Prepare the public API for multi-loader support

Well, sort of. For now, we just mark a whole bunch of stuff as
@Deprecated.

src/main/java/dan200/computercraft/ComputerCraftAPIImpl.java

@@ -19,15 +19,17 @@ import dan200.computercraft.api.network.wired.IWiredElement;
 import dan200.computercraft.api.network.wired.IWiredNode;
 import dan200.computercraft.api.peripheral.IPeripheralProvider;
 import dan200.computercraft.api.redstone.IBundledRedstoneProvider;
+import dan200.computercraft.api.turtle.TurtleRefuelHandler;
 import dan200.computercraft.core.apis.ApiFactories;
 import dan200.computercraft.core.asm.GenericMethod;
 import dan200.computercraft.core.filesystem.FileMount;
-import dan200.computercraft.shared.computer.core.ResourceMount;
 import dan200.computercraft.impl.ComputerCraftAPIService;
+import dan200.computercraft.impl.TurtleRefuelHandlers;
 import dan200.computercraft.impl.detail.DetailRegistryImpl;
 import dan200.computercraft.shared.BundledRedstone;
 import dan200.computercraft.shared.MediaProviders;
 import dan200.computercraft.shared.Peripherals;
+import dan200.computercraft.shared.computer.core.ResourceMount;
 import dan200.computercraft.shared.computer.core.ServerContext;
 import dan200.computercraft.shared.peripheral.generic.GenericPeripheralProvider;
 import dan200.computercraft.shared.peripheral.generic.data.BlockData;
@@ -205,6 +207,12 @@ public final class ComputerCraftAPIImpl implements ComputerCraftAPIService
         return tile == null ? LazyOptional.empty() : tile.getCapability( CAPABILITY_WIRED_ELEMENT, side );
     }
 
+    @Override
+    public void registerRefuelHandler( @Nonnull TurtleRefuelHandler handler )
+    {
+        TurtleRefuelHandlers.register( handler );
+    }
+
     @Override
     public DetailRegistry<ItemStack> getItemStackDetailRegistry()
     {

src/main/java/dan200/computercraft/api/ComputerCraftAPI.java

@@ -21,6 +21,7 @@ import dan200.computercraft.api.peripheral.IComputerAccess;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.api.peripheral.IPeripheralProvider;
 import dan200.computercraft.api.redstone.IBundledRedstoneProvider;
+import dan200.computercraft.api.turtle.TurtleRefuelHandler;
 import dan200.computercraft.impl.ComputerCraftAPIService;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
@@ -37,7 +38,7 @@ import javax.annotation.Nullable;
 /**
  * The static entry point to the ComputerCraft API.
  * <p>
- * Members in this class must be called after mod_ComputerCraft has been initialised, but may be called before it is
+ * Members in this class must be called after ComputerCraft has been initialised, but may be called before it is
  * fully loaded.
  */
 public final class ComputerCraftAPI
@@ -122,7 +123,9 @@ public final class ComputerCraftAPI
      * @param provider The peripheral provider to register.
      * @see IPeripheral
      * @see IPeripheralProvider
+     * @deprecated Use {@link ForgeComputerCraftAPI#registerPeripheralProvider(IPeripheralProvider)} instead.
      */
+    @Deprecated( forRemoval = true )
     public static void registerPeripheralProvider( @Nonnull IPeripheralProvider provider )
     {
         getInstance().registerPeripheralProvider( provider );
@@ -144,7 +147,9 @@ public final class ComputerCraftAPI
      *
      * @param capability The capability to register.
      * @see GenericSource
+     * @deprecated Use {@link ForgeComputerCraftAPI} instead.
      */
+    @Deprecated( forRemoval = true )
     public static void registerGenericCapability( @Nonnull Capability<?> capability )
     {
         getInstance().registerGenericCapability( capability );
@@ -212,7 +217,7 @@ public final class ComputerCraftAPI
      * @param <T>      The type of object that this provider can provide details for.
      * @deprecated Use {@link DetailRegistry#addProvider(IDetailProvider)} to register your provider.
      */
-    @Deprecated
+    @Deprecated( forRemoval = true )
     public static <T> void registerDetailProvider( @Nonnull Class<T> type, @Nonnull IDetailProvider<T> provider )
     {
         getInstance().registerDetailProvider( type, provider );
@@ -239,13 +244,20 @@ public final class ComputerCraftAPI
      * @param side  The side to extract the network element from
      * @return The element's node
      * @see IWiredElement#getNode()
+     * @deprecated Use {@link ForgeComputerCraftAPI#getWiredElementAt(BlockGetter, BlockPos, Direction)}
      */
     @Nonnull
+    @Deprecated( forRemoval = true )
     public static LazyOptional<IWiredElement> getWiredElementAt( @Nonnull BlockGetter world, @Nonnull BlockPos pos, @Nonnull Direction side )
     {
         return getInstance().getWiredElementAt( world, pos, side );
     }
 
+    public static void registerRefuelHandler( @Nonnull TurtleRefuelHandler handler )
+    {
+        getInstance().registerRefuelHandler( handler );
+    }
+
     @Nonnull
     private static ComputerCraftAPIService getInstance()
     {

src/main/java/dan200/computercraft/api/ForgeComputerCraftAPI.java

@@ -0,0 +1,73 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api;
+
+import dan200.computercraft.api.lua.GenericSource;
+import dan200.computercraft.api.network.wired.IWiredElement;
+import dan200.computercraft.api.peripheral.IPeripheral;
+import dan200.computercraft.api.peripheral.IPeripheralProvider;
+import dan200.computercraft.impl.ComputerCraftAPIService;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.world.level.BlockGetter;
+import net.minecraftforge.common.capabilities.Capability;
+import net.minecraftforge.common.util.LazyOptional;
+
+import javax.annotation.Nonnull;
+
+/**
+ * The forge-specific entrypoint for ComputerCraft's API.
+ */
+public final class ForgeComputerCraftAPI
+{
+    private ForgeComputerCraftAPI()
+    {
+    }
+
+    /**
+     * Registers a peripheral provider to convert blocks into {@link IPeripheral} implementations.
+     *
+     * @param provider The peripheral provider to register.
+     * @see IPeripheral
+     * @see IPeripheralProvider
+     */
+    public static void registerPeripheralProvider( @Nonnull IPeripheralProvider provider )
+    {
+        getInstance().registerPeripheralProvider( provider );
+    }
+
+    /**
+     * Registers a capability that can be used by generic peripherals.
+     *
+     * @param capability The capability to register.
+     * @see GenericSource
+     */
+    public static void registerGenericCapability( @Nonnull Capability<?> capability )
+    {
+        getInstance().registerGenericCapability( capability );
+    }
+
+    /**
+     * Get the wired network element for a block in world.
+     *
+     * @param world The world the block exists in
+     * @param pos   The position the block exists in
+     * @param side  The side to extract the network element from
+     * @return The element's node
+     * @see IWiredElement#getNode()
+     */
+    @Nonnull
+    public static LazyOptional<IWiredElement> getWiredElementAt( @Nonnull BlockGetter world, @Nonnull BlockPos pos, @Nonnull Direction side )
+    {
+        return getInstance().getWiredElementAt( world, pos, side );
+    }
+
+    @Nonnull
+    private static ComputerCraftAPIService getInstance()
+    {
+        return ComputerCraftAPIService.get();
+    }
+}

src/main/java/dan200/computercraft/api/detail/DetailRegistry.java

@@ -14,7 +14,7 @@ import java.util.Map;
  * <p>
  * These are used by computer methods such as {@code turtle.getItemDetail()} or {@code turtle.inspect()}.
  * <p>
- * Specific instances of this registry are available from {@link DetailRegistries} and loader-specific versions
+ * Specific instances of this registry are available from {@link VanillaDetailRegistries} and loader-specific versions
  * also in this package.
  *
  * @param <T> The type of object that this registry provides details for.

