("data"));
     GuiDisplay DEFAULT_DISPLAY = new ItemBased(Items.BARRIER);
-    TooltipDisplay TOOLTIP_DISPLAY = createTooltipDisplay();
 
-    private static TooltipDisplay createTooltipDisplay() {
+    TooltipDisplay TOOLTIP_HIDE_ALL_COMPONENTS = createHideAllTooltip();
+
+    private static TooltipDisplay createHideAllTooltip() {
         LinkedHashSet<DataComponentType<?>> set = new LinkedHashSet<>();
         for(DataComponentType<?> type : BuiltInRegistries.DATA_COMPONENT_TYPE) {
             if(type != DataComponents.LORE) {
@@ -106,7 +107,7 @@ public interface GuiDisplay {
         @Override
         public ItemStackTemplate createItemStackTemplate() {
             return new ItemStackTemplate(item, DataComponentPatch.builder()
-                    .set(DataComponents.TOOLTIP_DISPLAY, TOOLTIP_DISPLAY)
+                    .set(DataComponents.TOOLTIP_DISPLAY, TOOLTIP_HIDE_ALL_COMPONENTS)
                     .set(DataComponents.RARITY, Rarity.COMMON)
                     .build());
         }
@@ -130,6 +131,7 @@ public interface GuiDisplay {
         public ItemStackTemplate createItemStackTemplate() {
             return new ItemStackTemplate(Items.PLAYER_HEAD, DataComponentPatch.builder()
                     .set(DataComponents.PROFILE, ResolvableProfile.createUnresolved(uuid))
+                    .set(DataComponents.TOOLTIP_DISPLAY, TOOLTIP_HIDE_ALL_COMPONENTS)
                     .build()
             );
         }

src/main/java/io/github/skippyall/minions/gui/MinionLookGui.java

@@ -1,98 +0,0 @@
-package io.github.skippyall.minions.gui;
-
-import com.mojang.authlib.GameProfile;
-import eu.pb4.sgui.api.elements.GuiElementBuilder;
-import eu.pb4.sgui.api.gui.SimpleGui;
-import io.github.skippyall.minions.gui.input.TextInput;
-import io.github.skippyall.minions.minion.MinionData;
-import io.github.skippyall.minions.minion.MinionItem;
-import io.github.skippyall.minions.minion.MinionProfileUtils;
-import io.github.skippyall.minions.minion.skin.SkinProvider;
-import io.github.skippyall.minions.registration.MinionRegistries;
-import io.github.skippyall.minions.registration.SkinProviders;
-import net.fabricmc.fabric.api.entity.FakePlayer;
-import net.minecraft.core.component.DataComponents;
-import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.inventory.MenuType;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.Items;
-import net.minecraft.world.item.component.ResolvableProfile;
-
-import java.util.Optional;
-
-public class MinionLookGui extends SimpleGui {
-    private ItemStack minionItem;
-    private SkinProvider currentSkinProvider;
-
-    public MinionLookGui(ServerPlayer player, ItemStack minionItem) {
-        super(MenuType.GENERIC_9x3, player, false);
-        this.minionItem = minionItem;
-        this.currentSkinProvider = SkinProviders.NAME;
-    }
-
-    public void update() {
-        updateName();
-        updateSkin();
-        updateSkinProvider();
-    }
-
-    private void updateName() {
-        setSlot(10, new GuiElementBuilder()
-                .setItem(Items.OAK_SIGN)
-                .setName(Component.literal(getData().name()))
-                .setCallback(() -> {
-                    openRenameGui(player, minionItem);
-                })
-        );
-    }
-
-    private void updateSkin() {
-        GuiElementBuilder builder = new GuiElementBuilder()
-                .setItem(Items.PLAYER_HEAD)
-                .setCallback(() -> currentSkinProvider.openSkinMenu(player)
-                        .thenCompose(profile -> profile.resolveProfile(player.level().getServer().services().profileResolver()))
-                        .thenAccept(skin -> MinionItem.setData(player.level().getServer(), getData().withSkin(Optional.of(skin.properties())), minionItem)));
-        if(MinionItem.getData(player.level().getServer(), minionItem) != null && MinionItem.getData(player.level().getServer(), minionItem).skin().isPresent()) {
-            builder.setComponent(DataComponents.PROFILE, ResolvableProfile.createResolved(new GameProfile(FakePlayer.DEFAULT_UUID, "", getData().skin().get())));
-        }
-        setSlot(16, builder);
-    }
-
-    private void cycleSkinProvider() {
-        int currentId = MinionRegistries.SKIN_PROVIDERS.getId(currentSkinProvider);
-        currentId++;
-        if(MinionRegistries.SKIN_PROVIDERS.size() == currentId) {
-            currentId = 0;
-        }
-
-        currentSkinProvider = MinionRegistries.SKIN_PROVIDERS.byId(currentId);
-        updateSkinProvider();
-    }
-
-    private void updateSkinProvider() {
-        setSlot(25, new GuiElementBuilder()
-                .setItem(Items.GREEN_STAINED_GLASS_PANE)
-                .setComponent(DataComponents.CUSTOM_NAME, currentSkinProvider.getDisplayName())
-                .setCallback(this::cycleSkinProvider)
-        );
-    }
-
-    private MinionData getData() {
-        return MinionItem.getDataOrDefault(player.level().getServer(), minionItem);
-    }
-
-    public static void open(ServerPlayer player, ItemStack minionItem) {
-        MinionLookGui gui = new MinionLookGui(player, minionItem);
-        gui.update();
-        gui.open();
-    }
-
-    public void openRenameGui(ServerPlayer player, ItemStack minionItem) {
-        TextInput.inputSync(player, Component.translatable("minions.gui.look.rename.title"), "Minion", name -> MinionProfileUtils.checkMinionNameWithoutPrefix(player.level().getServer(), name))
-                .thenAccept(name -> {
-                    MinionItem.setData(player.level().getServer(), getData().withName(MinionProfileUtils.getPrefix() + name), minionItem);
-                    open();
-                });
-    }
-}

src/main/java/io/github/skippyall/minions/gui/MinionLookGui.kt

@@ -0,0 +1,131 @@
+package io.github.skippyall.minions.gui
+
+import com.mojang.authlib.GameProfile
+import eu.pb4.sgui.api.elements.GuiElementBuilder
+import eu.pb4.sgui.api.gui.SimpleGui
+import io.github.skippyall.minions.gui.input.TextInput
+import io.github.skippyall.minions.minion.MinionData
+import io.github.skippyall.minions.minion.MinionItem
+import io.github.skippyall.minions.minion.MinionProfileUtils
+import io.github.skippyall.minions.minion.skin.SkinProvider
+import io.github.skippyall.minions.registration.MinionRegistries
+import io.github.skippyall.minions.registration.SkinProviders
+import kotlinx.coroutines.future.await
+import kotlinx.coroutines.launch
+import net.fabricmc.fabric.api.entity.FakePlayer
+import net.minecraft.core.component.DataComponents
+import net.minecraft.network.chat.Component
+import net.minecraft.server.level.ServerPlayer
+import net.minecraft.world.inventory.MenuType
+import net.minecraft.world.item.ItemStack
+import net.minecraft.world.item.Items
+import net.minecraft.world.item.component.ResolvableProfile
+import java.util.*
+
+class MinionLookGui(
+    viewer: ServerPlayer,
+    private val minionItem: ItemStack
+) : MinionsGui(viewer) {
+    private lateinit var gui: SimpleGui
+
+    private var currentSkinProvider: SkinProvider = SkinProviders.NAME
+
+    private val data: MinionData
+        get() = MinionItem.getDataOrDefault(viewer.level().server, minionItem)
+
+    init {
+        open()
+    }
+
+    override fun open() {
+        gui = object : SimpleGui(MenuType.GENERIC_9x3, viewer, false) {
+            override fun onPlayerClose(success: Boolean) {
+                onBackingClosed()
+            }
+        }
+        update()
+        gui.open()
+    }
+
+    override fun closeBacking() {
+        gui.close()
+    }
+
+    fun update() {
+        updateName()
+        updateSkin()
+        updateSkinProvider()
+    }
+
+    private fun updateName() {
+        gui.setSlot(
+            10, GuiElementBuilder()
+                .setItem(Items.OAK_SIGN)
+                .setName(Component.literal(this.data.name))
+                .setCallback(this::openRenameGui)
+        )
+    }
+
+    private fun updateSkin() {
+        val builder = GuiElementBuilder()
+            .setItem(Items.PLAYER_HEAD)
+            .setCallback(this::openSkinGui)
+
+        if (MinionItem.getData(viewer.level().server, minionItem)?.skin?.isPresent ?: false) {
+            builder.setComponent(
+                DataComponents.PROFILE,
+                ResolvableProfile.createResolved(GameProfile(FakePlayer.DEFAULT_UUID, "", this.data.skin.get()))
+            )
+        }
+
+        gui.setSlot(16, builder)
+    }
+
+    private fun updateSkinProvider() {
+        gui.setSlot(
+            25, GuiElementBuilder()
+                .setItem(Items.GREEN_STAINED_GLASS_PANE)
+                .setComponent(DataComponents.CUSTOM_NAME, currentSkinProvider.getDisplayName())
+                .setCallback(Runnable { this.cycleSkinProvider() })
+        )
+    }
+
+    fun openSkinGui() {
+        scope.launch {
+            val profile = currentSkinProvider.openSkinMenu(this@MinionLookGui).await()
+            val skin = profile?.resolveProfile(viewer.level().server.services().profileResolver())?.await()
+
+            data.skin = Optional.ofNullable(skin?.properties())
+
+            updateSkin()
+        }
+    }
+
+    private fun cycleSkinProvider() {
+        var currentId = MinionRegistries.SKIN_PROVIDERS.getId(currentSkinProvider)
+        currentId++
+        if (MinionRegistries.SKIN_PROVIDERS.size() == currentId) {
+            currentId = 0
+        }
+
+        currentSkinProvider = MinionRegistries.SKIN_PROVIDERS.byId(currentId)!!
+        updateSkinProvider()
+    }
+
+    fun openRenameGui() {
+        scope.launch {
+            val newName = TextInput.input(
+                this@MinionLookGui,
+                Component.translatable("minions.gui.look.rename.title"),
+                "Minion",
+            ) { name ->
+                MinionProfileUtils.checkMinionNameWithoutPrefix(viewer.level().server, name)
+            }.await()
+
+            if(newName != null) {
+                data.name = newName
+                updateName()
+            }
+        }
+    }
+}

src/main/java/io/github/skippyall/minions/gui/MinionsGui.java

@@ -1,76 +0,0 @@
-package io.github.skippyall.minions.gui;
-
-import eu.pb4.sgui.api.elements.GuiElementBuilder;
-import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.item.Items;
-import org.jetbrains.annotations.Nullable;
-
-public abstract class MinionsGui {
-    protected final @Nullable MinionsGui parent;
-    protected final ServerPlayer viewer;
-    protected @Nullable MinionsGui child = null;
-    private boolean open = true;
-
-    public MinionsGui(MinionsGui parent) {
-        this.viewer = parent.viewer;
-        this.parent = parent;
-        parent.child = this;
-    }
-
-    public MinionsGui(ServerPlayer viewer) {
-        this.viewer = viewer;
-        this.parent = null;
-    }
-
-    public ServerPlayer getViewer() {
-        return viewer;
-    }
-
-    protected abstract void open();
-
-    protected void reopen() {
-        open();
-    }
-
-    public void onBackingClosed() {
-        if(child != null && child.open) {
-            return;
-        }
-
-        close(true);
-    }
-
-    public void close() {
-        close(false);
-    }
-
-    public void close(boolean alreadyClosed) {
-        if(open) {
-            open = false;
-            if(child != null) {
-                child.close(alreadyClosed);
-            } else if(!alreadyClosed) {
-                closeBacking();
-            }
-        }
-    }
-
-    public void goBack() {
-        if(parent != null) {
-            open = false;
-            parent.child = null;
-            parent.reopen();
-        } else {
-            close(false);
-        }
-    }
-
-    public GuiElementBuilder backButton() {
-        return new GuiElementBuilder(Items.MANGROVE_DOOR)
-                .setName(Component.translatable("gui.back"))
-                .setCallback(this::goBack);
-    }
-
-    protected abstract void closeBacking();
-}

src/main/java/io/github/skippyall/minions/gui/MinionsGui.kt

@@ -0,0 +1,84 @@
+package io.github.skippyall.minions.gui
+
+import eu.pb4.sgui.api.elements.GuiElementBuilder
+import kotlinx.coroutines.CompletableJob
+import kotlinx.coroutines.CoroutineName
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.cancel
+import net.minecraft.network.chat.Component
+import net.minecraft.server.level.ServerPlayer
+import net.minecraft.world.item.Items
+
+abstract class MinionsGui {
+    protected val parent: MinionsGui?
+    @JvmField
+    val viewer: ServerPlayer
+    protected var child: MinionsGui? = null
+    private var open = true
+
+    private val job: CompletableJob
+    val scope: CoroutineScope
+
+    constructor(parent: MinionsGui) {
+        this.viewer = parent.viewer
+        this.parent = parent
+        parent.child = this
+        job = Job(parent.job)
+        scope = CoroutineScope(Dispatchers.Unconfined.plus(CoroutineName("MinionsGui")).plus(job))
+    }
+
+    constructor(viewer: ServerPlayer) {
+        this.viewer = viewer
+        this.parent = null
+        job = Job(null)
+        scope = CoroutineScope(Dispatchers.Unconfined.plus(CoroutineName("MinionsGui")).plus(job))
+    }
+
+    protected abstract fun open()
+
+    protected open fun reopen() {
+        open()
+    }
+
+    fun onBackingClosed() {
+        if (child != null && child!!.open) {
+            return
+        }
+
+        close(true)
+    }
+
+    @JvmOverloads
+    fun close(alreadyClosed: Boolean = false) {
+        if (open) {
+            scope.cancel(null)
+            open = false
+            if (child != null) {
+                child!!.close(alreadyClosed)
+            } else if (!alreadyClosed) {
+                closeBacking()
+            }
+        }
+    }
+
+    fun goBack() {
+        if (parent != null) {
+            open = false
+            parent.child = null
+            parent.reopen()
+            close(true)
+        } else {
+            close(false)
+        }
+    }
+
+    fun backButton(): GuiElementBuilder? {
+        return GuiElementBuilder(Items.MANGROVE_DOOR)
+            .setName(Component.translatable("gui.back"))
+            .setCallback(Runnable { this.goBack() })
+    }
+
+    protected abstract fun closeBacking()
+}

src/main/java/io/github/skippyall/minions/gui/PaginatedList.java

@@ -6,9 +6,12 @@ import net.minecraft.core.IdMap;
 import net.minecraft.network.chat.Component;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.item.Items;
+import org.jspecify.annotations.Nullable;
 
 import java.util.List;
+import java.util.concurrent.CompletableFuture;
 import java.util.function.BiFunction;
+import java.util.function.Function;
 
 public class PaginatedList extends MinionsGui {
     private int page = 0;
@@ -16,6 +19,7 @@ public class PaginatedList extends MinionsGui {
     private final Component title;
     private final int size;
     private final BiFunction<Integer, PaginatedList, GuiElementBuilder> display;
+    private @Nullable Runnable onClose = null;
 
     public PaginatedList(MinionsGui parent, Component title, int size, BiFunction<Integer, PaginatedList, GuiElementBuilder> display) {
         super(parent);
@@ -25,12 +29,20 @@ public class PaginatedList extends MinionsGui {
         open();
     }
 
