Keep data component types fully immutable

api/src/main/java/com/viaversion/viaversion/api/minecraft/HolderSet.java

@@ -22,6 +22,8 @@
  */
 package com.viaversion.viaversion.api.minecraft;
 
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
+
 /**
  * Set of ids that either holds a string tag key or an array of ids.
  */
@@ -76,4 +78,12 @@ public interface HolderSet {
      * @return true if this holder set has direct ids, false if it has a tag key
      */
     boolean hasIds();
+
+    /**
+     * Returns a new holder set with the ids rewritten.
+     *
+     * @param idRewriter the id rewriter
+     * @return a new holder set with the ids rewritten, or self if it has a tag key
+     */
+    HolderSet rewrite(Int2IntFunction idRewriter);
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/HolderSetImpl.java

@@ -23,6 +23,7 @@
 package com.viaversion.viaversion.api.minecraft;
 
 import com.viaversion.viaversion.util.EitherImpl;
+import it.unimi.dsi.fastutil.ints.Int2IntFunction;
 
 final class HolderSetImpl extends EitherImpl<String, int[]> implements HolderSet {
 
@@ -53,4 +54,18 @@ final class HolderSetImpl extends EitherImpl<String, int[]> implements HolderSet
     public boolean hasIds() {
         return isRight();
     }
+
+    @Override
+    public HolderSet rewrite(final Int2IntFunction idRewriter) {
+        if (hasTagKey()) {
+            return this;
+        }
+
+        final int[] ids = ids();
+        final int[] mappedIds = new int[ids.length];
+        for (int i = 0; i < mappedIds.length; i++) {
+            mappedIds[i] = idRewriter.apply(ids[i]);
+        }
+        return new HolderSetImpl(mappedIds);
+    }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/AdventureModePredicate.java

@@ -44,9 +44,10 @@ public record AdventureModePredicate(BlockPredicate[] predicates, boolean showIn
     };
 
     public AdventureModePredicate rewrite(final Int2IntFunction blockIdRewriter) {
+        final BlockPredicate[] predicates = new BlockPredicate[this.predicates.length];
         for (int i = 0; i < predicates.length; i++) {
-            predicates[i] = predicates[i].rewrite(blockIdRewriter);
+            predicates[i] = this.predicates[i].rewrite(blockIdRewriter);
         }
-        return this;
+        return new AdventureModePredicate(predicates, showInTooltip);
     }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/BlockPredicate.java

@@ -62,10 +62,7 @@ public record BlockPredicate(@Nullable HolderSet holderSet, StatePropertyMatcher
             return this;
         }
 
-        final int[] ids = holderSet.ids();
-        for (int i = 0; i < ids.length; i++) {
-            ids[i] = blockIdRewriter.apply(ids[i]);
-        }
-        return this;
+        final HolderSet updatedHolders = holderSet.rewrite(blockIdRewriter);
+        return new BlockPredicate(updatedHolders, propertyMatchers, tag);
     }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/PotDecorations.java

@@ -76,9 +76,10 @@ public final class PotDecorations {
     }
 
     public PotDecorations rewrite(final Int2IntFunction idRewriteFunction) {
+        final int[] newItems = new int[itemIds.length];
         for (int i = 0; i < itemIds.length; i++) {
-            itemIds[i] = idRewriteFunction.apply(itemIds[i]);
+            newItems[i] = idRewriteFunction.applyAsInt(itemIds[i]);
         }
-        return this;
+        return new PotDecorations(newItems);
     }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/ToolProperties.java

@@ -47,9 +47,10 @@ public record ToolProperties(ToolRule[] rules, float defaultMiningSpeed, int dam
     };
 
     public ToolProperties rewrite(final Int2IntFunction blockIdRewriter) {
+        final ToolRule[] rules = new ToolRule[this.rules.length];
         for (int i = 0; i < rules.length; i++) {
-            rules[i] = rules[i].rewrite(blockIdRewriter);
+            rules[i] = this.rules[i].rewrite(blockIdRewriter);
         }
-        return this;
+        return new ToolProperties(rules, defaultMiningSpeed, damagePerBlock);
     }
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/ToolRule.java

@@ -51,14 +51,6 @@ public record ToolRule(HolderSet blocks, @Nullable Float speed, @Nullable Boolea
     public static final Type<ToolRule[]> ARRAY_TYPE = new ArrayType<>(TYPE);
 
     public ToolRule rewrite(final Int2IntFunction blockIdRewriter) {
-        if (blocks.hasTagKey()) {
-            return this;
-        }
-
-        final int[] ids = blocks.ids();
-        for (int i = 0; i < ids.length; i++) {
-            ids[i] = blockIdRewriter.apply(ids[i]);
-        }
-        return this;
+        return blocks.hasIds() ? new ToolRule(blocks.rewrite(blockIdRewriter), speed, correctForDrops) : this;
     }
 }