src/main/java/dan200/computercraft/api/detail/ForgeDetailRegistries.java

@@ -0,0 +1,20 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.detail;
+
+import dan200.computercraft.impl.ComputerCraftAPIService;
+import net.minecraftforge.fluids.FluidStack;
+
+/**
+ * {@link DetailRegistry}s for Forge-specific types.
+ */
+public class ForgeDetailRegistries
+{
+    /**
+     * Provides details for {@link FluidStack}.
+     */
+    public static final DetailRegistry<FluidStack> FLUID_STACK = ComputerCraftAPIService.get().getFluidStackDetailRegistry();
+}

src/main/java/dan200/computercraft/api/detail/VanillaDetailRegistries.java

@@ -8,12 +8,11 @@ package dan200.computercraft.api.detail;
 import dan200.computercraft.impl.ComputerCraftAPIService;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.block.Block;
-import net.minecraftforge.fluids.FluidStack;
 
 /**
  * {@link DetailRegistry}s for built-in Minecraft types.
  */
-public class DetailRegistries
+public class VanillaDetailRegistries
 {
     /**
      * Provides details for {@link ItemStack}s.
@@ -25,8 +24,4 @@ public class DetailRegistries
      */
     public static final DetailRegistry<BlockReference> BLOCK_IN_WORLD = ComputerCraftAPIService.get().getBlockInWorldDetailRegistry();
 
-    /**
-     * Provides details for {@link FluidStack}.
-     */
-    public static final DetailRegistry<FluidStack> FLUID_STACK = ComputerCraftAPIService.get().getFluidStackDetailRegistry();
 }

src/main/java/dan200/computercraft/api/lua/GenericSource.java

@@ -6,6 +6,7 @@
 package dan200.computercraft.api.lua;
 
 import dan200.computercraft.api.ComputerCraftAPI;
+import dan200.computercraft.api.ForgeComputerCraftAPI;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.api.peripheral.IPeripheralProvider;
 import dan200.computercraft.core.asm.LuaMethod;
@@ -42,7 +43,7 @@ import javax.annotation.Nonnull;
  * }</pre>
  *
  * @see ComputerCraftAPI#registerGenericSource(GenericSource)
- * @see ComputerCraftAPI#registerGenericCapability(Capability) New capabilities (those not built into Forge) must be
+ * @see ForgeComputerCraftAPI#registerGenericCapability(Capability) New capabilities (those not built into Forge) must be
  * explicitly given to the generic peripheral system, as there is no way to enumerate all capabilities.
  */
 public interface GenericSource

src/main/java/dan200/computercraft/api/peripheral/IPeripheralProvider.java

@@ -5,6 +5,7 @@
  */
 package dan200.computercraft.api.peripheral;
 
+import dan200.computercraft.api.ForgeComputerCraftAPI;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.world.level.Level;
@@ -31,7 +32,7 @@ public interface IPeripheralProvider
      * @param pos   The position the block is at.
      * @param side  The side to get the peripheral from.
      * @return A peripheral, or {@link LazyOptional#empty()} if there is not a peripheral here you'd like to handle.
-     * @see dan200.computercraft.api.ComputerCraftAPI#registerPeripheralProvider(IPeripheralProvider)
+     * @see ForgeComputerCraftAPI#registerPeripheralProvider(IPeripheralProvider)
      */
     @Nonnull
     LazyOptional<IPeripheral> getPeripheral( @Nonnull Level world, @Nonnull BlockPos pos, @Nonnull Direction side );

src/main/java/dan200/computercraft/api/pocket/PocketUpgradeDataProvider.java

@@ -25,6 +25,6 @@ public abstract class PocketUpgradeDataProvider extends UpgradeDataProvider<IPoc
 {
     public PocketUpgradeDataProvider( @Nonnull DataGenerator generator )
     {
-        super( generator, "Pocket Computer Upgrades", "computercraft/pocket_upgrades", PocketUpgradeSerialiser.registry() );
+        super( generator, "Pocket Computer Upgrades", "computercraft/pocket_upgrades", PocketUpgradeSerialiser.REGISTRY_ID );
     }
 }

src/main/java/dan200/computercraft/api/pocket/PocketUpgradeSerialiser.java

@@ -40,8 +40,6 @@ public interface PocketUpgradeSerialiser<T extends IPocketUpgrade> extends Upgra
      * <p>
      * This is largely intended for use with Forge Registry methods/classes, such as {@link DeferredRegister} and
      * {@link RegistryManager#getRegistry(ResourceKey)}.
-     *
-     * @see #registry()
      */
     ResourceKey<Registry<PocketUpgradeSerialiser<?>>> REGISTRY_ID = ResourceKey.createRegistryKey( new ResourceLocation( ComputerCraft.MOD_ID, "pocket_upgrade_serialiser" ) );
 
@@ -50,7 +48,9 @@ public interface PocketUpgradeSerialiser<T extends IPocketUpgrade> extends Upgra
      *
      * @return The registry for pocket upgrade serialisers.
      * @see #REGISTRY_ID
+     * @deprecated Use {@link #REGISTRY_ID} directly.
      */
+    @Deprecated( forRemoval = true )
     static IForgeRegistry<PocketUpgradeSerialiser<?>> registry()
     {
         return RegistryManager.ACTIVE.getRegistry( REGISTRY_ID );

src/main/java/dan200/computercraft/api/turtle/ITurtleAccess.java

@@ -44,6 +44,20 @@ public interface ITurtleAccess
     @Nonnull
     BlockPos getPosition();
 
+    /**
+     * Determine if this turtle has been removed.
+     * <p>
+     * It's possible for a turtle to be removed while a {@link ITurtleCommand} is executed, for instance if interacting
+     * with a block causes the turtle to be blown up. It's recommended you check the turtle is still present before
+     * trying to interact with it again.
+     * <p>
+     * If a turtle has been removed {@link #getLevel()} and {@link #getPosition()} will continue to function as before.
+     * All other methods will fail.
+     *
+     * @return Whether this turtle has been removed.
+     */
+    boolean isRemoved();
+
     /**
      * Attempt to move this turtle to a new position.
      * <p>
@@ -161,9 +175,10 @@ public interface ITurtleAccess
      * @return This turtle's inventory
      * @see #getInventory()
      * @see IItemHandlerModifiable
-     * @see net.minecraftforge.items.CapabilityItemHandler#ITEM_HANDLER_CAPABILITY
+     * @deprecated Use {@link #getInventory()} directly.
      */
     @Nonnull
+    @Deprecated( forRemoval = true )
     IItemHandlerModifiable getItemHandler();
 
     /**

src/main/java/dan200/computercraft/api/turtle/TurtleRefuelHandler.java

@@ -0,0 +1,35 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.turtle;
+
+import dan200.computercraft.api.ComputerCraftAPI;
+import net.minecraft.world.item.ItemStack;
+
+import java.util.OptionalInt;
+
+/**
+ * A function called when a turtle attempts to refuel via {@code turtle.refuel()}. This may be used to provide
+ * alternative fuel sources, such as consuming RF batteries.
+ *
+ * @see ComputerCraftAPI#registerRefuelHandler(TurtleRefuelHandler)
+ */
+public interface TurtleRefuelHandler
+{
+    /**
+     * Refuel a turtle using an item.
+     *
+     * @param turtle The turtle to refuel.
+     * @param stack  The stack to refuel with.
+     * @param slot   The slot the stack resides within. This may be used to modify the inventory afterwards.
+     * @param limit  The maximum number of refuel operations to perform. This will often correspond to the number of
+     *               items to consume.
+     *               <p>
+     *               This value may be zero. In this case, you should still detect if the item can be handled (returning
+     *               {@code OptionalInt#of(0)} if so), but should <em>NOT</em> modify the stack or inventory.
+     * @return The amount of fuel gained, or {@link OptionalInt#empty()} if this handler does not accept the given item.
+     */
+    OptionalInt refuel( ITurtleAccess turtle, ItemStack stack, int slot, int limit );
+}

src/main/java/dan200/computercraft/api/turtle/TurtleUpgradeDataProvider.java

@@ -35,7 +35,7 @@ public abstract class TurtleUpgradeDataProvider extends UpgradeDataProvider<ITur
 
     public TurtleUpgradeDataProvider( DataGenerator generator )
     {
-        super( generator, "Turtle Upgrades", "computercraft/turtle_upgrades", TurtleUpgradeSerialiser.registry() );
+        super( generator, "Turtle Upgrades", "computercraft/turtle_upgrades", TurtleUpgradeSerialiser.REGISTRY_ID );
     }
 