+    public PaginatedList(MinionsGui parent, Component title, int size, BiFunction<Integer, PaginatedList, GuiElementBuilder> display, Runnable onClose) {
+        this(parent, title, size, display);
+        this.onClose = onClose;
+    }
+
     @Override
     protected void open() {
         gui = new SimpleGui(MenuType.GENERIC_9x6, viewer, false) {
             @Override
             public void onPlayerClose(boolean success) {
                 onBackingClosed();
+                if(onClose != null) {
+                    onClose.run();
+                }
             }
         };
         gui.setTitle(title);
@@ -53,6 +65,17 @@ public class PaginatedList extends MinionsGui {
         new PaginatedList(parent, title, list.size(), (i, gui) -> display.apply(list.byId(i), gui));
     }
 
+    public static <T> CompletableFuture<T> createListFuture(MinionsGui parent, Component title, List<T> list, Function<T, GuiElementBuilder> display) {
+        CompletableFuture<T> future = new CompletableFuture<>();
+        new PaginatedList(parent, title, list.size(), (i, me) -> display.apply(list.get(i))
+                .setCallback(() -> {
+                    future.complete(list.get(i));
+                    me.goBack();
+                })
+        );
+        return future;
+    }
+
     private void addItems() {
         int slot = 9;
         for(int i = 36 * page; i < Math.min(36 * (page + 1), size); i++) {

src/main/java/io/github/skippyall/minions/gui/input/BooleanInput.kt

@@ -0,0 +1,55 @@
+package io.github.skippyall.minions.gui.input
+
+import eu.pb4.sgui.api.elements.GuiElementBuilder
+import eu.pb4.sgui.api.gui.SimpleGui
+import io.github.skippyall.minions.gui.MinionsGui
+import io.github.skippyall.minions.gui.minion.SimpleMinionsGui
+import net.minecraft.network.chat.Component
+import net.minecraft.world.inventory.MenuType
+import net.minecraft.world.item.Items
+import java.util.concurrent.CompletableFuture
+
+object BooleanInput {
+    @JvmStatic
+    @JvmOverloads
+    fun confirm(
+        parent: MinionsGui,
+        title: Component,
+        falseText: Component = Component.translatable("minions.gui.abort"),
+        trueText: Component = Component.translatable("minions.gui.confirm")
+    ): CompletableFuture<Boolean> {
+        val future = CompletableFuture<Boolean>()
+
+        SimpleMinionsGui(parent) { onClose: Runnable, me: SimpleMinionsGui ->
+            val gui: SimpleGui = object : SimpleGui(MenuType.GENERIC_3x3, parent.viewer, false) {
+                override fun onPlayerClose(success: Boolean) {
+                    future.complete(false)
+                    onClose.run()
+                }
+            }
+            gui.setTitle(title)
+
+            gui.setSlot(
+                3, GuiElementBuilder(Items.REDSTONE_BLOCK)
+                    .setName(falseText)
+                    .setCallback(Runnable {
+                        future.complete(false)
+                        me.goBack()
+                    })
+            )
+
+            gui.setSlot(
+                5, GuiElementBuilder(Items.EMERALD_BLOCK)
+                    .setName(trueText)
+                    .setCallback(Runnable {
+                        future.complete(true)
+                        me.goBack()
+                    })
+            )
+
+            gui.open()
+            gui
+        }
+        return future
+    }
+}

src/main/java/io/github/skippyall/minions/gui/input/ChoiceInput.java

@@ -1,122 +0,0 @@
-package io.github.skippyall.minions.gui.input;
-
-import eu.pb4.sgui.api.elements.GuiElementBuilder;
-import eu.pb4.sgui.api.gui.SimpleGui;
-import io.github.skippyall.minions.gui.Displayable;
-import io.github.skippyall.minions.gui.GuiDisplay;
-import io.github.skippyall.minions.gui.MinionsGui;
-import io.github.skippyall.minions.gui.minion.SimpleMinionsGui;
-import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.inventory.MenuType;
-import net.minecraft.world.item.Items;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.concurrent.CompletableFuture;
-import java.util.function.BiFunction;
-import java.util.function.Function;
-
-public class ChoiceInput {
-    public static <T> BiFunction<ServerPlayer, T, CompletableFuture<T>> createDialogOpener(MenuType<?> screen, Component title, Function<T, GuiDisplay> displayFunction, T[] values, @Nullable T fallback) {
-        return (player, object) -> {
-            CompletableFuture<T> future = new CompletableFuture<>();
-
-            SimpleGui gui = new SimpleGui(screen, player, false) {
-                @Override
-                public void onPlayerClose(boolean success) {
-                    if(fallback == null) {
-                        future.cancel(false);
-                    } else {
-                        future.complete(fallback);
-                    }
-                }
-            };
-
-            gui.setTitle(title);
-
-            for(T value : values) {
-                gui.addSlot(new GuiElementBuilder(displayFunction.apply(value).createItemStack())
-                        .setCallback(() -> future.complete(value))
-                );
-            }
-            gui.open();
-            return future;
-        };
-    }
-
-    public static <T extends Displayable> BiFunction<ServerPlayer, T, CompletableFuture<T>> createDialogOpener(T[] values) {
-        return createDialogOpener(MenuType.GENERIC_9x3, Component.empty(), t -> t != null ? t.getDisplay() : null, values, null);
-    }
-
-    public static CompletableFuture<Void> confirm(ServerPlayer player, Component title) {
-        CompletableFuture<Void> future = new CompletableFuture<>();
-
-        SimpleGui gui = new SimpleGui(MenuType.GENERIC_3x3, player, false) {
-            @Override
-            public void onPlayerClose(boolean success) {
-                future.cancel(false);
-            }
-        };
-
-        gui.setTitle(title);
-
-        gui.setSlot(3, new GuiElementBuilder(Items.REDSTONE_BLOCK)
-                .setName(Component.translatable("minions.gui.abort"))
-                .setCallback(() -> future.cancel(false))
-        );
-
-        gui.setSlot(5, new GuiElementBuilder(Items.EMERALD_BLOCK)
-                .setName(Component.translatable("minions.gui.confirm"))
-                .setCallback(() -> future.complete(null))
-        );
-
-        gui.open();
-        return future;
-    }
-
-    public static CompletableFuture<Boolean> confirm(MinionsGui parent, Component title) {
-        CompletableFuture<Boolean> future = new CompletableFuture<>();
-
-        new SimpleMinionsGui(parent, (onClose, me) -> {
-            SimpleGui gui = new SimpleGui(MenuType.GENERIC_3x3, parent.getViewer(), false) {
-                @Override
-                public void onPlayerClose(boolean success) {
-                    future.complete(false);
-                    onClose.run();
-                }
-            };
-
-            gui.setTitle(title);
-
-            gui.setSlot(3, new GuiElementBuilder(Items.REDSTONE_BLOCK)
-                    .setName(Component.translatable("minions.gui.abort"))
-                    .setCallback(() -> {
-                        future.complete(false);
-                        me.goBack();
-                    })
-            );
-
-            gui.setSlot(5, new GuiElementBuilder(Items.EMERALD_BLOCK)
-                    .setName(Component.translatable("minions.gui.confirm"))
-                    .setCallback(() -> {
-                        future.complete(true);
-                        me.goBack();
-                    })
-            );
-
-            gui.open();
-            return gui;
-        });
-        return future;
-    }
-
-    public static BiFunction<ServerPlayer, Boolean, CompletableFuture<Boolean>> inputBoolean(Component title) {
-        return createDialogOpener(MenuType.GENERIC_3x3, title, value -> {
-            if(value) {
-                return new GuiDisplay.ItemBased(Items.EMERALD_BLOCK);
-            } else {
-                return new GuiDisplay.ItemBased(Items.REDSTONE_BLOCK);
-            }
-        }, new Boolean[]{false, true}, false);
-    }
-}

src/main/java/io/github/skippyall/minions/gui/input/Result.java

@@ -1,14 +1,13 @@
 package io.github.skippyall.minions.gui.input;
 
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
-public interface Result<T, E> {
+public sealed interface Result<T, E> permits Result.Success, Result.Error {
     static <T> Result<T, String> wrap(UnsafeOperation<T> toWrap) {
         return wrapCustomError(toWrap, Exception::getMessage);
     }
@@ -27,7 +26,7 @@ public interface Result<T, E> {
 
     static <T, E> Result<T, E> ofNullable(@Nullable T value, E error) {
         if(value != null) {
-            return new Success<>(value);
+            return new Success<T, E>(value);
         } else {
             return new Error<>(error);
         }
@@ -35,7 +34,7 @@ public interface Result<T, E> {
 
     static <T, E> Result<T, E> ofNullable(@Nullable T value, Supplier<E> error) {
         if(value != null) {
-            return new Success<>(value);
+            return new Success<T, E>(value);
         } else {
             return new Error<>(error.get());
         }
@@ -49,13 +48,13 @@ public interface Result<T, E> {
 
     E getErrorOrThrow();
 
-    @NotNull Optional<T> getOptional();
+    Optional<T> getOptional();
 
-    @NotNull Optional<E> getOptionalError();
+    Optional<E> getOptionalError();
 
-    void ifSuccess(@NotNull Consumer<T> handler);
+    void ifSuccess(Consumer<T> handler);
 
-    void ifError(@NotNull Consumer<Error<T, E>> handler);
+    void ifError(Consumer<Error<T, E>> handler);
 
     <U> Result<U,E> map(Function<T, U> mapper);
 
@@ -75,7 +74,7 @@ public interface Result<T, E> {
         }
 
         @Override
-        public @NotNull Optional<E> getOptionalError() {
+        public Optional<E> getOptionalError() {
             return Optional.empty();
         }
 
@@ -90,17 +89,17 @@ public interface Result<T, E> {
         }
 
         @Override
-        public @NotNull Optional<T> getOptional() {
+        public Optional<T> getOptional() {
             return Optional.ofNullable(result);
         }
 
         @Override
-        public void ifSuccess(@NotNull Consumer<T> handler) {
+        public void ifSuccess(Consumer<T> handler) {
             handler.accept(result);
         }
 
         @Override
-        public void ifError(@NotNull Consumer<Error<T, E>> handler) {
+        public void ifError(Consumer<Error<T, E>> handler) {
 
         }
 
@@ -143,22 +142,22 @@ public interface Result<T, E> {
         }
 
         @Override
-        public @NotNull Optional<T> getOptional() {
+        public Optional<T> getOptional() {
             return Optional.empty();
         }
 
         @Override
-        public @NotNull Optional<E> getOptionalError() {
+        public Optional<E> getOptionalError() {
             return Optional.ofNullable(message);
         }
 
         @Override
-        public void ifSuccess(@NotNull Consumer<T> handler) {
+        public void ifSuccess(Consumer<T> handler) {
 
         }
 
         @Override
-        public void ifError(@NotNull Consumer<Error<T, E>> handler) {
+        public void ifError(Consumer<Error<T, E>> handler) {
             handler.accept(this);
         }
 

src/main/java/io/github/skippyall/minions/gui/input/TextInput.java

@@ -1,125 +0,0 @@
-package io.github.skippyall.minions.gui.input;
-
-import eu.pb4.sgui.api.elements.GuiElementBuilder;
-import eu.pb4.sgui.api.gui.AnvilInputGui;
-import io.github.skippyall.minions.gui.MinionsGui;
-import io.github.skippyall.minions.gui.minion.SimpleMinionsGui;
-import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.inventory.AnvilMenu;
-import net.minecraft.world.item.Items;
-
-import java.util.concurrent.CompletableFuture;
-import java.util.function.Function;
-
-public class TextInput<T> extends AnvilInputGui {
-    private final GuiElementBuilder valid = new GuiElementBuilder()
-            .setItem(Items.EMERALD_BLOCK)
-            .setName(Component.literal("OK"))
-            .setCallback(this::onConfirm);
-
-    private final GuiElementBuilder invalid = new GuiElementBuilder()
-            .setItem(Items.REDSTONE_BLOCK);
-    private final Function<String, CompletableFuture<Result<T, Component>>> parser;
-    private final CompletableFuture<T> future;
-    private Result<T, Component> result;
-    private boolean isConfirm;
-
-    public TextInput(ServerPlayer player, Component title, String defaultValue, Function<String, CompletableFuture<Result<T, Component>>> parser, CompletableFuture<T> future) {
-        super(player, false);
-        setTitle(title);
-        setDefaultInputValue(defaultValue);
-        this.parser = parser;
-        this.future = future;
-
-        updateConfirmButton(defaultValue);
-    }
-
-    public static <T> CompletableFuture<T> inputSync(ServerPlayer player, Component title, String defaultValue, Function<String, Result<T, Component>> parser) {
-        return input(player, title, defaultValue, (String string) -> CompletableFuture.completedFuture(parser.apply(string)));
-    }
-
-    public static <T> CompletableFuture<T> inputSync(MinionsGui gui, Component title, String defaultValue, Function<String, Result<T, Component>> parser) {
-        return input(gui, title, defaultValue, (String string) -> CompletableFuture.completedFuture(parser.apply(string)));
-    }
-
-    public static <T> CompletableFuture<T> input(ServerPlayer player, Component title, String defaultValue, Function<String, CompletableFuture<Result<T, Component>>> parser) {
-        CompletableFuture<T> future = new CompletableFuture<>();
-        new TextInput<>(player, title, defaultValue, parser, future).open();
-        return future;
-    }
-
-    public static <T> CompletableFuture<T> input(MinionsGui gui, Component title, String defaultValue, Function<String, CompletableFuture<Result<T, Component>>> parser) {
-        CompletableFuture<T> future = new CompletableFuture<>();
-        new SimpleMinionsGui(gui, (onClose, me) -> {
-            TextInput<T> input = new TextInput<>(gui.getViewer(), title, defaultValue, parser, future);
-            future.whenComplete((v, e) -> {
-                if(e != null) {
-                    onClose.run();
-                } else {
-                    me.goBack();
-                }
-            });
-            input.open();
-            return input;
-        });
-        return future;
-    }
-
-    public static CompletableFuture<String> inputString(ServerPlayer player, Component title, String defaultValue) {
-        return inputSync(player, title, defaultValue, Result.Success::new);
-    }
-
-    public static CompletableFuture<String> inputString(MinionsGui gui, Component title, String defaultValue) {
-        return inputSync(gui, title, defaultValue, Result.Success::new);
-    }
-
-    public static CompletableFuture<Long> inputLong(ServerPlayer player, Component title, String defaultValue) {
-        return inputSync(player, title, defaultValue, string -> Result.wrapCustomError(() -> Long.valueOf(string), Component.translatable("minions.command.input.int.fail")));
-    }
-
-    public static CompletableFuture<Long> inputLong(MinionsGui gui, Component title, String defaultValue) {
-        return inputSync(gui, title, defaultValue, string -> Result.wrapCustomError(() -> Long.valueOf(string), Component.translatable("minions.command.input.int.fail")));
-    }
-
-    public static CompletableFuture<Double> inputDouble(ServerPlayer player, Component title, String defaultValue) {
-        return inputSync(player, title, defaultValue, string -> Result.wrapCustomError(() -> Double.valueOf(string), Component.translatable("minions.command.input.float.fail")));
-    }
-
-    public static CompletableFuture<Double> inputDouble(MinionsGui gui, Component title, String defaultValue) {
-        return inputSync(gui, title, defaultValue, string -> Result.wrapCustomError(() -> Double.valueOf(string), Component.translatable("minions.command.input.float.fail")));
-    }
-
-    @Override
-    public void onInput(String input) {
-        updateConfirmButton(input);
-    }
-
-    public void updateConfirmButton(String input) {
-        parser.apply(input).thenAccept(result -> {
-            this.result = result;
-            if(result.isSuccess()) {
-                setSlot(AnvilMenu.RESULT_SLOT, valid);
-            } else {
-                Component text = result.getErrorOrThrow();
-                setSlot(AnvilMenu.RESULT_SLOT, invalid.setName(text));
-            }
-        });
-    }
-
-    @Override
-    public void onPlayerClose(boolean success) {
-        if(!future.isDone() && !isConfirm) {
-            future.cancel(false);
-        }
-    }
-
-    public void onConfirm() {
-        if(result != null) {
-            result.ifSuccess(success -> {
-                isConfirm = true;
-                future.complete(success);
-            });
-        }
-    }
-}

