Emulate entrySet on dynamic resources model registry

Related: #429

forge/src/main/java/org/embeddedt/modernfix/forge/dynresources/ModelBakeEventHelper.java

@@ -2,6 +2,7 @@ package org.embeddedt.modernfix.forge.dynresources;
 
 import com.google.common.collect.ForwardingMap;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Iterators;
 import com.google.common.collect.Sets;
 import com.google.common.graph.GraphBuilder;
 import com.google.common.graph.MutableGraph;
@@ -19,9 +20,11 @@ import org.embeddedt.modernfix.ModernFix;
 import org.embeddedt.modernfix.util.ForwardingInclDefaultsMap;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.AbstractSet;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -158,6 +161,11 @@ public class ModelBakeEventHelper {
                 return ourModelLocations.contains(key) || super.containsKey(key);
             }
 
+            @Override
+            public Set<Entry<ResourceLocation, BakedModel>> entrySet() {
+                return new DynamicModelEntrySet(this, ourModelLocations);
+            }
+
             @Override
             public void replaceAll(BiFunction<? super ResourceLocation, ? super BakedModel, ? extends BakedModel> function) {
                 ModernFix.LOGGER.warn("Mod '{}' is calling replaceAll on the model registry. Some hacks will be used to keep this fast, but they may not be 100% compatible.", modId);
@@ -185,4 +193,61 @@ public class ModelBakeEventHelper {
             }
         };
     }
+
+    private static class DynamicModelEntrySet extends AbstractSet<Map.Entry<ResourceLocation, BakedModel>> {
+        private final Map<ResourceLocation, BakedModel> modelRegistry;
+        private final Set<ResourceLocation> modelLocations;
+
+        private DynamicModelEntrySet(Map<ResourceLocation, BakedModel> modelRegistry, Set<ResourceLocation> modelLocations) {
+            this.modelRegistry = modelRegistry;
+            this.modelLocations = modelLocations;
+        }
+
+        @Override
+        public Iterator<Map.Entry<ResourceLocation, BakedModel>> iterator() {
+            return Iterators.transform(Iterators.unmodifiableIterator(this.modelLocations.iterator()), DynamicModelEntry::new);
+        }
+
+        @Override
+        public boolean contains(Object o) {
+            if(o instanceof Map.Entry entry) {
+                return modelRegistry.containsKey(entry.getKey());
+            } else {
+                return false;
+            }
+        }
+
+        @Override
+        public int size() {
+            return modelRegistry.size();
+        }
+
+        @Override
+        public boolean removeAll(Collection<?> c) {
+            throw new UnsupportedOperationException();
+        }
+
+        private class DynamicModelEntry implements Map.Entry<ResourceLocation, BakedModel> {
+            private final ResourceLocation location;
+
+            private DynamicModelEntry(ResourceLocation location) {
+                this.location = location;
+            }
+
+            @Override
+            public ResourceLocation getKey() {
+                return this.location;
+            }
+
+            @Override
+            public BakedModel getValue() {
+                return modelRegistry.get(this.location);
+            }
+
+            @Override
+            public BakedModel setValue(BakedModel value) {
+                return modelRegistry.put(this.location, value);
+            }
+        }
+    }
 }