Make upgrade recipe requirements a little more lax

- Move some common upgrade code to IUpgradeBase. 99% sure this this
   preserves binary compatibility (on the JVM at least).

 - Instead of requiring the share tag to match, allow upgrades to
   specify their own predicate. IMO this is a little ugly, but required
   to fix #614 as other mods chuck their own NBT on items.

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

@@ -0,0 +1,81 @@
+package dan200.computercraft.api;
+
+import dan200.computercraft.api.pocket.IPocketUpgrade;
+import dan200.computercraft.api.turtle.ITurtleUpgrade;
+import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.util.Identifier;
+
+import javax.annotation.Nonnull;
+
+/**
+ * Common functionality between {@link ITurtleUpgrade} and {@link IPocketUpgrade}.
+ */
+public interface IUpgradeBase
+{
+    /**
+     * Gets a unique identifier representing this type of turtle upgrade. eg: "computercraft:wireless_modem"
+     * or "my_mod:my_upgrade".
+     *
+     * You should use a unique resource domain to ensure this upgrade is uniquely identified.
+     * The upgrade will fail registration if an already used ID is specified.
+     *
+     * @return The unique ID for this upgrade.
+     */
+    @Nonnull
+    Identifier getUpgradeID();
+
+    /**
+     * Return an unlocalised string to describe this type of computer in item names.
+     *
+     * Examples of built-in adjectives are "Wireless", "Mining" and "Crafty".
+     *
+     * @return The localisation key for this upgrade's adjective.
+     */
+    @Nonnull
+    String getUnlocalisedAdjective();
+
+    /**
+     * Return an item stack representing the type of item that a computer must be crafted
+     * with to create a version which holds this upgrade. This item stack is also used
+     * to determine the upgrade given by {@code turtle.equipLeft()} or {@code pocket.equipBack()}
+     *
+     * This should be constant over a session (or at least a datapack reload). It is recommended
+     * that you cache the stack too, in order to prevent constructing it every time the method
+     * is called.
+     *
+     * @return The item stack to craft with, or {@link ItemStack#EMPTY} if it cannot be crafted.
+     */
+    @Nonnull
+    ItemStack getCraftingItem();
+
+    /**
+     * Determine if an item is suitable for being used for this upgrade.
+     *
+     * When un-equipping an upgrade, we return {@link #getCraftingItem()} rather than
+     * the original stack. In order to prevent people losing items with enchantments (or
+     * repairing items with non-0 damage), we impose additional checks on the item.
+     *
+     * The default check requires that any non-capability NBT is exactly the same as the
+     * crafting item, but this may be relaxed for your upgrade.
+     *
+     * @param stack The stack to check. This is guaranteed to be non-empty and have the same item as
+     *              {@link #getCraftingItem()}.
+     * @return If this stack may be used to equip this upgrade.
+     * @see net.minecraftforge.common.crafting.NBTIngredient#test(ItemStack) For the implementation of the default
+     * check.
+     */
+    default boolean isItemSuitable( @Nonnull ItemStack stack )
+    {
+        ItemStack crafting = getCraftingItem();
+
+        // A more expanded form of ItemStack.areShareTagsEqual, but allowing an empty tag to be equal to a
+        // null one.
+        CompoundTag shareTag = stack.getTag();
+        CompoundTag craftingShareTag = crafting.getTag();
+        if( shareTag == craftingShareTag ) return true;
+        if( shareTag == null ) return craftingShareTag.isEmpty();
+        if( craftingShareTag == null ) return shareTag.isEmpty();
+        return shareTag.equals( craftingShareTag );
+    }
+}

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

@@ -10,56 +10,18 @@ import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 import dan200.computercraft.api.ComputerCraftAPI;
+import dan200.computercraft.api.IUpgradeBase;
 import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.api.turtle.ITurtleUpgrade;
 
-import net.minecraft.item.ItemStack;
-import net.minecraft.util.Identifier;
 import net.minecraft.world.World;
 
 /**
  * Additional peripherals for pocket computers.
  *
- * This is similar to {@link ITurtleUpgrade}.
+ * @see ComputerCraftAPI#registerPocketUpgrade(IPocketUpgrade)
  */
-public interface IPocketUpgrade {
-
-    /**
-     * Gets a unique identifier representing this type of turtle upgrade. eg: "computercraft:wireless_modem" or "my_mod:my_upgrade".
-     *
-     * You should use a unique resource domain to ensure this upgrade is uniquely identified. The upgrade will fail registration if an already used ID is
-     * specified.
-     *
-     * @return The upgrade's id.
-     * @see IPocketUpgrade#getUpgradeID()
-     * @see ComputerCraftAPI#registerPocketUpgrade(IPocketUpgrade)
-     */
-    @Nonnull
-    Identifier getUpgradeID();
-
-    /**
-     * Return an unlocalised string to describe the type of pocket computer this upgrade provides.
-     *
-     * An example of a built-in adjectives is "Wireless" - this is converted to "Wireless Pocket Computer".
-     *
-     * @return The unlocalised adjective.
-     * @see ITurtleUpgrade#getUnlocalisedAdjective()
-     */
-    @Nonnull
-    String getUnlocalisedAdjective();
-
-    /**
-     * Return an item stack representing the type of item that a pocket computer must be crafted with to create a pocket computer which holds this upgrade.
-     * This item stack is also used to determine the upgrade given by {@code pocket.equip()}/{@code pocket.unequip()}.
-     *
-     * Ideally this should be constant over a session. It is recommended that you cache the item too, in order to prevent constructing it every time the
-     * method is called.
-     *
-     * @return The item stack used for crafting. This can be {@link ItemStack#EMPTY} if crafting is disabled.
-     */
-    @Nonnull
-    ItemStack getCraftingItem();
-
+public interface IPocketUpgrade extends IUpgradeBase
+{
     /**
      * Creates a peripheral for the pocket computer.
      *