src/main/java/io/github/skippyall/minions/gui/input/TextInput.kt

@@ -0,0 +1,149 @@
+package io.github.skippyall.minions.gui.input
+
+import eu.pb4.sgui.api.elements.GuiElementBuilder
+import eu.pb4.sgui.api.gui.AnvilInputGui
+import io.github.skippyall.minions.gui.MinionsGui
+import kotlinx.coroutines.launch
+import net.minecraft.network.chat.Component
+import net.minecraft.world.inventory.AnvilMenu
+import net.minecraft.world.item.Items
+import java.util.concurrent.CompletableFuture
+
+class TextInput<T : Any>(
+    parent: MinionsGui,
+    val title: Component,
+    val defaultValue: String,
+    val parser: suspend (String) -> Result<T, Component>
+) : MinionsGui(parent) {
+    private val valid: GuiElementBuilder = GuiElementBuilder()
+        .setItem(Items.EMERALD_BLOCK)
+        .setName(Component.literal("OK"))
+        .setCallback(Runnable { this.onConfirm() })
+
+    private val invalid: GuiElementBuilder = GuiElementBuilder()
+        .setItem(Items.REDSTONE_BLOCK)
+
+    private lateinit var gui: AnvilInputGui
+
+    private var result: Result<T, Component>? = null
+    val future = CompletableFuture<T?>()
+
+    init {
+        open()
+    }
+
+    override fun open() {
+        gui = object : AnvilInputGui(viewer, false) {
+            override fun onInput(input: String) {
+                updateConfirmButton(input)
+            }
+
+            override fun onPlayerClose(success: Boolean) {
+                onBackingClosed()
+                if (!future.isDone) {
+                    future.complete(null)
+                }
+            }
+        }
+
+        gui.setTitle(title)
+        gui.setDefaultInputValue(defaultValue)
+        updateConfirmButton(defaultValue)
+        gui.open()
+    }
+
+    override fun closeBacking() {
+        gui.close()
+    }
+
+    fun updateConfirmButton(input: String) {
+        scope.launch {
+            val result = parser(input)
+            this@TextInput.result = result
+            if (result.isSuccess()) {
+                gui.setSlot(AnvilMenu.RESULT_SLOT, valid)
+            } else {
+                val text = result.getErrorOrThrow()
+                gui.setSlot(AnvilMenu.RESULT_SLOT, invalid.setName(text))
+            }
+        }
+    }
+
+    fun onConfirm() {
+        result?.ifSuccess { success: T ->
+            future.complete(success)
+            goBack()
+        }
+    }
+
+    companion object {
+        @JvmStatic
+        fun <T : Any>input(
+            gui: MinionsGui,
+            title: Component,
+            defaultValue: String,
+            parser: suspend (String) -> Result<T, Component>,
+        ): CompletableFuture<T?> {
+            val input = TextInput(
+                parent = gui,
+                title = title,
+                defaultValue = defaultValue,
+                parser = parser,
+            )
+
+            return input.future
+        }
+
+        @JvmStatic
+        fun inputString(
+            gui: MinionsGui,
+            title: Component,
+            defaultValue: String,
+        ): CompletableFuture<String?> {
+            return input<String>(
+                gui = gui,
+                title = title,
+                defaultValue = defaultValue,
+                parser = { result -> Result.Success(result) },
+            )
+        }
+
+        @JvmStatic
+        fun inputLong(
+            gui: MinionsGui,
+            title: Component,
+            defaultValue: Long,
+        ): CompletableFuture<Long?> {
+            return input<Long>(
+                gui = gui,
+                title = title,
+                defaultValue = defaultValue.toString(),
+                parser = { string ->
+                    Result.wrapCustomError<Long, Component>(
+                        { string.toLong() },
+                        Component.translatable("value_type.minions.long.not_long")
+                    )
+                },
+            )
+        }
+
+        @JvmStatic
+        fun inputDouble(
+            gui: MinionsGui,
+            title: Component,
+            defaultValue: Double,
+        ): CompletableFuture<Double?> {
+            return input<Double>(
+                gui = gui,
+                title = title,
+                defaultValue = defaultValue.toString(),
+                parser = { string ->
+                    Result.wrapCustomError<Double, Component>(
+                        { string.toDouble() },
+                        Component.translatable("value_type.minions.long.not_long")
+                    )
+                },
+            )
+        }
+    }
+}

src/main/java/io/github/skippyall/minions/gui/input/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.gui.input;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/gui/instruction/ArgumentGui.java

@@ -7,7 +7,6 @@ import io.github.skippyall.minions.gui.MinionsGui;
 import io.github.skippyall.minions.gui.PaginatedList;
 import io.github.skippyall.minions.gui.minion.GuiContext;
 import io.github.skippyall.minions.minion.MinionRuntime;
-import io.github.skippyall.minions.minion.fakeplayer.MinionFakePlayer;
 import io.github.skippyall.minions.program.instruction.ConfiguredInstruction;
 import io.github.skippyall.minions.program.supplier.Parameter;
 import io.github.skippyall.minions.program.supplier.ValueSupplier;
@@ -19,7 +18,7 @@ import net.minecraft.network.chat.Component;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.Items;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 public class ArgumentGui extends MinionsGui {
     private final GuiContext.ValueSupplier context;
@@ -29,7 +28,7 @@ public class ArgumentGui extends MinionsGui {
     private SimpleGui gui;
 
     private @Nullable ValueSupplierType<MinionRuntime> argumentType;
-    private @Nullable ValueSupplierList.ValueSupplierEntry<?, MinionRuntime> entry;
+    private ValueSupplierList. @Nullable ValueSupplierEntry<?, MinionRuntime> entry;
 
     public ArgumentGui(MinionsGui parent, GuiContext.ValueSupplier context) {
         super(parent);
@@ -38,9 +37,7 @@ public class ArgumentGui extends MinionsGui {
         this.context = context;
 
         this.entry = instruction.getArguments().getEntry(parameter);
-        if(entry != null) {
         this.argumentType = entry.getSupplier().getType();
-        }
         open();
     }
 

src/main/java/io/github/skippyall/minions/gui/instruction/ConfigureInstructionGui.java

@@ -4,7 +4,7 @@ import eu.pb4.sgui.api.elements.GuiElementBuilder;
 import eu.pb4.sgui.api.gui.SimpleGui;
 import io.github.skippyall.minions.clipboard.ClipboardItem;
 import io.github.skippyall.minions.gui.MinionsGui;
-import io.github.skippyall.minions.gui.input.ChoiceInput;
+import io.github.skippyall.minions.gui.input.BooleanInput;
 import io.github.skippyall.minions.gui.minion.GuiContext;
 import io.github.skippyall.minions.minion.MinionListener;
 import io.github.skippyall.minions.minion.MinionRuntime;
@@ -19,6 +19,8 @@ import net.minecraft.sounds.SoundSource;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.item.Items;
 
+import java.util.List;
+
 public class ConfigureInstructionGui extends MinionsGui implements ConfiguredInstructionListener, MinionListener {
     private String name;
     private final ConfiguredInstruction<MinionRuntime> instruction;
@@ -53,14 +55,16 @@ public class ConfigureInstructionGui extends MinionsGui implements ConfiguredIns
         gui.setSlot(6, new GuiElementBuilder(Items.ANVIL)
                 .setName(Component.translatable("minions.gui.instruction.configure.rename"))
                 .setCallback(() -> InstructionGui.inputInstructionName(this, context, name).thenAccept(newName -> {
+                    if(newName != null) {
                         minion.getInstructionManager().setInstructionName(name, newName);
+                    }
                     reopen();
                 }))
         );
 
         gui.setSlot(7, new GuiElementBuilder(Items.LAVA_BUCKET)
                 .setName(Component.translatable("minions.gui.instruction.configure.delete"))
-                .setCallback(() -> ChoiceInput.confirm(this, Component.translatable("minions.gui.instruction.configure.delete.confirm", name))
+                .setCallback(() -> BooleanInput.confirm(this, Component.translatable("minions.gui.instruction.configure.delete.confirm", name))
                         .thenAccept((confirmed) -> {
                             if(confirmed) {
                                 minion.getInstructionManager().removeInstruction(name);
@@ -84,6 +88,7 @@ public class ConfigureInstructionGui extends MinionsGui implements ConfiguredIns
                 })
         );
 
+        updateLastError();
         updateRunSlot();
         gui.open();
     }
@@ -105,6 +110,7 @@ public class ConfigureInstructionGui extends MinionsGui implements ConfiguredIns
     @Override
     public void onRun(ConfiguredInstruction<?> instruction) {
         updateRunSlot();
+        updateLastError();
     }
 
     @Override
@@ -118,6 +124,8 @@ public class ConfigureInstructionGui extends MinionsGui implements ConfiguredIns
     }
 
     private void updateRunSlot() {
+        List<Component> errors = instruction.preCheck();
+        if(errors.isEmpty()) {
             if (!instruction.isRunning()) {
                 gui.setSlot(26, new GuiElementBuilder(Items.ARROW)
                         .setName(Component.translatable("minions.gui.instruction.run"))
@@ -129,6 +137,26 @@ public class ConfigureInstructionGui extends MinionsGui implements ConfiguredIns
                         .setCallback(() -> instruction.stop(minion.getInstructionManager()))
                 );
             }
+        } else {
+            GuiElementBuilder builder = new GuiElementBuilder(Items.RED_WOOL)
+                    .setName(Component.translatable("minions.gui.instruction.errors"));
+            for(Component error : errors) {
+                builder.addLoreLine(error);
+            }
+            gui.setSlot(26, builder);
+        }
+    }
+
+    private void updateLastError() {
+        List<Component> errors = instruction.getLastErrors();
+        if(!errors.isEmpty()) {
+            GuiElementBuilder builder = new GuiElementBuilder(Items.RED_WOOL)
+                    .setName(Component.translatable("minions.gui.instruction.last_errors"));
+            for(Component error : errors) {
+                builder.addLoreLine(error);
+            }
+            gui.setSlot(17, builder);
+        }
     }
 
     private void updateSuppliers() {

src/main/java/io/github/skippyall/minions/gui/instruction/ConverterGui.java

@@ -14,7 +14,7 @@ import net.minecraft.core.RegistryAccess;
 import net.minecraft.network.chat.Component;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.item.Items;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 public class ConverterGui extends MinionsGui {
     private @Nullable ValueConverterType<?> valueConverterType;
@@ -28,7 +28,6 @@ public class ConverterGui extends MinionsGui {
 
     public ConverterGui(MinionsGui parent, @Nullable ValueConverter<?,?> converter, ValueType<?> from, ValueType<?> to, ConverterList list, boolean isNew, int index) {
         super(parent);
-        open();
         this.converter = converter;
         if(converter != null) {
             this.valueConverterType = converter.getType();
@@ -38,6 +37,8 @@ public class ConverterGui extends MinionsGui {
         this.list = list;
         this.isNew = isNew;
         this.index = index;
+
+        open();
     }
 
     @Override

src/main/java/io/github/skippyall/minions/gui/instruction/ConverterListGui.java

@@ -12,6 +12,7 @@ import io.github.skippyall.minions.util.TranslationUtil;
 import net.minecraft.network.chat.Component;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.item.Items;
+import org.jspecify.annotations.Nullable;
 
 public class ConverterListGui extends MinionsGui {
     private ConverterList converters;
@@ -54,53 +55,121 @@ public class ConverterListGui extends MinionsGui {
 
         gui.setSlot(23, new GuiElementBuilder(Items.ARROW)
                 .setCallback(() -> {
-                    if(page * 4 + 4 < converters.getConverters().size()) {
+                    if(page * 4 + 4 < converters.getConverters().size() + 1) {
                         page++;
                         updateConverters();
                     }
                 })
         );
 
-        gui.setSlot(8, backButton());
+        gui.setSlot(26, backButton());
 
         gui.open();
     }
 
+    private ValueType<?> getInputTypeOfConverter(int converterIndex) {
+        if(converterIndex < converters.getConverters().size() && converterIndex >= 0) {
+            return converters.getConverters().get(converterIndex).getFrom();
+        } else if(converterIndex == converters.getConverters().size()) {
+            return outputType;
+        } else {
+            throw new IndexOutOfBoundsException("Can't get input type of converter " + converterIndex + ", list size " + converters.getConverters().size());
+        }
+    }
+
+    private ValueType<?> getOutputTypeOfConverter(int converterIndex) {
+        if(converterIndex < converters.getConverters().size() && converterIndex >= 0) {
+            return converters.getConverters().get(converterIndex).getTo();
+        } else if(converterIndex == -1) {
+            return inputType;
+        } else {
+            throw new IndexOutOfBoundsException("Can't get output type of converter " + converterIndex + ", list size " + converters.getConverters().size());
+        }
+    }
+
     public void updateConverters() {
+        for(int slot = 0; slot < 18; slot++) {
+            gui.clearSlot(slot);
+        }
+
         int lastConverter = Math.min(5, converters.getConverters().size() + 2 - page * 4);
         for(int i = 0; i < lastConverter; i++) {
             //Each page has 5 converters, but the last is displayed on the next page as well
-            int converterIndex = page * 4 + i;
-            //without input element
-            int actualConverterIndex = converterIndex - 1;
+            //The input element index is -1, the output element index is the list size
+            int converterIndex = page * 4 + i - 1;
             int slot = 9 + 2 * i;
-            if(converterIndex == 0) {
-                gui.setSlot(slot, new GuiElementBuilder(Items.DROPPER));
-            } else if(converterIndex == converters.getConverters().size() + 1) {
+
+            if(converterIndex == converters.getConverters().size()) {
                 gui.setSlot(slot, new GuiElementBuilder(Items.HOPPER));
             } else {
-                ValueConverter<?, ?> converter = converters.getConverters().get(actualConverterIndex);
-                ValueType<?> fromType = actualConverterIndex >= 1 ? converters.getConverters().get(actualConverterIndex - 1).getTo() : inputType;
-                ValueType<?> toType = actualConverterIndex < converters.getConverters().size() - 1 ? converters.getConverters().get(actualConverterIndex + 1).getFrom() : outputType;
+                ValueType<?> thisConverterOutput = getOutputTypeOfConverter(converterIndex);
+                ValueType<?> nextConverterInput = getInputTypeOfConverter(converterIndex + 1);
 