     /**

src/main/java/dan200/computercraft/api/turtle/TurtleUpgradeSerialiser.java

@@ -78,8 +78,6 @@ public interface TurtleUpgradeSerialiser<T extends ITurtleUpgrade> extends Upgra
      * <p>
      * This is largely intended for use with Forge Registry methods/classes, such as {@link DeferredRegister} and
      * {@link RegistryManager#getRegistry(ResourceKey)}.
-     *
-     * @see #registry()
      */
     ResourceKey<Registry<TurtleUpgradeSerialiser<?>>> REGISTRY_ID = ResourceKey.createRegistryKey( new ResourceLocation( ComputerCraft.MOD_ID, "turtle_upgrade_serialiser" ) );
 
@@ -88,7 +86,9 @@ public interface TurtleUpgradeSerialiser<T extends ITurtleUpgrade> extends Upgra
      *
      * @return The registry for pocket upgrade serialisers.
      * @see #REGISTRY_ID
+     * @deprecated Use {@link #REGISTRY_ID} directly.
      */
+    @Deprecated( forRemoval = true )
     static IForgeRegistry<TurtleUpgradeSerialiser<?>> registry()
     {
         return RegistryManager.ACTIVE.getRegistry( REGISTRY_ID );

src/main/java/dan200/computercraft/api/turtle/event/TurtleEvent.java

@@ -16,7 +16,10 @@ import java.util.Objects;
  * so sever specific methods on {@link ITurtleAccess} are safe to use.
  * <p>
  * You should generally not need to subscribe to this event, preferring one of the more specific classes.
+ *
+ * @deprecated No longer needed, see {@link TurtleRefuelEvent}.
  */
+@Deprecated( forRemoval = true )
 public abstract class TurtleEvent extends Event
 {
     private final ITurtleAccess turtle;

src/main/java/dan200/computercraft/api/turtle/event/TurtleRefuelEvent.java

@@ -6,6 +6,7 @@
 package dan200.computercraft.api.turtle.event;
 
 import dan200.computercraft.api.turtle.ITurtleAccess;
+import dan200.computercraft.api.turtle.TurtleRefuelHandler;
 import net.minecraft.world.item.ItemStack;
 
 import javax.annotation.Nonnull;
@@ -16,7 +17,10 @@ import java.util.Objects;
  * Fired when a turtle attempts to refuel from an item.
  * <p>
  * One may use {@link #setHandler(Handler)} to register a custom fuel provider for a given item.
+ *
+ * @deprecated Use {@link TurtleRefuelHandler} instead.
  */
+@Deprecated( forRemoval = true )
 public class TurtleRefuelEvent extends TurtleEvent
 {
     private final ItemStack stack;

src/main/java/dan200/computercraft/api/upgrades/UpgradeDataProvider.java

@@ -10,13 +10,15 @@ import com.google.gson.JsonParseException;
 import dan200.computercraft.api.turtle.TurtleUpgradeSerialiser;
 import dan200.computercraft.internal.upgrades.SerialiserWithCraftingItem;
 import dan200.computercraft.internal.upgrades.SimpleSerialiser;
+import net.minecraft.core.Registry;
 import net.minecraft.data.CachedOutput;
 import net.minecraft.data.DataGenerator;
 import net.minecraft.data.DataProvider;
+import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.Item;
 import net.minecraftforge.registries.ForgeRegistries;
-import net.minecraftforge.registries.IForgeRegistry;
+import net.minecraftforge.registries.RegistryManager;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -28,8 +30,8 @@ import java.util.function.Consumer;
 import java.util.function.Function;
 
 /**
- * A data generator/provider for turtle and pocket computer upgrades. This should not be extended direclty, instead see
+ * A data generator/provider for turtle and pocket computer upgrades. This should not be extended directly, instead see
- * the other sub-classes.
+ * the other subclasses.
  *
  * @param <T> The base class of upgrades.
  * @param <R> The upgrade serialiser to register for.
@@ -41,11 +43,11 @@ public abstract class UpgradeDataProvider<T extends IUpgradeBase, R extends Upgr
     private final DataGenerator generator;
     private final String name;
     private final String folder;
-    private final IForgeRegistry<R> registry;
+    private final ResourceKey<Registry<R>> registry;
 
     private List<T> upgrades;
 
-    protected UpgradeDataProvider( @Nonnull DataGenerator generator, @Nonnull String name, @Nonnull String folder, @Nonnull IForgeRegistry<R> registry )
+    protected UpgradeDataProvider( @Nonnull DataGenerator generator, @Nonnull String name, @Nonnull String folder, @Nonnull ResourceKey<Registry<R>> registry )
     {
         this.generator = generator;
         this.name = name;
@@ -94,7 +96,7 @@ public abstract class UpgradeDataProvider<T extends IUpgradeBase, R extends Upgr
 
     /**
      * Add all turtle or pocket computer upgrades.
-     *
+     * <p>
      * <strong>Example usage:</strong>
      * <pre>{@code
      * protected void addUpgrades(@Nonnull Consumer<Upgrade<TurtleUpgradeSerialiser<?>>> addUpgrade) {
@@ -109,6 +111,7 @@ public abstract class UpgradeDataProvider<T extends IUpgradeBase, R extends Upgr
     @Override
     public final void run( @Nonnull CachedOutput cache ) throws IOException
     {
+        var registry = RegistryManager.ACTIVE.getRegistry( this.registry );
         Path base = generator.getOutputFolder().resolve( "data" );
 
         Set<ResourceLocation> seen = new HashSet<>();
@@ -153,7 +156,7 @@ public abstract class UpgradeDataProvider<T extends IUpgradeBase, R extends Upgr
     @Nonnull
     public final R existingSerialiser( @Nonnull ResourceLocation id )
     {
-        var result = registry.getValue( id );
+        var result = RegistryManager.ACTIVE.getRegistry( registry ).getValue( id );
         if( result == null ) throw new IllegalArgumentException( "No such serialiser " + registry );
         return result;
     }

src/main/java/dan200/computercraft/impl/ComputerCraftAPIService.java

@@ -19,6 +19,7 @@ import dan200.computercraft.api.network.wired.IWiredElement;
 import dan200.computercraft.api.network.wired.IWiredNode;
 import dan200.computercraft.api.peripheral.IPeripheralProvider;
 import dan200.computercraft.api.redstone.IBundledRedstoneProvider;
+import dan200.computercraft.api.turtle.TurtleRefuelHandler;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.world.item.ItemStack;
@@ -83,6 +84,8 @@ public interface ComputerCraftAPIService
     @Nonnull
     LazyOptional<IWiredElement> getWiredElementAt( @Nonnull BlockGetter world, @Nonnull BlockPos pos, @Nonnull Direction side );
 
+    void registerRefuelHandler( @Nonnull TurtleRefuelHandler handler );
+
     DetailRegistry<ItemStack> getItemStackDetailRegistry();
 