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

@@ -10,11 +10,10 @@ import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 import dan200.computercraft.api.ComputerCraftAPI;
+import dan200.computercraft.api.IUpgradeBase;
 import dan200.computercraft.api.client.TransformedModel;
 import dan200.computercraft.api.peripheral.IPeripheral;
 
-import net.minecraft.item.ItemStack;
-import net.minecraft.util.Identifier;
 import net.minecraft.util.math.Direction;
 
 import net.fabricmc.api.EnvType;
@@ -25,27 +24,8 @@ import net.fabricmc.api.Environment;
  *
  * @see ComputerCraftAPI#registerTurtleUpgrade(ITurtleUpgrade)
  */
-public interface ITurtleUpgrade {
-    /**
-     * Gets a unique identifier representing this type of turtle upgrade. eg: "computercraft:wireless_modem" or "my_mod:my_upgrade". You should use a unique
-     * resource domain to ensure this upgrade is uniquely identified. The turtle will fail registration if an already used ID is specified.
-     *
-     * @return The unique ID for this upgrade.
-     * @see ComputerCraftAPI#registerTurtleUpgrade(ITurtleUpgrade)
-     */
-    @Nonnull
-    Identifier getUpgradeID();
-
-    /**
-     * Return an unlocalised string to describe this type of turtle in turtle item names.
-     *
-     * Examples of built-in adjectives are "Wireless", "Mining" and "Crafty".
-     *
-     * @return The localisation key for this upgrade's adjective.
-     */
-    @Nonnull
-    String getUnlocalisedAdjective();
-
+public interface ITurtleUpgrade extends IUpgradeBase
+{
     /**
      * Return whether this turtle adds a tool or a peripheral to the turtle.
      *
@@ -55,18 +35,6 @@ public interface ITurtleUpgrade {
     @Nonnull
     TurtleUpgradeType getType();
 
-    /**
-     * Return an item stack representing the type of item that a turtle must be crafted with to create a turtle which holds this upgrade. This item stack is
-     * also used to determine the upgrade given by {@code turtle.equip()}
-     *
-     * Ideally this should be constant over a session. It is recommended that you cache the item too, in order to prevent constructing it every time the
-     * method is called.
-     *
-     * @return The item stack to craft with, or {@link ItemStack#EMPTY} if it cannot be crafted.
-     */
-    @Nonnull
-    ItemStack getCraftingItem();
-
     /**
      * Will only be called for peripheral upgrades. Creates a peripheral for a turtle being placed using this upgrade.
      *

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

@@ -59,7 +59,8 @@ public final class PocketUpgrades {
 
         for (IPocketUpgrade upgrade : upgrades.values()) {
             ItemStack craftingStack = upgrade.getCraftingItem();
-            if (!craftingStack.isEmpty() && InventoryUtil.areItemsSimilar(stack, craftingStack)) {
+            if( !craftingStack.isEmpty() && craftingStack.getItem() == stack.getItem() && upgrade.isItemSuitable( stack ) )
+            {
                 return upgrade;
             }
         }

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

@@ -19,7 +19,6 @@ import javax.annotation.Nullable;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
-import dan200.computercraft.shared.util.InventoryUtil;
 
 import net.minecraft.item.ItemStack;
 
@@ -96,7 +95,8 @@ public final class TurtleUpgrades {
             }
 
             ItemStack craftingStack = wrapper.upgrade.getCraftingItem();
-            if (!craftingStack.isEmpty() && InventoryUtil.areItemsSimilar(stack, craftingStack)) {
+            if( !craftingStack.isEmpty() && craftingStack.getItem() == stack.getItem() && wrapper.upgrade.isItemSuitable( stack ) )
+            {
                 return wrapper.upgrade;
             }
         }

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

@@ -11,6 +11,8 @@ import java.util.function.Function;
 
 import javax.annotation.Nonnull;
 