-                gui.setSlot(slot, new GuiElementBuilder(GuiDisplay.getDisplayStackWithName(MinionRegistries.VALUE_CONVERTER_TYPES, converter.getType(), viewer.registryAccess()))
-                        .addLoreLine(converter.getDisplayText())
-                        .setCallback(() -> new ConverterGui(this, converter, fromType, toType, converters, false, actualConverterIndex))
-                );
+                //What should be shown at the converter's slot
+                if (converterIndex == -1) {
+                    gui.setSlot(slot, new GuiElementBuilder(Items.DROPPER));
+                } else {
+                    ValueType<?> previousConverterOutput = getOutputTypeOfConverter(converterIndex - 1);
+
+                    ValueConverter<?, ?> converter = converters.getConverters().get(converterIndex);
+                    gui.setSlot(slot, createConverterDisplay(converter, previousConverterOutput, nextConverterInput, converterIndex));
+
+                    GuiElementBuilder warning = createConverterWarning(converter);
+                    if (warning != null) {
+                        gui.setSlot(slot - 8, warning);
+                    }
                 }
-            if(i != 4 && actualConverterIndex != converters.getConverters().size()) {
-                ValueType<?> fromType = actualConverterIndex >= 0 ? converters.getConverters().get(actualConverterIndex).getTo() : inputType;
-                ValueType<?> toType = actualConverterIndex < converters.getConverters().size() - 1 ? converters.getConverters().get(actualConverterIndex + 1).getFrom() : outputType;
 
-                gui.setSlot(slot + 1, new GuiElementBuilder(Items.MAGENTA_GLAZED_TERRACOTTA)
+                //show cast in the next slot
+                if (i != 4 && converterIndex != converters.getConverters().size()) {
+                    gui.setSlot(slot + 1, createCastDisplay(thisConverterOutput, nextConverterInput, converterIndex + 1));
+
+                    GuiElementBuilder warning = createCastWarning(thisConverterOutput, nextConverterInput);
+                    if (warning != null) {
+                        gui.setSlot(slot - 8, warning);
+                    }
+                }
+            }
+        }
+    }
+
+    private GuiElementBuilder createConverterDisplay(ValueConverter<?, ?> converter, ValueType<?> fromType, ValueType<?> toType, int converterIndex) {
+        return new GuiElementBuilder(GuiDisplay.getDisplayStackWithName(MinionRegistries.VALUE_CONVERTER_TYPES, converter.getType(), viewer.registryAccess()))
+                .addLoreLine(converter.getDisplayText())
+                .setCallback(() -> new ConverterGui(this, converter, fromType, toType, converters, false, converterIndex));
+    }
+
+    private GuiElementBuilder createCastDisplay(ValueType<?> fromType, ValueType<?> toType, int newConverterIndex) {
+        return new GuiElementBuilder(Items.MAGENTA_GLAZED_TERRACOTTA)
                 .setName(Component.translatable(
                         "minions.gui.instruction.converters.cast",
                         Component.translatable(TranslationUtil.getTranslationKey(fromType, MinionRegistries.VALUE_TYPES)),
                         Component.translatable(TranslationUtil.getTranslationKey(toType, MinionRegistries.VALUE_TYPES))
                 ))
-                        .setCallback(() -> new ConverterGui(this, null, fromType, toType, converters, true, actualConverterIndex + 1))
-                );
+                .setCallback(() -> new ConverterGui(this, null, fromType, toType, converters, true, newConverterIndex));
     }
+
+    private @Nullable GuiElementBuilder createCastWarning(ValueType<?> fromType, ValueType<?> toType) {
+        Component warning = ConverterList.createCastWarning(fromType, toType);
+
+        if(warning != null) {
+            return new GuiElementBuilder(Items.RED_BANNER)
+                    .setName(Component.translatable("minions.generic.error"))
+                    .addLoreLine(warning);
+        } else {
+            return null;
+        }
+    }
+
+    private @Nullable GuiElementBuilder createConverterWarning(ValueConverter<?,?> converter) {
+        Component warning = ConverterList.createConverterWarning(converter);
+
+        if(warning != null) {
+            return new GuiElementBuilder(Items.RED_BANNER)
+                    .setName(Component.translatable("minions.generic.error"))
+                    .addLoreLine(warning);
+        } else {
+            return null;
         }
     }
 

src/main/java/io/github/skippyall/minions/gui/instruction/InstructionGui.java

@@ -24,7 +24,7 @@ import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.Items;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 import java.util.NoSuchElementException;
 import java.util.concurrent.CompletableFuture;
@@ -32,7 +32,7 @@ import java.util.concurrent.CompletableFuture;
 public class InstructionGui {
     public static void openInstructionMainMenu(MinionsGui parent, GuiContext.Minion context) {
         new SimpleMinionsGui(parent, (onClose, me) -> {
-            ServerPlayer player = parent.getViewer();
+            ServerPlayer player = parent.viewer;
 
             SimpleGui gui = new SimpleGui(MenuType.GENERIC_3x3, player, false) {
                 @Override
@@ -61,10 +61,10 @@ public class InstructionGui {
 
     public static void createNewInstruction(MinionsGui parent, GuiContext.Minion context) {
         MinionFakePlayer minion = context.getMinion();
-        ServerPlayer viewer = parent.getViewer();
+        ServerPlayer viewer = parent.viewer;
         selectInstructionModuleMenu(parent, context).thenAccept(instructionType ->
                 inputInstructionName(parent, context, "Instruction").thenAccept(name -> {
-                    if (!minion.isRemoved() && !minion.hasDisconnected()) {
+                    if (!minion.isRemoved() && !minion.hasDisconnected() && name != null) {
                         ConfiguredInstruction<MinionRuntime> configuredInstruction = minion.getInstructionManager().createInstruction(name, instructionType);
                         new ConfigureInstructionGui(parent, GuiContext.Instruction.create(context, configuredInstruction, name));
                     }
@@ -72,8 +72,8 @@ public class InstructionGui {
         );
     }
 
-    public static CompletableFuture<String> inputInstructionName(MinionsGui parent, GuiContext.Minion context, String defaultValue) {
-        return TextInput.inputSync(parent, Component.translatable("minions.gui.instruction.enter_name"), defaultValue, name -> {
+    public static CompletableFuture<@Nullable String> inputInstructionName(MinionsGui parent, GuiContext.Minion context, String defaultValue) {
+        return TextInput.input(parent, Component.translatable("minions.gui.instruction.enter_name"), defaultValue, (name, _) -> {
             if (context.getMinion().getInstructionManager().hasInstruction(name)) {
                 return new Result.Error<>(Component.translatable("minions.gui.instruction.name_already_used"));
             }
@@ -92,7 +92,7 @@ public class InstructionGui {
 
     public static CompletableFuture<InstructionType<MinionRuntime>> selectInstructionModuleMenu(MinionsGui parent, GuiContext.Minion context) {
         MinionFakePlayer minion = context.getMinion();
-        ServerPlayer viewer = parent.getViewer();
+        ServerPlayer viewer = parent.viewer;
 
         if (minion.getModuleInventory().getModules().isEmpty()) {
             viewer.sendSystemMessage(Component.translatable("minions.gui.instruction.no_modules"));
@@ -137,7 +137,7 @@ public class InstructionGui {
         CompletableFuture<InstructionType<MinionRuntime>> future = new CompletableFuture<>();
 
         new SimpleMinionsGui(parent, (closeHandler, me) -> {
-            SimpleGui gui = new SimpleGui(MenuType.GENERIC_9x4, parent.getViewer(), false) {
+            SimpleGui gui = new SimpleGui(MenuType.GENERIC_9x4, parent.viewer, false) {
                 @Override
                 public void onPlayerClose(boolean success) {
                     if (!future.isDone()) {
@@ -151,7 +151,7 @@ public class InstructionGui {
             gui.setSlot(8, me.backButton());
             int slot = 9;
             for (InstructionType<MinionRuntime> instructionType : module.instructions()) {
-                gui.setSlot(slot, createInstructionElement(instructionType, parent.getViewer().registryAccess())
+                gui.setSlot(slot, createInstructionElement(instructionType, parent.viewer.registryAccess())
                         .setCallback(() -> future.complete(instructionType))
                 );
                 slot++;
@@ -163,7 +163,7 @@ public class InstructionGui {
         return future;
     }
 
-    public static GuiElementBuilder createInstructionElement(InstructionType<MinionRuntime> instructionType, RegistryAccess manager) {
+    public static GuiElementBuilder createInstructionElement(@Nullable InstructionType<MinionRuntime> instructionType, RegistryAccess manager) {
         GuiElementBuilder instructionBuilder;
         if (instructionType != null) {
             instructionBuilder = new GuiElementBuilder(GuiDisplay.getDisplayStackWithName(MinionRegistries.INSTRUCTION_TYPES, instructionType, manager));

src/main/java/io/github/skippyall/minions/gui/instruction/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.gui.instruction;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/gui/minion/GuiContext.java

@@ -1,43 +0,0 @@
-package io.github.skippyall.minions.gui.minion;
-
-import io.github.skippyall.minions.minion.MinionRuntime;
-import io.github.skippyall.minions.minion.fakeplayer.MinionFakePlayer;
-import io.github.skippyall.minions.program.instruction.ConfiguredInstruction;
-import io.github.skippyall.minions.program.supplier.Parameter;
-import net.minecraft.server.level.ServerPlayer;
-
-public interface GuiContext {
-    ServerPlayer getViewer();
-
-    static GuiContext create(ServerPlayer viewer) {
-        return new GuiContextImpl(viewer);
-    }
-
-    interface Minion extends GuiContext {
-        MinionFakePlayer getMinion();
-
-        static GuiContext.Minion create(GuiContext context, MinionFakePlayer minion) {
-            return new GuiContextImpl.MinionImpl(context, minion);
-        }
-    }
-
-    interface Instruction extends Minion {
-        ConfiguredInstruction<MinionRuntime> getInstruction();
-
-        String getName();
-
-        void setName(String name);
-
-        static GuiContext.Instruction create(GuiContext.Minion context, ConfiguredInstruction<MinionRuntime> instruction, String name) {
-            return new GuiContextImpl.InstructionImpl(context, instruction, name);
-        }
-    }
-
-    interface ValueSupplier extends Instruction {
-        Parameter<?> getParameter();
-
-        static GuiContext.ValueSupplier create(GuiContext.Instruction context, Parameter<?> parameter) {
-            return new GuiContextImpl.ValueSupplierImpl(context, parameter);
-        }
-    }
-}

src/main/java/io/github/skippyall/minions/gui/minion/GuiContext.kt

@@ -0,0 +1,66 @@
+package io.github.skippyall.minions.gui.minion
+
+import io.github.skippyall.minions.gui.minion.GuiContextImpl.InstructionImpl
+import io.github.skippyall.minions.gui.minion.GuiContextImpl.MinionImpl
+import io.github.skippyall.minions.gui.minion.GuiContextImpl.ValueSupplierImpl
+import io.github.skippyall.minions.minion.MinionRuntime
+import io.github.skippyall.minions.minion.fakeplayer.MinionFakePlayer
+import io.github.skippyall.minions.program.instruction.ConfiguredInstruction
+import io.github.skippyall.minions.program.supplier.Parameter
+import net.minecraft.server.level.ServerPlayer
+
+interface GuiContext {
+    val viewer: ServerPlayer
+
+    companion object {
+        @JvmStatic
+        fun create(viewer: ServerPlayer): GuiContext {
+            return GuiContextImpl(viewer)
+        }
+    }
+
+    interface Minion : GuiContext {
+        val minion: MinionFakePlayer
+
+        companion object {
+            @JvmStatic
+            fun create(context: GuiContext, minion: MinionFakePlayer): Minion {
+                return MinionImpl(
+                    if(context is MinionImpl) context.context else context,
+                    minion
+                )
+            }
+        }
+    }
+
+    interface Instruction : Minion {
+        val instruction: ConfiguredInstruction<MinionRuntime>
+
+        var name: String
+
+        companion object {
+            @JvmStatic
+            fun create(context: Minion, instruction: ConfiguredInstruction<MinionRuntime>, name: String): Instruction {
+                return InstructionImpl(
+                    if(context is InstructionImpl) context.context else context,
+                    instruction,
+                    name
+                )
+            }
+        }
+    }
+
+    interface ValueSupplier : Instruction {
+        val parameter: Parameter<*>
+
+        companion object {
+            @JvmStatic
+            fun create(context: Instruction, parameter: Parameter<*>): ValueSupplier {
+                return ValueSupplierImpl(
+                    if(context is ValueSupplierImpl) context.context else context,
+                    parameter
+                )
+            }
+        }
+    }
+}

src/main/java/io/github/skippyall/minions/gui/minion/GuiContextImpl.java

@@ -1,120 +0,0 @@
-package io.github.skippyall.minions.gui.minion;
-
-import io.github.skippyall.minions.minion.MinionRuntime;
-import io.github.skippyall.minions.minion.fakeplayer.MinionFakePlayer;
-import io.github.skippyall.minions.program.instruction.ConfiguredInstruction;
-import io.github.skippyall.minions.program.supplier.Parameter;
-import net.minecraft.server.level.ServerPlayer;
-
-//If only this mod was kotlin
-public class GuiContextImpl implements GuiContext {
-    private final ServerPlayer viewer;
-
-    public GuiContextImpl(ServerPlayer viewer) {
-        this.viewer = viewer;
-    }
-
-    @Override
-    public ServerPlayer getViewer() {
-        return viewer;
-    }
-
-    public static class MinionImpl extends DelegatingGuiContextImpl<GuiContext> implements GuiContext.Minion {
-        private final MinionFakePlayer minion;
-
-        public MinionImpl(GuiContext context, MinionFakePlayer minion) {
-            super(context instanceof DelegatingGuiContextImpl<?> impl ? impl.context : context);
-            this.minion = minion;
-        }
-
-        @Override
-        public MinionFakePlayer getMinion() {
-            return minion;
-        }
-    }
-
-    public static class InstructionImpl extends DelegatingMinionImpl<GuiContext.Minion> implements GuiContext.Instruction {
-        private final ConfiguredInstruction<MinionRuntime> instruction;
-        private String name;
-
-        public InstructionImpl(GuiContext.Minion context, ConfiguredInstruction<MinionRuntime> instruction, String name) {
-            super(context instanceof DelegatingMinionImpl<?> impl ? impl.context : context);
-            this.instruction = instruction;
-            this.name = name;
-        }
-
-        @Override
-        public ConfiguredInstruction<MinionRuntime> getInstruction() {
-            return instruction;
-        }
-
-        @Override
-        public String getName() {
-            return name;
-        }
-
-        @Override
-        public void setName(String name) {
-            this.name = name;
-        }
-    }
-
-    public static class ValueSupplierImpl extends DelegatingInstructionImpl<GuiContext.Instruction> implements GuiContext.ValueSupplier {
-        private final Parameter<?> parameter;
-
-        public ValueSupplierImpl(GuiContext.Instruction context, Parameter<?> parameter) {
-            super(context instanceof DelegatingInstructionImpl<?> impl ? impl.context : context);
-            this.parameter = parameter;
-        }
-
-        @Override
-        public Parameter<?> getParameter() {
-            return parameter;
-        }
-    }
-
-    public static class DelegatingGuiContextImpl<C extends GuiContext> implements GuiContext {
-        protected final C context;
-
-        public DelegatingGuiContextImpl(C context) {
-            this.context = context;
-        }
-
-        @Override
-        public ServerPlayer getViewer() {
-            return context.getViewer();
-        }
-    }
-
-    public static class DelegatingMinionImpl<C extends GuiContext.Minion> extends DelegatingGuiContextImpl<C> implements GuiContext.Minion {
-        public DelegatingMinionImpl(C context) {
-            super(context);
-        }
-
-        @Override
-        public MinionFakePlayer getMinion() {
-            return context.getMinion();
-        }
-    }
-
-    public static class DelegatingInstructionImpl<C extends GuiContext.Instruction> extends DelegatingMinionImpl<C> implements GuiContext.Instruction {
-        public DelegatingInstructionImpl(C context) {
-            super(context);
-        }
-
-        @Override
-        public ConfiguredInstruction<MinionRuntime> getInstruction() {
-            return context.getInstruction();
-        }
-
-        @Override
-        public String getName() {
-            return context.getName();
-        }
-
-        @Override
-        public void setName(String name) {
-            context.setName(name);
-        }
-    }
-}

src/main/java/io/github/skippyall/minions/gui/minion/GuiContextImpl.kt

@@ -0,0 +1,26 @@
+package io.github.skippyall.minions.gui.minion
+
+import io.github.skippyall.minions.minion.MinionRuntime
+import io.github.skippyall.minions.minion.fakeplayer.MinionFakePlayer
+import io.github.skippyall.minions.program.instruction.ConfiguredInstruction
+import io.github.skippyall.minions.program.supplier.Parameter
+import net.minecraft.server.level.ServerPlayer
+
+//Thank you kotlin
+class GuiContextImpl(override val viewer: ServerPlayer) : GuiContext {
+    class MinionImpl(
+        val context: GuiContext,
+        override val minion: MinionFakePlayer
+    ) : GuiContext by context, GuiContext.Minion
+
+    class InstructionImpl(
+        val context: GuiContext.Minion,
+        override val instruction: ConfiguredInstruction<MinionRuntime>,
+        override var name: String
+    ) : GuiContext.Minion by context, GuiContext.Instruction
+
+    class ValueSupplierImpl(
+        val context: GuiContext.Instruction,
+        override val parameter: Parameter<*>
+    ) : GuiContext.Instruction by context, GuiContext.ValueSupplier
+}

src/main/java/io/github/skippyall/minions/gui/minion/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.gui.minion;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/gui/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.gui;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/listener/BlockEntityMinionListener.java