     DetailRegistry<BlockReference> getBlockInWorldDetailRegistry();

src/main/java/dan200/computercraft/impl/TurtleRefuelHandlers.java

@@ -0,0 +1,68 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.impl;
+
+import dan200.computercraft.api.turtle.ITurtleAccess;
+import dan200.computercraft.api.turtle.TurtleRefuelHandler;
+import dan200.computercraft.api.turtle.event.TurtleRefuelEvent;
+import net.minecraft.world.item.ItemStack;
+import net.minecraftforge.common.MinecraftForge;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.OptionalInt;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * Registry of {@link TurtleRefuelHandler}s.
+ */
+public final class TurtleRefuelHandlers
+{
+    private static final List<TurtleRefuelHandler> handlers = new CopyOnWriteArrayList<>();
+
+    static
+    {
+        // Register a fallback handler for our event.
+        handlers.add( ( turtle, stack, slot, limit ) -> {
+            @SuppressWarnings( "removal" ) TurtleRefuelEvent event = new TurtleRefuelEvent( turtle, stack );
+            MinecraftForge.EVENT_BUS.post( event );
+            if( event.getHandler() == null ) return OptionalInt.empty();
+            if( limit == 0 ) return OptionalInt.of( 0 );
+            return OptionalInt.of( event.getHandler().refuel( turtle, stack, slot, limit ) );
+        } );
+    }
+
+    private TurtleRefuelHandlers()
+    {
+    }
+
+    public static void register( TurtleRefuelHandler handler )
+    {
+        Objects.requireNonNull( handler, "handler cannot be null" );
+        handlers.add( handler );
+    }
+
+    public static OptionalInt refuel( ITurtleAccess turtle, ItemStack stack, int slot, int limit )
+    {
+        for( var handler : handlers )
+        {
+            var fuel = handler.refuel( turtle, stack, slot, limit );
+            if( fuel.isPresent() )
+            {
+                var refuelled = fuel.getAsInt();
+                if( refuelled < 0 ) throw new IllegalStateException( handler + " returned a negative value" );
+                if( limit == 0 && refuelled != 0 )
+                {
+                    throw new IllegalStateException( handler + " refuelled despite given a limit of 0" );
+                }
+
+                return fuel;
+            }
+        }
+
+        return OptionalInt.empty();
+    }
+}

src/main/java/dan200/computercraft/shared/Registry.java

@@ -8,7 +8,9 @@ package dan200.computercraft.shared;
 import com.mojang.brigadier.arguments.ArgumentType;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.ComputerCraftAPI;
-import dan200.computercraft.api.detail.DetailRegistries;
+import dan200.computercraft.api.ForgeComputerCraftAPI;
+import dan200.computercraft.api.detail.ForgeDetailRegistries;
+import dan200.computercraft.api.detail.VanillaDetailRegistries;
 import dan200.computercraft.api.media.IMedia;
 import dan200.computercraft.api.network.wired.IWiredElement;
 import dan200.computercraft.api.peripheral.IPeripheral;
@@ -409,13 +411,13 @@ public final class Registry
 
         // Register generic capabilities. This can technically be done off-thread, but we need it to happen
         // after Forge's common setup, so this is easiest.
-        ComputerCraftAPI.registerGenericCapability( ForgeCapabilities.ITEM_HANDLER );
+        ForgeComputerCraftAPI.registerGenericCapability( ForgeCapabilities.ITEM_HANDLER );
-        ComputerCraftAPI.registerGenericCapability( ForgeCapabilities.ENERGY );
+        ForgeComputerCraftAPI.registerGenericCapability( ForgeCapabilities.ENERGY );
-        ComputerCraftAPI.registerGenericCapability( ForgeCapabilities.FLUID_HANDLER );
+        ForgeComputerCraftAPI.registerGenericCapability( ForgeCapabilities.FLUID_HANDLER );
 
-        DetailRegistries.ITEM_STACK.addProvider( ItemData::fill );
+        VanillaDetailRegistries.ITEM_STACK.addProvider( ItemData::fill );
-        DetailRegistries.BLOCK_IN_WORLD.addProvider( BlockData::fill );
+        VanillaDetailRegistries.BLOCK_IN_WORLD.addProvider( BlockData::fill );
-        DetailRegistries.FLUID_STACK.addProvider( FluidData::fill );
+        ForgeDetailRegistries.FLUID_STACK.addProvider( FluidData::fill );
 
         CauldronInteraction.WATER.put( ModItems.TURTLE_NORMAL.get(), ItemTurtle.CAULDRON_INTERACTION );
         CauldronInteraction.WATER.put( ModItems.TURTLE_ADVANCED.get(), ItemTurtle.CAULDRON_INTERACTION );

src/main/java/dan200/computercraft/shared/computer/apis/CommandAPI.java

@@ -9,7 +9,7 @@ import com.mojang.brigadier.tree.CommandNode;
 import com.mojang.brigadier.tree.LiteralCommandNode;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.detail.BlockReference;
-import dan200.computercraft.api.detail.DetailRegistries;
+import dan200.computercraft.api.detail.VanillaDetailRegistries;
 import dan200.computercraft.api.lua.*;
 import dan200.computercraft.shared.computer.blocks.TileCommandComputer;
 import dan200.computercraft.shared.util.NBTUtil;
@@ -77,7 +77,7 @@ public class CommandAPI implements ILuaAPI
     {
         // Get the details of the block
         BlockReference block = new BlockReference( world, pos );
-        Map<String, Object> table = DetailRegistries.BLOCK_IN_WORLD.getDetails( block );
+        Map<String, Object> table = VanillaDetailRegistries.BLOCK_IN_WORLD.getDetails( block );
 
         BlockEntity tile = block.blockEntity();
         if( tile != null ) table.put( "nbt", NBTUtil.toLua( tile.saveWithFullMetadata() ) );

src/main/java/dan200/computercraft/shared/network/client/UpgradesLoadedMessage.java

@@ -72,8 +72,8 @@ public class UpgradesLoadedMessage implements NetworkMessage
     @Override
     public void toBytes( @Nonnull FriendlyByteBuf buf )
     {
-        toBytes( buf, TurtleUpgradeSerialiser.registry(), turtleUpgrades );
+        toBytes( buf, RegistryManager.ACTIVE.getRegistry( TurtleUpgradeSerialiser.REGISTRY_ID ), turtleUpgrades );
-        toBytes( buf, PocketUpgradeSerialiser.registry(), pocketUpgrades );
+        toBytes( buf, RegistryManager.ACTIVE.getRegistry( PocketUpgradeSerialiser.REGISTRY_ID ), pocketUpgrades );
     }
 
     private <R extends UpgradeSerialiser<? extends T>, T extends IUpgradeBase> void toBytes(

src/main/java/dan200/computercraft/shared/peripheral/generic/methods/FluidMethods.java

@@ -6,7 +6,7 @@
 package dan200.computercraft.shared.peripheral.generic.methods;
 
 import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.api.detail.DetailRegistries;
+import dan200.computercraft.api.detail.ForgeDetailRegistries;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.api.peripheral.GenericPeripheral;
@@ -74,7 +74,7 @@ public class FluidMethods implements GenericPeripheral
         for( int i = 0; i < size; i++ )
         {
             FluidStack stack = fluids.getFluidInTank( i );
-            if( !stack.isEmpty() ) result.put( i + 1, DetailRegistries.FLUID_STACK.getBasicDetails( stack ) );
+            if( !stack.isEmpty() ) result.put( i + 1, ForgeDetailRegistries.FLUID_STACK.getBasicDetails( stack ) );
         }
 
         return result;

src/main/java/dan200/computercraft/shared/peripheral/generic/methods/InventoryMethods.java