+import org.apache.commons.lang3.tuple.Pair;
+
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.client.TransformedModel;
 import dan200.computercraft.api.turtle.AbstractTurtleUpgrade;
@@ -29,8 +31,6 @@ 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 org.apache.commons.lang3.tuple.Pair;
-
 import net.minecraft.block.Block;
 import net.minecraft.block.BlockState;
 import net.minecraft.block.Blocks;
@@ -41,9 +41,9 @@ import net.minecraft.entity.Entity;
 import net.minecraft.entity.attribute.EntityAttributes;
 import net.minecraft.entity.damage.DamageSource;
 import net.minecraft.entity.decoration.ArmorStandEntity;
-import net.minecraft.fluid.FluidState;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.CompoundTag;
 import net.minecraft.util.ActionResult;
 import net.minecraft.util.Hand;
 import net.minecraft.util.Identifier;
@@ -59,6 +59,9 @@ import net.fabricmc.fabric.api.event.player.AttackEntityCallback;
 public class TurtleTool extends AbstractTurtleUpgrade {
     protected final ItemStack item;
 
+    private static final int TAG_LIST = 9;
+    private static final int TAG_COMPOUND = 10;
+
     public TurtleTool(Identifier id, String adjective, Item item) {
         super(id, TurtleUpgradeType.TOOL, adjective, item);
         this.item = new ItemStack(item);
@@ -74,6 +77,24 @@ public class TurtleTool extends AbstractTurtleUpgrade {
         this.item = toolItem;
     }
 
+    @Override
+    public boolean isItemSuitable( @Nonnull ItemStack stack )
+    {
+        CompoundTag tag = stack.getTag();
+        if( tag == null || tag.isEmpty() ) return true;
+
+        // Check we've not got anything vaguely interesting on the item. We allow other mods to add their
+        // own NBT, with the understanding such details will be lost to the mist of time.
+        if( stack.isDamaged() || stack.hasEnchantments() || stack.hasCustomName() ) return false;
+        if( tag.contains( "AttributeModifiers", TAG_LIST ) &&
+            !tag.getList( "AttributeModifiers", TAG_COMPOUND ).isEmpty() )
+        {
+            return false;
+        }
+
+        return true;
+    }
+
     @Nonnull
     @Override
     public TurtleCommandResult useTool(@Nonnull ITurtleAccess turtle, @Nonnull TurtleSide side, @Nonnull TurtleVerb verb, @Nonnull Direction direction) {
@@ -183,7 +204,6 @@ public class TurtleTool extends AbstractTurtleUpgrade {
         }
 
         BlockState state = world.getBlockState(blockPosition);
-        FluidState fluidState = world.getFluidState(blockPosition);
 
         TurtlePlayer turtlePlayer = TurtlePlaceCommand.createPlayer(turtle, turtlePosition, direction);
         turtlePlayer.loadInventory(this.item.copy());

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

@@ -14,7 +14,6 @@ import net.minecraft.block.entity.BlockEntity;
 import net.minecraft.entity.Entity;
 import net.minecraft.inventory.Inventory;
 import net.minecraft.item.ItemStack;
-import net.minecraft.nbt.CompoundTag;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Direction;
 import net.minecraft.util.math.Vec3d;
@@ -28,53 +27,6 @@ public final class InventoryUtil {
         return a == b || (a.getItem() == b.getItem() && ItemStack.areTagsEqual(a, b));
     }
 
-    /**
-     * Determines if two items are "mostly" equivalent. Namely, they have the same item and damage, and identical share stacks.
-     *
-     * sufficient to ensure basic information (such as enchantments) are the same, while not having to worry about capabilities.
-     *
-     * @param a The first stack to check
-     * @param b The second stack to check
-     * @return If these items are largely the same.
-     */
-    public static boolean areItemsSimilar(@Nonnull ItemStack a, @Nonnull ItemStack b) {
-        if (a == b) {
-            return true;
-        }
-        if (a.isEmpty()) {
-            return !b.isEmpty();
-        }
-
-        if (a.getItem() != b.getItem()) {
-            return false;
-        }
-
-        // A more expanded form of ItemStack.areShareTagsEqual, but allowing an empty tag to be equal to a
-        // null one.
-        CompoundTag shareTagA = a.getTag();
-        CompoundTag shareTagB = b.getTag();
-        if (shareTagA == shareTagB) {
-            return true;
-        }
-        if (shareTagA == null) {
-            return shareTagB.isEmpty();
-        }
-        if (shareTagB == null) {
-            return shareTagA.isEmpty();
-        }
-        return shareTagA.equals(shareTagB);
-    }
-
-    @Nonnull
-    public static ItemStack copyItem(@Nonnull ItemStack a) {
-        return a.copy();
-    }
-
-    public static ItemStorage getStorage(World world, BlockPos pos, Direction side) {
-        Inventory inventory = getInventory(world, pos, side);
-        return inventory == null ? null : ItemStorage.wrap(inventory, side);
-    }
-
     // Methods for finding inventories:
 
     public static Inventory getInventory(World world, BlockPos pos, Direction side) {