@@ -13,7 +13,7 @@ import net.minecraft.server.MinecraftServer;
 import net.minecraft.world.level.Level;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.entity.BlockEntityType;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 import java.util.Optional;
 import java.util.UUID;
@@ -45,9 +45,9 @@ public abstract class BlockEntityMinionListener<E extends BlockEntity> implement
         this.minion = null;
     }
 
-    public static <T extends BlockEntityMinionListener<?>> T getListener(Level world, BlockPos pos, UUID minionUuid, Class<T> clazz) {
+    public static <T extends BlockEntityMinionListener<?>> @Nullable T getListener(Level world, BlockPos pos, @Nullable UUID minionUuid, Class<T> clazz) {
         if(minionUuid != null) {
-            for (MinionListener listener : MinionPersistentState.get(world.getServer()).getMinionData(minionUuid).listeners()) {
+            for (MinionListener listener : MinionPersistentState.get(world.getServer()).getMinionData(minionUuid).getListeners()) {
                 if (listener instanceof BlockEntityMinionListener<?> tl && tl.pos.equals(pos) && tl.worldKey.equals(world.dimension()) && clazz.isInstance(tl)) {
                     return clazz.cast(tl);
                 }
@@ -95,13 +95,13 @@ public abstract class BlockEntityMinionListener<E extends BlockEntity> implement
     }
 
     public void add(MinecraftServer server) {
-        MinionPersistentState.get(server).getMinionData(minionUuid).listeners().addListener(this);
+        MinionPersistentState.get(server).getMinionData(minionUuid).getListeners().addListener(this);
         MinionPersistentState.get(server).setDirty();
         this.minion = (MinionFakePlayer) server.getPlayerList().getPlayer(minionUuid);
     }
 
     public void remove(MinecraftServer server) {
-        MinionPersistentState.get(server).getMinionData(minionUuid).listeners().removeListener(this);
+        MinionPersistentState.get(server).getMinionData(minionUuid).getListeners().removeListener(this);
         MinionPersistentState.get(server).setDirty();
     }
 

src/main/java/io/github/skippyall/minions/listener/ListenerManager.java

@@ -1,37 +0,0 @@
-package io.github.skippyall.minions.listener;
-
-import org.jetbrains.annotations.NotNull;
-
-import java.util.Iterator;
-import java.util.Set;
-import java.util.concurrent.CopyOnWriteArraySet;
-
-public class ListenerManager<T> implements Iterable<T> {
-    protected final Set<T> listeners;
-
-    public ListenerManager() {
-        this(new CopyOnWriteArraySet<>());
-    }
-
-    protected ListenerManager(Set<T> listeners) {
-        this.listeners = listeners;
-    }
-
-    public void addListener(T listener) {
-        listeners.add(listener);
-    }
-
-    public void removeListener(T listener) {
-        listeners.remove(listener);
-    }
-
-    @Override
-    public @NotNull Iterator<T> iterator() {
-        return listeners.iterator();
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        return super.equals(obj);
-    }
-}

src/main/java/io/github/skippyall/minions/listener/ListenerManager.kt

@@ -0,0 +1,29 @@
+package io.github.skippyall.minions.listener
+
+import java.util.concurrent.CopyOnWriteArraySet
+
+open class ListenerManager<T>(
+    protected val listeners: MutableSet<T> = CopyOnWriteArraySet(),
+    val onChange: () -> Unit = {},
+) : MutableIterable<T> by listeners {
+
+    fun addListener(listener: T) {
+        listeners.add(listener)
+        onChange()
+    }
+
+    fun removeListener(listener: T) {
+        listeners.remove(listener)
+        onChange()
+    }
+
+    override fun iterator(): MutableIterator<T> {
+        val iterator = listeners.iterator()
+        return object : MutableIterator<T> by iterator {
+            override fun remove() {
+                iterator.remove()
+                onChange()
+            }
+        }
+    }
+}

src/main/java/io/github/skippyall/minions/listener/SerializableListenerManager.java

@@ -1,46 +0,0 @@
-package io.github.skippyall.minions.listener;
-
-import com.mojang.serialization.Codec;
-import com.mojang.serialization.MapCodec;
-import net.minecraft.core.Registry;
-import net.minecraft.resources.Identifier;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Optional;
-import java.util.Set;
-import java.util.concurrent.CopyOnWriteArraySet;
-
-public class SerializableListenerManager<T extends SerializableListenerManager.SerializableListener> extends ListenerManager<T> {
-    public SerializableListenerManager() {
-        super();
-    }
-
-    protected SerializableListenerManager(Set<T> listeners) {
-        super(listeners);
-    }
-
-    public static <T extends SerializableListener> Codec<SerializableListenerManager<T>> getCodec(Registry<Codec<? extends T>> registry) {
-        return registry.byNameCodec().<T>dispatch(
-                    listener -> listener.getCodecId().map(registry::getValue).orElse(MapCodec.unitCodec(null)),
-                    codec -> codec.fieldOf("data")
-            ).listOf().xmap(
-                    list -> new SerializableListenerManager<>(new CopyOnWriteArraySet<>(list)),
-                    manager -> {
-                        List<T> serializableListeners = new ArrayList<>();
-                        for(T listener : manager.listeners) {
-                            if(listener.getCodecId().isPresent()) {
-                                serializableListeners.add(listener);
-                            }
-                        }
-                        return serializableListeners;
-                    }
-            );
-    }
-
-    public interface SerializableListener {
-        default Optional<Identifier> getCodecId() {
-            return Optional.empty();
-        }
-    }
-}

src/main/java/io/github/skippyall/minions/listener/SerializableListenerManager.kt

@@ -0,0 +1,47 @@
+package io.github.skippyall.minions.listener
+
+import com.mojang.serialization.Codec
+import com.mojang.serialization.MapCodec
+import io.github.skippyall.minions.listener.SerializableListenerManager.SerializableListener
+import net.minecraft.core.Registry
+import net.minecraft.resources.Identifier
+import java.util.*
+import java.util.concurrent.CopyOnWriteArraySet
+
+class SerializableListenerManager<T : SerializableListener>(
+    listeners: MutableSet<T> = CopyOnWriteArraySet(),
+    onChange: () -> Unit = {},
+) : ListenerManager<T>(listeners, onChange) {
+
+    interface SerializableListener {
+        val codecId: Optional<Identifier>
+            get() = Optional.empty<Identifier>()
+    }
+
+    companion object {
+        @JvmStatic
+        @JvmOverloads
+        fun <T : SerializableListener> getCodec(
+            registry: Registry<Codec<out T>>,
+            onChange: () -> Unit = {},
+        ): Codec<SerializableListenerManager<T>> {
+            return registry.byNameCodec().dispatch(
+                { listener -> listener.codecId.map(registry::getValue)
+                        .orElseGet { MapCodec.unitCodec(null) }
+                },
+                { codec -> codec.fieldOf("data") }
+            ).listOf().xmap(
+                { list -> SerializableListenerManager<T>(CopyOnWriteArraySet<T>(list), onChange) },
+                { manager ->
+                    val serializableListeners: MutableList<T> = mutableListOf()
+                    for (listener in manager.listeners) {
+                        if (listener.codecId.isPresent) {
+                            serializableListeners.add(listener)
+                        }
+                    }
+                    return@xmap serializableListeners
+                }
+            )
+        }
+    }
+}

src/main/java/io/github/skippyall/minions/listener/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.listener;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/minion/MinionData.java

@@ -1,58 +0,0 @@
-package io.github.skippyall.minions.minion;
-
-import com.mojang.authlib.properties.PropertyMap;
-import com.mojang.serialization.Codec;
-import com.mojang.serialization.codecs.RecordCodecBuilder;
-import io.github.skippyall.minions.listener.SerializableListenerManager;
-import io.github.skippyall.minions.registration.MinionRegistries;
-import net.minecraft.core.UUIDUtil;
-import net.minecraft.server.MinecraftServer;
-import net.minecraft.util.ExtraCodecs;
-import java.util.Optional;
-import java.util.UUID;
-
-public record MinionData(
-        UUID uuid,
-        String name,
-        Optional<PropertyMap> skin,
-        boolean isSpawned,
-        SerializableListenerManager<MinionListener> listeners,
-        MinionConfig config
-) {
-    public static final Codec<MinionData> CODEC = RecordCodecBuilder.create(instance ->
-            instance.group(
-                    UUIDUtil.AUTHLIB_CODEC.fieldOf("uuid").forGetter(MinionData::uuid),
-                    Codec.STRING.fieldOf("name").forGetter(MinionData::name),
-                    ExtraCodecs.PROPERTY_MAP.optionalFieldOf("skin").forGetter(MinionData::skin),
-                    Codec.BOOL.optionalFieldOf("isSpawned", false).forGetter(MinionData::isSpawned),
-                    SerializableListenerManager.getCodec(MinionRegistries.MINION_LISTENER_CODECS).optionalFieldOf("listeners").xmap(
-                            optional -> optional.orElseGet(SerializableListenerManager::new),
-                            Optional::of
-                    ).forGetter(MinionData::listeners),
-                    MinionConfig.CODEC.optionalFieldOf("config", new MinionConfig()).forGetter(MinionData::config)
-            ).apply(instance, MinionData::new)
-    );
-
-    public static MinionData createDefault(MinecraftServer server) {
-        return new MinionData(
-                UUID.randomUUID(),
-                MinionProfileUtils.newDefaultMinionName(server),
-                Optional.empty(),
-                false,
-                new SerializableListenerManager<>(),
-                new MinionConfig()
-        );
-    }
-
-    public MinionData withName(String name) {
-        return new MinionData(uuid, name, skin, isSpawned, listeners, config);
-    }
-
-    public MinionData withSkin(Optional<PropertyMap> skin) {
-        return new MinionData(uuid, name, skin, isSpawned, listeners, config);
-    }
-
-    public MinionData withSpawned(boolean isSpawned) {
-        return new MinionData(uuid, name, skin, isSpawned, listeners, config);
-    }
-}

src/main/java/io/github/skippyall/minions/minion/MinionData.kt

@@ -0,0 +1,81 @@
+package io.github.skippyall.minions.minion
+
+import com.mojang.authlib.properties.PropertyMap
+import com.mojang.serialization.Codec
+import com.mojang.serialization.codecs.RecordCodecBuilder
+import io.github.skippyall.minions.listener.SerializableListenerManager
+import io.github.skippyall.minions.registration.MinionRegistries
+import net.minecraft.core.UUIDUtil
+import net.minecraft.server.MinecraftServer
+import net.minecraft.util.ExtraCodecs
+import java.util.*
+import kotlin.properties.ReadWriteProperty
+import kotlin.reflect.KProperty
+
+class MinionData(
+    initialUuid: UUID,
+    initialName: String,
+    initialSkin: Optional<PropertyMap>,
+    initialIsSpawned: Boolean,
+    val listeners: SerializableListenerManager<MinionListener>,
+    initialConfig: MinionConfig,
+    var onDirty: Runnable = {},
+) {
+    var uuid by DirtyProperty(initialUuid, this::setDirty)
+    var name by DirtyProperty(initialName, this::setDirty)
+    var skin by DirtyProperty(initialSkin, this::setDirty)
+    var isSpawned by DirtyProperty(initialIsSpawned, this::setDirty)
+    var config by DirtyProperty(initialConfig, this::setDirty)
+
+    fun setDirty() {
+        this@MinionData.onDirty.run()
+    }
+
+    companion object {
+        @JvmField
+        val CODEC: Codec<MinionData> =
+            RecordCodecBuilder.create { instance ->
+                instance.group(
+                    UUIDUtil.AUTHLIB_CODEC.fieldOf("uuid").forGetter(MinionData::uuid),
+                    Codec.STRING.fieldOf("name").forGetter(MinionData::name),
+                    ExtraCodecs.PROPERTY_MAP.optionalFieldOf("skin").forGetter(MinionData::skin),
+                    Codec.BOOL.optionalFieldOf("isSpawned", false).forGetter(MinionData::isSpawned),
+                    SerializableListenerManager.getCodec<MinionListener>(MinionRegistries.MINION_LISTENER_CODECS)
+                            .optionalFieldOf("listeners").xmap(
+                                { optional -> optional.orElseGet { SerializableListenerManager() } },
+                                Optional<SerializableListenerManager<MinionListener>>::of
+                            ).forGetter(MinionData::listeners),
+                    MinionConfig.CODEC.optionalFieldOf("config", MinionConfig())
+                            .forGetter(MinionData::config)
+                ).apply(
+                    instance,
+                    ::MinionData
+                )
+            }
+
+        @JvmStatic
+        fun createDefault(server: MinecraftServer): MinionData {
+            return MinionData(
+                UUID.randomUUID(),
+                MinionProfileUtils.newDefaultMinionName(server),
+                Optional.empty<PropertyMap>(),
+                false,
+                SerializableListenerManager(),
+                MinionConfig()
+            ) {
+                MinionPersistentState.get(server).isDirty = true
+            }
+        }
+    }
+
+    class DirtyProperty<V>(var value: V, val onDirty: () -> Unit) : ReadWriteProperty<Any?, V> {
+        override fun getValue(thisRef: Any?, property: KProperty<*>): V {
+            return value
+        }
+
+        override fun setValue(thisRef: Any?, property: KProperty<*>, value: V) {
+            this.value = value
+            onDirty()
+        }
+    }
+}

src/main/java/io/github/skippyall/minions/minion/MinionItem.java

@@ -1,14 +1,8 @@
 package io.github.skippyall.minions.minion;
 