@@ -6,7 +6,7 @@
 package dan200.computercraft.shared.peripheral.generic.methods;
 
 import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.api.detail.DetailRegistries;
+import dan200.computercraft.api.detail.VanillaDetailRegistries;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.api.lua.LuaFunction;
@@ -99,7 +99,7 @@ public class InventoryMethods implements GenericPeripheral
         for( int i = 0; i < size; i++ )
         {
             ItemStack stack = inventory.getStackInSlot( i );
-            if( !stack.isEmpty() ) result.put( i + 1, DetailRegistries.ITEM_STACK.getBasicDetails( stack ) );
+            if( !stack.isEmpty() ) result.put( i + 1, VanillaDetailRegistries.ITEM_STACK.getBasicDetails( stack ) );
         }
 
         return result;
@@ -149,7 +149,7 @@ public class InventoryMethods implements GenericPeripheral
         assertBetween( slot, 1, inventory.getSlots(), "Slot out of range (%s)" );
 
         ItemStack stack = inventory.getStackInSlot( slot - 1 );
-        return stack.isEmpty() ? null : DetailRegistries.ITEM_STACK.getDetails( stack );
+        return stack.isEmpty() ? null : VanillaDetailRegistries.ITEM_STACK.getDetails( stack );
     }
 
     /**

src/main/java/dan200/computercraft/shared/peripheral/modem/wired/BlockCable.java

@@ -6,7 +6,7 @@
 package dan200.computercraft.shared.peripheral.modem.wired;
 
 import com.google.common.collect.ImmutableMap;
-import dan200.computercraft.api.ComputerCraftAPI;
+import dan200.computercraft.api.ForgeComputerCraftAPI;
 import dan200.computercraft.shared.Registry;
 import dan200.computercraft.shared.common.BlockGeneric;
 import dan200.computercraft.shared.util.WaterloggableHelpers;
@@ -86,7 +86,7 @@ public class BlockCable extends BlockGeneric implements SimpleWaterloggedBlock
     {
         if( !state.getValue( CABLE ) ) return false;
         if( state.getValue( MODEM ).getFacing() == direction ) return true;
-        return ComputerCraftAPI.getWiredElementAt( world, pos.relative( direction ), direction.getOpposite() ).isPresent();
+        return ForgeComputerCraftAPI.getWiredElementAt( world, pos.relative( direction ), direction.getOpposite() ).isPresent();
     }
 
     @Nonnull

src/main/java/dan200/computercraft/shared/peripheral/modem/wired/TileCable.java

@@ -6,7 +6,7 @@
 package dan200.computercraft.shared.peripheral.modem.wired;
 
 import com.google.common.base.Objects;
-import dan200.computercraft.api.ComputerCraftAPI;
+import dan200.computercraft.api.ForgeComputerCraftAPI;
 import dan200.computercraft.api.network.wired.IWiredElement;
 import dan200.computercraft.api.network.wired.IWiredNode;
 import dan200.computercraft.api.peripheral.IPeripheral;
@@ -346,7 +346,7 @@ public class TileCable extends TileGeneric
             BlockPos offset = current.relative( facing );
             if( !world.isLoaded( offset ) ) continue;
 
-            LazyOptional<IWiredElement> element = ComputerCraftAPI.getWiredElementAt( world, offset, facing.getOpposite() );
+            LazyOptional<IWiredElement> element = ForgeComputerCraftAPI.getWiredElementAt( world, offset, facing.getOpposite() );
             if( !element.isPresent() ) continue;
 
             element.addListener( connectedNodeChanged );

src/main/java/dan200/computercraft/shared/peripheral/modem/wired/TileWiredModemFull.java

@@ -6,7 +6,7 @@
 package dan200.computercraft.shared.peripheral.modem.wired;
 
 import com.google.common.base.Objects;
-import dan200.computercraft.api.ComputerCraftAPI;
+import dan200.computercraft.api.ForgeComputerCraftAPI;
 import dan200.computercraft.api.network.wired.IWiredElement;
 import dan200.computercraft.api.network.wired.IWiredNode;
 import dan200.computercraft.api.peripheral.IPeripheral;
@@ -308,7 +308,7 @@ public class TileWiredModemFull extends TileGeneric
             BlockPos offset = current.relative( facing );
             if( !world.isLoaded( offset ) ) continue;
 
-            LazyOptional<IWiredElement> element = ComputerCraftAPI.getWiredElementAt( world, offset, facing.getOpposite() );
+            LazyOptional<IWiredElement> element = ForgeComputerCraftAPI.getWiredElementAt( world, offset, facing.getOpposite() );
             if( !element.isPresent() ) continue;
 
             element.addListener( connectedNodeChanged );

src/main/java/dan200/computercraft/shared/turtle/FurnaceRefuelHandler.java

@@ -5,20 +5,15 @@
  */
 package dan200.computercraft.shared.turtle;
 
-import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.turtle.ITurtleAccess;
-import dan200.computercraft.api.turtle.event.TurtleRefuelEvent;
+import dan200.computercraft.api.turtle.TurtleRefuelHandler;
-import dan200.computercraft.shared.util.InventoryUtil;
-import dan200.computercraft.shared.util.WorldUtil;
 import net.minecraft.world.item.ItemStack;
 import net.minecraftforge.common.ForgeHooks;
-import net.minecraftforge.eventbus.api.SubscribeEvent;
-import net.minecraftforge.fml.common.Mod;
 
 import javax.annotation.Nonnull;
+import java.util.OptionalInt;
 
-@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID )
+public final class FurnaceRefuelHandler implements TurtleRefuelHandler
-public final class FurnaceRefuelHandler implements TurtleRefuelEvent.Handler
 {
     private static final FurnaceRefuelHandler INSTANCE = new FurnaceRefuelHandler();
 
@@ -27,37 +22,29 @@ public final class FurnaceRefuelHandler implements TurtleRefuelEvent.Handler
     }
 
     @Override
-    public int refuel( @Nonnull ITurtleAccess turtle, @Nonnull ItemStack currentStack, int slot, int limit )
+    public OptionalInt refuel( @Nonnull ITurtleAccess turtle, @Nonnull ItemStack currentStack, int slot, int limit )
     {
+        int fuelPerItem = getFuelPerItem( currentStack );
+        if( fuelPerItem <= 0 ) return OptionalInt.empty();
+        if( limit == 0 ) return OptionalInt.of( 0 );
+
         int fuelSpaceLeft = turtle.getFuelLimit() - turtle.getFuelLevel();
-        int fuelPerItem = getFuelPerItem( turtle.getItemHandler().getStackInSlot( slot ) );
         int fuelItemLimit = (int) Math.ceil( fuelSpaceLeft / (double) fuelPerItem );
         if( limit > fuelItemLimit ) limit = fuelItemLimit;
 
-        ItemStack stack = turtle.getItemHandler().extractItem( slot, limit, false );
+        ItemStack stack = turtle.getInventory().removeItem( slot, limit );
         int fuelToGive = fuelPerItem * stack.getCount();
         // Store the replacement item in the inventory
         ItemStack replacementStack = ForgeHooks.getCraftingRemainingItem( stack );
-        if( !replacementStack.isEmpty() )
+        if( !replacementStack.isEmpty() ) TurtleUtil.storeItemOrDrop( turtle, replacementStack );
-        {
-            ItemStack remainder = InventoryUtil.storeItems( replacementStack, turtle.getItemHandler(), turtle.getSelectedSlot() );
-            if( !remainder.isEmpty() )
-            {
-                WorldUtil.dropItemStack( remainder, turtle.getLevel(), turtle.getPosition(), turtle.getDirection().getOpposite() );
-            }
-        }
 