-import eu.pb4.polymer.core.api.item.PolymerItem;
 import io.github.skippyall.minions.gui.MinionLookGui;
 import io.github.skippyall.minions.minion.fakeplayer.MinionFakePlayer;
 import io.github.skippyall.minions.registration.MinionComponentTypes;
-import net.fabricmc.fabric.api.networking.v1.context.PacketContext;
-import net.minecraft.core.HolderLookup;
-import net.minecraft.core.component.DataComponents;
-import net.minecraft.network.chat.Component;
-import net.minecraft.resources.Identifier;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
@@ -17,51 +11,29 @@ import net.minecraft.world.InteractionResult;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.Items;
-import net.minecraft.world.item.TooltipFlag;
-import net.minecraft.world.item.component.TooltipDisplay;
 import net.minecraft.world.item.context.UseOnContext;
 import net.minecraft.world.level.Level;
 import net.minecraft.world.phys.Vec2;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
-import java.util.function.Consumer;
-
-public class MinionItem extends Item implements PolymerItem {
+public class MinionItem extends Item {
     public MinionItem(Properties settings) {
         super(settings);
     }
 
-    @Override
-    public @Nullable Identifier getPolymerItemModel(ItemStack stack, PacketContext context, HolderLookup.Provider lookup) {
-        return null;
-    }
-
-    @Override
-    public Item getPolymerItem(ItemStack itemStack, PacketContext player) {
-        return Items.ARMOR_STAND;
-    }
-
-    @Override
-    public ItemStack getPolymerItemStack(ItemStack stack, TooltipFlag tooltipType, PacketContext player, HolderLookup.Provider lookup) {
-        ItemStack out = PolymerItem.super.getPolymerItemStack(stack, tooltipType, player, lookup);
-        out.set(DataComponents.ENCHANTMENT_GLINT_OVERRIDE, true);
-        return out;
-    }
-
-    @Override
+    /*@Override
     public void appendHoverText(ItemStack stack, TooltipContext context, TooltipDisplay component, Consumer<Component> tooltip, TooltipFlag type) {
-        MinionData data = null /*getData(stack)*/;
-        if(data != null) {
-            tooltip.accept(Component.translatable("minions.minion_item.tooltip", data.name()));
-        }
-    }
+        //MinionData data = getData(stack);
+        //if(data != null) {
+        //    tooltip.accept(Component.translatable("minions.minion_item.tooltip", data.name()));
+        //}
+    }*/
 
     @Override
     public InteractionResult use(Level world, Player user, InteractionHand hand) {
         if(user instanceof ServerPlayer serverPlayer) {
             ItemStack stack = user.getItemInHand(hand);
-            MinionLookGui.open(serverPlayer, stack);
+            new MinionLookGui(serverPlayer, stack);
             return InteractionResult.SUCCESS;
         }
 
@@ -79,7 +51,7 @@ public class MinionItem extends Item implements PolymerItem {
     }
 
     public static void setData(MinecraftServer server, MinionData data, ItemStack item) {
-        item.set(MinionComponentTypes.MINION_DATA, data.uuid());
+        item.set(MinionComponentTypes.MINION_DATA, data.getUuid());
         MinionPersistentState.get(server).updateMinionData(data);
     }
 

src/main/java/io/github/skippyall/minions/minion/MinionListener.java

@@ -3,7 +3,7 @@ package io.github.skippyall.minions.minion;
 import io.github.skippyall.minions.listener.SerializableListenerManager;
 import io.github.skippyall.minions.minion.fakeplayer.MinionFakePlayer;
 import io.github.skippyall.minions.program.instruction.ConfiguredInstruction;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 public interface MinionListener extends SerializableListenerManager.SerializableListener {
     default void onMinionSpawn(MinionFakePlayer minion) {}

src/main/java/io/github/skippyall/minions/minion/MinionPersistentState.java

@@ -7,6 +7,8 @@ import net.minecraft.server.MinecraftServer;
 import net.minecraft.world.level.Level;
 import net.minecraft.world.level.saveddata.SavedData;
 import net.minecraft.world.level.saveddata.SavedDataType;
+import org.jspecify.annotations.Nullable;
+
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -31,11 +33,12 @@ public class MinionPersistentState extends SavedData {
 
     public MinionPersistentState(List<MinionData> dataList) {
         for (MinionData data : dataList) {
-            minionData.put(data.uuid(), data);
+            data.setOnDirty(this::setDirty);
+            minionData.put(data.getUuid(), data);
         }
     }
 
-    public MinionData getMinionData(UUID uuid) {
+    public @Nullable MinionData getMinionData(UUID uuid) {
         return minionData.get(uuid);
     }
 
@@ -48,7 +51,8 @@ public class MinionPersistentState extends SavedData {
     }
 
     public void updateMinionData(MinionData data) {
-        minionData.put(data.uuid(), data);
+        minionData.put(data.getUuid(), data);
+        data.setOnDirty(this::setDirty);
         setDirty();
     }
 
@@ -62,7 +66,7 @@ public class MinionPersistentState extends SavedData {
 
     public Optional<MinionData> getMinionWithName(String name) {
         return minionData.values().stream()
-                .filter(data -> data.name().equals(name))
+                .filter(data -> data.getName().equals(name))
                 .findFirst();
     }
 

src/main/java/io/github/skippyall/minions/minion/MinionProfileUtils.java

@@ -8,6 +8,8 @@ import io.github.skippyall.minions.gui.input.Result;
 import net.minecraft.network.chat.Component;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.util.StringUtil;
+import org.jspecify.annotations.Nullable;
+
 import java.util.UUID;
 
 import static io.github.skippyall.minions.Minions.LOGGER;
@@ -17,7 +19,7 @@ public class MinionProfileUtils {
         return MinionsConfig.get().minion.minionPrefix;
     }
 
-    public static GameProfile makeNewMinionProfile(UUID uuidMinion, String username, PropertyMap skin) {
+    public static GameProfile makeNewMinionProfile(@Nullable UUID uuidMinion, String username, @Nullable PropertyMap skin) {
         if(uuidMinion == null) {
             uuidMinion = UUID.randomUUID();
         }

src/main/java/io/github/skippyall/minions/minion/fakeplayer/MinionFakePlayer.java

@@ -51,12 +51,14 @@ import net.minecraft.world.level.storage.ValueInput;
 import net.minecraft.world.level.storage.ValueOutput;
 import net.minecraft.world.phys.Vec2;
 import net.minecraft.world.phys.Vec3;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.Consumer;
 
+@NullMarked
 public class MinionFakePlayer extends ServerPlayer {
     public Runnable fixStartingPosition = () -> {};
 
@@ -73,16 +75,16 @@ public class MinionFakePlayer extends ServerPlayer {
         if(!data.isSpawned() || force) {
             MinecraftServer server = level.getServer();
 
-            PropertyMap skin = data.skin().orElse(null);
+            PropertyMap skin = data.getSkin().orElse(null);
 
-            GameProfile profile = MinionProfileUtils.makeNewMinionProfile(data.uuid(), data.name(), skin);
+            GameProfile profile = MinionProfileUtils.makeNewMinionProfile(data.getUuid(), data.getName(), skin);
             server.schedule(server.wrapRunnable(() -> doSpawn(data, profile, server, level, pos, rot)));
         }
     }
 
     private static void doSpawn(MinionData data, GameProfile profile, MinecraftServer server, ServerLevel level, @Nullable Vec3 pos, @Nullable Vec2 rot) {
         MinionFakePlayer instance = new MinionFakePlayer(server, level, profile, ClientInformation.createDefault());
-        MinionPersistentState.get(server).updateMinionData(data.withSpawned(true));
+        data.setSpawned(true);
 
         if(pos != null && rot != null) {
             instance.fixStartingPosition = () -> instance.snapTo(pos.x, pos.y, pos.z, rot.x, rot.y);
@@ -158,7 +160,7 @@ public class MinionFakePlayer extends ServerPlayer {
     }
 
     public SerializableListenerManager<MinionListener> listeners() {
-        return getData().listeners();
+        return getData().getListeners();
     }
 
     public void addMinionListener(MinionListener listener) {
@@ -174,7 +176,7 @@ public class MinionFakePlayer extends ServerPlayer {
     }
 
     public boolean canSpawnMobs() {
-        return moduleInventory.hasAbility(SpecialAbilities.MOB_SPAWNING) || getData().config().getOption(MinionConfigOptions.spawnAndDespawnMobs);
+        return moduleInventory.hasAbility(SpecialAbilities.MOB_SPAWNING) || getData().getConfig().getOption(MinionConfigOptions.spawnAndDespawnMobs);
     }
 
     public boolean canDespawnMobs() {
@@ -213,7 +215,7 @@ public class MinionFakePlayer extends ServerPlayer {
             }));
         }
 
-        MinionPersistentState.get(getServer()).updateMinionData(getData().withSpawned(false));
+        getData().setSpawned(false);
     }
 
     @Override
@@ -310,6 +312,7 @@ public class MinionFakePlayer extends ServerPlayer {
     public void dropAllDeathLoot(ServerLevel world, DamageSource damageSource) {
         super.dropAllDeathLoot(world, damageSource);
         ItemEntity entity = drop(toItemStack(world.getServer()), true, false);
+        //noinspection ConstantValue (Wrong nullability of drop)
         if (entity != null) {
             entity.setUnlimitedLifetime();
         }

src/main/java/io/github/skippyall/minions/minion/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.minion;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/minion/program/instruction/MineBlockExecution.java

@@ -16,9 +16,10 @@ import net.minecraft.world.level.storage.ValueInput;
 import net.minecraft.world.level.storage.ValueOutput;
 import net.minecraft.world.phys.BlockHitResult;
 import net.minecraft.world.phys.HitResult;
+import org.jspecify.annotations.Nullable;
 
 public class MineBlockExecution implements InstructionExecution<MinionRuntime> {
-    private BlockPos currentBlock;
+    private @Nullable BlockPos currentBlock;
     private float currentBlockDamage = 0;
     private boolean first = true;
     private boolean done = false;
@@ -38,7 +39,6 @@ public class MineBlockExecution implements InstructionExecution<MinionRuntime> {
             }
             if (player.blockActionRestricted(player.level(), hit.getBlockPos(), player.gameMode.getGameModeForPlayer())) {
                 done = true;
-                return;
             }
         } else {
             done = true;

src/main/java/io/github/skippyall/minions/minion/program/instruction/inventory/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.minion.program.instruction.inventory;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/minion/program/instruction/move/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.minion.program.instruction.move;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/minion/program/instruction/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.minion.program.instruction;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/minion/program/supplier/AnalogInputSupplier.java

@@ -22,7 +22,7 @@ import net.minecraft.resources.ResourceKey;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.Level;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 import java.util.concurrent.CompletableFuture;
 
@@ -79,7 +79,7 @@ public class AnalogInputSupplier implements ValueSupplier<Long, MinionRuntime> {
         public <T> CompletableFuture<ValueSupplier<?, MinionRuntime>> openConfiguration(MinionsGui parent, ValueType<T> valueType, @Nullable ValueSupplier<?, MinionRuntime> previous) {
             CompletableFuture<ValueSupplier<?, MinionRuntime>> future = new CompletableFuture<>();
             new SimpleMinionsGui(parent, (onClose, me) -> {
-                SimpleGui gui = new SimpleGui(MenuType.GENERIC_3x3, parent.getViewer(), false) {
+                SimpleGui gui = new SimpleGui(MenuType.GENERIC_3x3, parent.viewer, false) {
                     @Override
                     public void onPlayerClose(boolean success) {
                         onClose.run();
@@ -90,7 +90,7 @@ public class AnalogInputSupplier implements ValueSupplier<Long, MinionRuntime> {
                 gui.setSlot(2, me.backButton());
                 gui.setSlot(4, new GuiElementBuilder(MinionItems.REFERENCE_ITEM)
                         .setCallback(() -> {
-                            ItemStack cursor = parent.getViewer().containerMenu.getCarried();
+                            ItemStack cursor = parent.viewer.containerMenu.getCarried();
                             if (cursor.is(MinionItems.REFERENCE_ITEM) && cursor.get(MinionComponentTypes.REFERENCE) instanceof BlockPosClipboard pos) {
                                 future.complete(new AnalogInputSupplier(pos.world(), pos.pos()));
                                 me.goBack();

src/main/java/io/github/skippyall/minions/minion/program/supplier/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.minion.program.supplier;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/minion/skin/Base64SkinProvider.java

@@ -5,6 +5,7 @@ import com.mojang.authlib.GameProfile;
 import com.mojang.authlib.properties.Property;
 import com.mojang.authlib.properties.PropertyMap;
 import io.github.skippyall.minions.Minions;
+import io.github.skippyall.minions.gui.MinionsGui;
 import net.fabricmc.fabric.api.entity.FakePlayer;
 import net.minecraft.core.Holder;
 import net.minecraft.core.registries.Registries;
@@ -22,7 +23,6 @@ import net.minecraft.server.dialog.Input;
 import net.minecraft.server.dialog.NoticeDialog;
 import net.minecraft.server.dialog.action.CustomAll;
 import net.minecraft.server.dialog.input.TextInput;
-import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.item.component.ResolvableProfile;
 
 import java.util.HashMap;
@@ -39,9 +39,9 @@ public class Base64SkinProvider implements SkinProvider {
     private static Map<Long, CompletableFuture<ResolvableProfile>> futures = new HashMap<>();
 
     @Override
-    public CompletableFuture<ResolvableProfile> openSkinMenu(ServerPlayer player) {
+    public CompletableFuture<ResolvableProfile> openSkinMenu(MinionsGui parent) {
         dialogIdCounter++;
-        player.openDialog(getDialog());
+        parent.viewer.openDialog(getDialog());
         CompletableFuture<ResolvableProfile> future = new CompletableFuture<>();
         futures.put(dialogIdCounter, future);
         return future;

src/main/java/io/github/skippyall/minions/minion/skin/NameSkinProvider.java

@@ -1,17 +1,18 @@
 package io.github.skippyall.minions.minion.skin;
 
+import io.github.skippyall.minions.gui.MinionsGui;
 import io.github.skippyall.minions.gui.input.TextInput;
 import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.item.component.ResolvableProfile;
+import org.jspecify.annotations.Nullable;
 
 import java.util.concurrent.CompletableFuture;
 
 public class NameSkinProvider implements SkinProvider {
     @Override
-    public CompletableFuture<ResolvableProfile> openSkinMenu(ServerPlayer player) {
-        return TextInput.inputString(player, Component.translatable("minions.gui.look.skin.name.title"), "")
-                .thenApply(ResolvableProfile::createUnresolved);
+    public CompletableFuture<@Nullable ResolvableProfile> openSkinMenu(MinionsGui parent) {
+        return TextInput.inputString(parent, Component.translatable("minions.gui.look.skin.name.title"), "")
+                .thenApply(name -> name != null ? ResolvableProfile.createUnresolved(name) : null);
     }
 
     @Override

src/main/java/io/github/skippyall/minions/minion/skin/SkinProvider.java

@@ -1,13 +1,14 @@
 package io.github.skippyall.minions.minion.skin;
 
+import io.github.skippyall.minions.gui.MinionsGui;
 import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.item.component.ResolvableProfile;
+import org.jspecify.annotations.Nullable;
 
 import java.util.concurrent.CompletableFuture;
 
 public interface SkinProvider {
-    CompletableFuture<ResolvableProfile> openSkinMenu(ServerPlayer player);
+    CompletableFuture<@Nullable ResolvableProfile> openSkinMenu(MinionsGui parent);
 
     Component getDisplayName();
 }

src/main/java/io/github/skippyall/minions/minion/skin/UUIDSkinProvider.java

@@ -1,17 +1,18 @@
 package io.github.skippyall.minions.minion.skin;
 
+import io.github.skippyall.minions.gui.MinionsGui;
 import io.github.skippyall.minions.gui.input.TextInput;
 import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.item.component.ResolvableProfile;
+import org.jspecify.annotations.Nullable;
 
 import java.util.concurrent.CompletableFuture;
 
 public class UUIDSkinProvider implements SkinProvider {
     @Override
-    public CompletableFuture<ResolvableProfile> openSkinMenu(ServerPlayer player) {
-        return TextInput.inputString(player, Component.translatable("minions.gui.look.skin.uuid.title"), "")
-                .thenApply(ResolvableProfile::createUnresolved);
+    public CompletableFuture<@Nullable ResolvableProfile> openSkinMenu(MinionsGui parent) {
+        return TextInput.inputString(parent, Component.translatable("minions.gui.look.skin.uuid.title"), "")
+                .thenApply(name -> name != null ? ResolvableProfile.createUnresolved(name) : null);
     }
 
     @Override

src/main/java/io/github/skippyall/minions/minion/skin/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.minion.skin;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/mixins/ClientboundPlayerInfoUpdatePacket$EntryMixin.java

@@ -13,7 +13,7 @@ import org.spongepowered.asm.mixin.injection.ModifyArg;
 public class ClientboundPlayerInfoUpdatePacket$EntryMixin {
     @ModifyArg(method = "<init>(Lnet/minecraft/server/level/ServerPlayer;)V", at = @At(value = "INVOKE", target = "Lnet/minecraft/network/protocol/game/ClientboundPlayerInfoUpdatePacket$Entry;<init>(Ljava/util/UUID;Lcom/mojang/authlib/GameProfile;ZILnet/minecraft/world/level/GameType;Lnet/minecraft/network/chat/Component;ZILnet/minecraft/network/chat/RemoteChatSession$Data;)V"), index = 2)
     private static boolean removeMinionFromTabList(boolean original, @Local(argsOnly = true) ServerPlayer player) {
-        if(player instanceof MinionFakePlayer minion && !minion.getData().config().getOption(MinionConfigOptions.showInTabList)) {
+        if(player instanceof MinionFakePlayer minion && !minion.getData().getConfig().getOption(MinionConfigOptions.showInTabList)) {
             return false;
         }
 

src/main/java/io/github/skippyall/minions/mixins/EntityGetterMixin.java

@@ -3,7 +3,7 @@ package io.github.skippyall.minions.mixins;
 import io.github.skippyall.minions.mixinhelper.EntityViewMixinHelper;
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.level.EntityGetter;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.ModifyArg;

src/main/java/io/github/skippyall/minions/mixins/EntityMixin.java

@@ -4,7 +4,7 @@ import io.github.skippyall.minions.minion.fakeplayer.MinionFakePlayer;
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.entity.LivingEntity;
 import net.minecraft.world.level.Level;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.At;

src/main/java/io/github/skippyall/minions/mixins/MinecraftServerMixin.java

@@ -24,7 +24,7 @@ public class MinecraftServerMixin {
     public List<ServerPlayer> ignoreFakePlayers(List<ServerPlayer> original) {
         return original.stream()
                 .filter(player -> !(player instanceof MinionFakePlayer minion
-                        && !minion.getData().config().getOption(MinionConfigOptions.showInServerList)))
+                        && !minion.getData().getConfig().getOption(MinionConfigOptions.showInServerList)))
                 .collect(Collectors.toCollection(ArrayList::new));
     }
 

src/main/java/io/github/skippyall/minions/mixins/PlayerListMixin.java

@@ -59,7 +59,7 @@ public class PlayerListMixin {
 
     @WrapOperation(method = "placeNewPlayer", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/players/PlayerList;broadcastSystemMessage(Lnet/minecraft/network/chat/Component;Z)V"))
     public void noLoginMessage(PlayerList instance, Component message, boolean overlay, Operation<Void> original, @Local(argsOnly = true) ServerPlayer player) {
-        if(!(player instanceof MinionFakePlayer minion && !minion.getData().config().getOption(MinionConfigOptions.sendLoginMessage))) {
+        if(!(player instanceof MinionFakePlayer minion && !minion.getData().getConfig().getOption(MinionConfigOptions.sendLoginMessage))) {
             original.call(instance, message, overlay);
         }
     }
@@ -67,7 +67,7 @@ public class PlayerListMixin {
     @ModifyReceiver(method = "canPlayerLogin", at = @At(value = "INVOKE", target = "Ljava/util/List;size()I"))
     public List<ServerPlayer> noMinionCounting(List<ServerPlayer> instance) {
         return instance.stream()
-                .filter(player -> !(player instanceof MinionFakePlayer minion && !minion.getData().config().getOption(MinionConfigOptions.countForPlayerLimit)))
+                .filter(player -> !(player instanceof MinionFakePlayer minion && !minion.getData().getConfig().getOption(MinionConfigOptions.countForPlayerLimit)))
                 .collect(Collectors.toCollection(ArrayList::new));
     }
 }

src/main/java/io/github/skippyall/minions/mixins/ServerGamePacketListenerImplMixin.java

@@ -19,7 +19,7 @@ public class ServerGamePacketListenerImplMixin {
 
     @WrapOperation(method = "removePlayerFromWorld", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/players/PlayerList;broadcastSystemMessage(Lnet/minecraft/network/chat/Component;Z)V"))
     public void noLogoutMessage(PlayerList instance, Component message, boolean overlay, Operation<Void> original) {
-        if(!(player instanceof MinionFakePlayer minion && !minion.getData().config().getOption(MinionConfigOptions.sendLogoutMessage))) {
+        if(!(player instanceof MinionFakePlayer minion && !minion.getData().getConfig().getOption(MinionConfigOptions.sendLogoutMessage))) {
             original.call(instance, message, overlay);
         }
     }

src/main/java/io/github/skippyall/minions/mixins/SleepStatusMixin.java

@@ -13,7 +13,7 @@ import org.spongepowered.asm.mixin.injection.At;
 public class SleepStatusMixin {
     @WrapOperation(method = "update", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/level/ServerPlayer;isSpectator()Z"))
     public boolean excludeMinions(ServerPlayer instance, Operation<Boolean> original) {
-        if (instance instanceof MinionFakePlayer minion && !minion.getData().config().getOption(MinionConfigOptions.countForSleeping)) {
+        if (instance instanceof MinionFakePlayer minion && !minion.getData().getConfig().getOption(MinionConfigOptions.countForSleeping)) {
             return true;
         } else {
             return original.call(instance);

src/main/java/io/github/skippyall/minions/module/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.module;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/polymer/PolymerRegistration.java

@@ -0,0 +1,67 @@
+package io.github.skippyall.minions.polymer;
+
+import eu.pb4.polymer.core.api.block.PolymerBlock;
+import eu.pb4.polymer.core.api.block.PolymerBlockUtils;
+import eu.pb4.polymer.core.api.item.PolymerCreativeModeTabUtils;
+import eu.pb4.polymer.core.api.item.PolymerItem;
+import eu.pb4.polymer.core.api.other.PolymerComponent;
+import eu.pb4.polymer.resourcepack.api.PolymerResourcePackUtils;
+import eu.pb4.polymer.virtualentity.api.BlockWithElementHolder;
+import io.github.skippyall.minions.Minions;
+import io.github.skippyall.minions.polymer.block.AnalogInputBlockOverlay;
+import io.github.skippyall.minions.polymer.block.MinionTriggerBlockOverlay;
+import io.github.skippyall.minions.polymer.item.ClipboardItemOverlay;
+import io.github.skippyall.minions.polymer.item.MinionItemOverlay;
+import io.github.skippyall.minions.polymer.item.MinionsBlockItemOverlay;
+import io.github.skippyall.minions.polymer.item.SimpleItemOverlay;
+import io.github.skippyall.minions.registration.MinionBlocks;
+import io.github.skippyall.minions.registration.MinionComponentTypes;
+import io.github.skippyall.minions.registration.MinionCreativeTab;
+import io.github.skippyall.minions.registration.MinionItems;
+import net.minecraft.resources.Identifier;
+import net.minecraft.world.item.Item;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.level.block.Block;
+
+public class PolymerRegistration {
+    public static void register() {
+        VersionSync.register();
+        PolymerResourcePackUtils.addModAssets(Minions.MOD_ID);
+
+        registerBlockOverlay(MinionBlocks.MINION_TRIGGER_BLOCK, new MinionTriggerBlockOverlay());
+        PolymerBlockUtils.registerBlockEntity(MinionBlocks.MINION_TRIGGER_BE_TYPE);
+        registerBlockOverlay(MinionBlocks.ANALOG_INPUT_BLOCK, new AnalogInputBlockOverlay());
+
+        registerItemOverlay(MinionItems.MINION_TRIGGER_ITEM, new MinionsBlockItemOverlay(MinionItems.MINION_TRIGGER_ITEM, Items.COMPARATOR));
+        registerItemOverlay(MinionItems.ANALOG_INPUT_ITEM, new MinionsBlockItemOverlay(MinionItems.ANALOG_INPUT_ITEM, Items.REPEATER));
+
+        registerItemOverlay(MinionItems.REFERENCE_ITEM, new ClipboardItemOverlay());
+        registerItemOverlay(MinionItems.MINION_ITEM, new MinionItemOverlay());
+        registerSimpleItemOverlay(MinionItems.BASIC_UPGRADE_BASE, Items.NETHERITE_UPGRADE_SMITHING_TEMPLATE);
+        registerSimpleItemOverlay(MinionItems.ADVANCED_UPGRADE_BASE, Items.NETHERITE_UPGRADE_SMITHING_TEMPLATE);
+        registerSimpleItemOverlay(MinionItems.MOVE_MODULE, Items.IRON_BOOTS);
+        registerSimpleItemOverlay(MinionItems.ATTACK_MODULE, Items.IRON_PICKAXE);
+        registerSimpleItemOverlay(MinionItems.INTERACT_MODULE, Items.LEVER);
+        registerSimpleItemOverlay(MinionItems.MOB_SPAWNING_MODULE, Items.SPAWNER);
+
+        PolymerComponent.registerDataComponent(MinionComponentTypes.MINION_DATA, MinionComponentTypes.REFERENCE, MinionComponentTypes.MODULE);
+
+        PolymerCreativeModeTabUtils.registerPolymerCreativeModeTab(Identifier.fromNamespaceAndPath(Minions.MOD_ID, "main"), MinionCreativeTab.group);
+    }
+
+    private static void registerBlockOverlay(Block block, PolymerBlock overlay) {
+        PolymerBlock.registerOverlay(block, overlay);
+
+        if(overlay instanceof BlockWithElementHolder elementHolderOverlay) {
+            BlockWithElementHolder.registerOverlay(block, elementHolderOverlay);
+        }
+    }
+
+    private static void registerItemOverlay(Item item, PolymerItem overlay) {
+        PolymerItem.registerOverlay(item, overlay);
+    }
+
+    private static void registerSimpleItemOverlay(Item serverItem, Item polymerItem) {
+        registerItemOverlay(serverItem, SimpleItemOverlay.withoutModel(serverItem, polymerItem));
+    }
+}

src/main/java/io/github/skippyall/minions/polymer/VersionSync.java

@@ -8,11 +8,12 @@ import net.minecraft.network.codec.StreamCodec;
 import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
 import net.minecraft.resources.Identifier;
 import net.minecraft.server.network.ServerGamePacketListenerImpl;
+import org.jspecify.annotations.Nullable;
 
 public class VersionSync {
     public static final int NETWORK_VERSION = 1;
 
-    public static boolean isOnClient(PacketContext context) {
+    public static boolean isOnClient(@Nullable PacketContext context) {
         if(context != null && context.get(PacketContext.CONNECTION).getPacketListener() instanceof ServerGamePacketListenerImpl gamePacketListener) {
             return isOnClient(gamePacketListener);
         }

src/main/java/io/github/skippyall/minions/polymer/block/AnalogInputBlockOverlay.java

@@ -0,0 +1,14 @@
+package io.github.skippyall.minions.polymer.block;
+
+import eu.pb4.polymer.core.api.block.PolymerBlock;
+import net.fabricmc.fabric.api.networking.v1.context.PacketContext;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.state.BlockState;
+import org.jspecify.annotations.Nullable;
+
+public class AnalogInputBlockOverlay implements PolymerBlock {
+    @Override
+    public BlockState getPolymerBlockState(BlockState blockState, @Nullable PacketContext packetContext) {
+        return Blocks.AMETHYST_BLOCK.defaultBlockState();
+    }
+}

src/main/java/io/github/skippyall/minions/polymer/block/MinionTriggerBlockOverlay.java

@@ -0,0 +1,57 @@
+package io.github.skippyall.minions.polymer.block;
+
+import eu.pb4.polymer.core.api.block.PolymerBlock;
+import eu.pb4.polymer.core.api.utils.PolymerClientDecoded;
+import eu.pb4.polymer.resourcepack.api.PolymerResourcePackUtils;
+import eu.pb4.polymer.virtualentity.api.BlockWithElementHolder;
+import eu.pb4.polymer.virtualentity.api.ElementHolder;
+import eu.pb4.polymer.virtualentity.api.elements.ItemDisplayElement;
+import io.github.skippyall.minions.Minions;
+import io.github.skippyall.minions.block.miniontrigger.MinionTriggerBlock;
+import io.github.skippyall.minions.polymer.VersionSync;
+import net.fabricmc.fabric.api.networking.v1.context.PacketContext;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.resources.Identifier;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.network.ServerGamePacketListenerImpl;
+import net.minecraft.world.item.ItemDisplayContext;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.level.block.DiodeBlock;
+import net.minecraft.world.level.block.state.BlockState;
+import org.jspecify.annotations.Nullable;
+
+public class MinionTriggerBlockOverlay implements PolymerBlock, PolymerClientDecoded, BlockWithElementHolder {
+    @Override
+    public BlockState getPolymerBlockState(BlockState state, @Nullable PacketContext context) {
+        return VersionSync.isOnClient(context) ? state : net.minecraft.world.level.block.Blocks.COMPARATOR.defaultBlockState().setValue(DiodeBlock.POWERED, state.getValue(MinionTriggerBlock.POWERED));
+    }
+
+    @Override
+    public boolean handleMiningOnServer(ItemStack tool, BlockState state, BlockPos pos, ServerPlayer player) {
+        return false;
+    }
+
+    @Override
+    public @Nullable ElementHolder createElementHolder(ServerLevel world, BlockPos pos, BlockState initialBlockState) {
+        ElementHolder holder = new ElementHolder() {
+            @Override
+            public boolean startWatching(ServerGamePacketListenerImpl player) {
+                if(PolymerResourcePackUtils.hasMainPack(player) && !VersionSync.isOnClient(player)) {
+                    return super.startWatching(player);
+                } else {
+                    return false;
+                }
+            }
+        };
+        ItemStack stack = new ItemStack(Items.BARRIER);
+        stack.set(DataComponents.ITEM_MODEL, Identifier.fromNamespaceAndPath(Minions.MOD_ID, "minion_trigger_no_plate_" + (initialBlockState.getValue(MinionTriggerBlock.POWERED) ? "active" : "inactive")));
+
+        ItemDisplayElement element = new ItemDisplayElement(stack);
+        element.setItemDisplayContext(ItemDisplayContext.NONE);
+        holder.addElement(element);
+        return holder;
+    }
+}

src/main/java/io/github/skippyall/minions/polymer/block/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.polymer.block;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/polymer/item/ClipboardItemOverlay.java