-        return fuelToGive;
+        turtle.getInventory().setChanged();
+
+        return OptionalInt.of( fuelToGive );
     }
 
     private static int getFuelPerItem( @Nonnull ItemStack stack )
     {
         return (ForgeHooks.getBurnTime( stack, null ) * 5) / 100;
     }
-
-    @SubscribeEvent
-    public static void onTurtleRefuel( TurtleRefuelEvent event )
-    {
-        if( event.getHandler() == null && getFuelPerItem( event.getStack() ) > 0 ) event.setHandler( INSTANCE );
-    }
 }

src/main/java/dan200/computercraft/shared/turtle/TurtleUtil.java

@@ -0,0 +1,50 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.shared.turtle;
+
+import dan200.computercraft.api.turtle.ITurtleAccess;
+import dan200.computercraft.shared.util.DropConsumer;
+import dan200.computercraft.shared.util.InventoryUtil;
+import dan200.computercraft.shared.util.WorldUtil;
+import net.minecraft.world.item.ItemStack;
+
+import java.util.function.Function;
+
+public class TurtleUtil
+{
+    /**
+     * Store an item in this turtle, or drop it if there is room remaining.
+     *
+     * @param turtle The turtle to store items into.
+     * @param stack  The stack to store.
+     */
+    public static void storeItemOrDrop( ITurtleAccess turtle, ItemStack stack )
+    {
+        if( stack.isEmpty() ) return;
+        if( turtle.isRemoved() )
+        {
+            WorldUtil.dropItemStack( stack, turtle.getLevel(), turtle.getPosition(), null );
+            return;
+        }
+
+        // Put the remainder back in the turtle
+        ItemStack remainder = InventoryUtil.storeItems( stack, turtle.getItemHandler(), turtle.getSelectedSlot() );
+        if( remainder.isEmpty() ) return;
+
+        WorldUtil.dropItemStack( remainder, turtle.getLevel(), turtle.getPosition(), turtle.getDirection().getOpposite() );
+    }
+
+    public static Function<ItemStack, ItemStack> dropConsumer( ITurtleAccess turtle )
+    {
+        return stack -> turtle.isRemoved() ? stack : InventoryUtil.storeItems( stack, turtle.getItemHandler(), turtle.getSelectedSlot() );
+    }
+
+    public static void stopConsuming( ITurtleAccess turtle )
+    {
+        var direction = turtle.isRemoved() ? null : turtle.getDirection().getOpposite();
+        DropConsumer.clearAndDrop( turtle.getLevel(), turtle.getPosition(), direction );
+    }
+}

src/main/java/dan200/computercraft/shared/turtle/apis/TurtleAPI.java

@@ -5,7 +5,7 @@
  */
 package dan200.computercraft.shared.turtle.apis;
 
-import dan200.computercraft.api.detail.DetailRegistries;
+import dan200.computercraft.api.detail.VanillaDetailRegistries;
 import dan200.computercraft.api.lua.*;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleCommand;
@@ -820,7 +820,7 @@ public class TurtleAPI implements ILuaAPI
         if( stack.isEmpty() ) return new Object[] { null };
 
         Map<String, Object> table = detailed
-            ? DetailRegistries.ITEM_STACK.getDetails( stack )
+            ? VanillaDetailRegistries.ITEM_STACK.getDetails( stack )
             : ItemData.fillBasicSafe( new HashMap<>(), stack );
 
         return new Object[] { table };

src/main/java/dan200/computercraft/shared/turtle/core/TurtleBrain.java

@@ -287,6 +287,12 @@ public class TurtleBrain implements ITurtleAccess
         return owner.getBlockPos();
     }
 
+    @Override
+    public boolean isRemoved()
+    {
+        return owner.isRemoved();
+    }
+
     @Override
     public boolean teleportTo( @Nonnull Level world, @Nonnull BlockPos pos )
     {

src/main/java/dan200/computercraft/shared/turtle/core/TurtleCraftCommand.java

@@ -9,9 +9,8 @@ import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleCommand;
 import dan200.computercraft.api.turtle.TurtleAnimation;
 import dan200.computercraft.api.turtle.TurtleCommandResult;
+import dan200.computercraft.shared.turtle.TurtleUtil;
 import dan200.computercraft.shared.turtle.upgrades.TurtleInventoryCrafting;
-import dan200.computercraft.shared.util.InventoryUtil;
-import dan200.computercraft.shared.util.WorldUtil;
 import net.minecraft.world.item.ItemStack;
 
 import javax.annotation.Nonnull;
@@ -36,14 +35,7 @@ public class TurtleCraftCommand implements ITurtleCommand
         if( results == null ) return TurtleCommandResult.failure( "No matching recipes" );
 
         // Store or drop any remainders
-        for( ItemStack stack : results )
+        for( ItemStack stack : results ) TurtleUtil.storeItemOrDrop( turtle, stack );
-        {
-            ItemStack remainder = InventoryUtil.storeItems( stack, turtle.getItemHandler(), turtle.getSelectedSlot() );
-            if( !remainder.isEmpty() )
-            {
-                WorldUtil.dropItemStack( remainder, turtle.getLevel(), turtle.getPosition(), turtle.getDirection() );
-            }
-        }
 
         if( !results.isEmpty() ) turtle.playAnimation( TurtleAnimation.WAIT );
         return TurtleCommandResult.success();

src/main/java/dan200/computercraft/shared/turtle/core/TurtleDropCommand.java

@@ -45,11 +45,12 @@ public class TurtleDropCommand implements ITurtleCommand
         Direction direction = this.direction.toWorldDir( turtle );
 
         // Get things to drop
-        ItemStack stack = InventoryUtil.takeItems( quantity, turtle.getItemHandler(), turtle.getSelectedSlot(), 1, turtle.getSelectedSlot() );
+        ItemStack stack = turtle.getInventory().removeItem( turtle.getSelectedSlot(), quantity );
         if( stack.isEmpty() )
         {
             return TurtleCommandResult.failure( "No items to drop" );
         }
+        turtle.getInventory().setChanged();
 
         // Get inventory for thing in front
         Level world = turtle.getLevel();

src/main/java/dan200/computercraft/shared/turtle/core/TurtleEquipCommand.java

@@ -7,11 +7,8 @@ package dan200.computercraft.shared.turtle.core;
 
 import dan200.computercraft.api.turtle.*;
 import dan200.computercraft.shared.TurtleUpgrades;
-import dan200.computercraft.shared.util.InventoryUtil;
+import dan200.computercraft.shared.turtle.TurtleUtil;
-import dan200.computercraft.shared.util.WorldUtil;
-import net.minecraft.core.BlockPos;
 import net.minecraft.world.item.ItemStack;
-import net.minecraftforge.items.IItemHandler;
 
 import javax.annotation.Nonnull;
 
@@ -31,8 +28,7 @@ public class TurtleEquipCommand implements ITurtleCommand
         // Determine the upgrade to equipLeft
         ITurtleUpgrade newUpgrade;
         ItemStack newUpgradeStack;
-        IItemHandler inventory = turtle.getItemHandler();
+        ItemStack selectedStack = turtle.getInventory().getItem( turtle.getSelectedSlot() );
-        ItemStack selectedStack = inventory.getStackInSlot( turtle.getSelectedSlot() );
         if( !selectedStack.isEmpty() )
         {
             newUpgradeStack = selectedStack.copy();
@@ -59,22 +55,8 @@ public class TurtleEquipCommand implements ITurtleCommand
         }
 