@@ -0,0 +1,31 @@
+package io.github.skippyall.minions.polymer.item;
+
+import eu.pb4.polymer.core.api.item.PolymerItem;
+import net.fabricmc.fabric.api.networking.v1.context.PacketContext;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.resources.Identifier;
+import net.minecraft.world.item.Item;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.item.TooltipFlag;
+import org.jspecify.annotations.Nullable;
+
+public class ClipboardItemOverlay implements PolymerItem {
+    @Override
+    public Item getPolymerItem(ItemStack itemStack, PacketContext context) {
+        return /*VersionSync.isOnClient(context) ? this : */Items.PAPER;
+    }
+
+    @Override
+    public @Nullable Identifier getPolymerItemModel(ItemStack stack, PacketContext context, HolderLookup.Provider lookup) {
+        return null;
+    }
+
+    @Override
+    public ItemStack getPolymerItemStack(ItemStack itemStack, TooltipFlag tooltipType, PacketContext context, HolderLookup.Provider lookup) {
+        ItemStack stack = PolymerItem.super.getPolymerItemStack(itemStack, tooltipType, context, lookup);
+        stack.set(DataComponents.ENCHANTMENT_GLINT_OVERRIDE, true);
+        return stack;
+    }
+}

src/main/java/io/github/skippyall/minions/polymer/item/MinionItemOverlay.java

@@ -0,0 +1,31 @@
+package io.github.skippyall.minions.polymer.item;
+
+import eu.pb4.polymer.core.api.item.PolymerItem;
+import net.fabricmc.fabric.api.networking.v1.context.PacketContext;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.resources.Identifier;
+import net.minecraft.world.item.Item;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.item.TooltipFlag;
+import org.jspecify.annotations.Nullable;
+
+public class MinionItemOverlay implements PolymerItem {
+    @Override
+    public @Nullable Identifier getPolymerItemModel(ItemStack stack, PacketContext context, HolderLookup.Provider lookup) {
+        return null;
+    }
+
+    @Override
+    public Item getPolymerItem(ItemStack itemStack, PacketContext player) {
+        return Items.ARMOR_STAND;
+    }
+
+    @Override
+    public ItemStack getPolymerItemStack(ItemStack stack, TooltipFlag tooltipType, PacketContext player, HolderLookup.Provider lookup) {
+        ItemStack out = PolymerItem.super.getPolymerItemStack(stack, tooltipType, player, lookup);
+        out.set(DataComponents.ENCHANTMENT_GLINT_OVERRIDE, true);
+        return out;
+    }
+}

src/main/java/io/github/skippyall/minions/polymer/item/MinionsBlockItemOverlay.java

@@ -0,0 +1,55 @@
+package io.github.skippyall.minions.polymer.item;
+
+import eu.pb4.polymer.core.api.item.PolymerItem;
+import eu.pb4.polymer.resourcepack.api.PolymerResourcePackUtils;
+import io.github.skippyall.minions.polymer.VersionSync;
+import net.fabricmc.fabric.api.networking.v1.context.PacketContext;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.resources.Identifier;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.InteractionHand;
+import net.minecraft.world.InteractionResult;
+import net.minecraft.world.item.Item;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.phys.BlockHitResult;
+import org.jspecify.annotations.Nullable;
+
+public class MinionsBlockItemOverlay implements PolymerItem {
+    private final Item serverItem;
+    private final Item polymerItem;
+
+    public MinionsBlockItemOverlay(Item serverItem, Item polymerItem) {
+        this.serverItem = serverItem;
+        this.polymerItem = polymerItem;
+    }
+
+    @Override
+    public Item getPolymerItem(ItemStack itemStack, PacketContext context) {
+        if(VersionSync.isOnClient(context)) {
+            return serverItem;
+        } else {
+            return polymerItem;
+        }
+    }
+
+    @Override
+    public @Nullable Identifier getPolymerItemModel(ItemStack stack, PacketContext context, HolderLookup.Provider lookup) {
+        if(PolymerResourcePackUtils.hasMainPack(context)) {
+            return PolymerItem.super.getPolymerItemModel(stack, context, lookup);
+        } else {
+            return null;
+        }
+    }
+
+    @Override
+    public boolean isPolymerBlockInteraction(BlockState state, ServerPlayer player, InteractionHand hand, ItemStack stack, ServerLevel world, BlockHitResult blockHitResult, InteractionResult actionResult) {
+        return true;
+    }
+
+    @Override
+    public boolean isIgnoringBlockInteractionPlaySoundExceptedEntity(BlockState state, ServerPlayer player, InteractionHand hand, ItemStack stack, ServerLevel world, BlockHitResult blockHitResult) {
+        return true;
+    }
+}

src/main/java/io/github/skippyall/minions/polymer/item/SimpleItemOverlay.java

@@ -0,0 +1,48 @@
+package io.github.skippyall.minions.polymer.item;
+
+import eu.pb4.polymer.core.api.item.PolymerItem;
+import eu.pb4.polymer.resourcepack.api.PolymerResourcePackUtils;
+import io.github.skippyall.minions.polymer.VersionSync;
+import net.fabricmc.fabric.api.networking.v1.context.PacketContext;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.resources.Identifier;
+import net.minecraft.world.item.Item;
+import net.minecraft.world.item.ItemStack;
+import org.jspecify.annotations.Nullable;
+
+public class SimpleItemOverlay implements PolymerItem {
+    private final Item serverItem;
+    private final Item polymerItem;
+    private final boolean useModel;
+
+    private SimpleItemOverlay(Item serverItem, Item polymerItem, boolean useModel) {
+        this.serverItem = serverItem;
+        this.polymerItem = polymerItem;
+        this.useModel = useModel;
+    }
+
+    public static SimpleItemOverlay withModel(Item serverItem, Item polymerItem) {
+        return new SimpleItemOverlay(serverItem, polymerItem, true);
+    }
+
+    public static SimpleItemOverlay withoutModel(Item serverItem, Item polymerItem) {
+        return new SimpleItemOverlay(serverItem, polymerItem, false);
+    }
+
+    public Item getPolymerItem(ItemStack itemStack, PacketContext context) {
+        if(useModel && VersionSync.isOnClient(context)) {
+            return serverItem;
+        } else {
+            return polymerItem;
+        }
+    }
+
+    @Override
+    public @Nullable Identifier getPolymerItemModel(ItemStack stack, PacketContext context, HolderLookup.Provider lookup) {
+        if(PolymerResourcePackUtils.hasMainPack(context) && useModel) {
+            return PolymerItem.super.getPolymerItemModel(stack, context, lookup);
+        } else {
+            return null;
+        }
+    }
+}

src/main/java/io/github/skippyall/minions/polymer/item/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.polymer.item;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/polymer/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.polymer;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/program/consumer/ValueConsumer.java

@@ -4,7 +4,7 @@ import com.mojang.serialization.Codec;
 import io.github.skippyall.minions.program.InstructionRuntime;
 import io.github.skippyall.minions.program.value.ValueType;
 import io.github.skippyall.minions.registration.MinionRegistries;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * An <code>ValueSupplier</code> can be supplied to an instruction with a matching parameter.

src/main/java/io/github/skippyall/minions/program/consumer/ValueConsumerList.java

@@ -3,6 +3,7 @@ package io.github.skippyall.minions.program.consumer;
 import com.mojang.serialization.Codec;
 import io.github.skippyall.minions.program.InstructionRuntime;
 import io.github.skippyall.minions.program.supplier.Parameter;
+import org.jspecify.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -22,7 +23,7 @@ public class ValueConsumerList<R extends InstructionRuntime<R>> {
         this.valueConsumers = new HashMap<>(valueConsumers);
     }
 
-    public <T, A extends ValueConsumer<T,R>> A getValueConsumer(Parameter<T> parameter) {
+    public <T, A extends ValueConsumer<T,R>> @Nullable A getValueConsumer(Parameter<T> parameter) {
         ValueConsumer<?,R> argument = valueConsumers.get(parameter.name());
         return argument == null ? null : argument.cast(parameter.type());
     }

src/main/java/io/github/skippyall/minions/program/consumer/ValueConsumerType.java

@@ -4,7 +4,7 @@ import com.mojang.serialization.Codec;
 import io.github.skippyall.minions.program.InstructionRuntime;
 import io.github.skippyall.minions.program.value.ValueType;
 import net.minecraft.server.level.ServerPlayer;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 import java.util.concurrent.CompletableFuture;
 

src/main/java/io/github/skippyall/minions/program/consumer/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package io.github.skippyall.minions.program.consumer;
+
+import org.jspecify.annotations.NullMarked;

src/main/java/io/github/skippyall/minions/program/conversion/CastConverter.java

@@ -10,7 +10,7 @@ import io.github.skippyall.minions.registration.MinionRegistries;
 import io.github.skippyall.minions.registration.ValueConverters;
 import io.github.skippyall.minions.util.TranslationUtil;
 import net.minecraft.network.chat.Component;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 import java.util.concurrent.CompletableFuture;
 

src/main/java/io/github/skippyall/minions/program/conversion/Casts.java

@@ -7,7 +7,7 @@ import io.github.skippyall.minions.registration.MinionRegistries;
 import io.github.skippyall.minions.registration.ValueTypes;
 import io.github.skippyall.minions.util.TranslationUtil;
 import net.minecraft.network.chat.Component;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 public class Casts {
     public static <F,T> @Nullable Cast<F,T> getCast(ValueType<F> from, ValueType<T> to) {
@@ -28,11 +28,16 @@ public class Casts {
             return (Cast<F, T>) new Cast.CastCrafter<>(from, ValueTypes.STRING, String::valueOf).craftCast();
         }
 
+        if(from == ValueTypes.STRING && to == ValueTypes.DOUBLE) {
+            //noinspection unchecked
+            return (Cast<F, T>) new Cast.CastCrafter<>(ValueTypes.STRING, ValueTypes.DOUBLE, Double::parseDouble).canFail().lossy().craftCast();
+        }
+
         return null;
     }
 
     public static <F,T> @Nullable T cast(TypedValue<F> from, ValueType<T> to) {
-        @Nullable Cast<F,T> cast = getCast(from.type(), to);
+        Cast<F,T> cast = getCast(from.type(), to);
         if(cast != null) {
             return cast.cast(from.value());
         } else {

src/main/java/io/github/skippyall/minions/program/conversion/ConverterList.java

@@ -4,13 +4,16 @@ import com.mojang.serialization.Codec;
 import io.github.skippyall.minions.gui.input.Result;
 import io.github.skippyall.minions.program.value.TypedValue;
 import io.github.skippyall.minions.program.value.ValueType;
+import io.github.skippyall.minions.registration.MinionRegistries;
+import io.github.skippyall.minions.util.TranslationUtil;
 import net.minecraft.network.chat.Component;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Objects;
+import java.util.function.Consumer;
 
 public class ConverterList {
     public static final Codec<ConverterList> CODEC = ValueConverter.CODEC.listOf().xmap(ConverterList::new, l -> l.converters);
@@ -53,7 +56,11 @@ public class ConverterList {
     private <F,I,T> Result<TypedValue<?>, Component> convert(TypedValue<F> from, ValueConverter<I,T> converter, ListIterator<ValueConverter<?,?>> iterator) {
         Result<I, Component> inter = Casts.castOrError(from, converter.getFrom());
         if(inter instanceof Result.Error<I, Component> error) {
-            return new Result.Error<>(Component.translatable("minions.converter.list.passing_error", iterator.previousIndex(), error.message()));
+            return new Result.Error<>(
+                    Component.translatable("minions.converter.list.passing_error", iterator.previousIndex())
+                            .append("\n")
+                            .append(error.message())
+            );
         }
         Result<T, Component> to = converter.convert(inter.getOrThrow());
 
@@ -64,8 +71,37 @@ public class ConverterList {
         }
     }
 
-    public Result<@Nullable Void, Component> check() {
-        return new Result.Success<>(null);
+    public static @Nullable Component createConverterWarning(ValueConverter<?, ?> converter) {
+        return null;
+    }
+
+    public static @Nullable Component createCastWarning(ValueType<?> fromType, ValueType<?> toType) {
+        Component warning = null;
+
+        Cast<?,?> cast = Casts.getCast(fromType, toType);
+        if(cast == null) {
+            warning = Component.translatable("minions.converter.cast.not_found", TranslationUtil.getTranslation(fromType, MinionRegistries.VALUE_TYPES), TranslationUtil.getTranslation(toType, MinionRegistries.VALUE_TYPES));
+        }
+
+        return warning;
+    }
+
+    public void check(Consumer<Component> errorConsumer, ValueType<?> input, ValueType<?> output) {
+        Component firstCastWarning = createCastWarning(input, converters.isEmpty() ? output : converters.get(0).getFrom());
+        if(firstCastWarning != null) {
+            errorConsumer.accept(firstCastWarning);
+        }
+        for(int i = 0; i < converters.size(); i++) {
+            ValueConverter<?,?> converter = converters.get(i);
+            Component converterWarning = createConverterWarning(converter);
+            if(converterWarning != null) {
+                errorConsumer.accept(converterWarning);
+            }
+            Component castWarning = createCastWarning(converter.getTo(), i + 1 < converters.size() ? converters.get(i + 1).getFrom() : output);
+            if(castWarning != null) {
+                errorConsumer.accept(castWarning);
+            }
+        }
     }
 
     @Override

src/main/java/io/github/skippyall/minions/program/conversion/EqualityConverter.java

@@ -8,7 +8,7 @@ import io.github.skippyall.minions.registration.MinionRegistries;
 import io.github.skippyall.minions.registration.ValueConverters;
 import io.github.skippyall.minions.registration.ValueTypes;
 import net.minecraft.network.chat.Component;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 import java.util.concurrent.CompletableFuture;
 

src/main/java/io/github/skippyall/minions/program/conversion/ValueConverter.java

@@ -5,6 +5,7 @@ import io.github.skippyall.minions.gui.input.Result;
 import io.github.skippyall.minions.program.value.ValueType;
 import io.github.skippyall.minions.registration.MinionRegistries;
 import net.minecraft.network.chat.Component;
+import org.jspecify.annotations.Nullable;
 
 public interface ValueConverter<F,T> {
     Codec<ValueConverter<?,?>> CODEC = MinionRegistries.VALUE_CONVERTER_TYPES.byNameCodec().dispatch(ValueConverter::getType, ValueConverterType::getCodec);
@@ -19,7 +20,7 @@ public interface ValueConverter<F,T> {
 
     Component getDisplayText();
 
-    default <F2,T2> ValueConverter<F2,T2> cast(ValueType<F2> from, ValueType<T2> to) {
+    default <F2,T2> @Nullable ValueConverter<F2,T2> cast(ValueType<F2> from, ValueType<T2> to) {
         if(from == getFrom() && to == getTo()) {
             //noinspection unchecked
             return (ValueConverter<F2, T2>) this;