         // Do the swapping:
-        if( newUpgradeStack != null )
+        if( newUpgradeStack != null ) turtle.getInventory().removeItem( turtle.getSelectedSlot(), 1 );
-        {
+        if( oldUpgradeStack != null ) TurtleUtil.storeItemOrDrop( turtle, oldUpgradeStack );
-            // Consume new upgrades item
-            InventoryUtil.takeItems( 1, inventory, turtle.getSelectedSlot(), 1, turtle.getSelectedSlot() );
-        }
-        if( oldUpgradeStack != null )
-        {
-            // Store old upgrades item
-            ItemStack remainder = InventoryUtil.storeItems( oldUpgradeStack, inventory, turtle.getSelectedSlot() );
-            if( !remainder.isEmpty() )
-            {
-                // If there's no room for the items, drop them
-                BlockPos position = turtle.getPosition();
-                WorldUtil.dropItemStack( remainder, turtle.getLevel(), position, turtle.getDirection() );
-            }
-        }
         turtle.setUpgrade( side, newUpgrade );
 
         // Animate

src/main/java/dan200/computercraft/shared/turtle/core/TurtleInspectCommand.java

@@ -6,7 +6,7 @@
 package dan200.computercraft.shared.turtle.core;
 
 import dan200.computercraft.api.detail.BlockReference;
-import dan200.computercraft.api.detail.DetailRegistries;
+import dan200.computercraft.api.detail.VanillaDetailRegistries;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleCommand;
 import dan200.computercraft.api.turtle.TurtleCommandResult;
@@ -41,7 +41,7 @@ public class TurtleInspectCommand implements ITurtleCommand
         BlockReference block = new BlockReference( world, newPosition );
         if( block.state().isAir() ) return TurtleCommandResult.failure( "No block to inspect" );
 
-        Map<String, Object> table = DetailRegistries.BLOCK_IN_WORLD.getDetails( block );
+        Map<String, Object> table = VanillaDetailRegistries.BLOCK_IN_WORLD.getDetails( block );
 
         return TurtleCommandResult.success( new Object[] { table } );
 

src/main/java/dan200/computercraft/shared/turtle/core/TurtlePlaceCommand.java

@@ -11,6 +11,7 @@ import dan200.computercraft.api.turtle.ITurtleCommand;
 import dan200.computercraft.api.turtle.TurtleAnimation;
 import dan200.computercraft.api.turtle.TurtleCommandResult;
 import dan200.computercraft.shared.TurtlePermissions;
+import dan200.computercraft.shared.turtle.TurtleUtil;
 import dan200.computercraft.shared.util.DropConsumer;
 import dan200.computercraft.shared.util.InventoryUtil;
 import dan200.computercraft.shared.util.WorldUtil;
@@ -124,7 +125,6 @@ public class TurtlePlaceCommand implements ITurtleCommand
     {
         // See if there is an entity present
         final Level world = turtle.getLevel();
-        final BlockPos position = turtle.getPosition();
         Vec3 turtlePos = turtlePlayer.position();
         Vec3 rayDir = turtlePlayer.getViewVector( 1.0f );
         Pair<Entity, Vec3> hit = WorldUtil.rayTraceEntities( world, turtlePos, rayDir, 1.5 );
@@ -139,7 +139,7 @@ public class TurtlePlaceCommand implements ITurtleCommand
 
         boolean placed = doDeployOnEntity( stack, turtlePlayer, hitEntity, hitPos );
 
-        DropConsumer.clearAndDrop( world, position, turtle.getDirection().getOpposite() );
+        TurtleUtil.stopConsuming( turtle );
         return placed;
     }
 

src/main/java/dan200/computercraft/shared/turtle/core/TurtlePlayer.java

@@ -8,9 +8,8 @@ package dan200.computercraft.shared.turtle.core;
 import com.mojang.authlib.GameProfile;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.turtle.ITurtleAccess;
+import dan200.computercraft.shared.turtle.TurtleUtil;
 import dan200.computercraft.shared.util.DirectionUtil;
-import dan200.computercraft.shared.util.InventoryUtil;
-import dan200.computercraft.shared.util.WorldUtil;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.server.level.ServerLevel;
@@ -157,39 +156,33 @@ public final class TurtlePlayer extends FakePlayer
         getInventory().clearContent();
 
         int currentSlot = turtle.getSelectedSlot();
-        int slots = turtle.getItemHandler().getSlots();
+        int slots = turtle.getInventory().getContainerSize();
 
         // Load up the fake inventory
         getInventory().selected = 0;
         for( int i = 0; i < slots; i++ )
         {
-            getInventory().setItem( i, turtle.getItemHandler().getStackInSlot( (currentSlot + i) % slots ) );
+            getInventory().setItem( i, turtle.getInventory().getItem( (currentSlot + i) % slots ) );
         }
     }
 
     public void unloadInventory( ITurtleAccess turtle )
     {
         int currentSlot = turtle.getSelectedSlot();
-        int slots = turtle.getItemHandler().getSlots();
+        int slots = turtle.getInventory().getContainerSize();
 
         // Load up the fake inventory
         getInventory().selected = 0;
         for( int i = 0; i < slots; i++ )
         {
-            turtle.getItemHandler().setStackInSlot( (currentSlot + i) % slots, getInventory().getItem( i ) );
+            turtle.getInventory().setItem( (currentSlot + i) % slots, getInventory().getItem( i ) );
         }
 
         // Store (or drop) anything else we found
-        BlockPos dropPosition = turtle.getPosition();
-        Direction dropDirection = turtle.getDirection().getOpposite();
         int totalSize = getInventory().getContainerSize();
         for( int i = slots; i < totalSize; i++ )
         {
-            ItemStack remainder = InventoryUtil.storeItems( getInventory().getItem( i ), turtle.getItemHandler(), turtle.getSelectedSlot() );
+            TurtleUtil.storeItemOrDrop( turtle, getInventory().getItem( i ) );
-            if( !remainder.isEmpty() )
-            {
-                WorldUtil.dropItemStack( remainder, turtle.getLevel(), dropPosition, dropDirection );
-            }
         }
 
         getInventory().setChanged();

src/main/java/dan200/computercraft/shared/turtle/core/TurtleRefuelCommand.java

@@ -9,9 +9,8 @@ import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleCommand;
 import dan200.computercraft.api.turtle.TurtleAnimation;
 import dan200.computercraft.api.turtle.TurtleCommandResult;
-import dan200.computercraft.api.turtle.event.TurtleRefuelEvent;
+import dan200.computercraft.impl.TurtleRefuelHandlers;
 import net.minecraft.world.item.ItemStack;
-import net.minecraftforge.common.MinecraftForge;
 
 import javax.annotation.Nonnull;
 
@@ -32,13 +31,13 @@ public class TurtleRefuelCommand implements ITurtleCommand
         ItemStack stack = turtle.getInventory().getItem( slot );
         if( stack.isEmpty() ) return TurtleCommandResult.failure( "No items to combust" );
 
-        TurtleRefuelEvent event = new TurtleRefuelEvent( turtle, stack );
+        var refuelled = TurtleRefuelHandlers.refuel( turtle, stack, slot, limit );
-        MinecraftForge.EVENT_BUS.post( event );
+        if( refuelled.isEmpty() ) return TurtleCommandResult.failure( "Items not combustible" );
-        if( event.getHandler() == null ) return TurtleCommandResult.failure( "Items not combustible" );
 
-        if( limit != 0 )
+        var newFuel = refuelled.getAsInt();
+        if( newFuel != 0 )
         {
-            turtle.addFuel( event.getHandler().refuel( turtle, stack, slot, limit ) );
+            turtle.addFuel( newFuel );
             turtle.playAnimation( TurtleAnimation.WAIT );
         }
 

src/main/java/dan200/computercraft/shared/turtle/core/TurtleTransferToCommand.java

@@ -30,7 +30,7 @@ public class TurtleTransferToCommand implements ITurtleCommand
     public TurtleCommandResult execute( @Nonnull ITurtleAccess turtle )
     {
         // Take stack
-        ItemStack stack = InventoryUtil.takeItems( quantity, turtle.getItemHandler(), turtle.getSelectedSlot(), 1, turtle.getSelectedSlot() );
+        ItemStack stack = turtle.getInventory().removeItem( turtle.getSelectedSlot(), quantity );
         if( stack.isEmpty() )
         {
             turtle.playAnimation( TurtleAnimation.WAIT );

src/main/java/dan200/computercraft/shared/turtle/upgrades/TurtleTool.java

@@ -9,11 +9,10 @@ import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.ComputerCraftTags;
 import dan200.computercraft.api.turtle.*;
 import dan200.computercraft.shared.TurtlePermissions;
-import dan200.computercraft.shared.turtle.core.TurtleBrain;
+import dan200.computercraft.shared.turtle.TurtleUtil;
 import dan200.computercraft.shared.turtle.core.TurtlePlaceCommand;
 import dan200.computercraft.shared.turtle.core.TurtlePlayer;
 import dan200.computercraft.shared.util.DropConsumer;
-import dan200.computercraft.shared.util.InventoryUtil;
 import dan200.computercraft.shared.util.WorldUtil;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
@@ -42,7 +41,6 @@ import org.apache.commons.lang3.tuple.Pair;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.util.function.Function;
 
 import static net.minecraft.nbt.Tag.TAG_COMPOUND;
 import static net.minecraft.nbt.Tag.TAG_LIST;
@@ -117,8 +115,6 @@ public class TurtleTool extends AbstractTurtleUpgrade
         // Create a fake player, and orient it appropriately
         Level world = turtle.getLevel();
         BlockPos position = turtle.getPosition();
-        BlockEntity turtleTile = turtle instanceof TurtleBrain ? ((TurtleBrain) turtle).getOwner() : world.getBlockEntity( position );
-        if( turtleTile == null ) return TurtleCommandResult.failure( "Turtle has vanished from existence." );
 
         final TurtlePlayer turtlePlayer = TurtlePlayer.getWithPosition( turtle, position, direction );
 
@@ -141,7 +137,7 @@ public class TurtleTool extends AbstractTurtleUpgrade
             }
 
             // Start claiming entity drops
-            DropConsumer.set( hitEntity, turtleDropConsumer( turtleTile, turtle ) );
+            DropConsumer.set( hitEntity, TurtleUtil.dropConsumer( turtle ) );
 
             // Attack the entity
             boolean attacked = false;
@@ -166,7 +162,7 @@ public class TurtleTool extends AbstractTurtleUpgrade
             }
 
             // Stop claiming drops
-            stopConsuming( turtleTile, turtle );
+            TurtleUtil.stopConsuming( turtle );
 
             // Put everything we collected into the turtles inventory, then return
             if( attacked )
@@ -181,8 +177,7 @@ public class TurtleTool extends AbstractTurtleUpgrade
 
     private TurtleCommandResult dig( ITurtleAccess turtle, Direction direction )
     {
-        // TODO: HOE_TILL really, if it's ever implemented
+        if( item.canPerformAction( ToolActions.SHOVEL_FLATTEN ) || item.canPerformAction( ToolActions.HOE_TILL ) )
-        if( item.canPerformAction( ToolActions.SHOVEL_FLATTEN ) || item.canPerformAction( ToolActions.HOE_DIG ) )
         {
             if( TurtlePlaceCommand.deployCopiedItem( item.copy(), turtle, direction, null, null ) )
             {
@@ -193,8 +188,6 @@ public class TurtleTool extends AbstractTurtleUpgrade
         // Get ready to dig
         Level world = turtle.getLevel();
         BlockPos turtlePosition = turtle.getPosition();
-        BlockEntity turtleTile = turtle instanceof TurtleBrain ? ((TurtleBrain) turtle).getOwner() : world.getBlockEntity( turtlePosition );
-        if( turtleTile == null ) return TurtleCommandResult.failure( "Turtle has vanished from existence." );
 
         BlockPos blockPosition = turtlePosition.relative( direction );
         if( world.isEmptyBlock( blockPosition ) || WorldUtil.isLiquidBlock( world, blockPosition ) )
@@ -227,7 +220,7 @@ public class TurtleTool extends AbstractTurtleUpgrade
         if( !breakable.isSuccess() ) return breakable;
 
         // Consume the items the block drops
-        DropConsumer.set( world, blockPosition, turtleDropConsumer( turtleTile, turtle ) );
+        DropConsumer.set( world, blockPosition, TurtleUtil.dropConsumer( turtle ) );
 
         BlockEntity tile = world.getBlockEntity( blockPosition );
 
@@ -246,23 +239,12 @@ public class TurtleTool extends AbstractTurtleUpgrade
             state.getBlock().playerDestroy( world, turtlePlayer, blockPosition, state, tile, turtlePlayer.getMainHandItem() );
         }
 
-        stopConsuming( turtleTile, turtle );
+        TurtleUtil.stopConsuming( turtle );
 
         return TurtleCommandResult.success();
 
     }
 
-    private static Function<ItemStack, ItemStack> turtleDropConsumer( BlockEntity tile, ITurtleAccess turtle )
-    {
-        return drop -> tile.isRemoved() ? drop : InventoryUtil.storeItems( drop, turtle.getItemHandler(), turtle.getSelectedSlot() );
-    }
-
-    private static void stopConsuming( BlockEntity tile, ITurtleAccess turtle )
-    {
-        Direction direction = tile.isRemoved() ? null : turtle.getDirection().getOpposite();
-        DropConsumer.clearAndDrop( turtle.getLevel(), turtle.getPosition(), direction );
-    }
-
     protected boolean isTriviallyBreakable( BlockGetter reader, BlockPos pos, BlockState state )
     {
         return state.is( ComputerCraftTags.Blocks.TURTLE_ALWAYS_BREAKABLE )

src/main/java/dan200/computercraft/shared/util/InventoryUtil.java

@@ -127,12 +127,6 @@ public final class InventoryUtil
 
     // Methods for taking out of inventories
 
-    @Nonnull
-    public static ItemStack takeItems( int count, IItemHandler inventory, int begin )
-    {
-        return takeItems( count, inventory, 0, inventory.getSlots(), begin );
-    }
-
     @Nonnull
     public static ItemStack takeItems( int count, IItemHandler inventory )
     {

src/testMod/kotlin/dan200/computercraft/gametest/Turtle_Test.kt

@@ -6,7 +6,7 @@
 package dan200.computercraft.gametest
 
 import dan200.computercraft.api.detail.BasicItemDetailProvider
-import dan200.computercraft.api.detail.DetailRegistries
+import dan200.computercraft.api.detail.VanillaDetailRegistries
 import dan200.computercraft.api.lua.ObjectArguments
 import dan200.computercraft.core.apis.PeripheralAPI
 import dan200.computercraft.gametest.api.*
@@ -172,7 +172,7 @@ class Turtle_Test {
     fun Item_detail_provider(helper: GameTestHelper) = helper.sequence {
         // Register a dummy provider for printout items
         thenExecute {
-            DetailRegistries.ITEM_STACK.addProvider(
+            VanillaDetailRegistries.ITEM_STACK.addProvider(
                 object :
                     BasicItemDetailProvider<ItemPrintout>("printout", ItemPrintout::class.java) {
                     override fun provideDetails(data: MutableMap<in String, Any>, stack: ItemStack, item: ItemPrintout) {

src/testMod/kotlin/dan200/computercraft/gametest/api/TestExtensions.kt

@@ -174,7 +174,7 @@ fun GameTestHelper.assertContainerExactly(pos: BlockPos, items: List<ItemStack>)
     }
 }
 
-private fun getName(type: BlockEntityType<*>): ResourceLocation = ForgeRegistries.BLOCK_ENTITIES.getKey(type)!!
+private fun getName(type: BlockEntityType<*>): ResourceLocation = ForgeRegistries.BLOCK_ENTITY_TYPES.getKey(type)!!
 
 /**
  * Get a [BlockEntity] of a specific type.