Fix error from missing client classes

Author: jpenilla

src/main/java/io/papermc/codebook/pages/UnpickPage.java

@@ -26,6 +26,11 @@
 import daomephsta.unpick.api.classresolvers.ClassResolvers;
 import daomephsta.unpick.api.classresolvers.IClassResolver;
 import daomephsta.unpick.api.constantgroupers.ConstantGroupers;
+import daomephsta.unpick.constantmappers.datadriven.parser.v3.UnpickV3Reader;
+import daomephsta.unpick.constantmappers.datadriven.tree.ForwardingUnpickV3Visitor;
+import daomephsta.unpick.constantmappers.datadriven.tree.GroupDefinition;
+import daomephsta.unpick.constantmappers.datadriven.tree.expr.Expression;
+import daomephsta.unpick.constantmappers.datadriven.tree.expr.FieldExpression;
 import dev.denwav.hypo.asm.AsmClassData;
 import dev.denwav.hypo.core.HypoContext;
 import dev.denwav.hypo.model.data.ClassData;
@@ -82,21 +87,20 @@ public void exec() {
         if (isZip) {
             try (final FileSystem definitionsFs = FileSystems.newFileSystem(this.unpickDefinitions)) {
                 final Path definitionsPath = definitionsFs.getPath("extras/definitions.unpick");
-                this.unpick(definitionsPath, zips, this.context);
+                this.unpick(definitionsPath, zips);
             } catch (final IOException e) {
                 throw new UncheckedIOException(e);
             }
         } else {
             try {
-                this.unpick(this.unpickDefinitions, zips, this.context);
+                this.unpick(this.unpickDefinitions, zips);
             } catch (final IOException e) {
                 throw new UncheckedIOException(e);
             }
         }
     }
 
-    private void unpick(final Path definitionsPath, final List<ZipFile> zips, final HypoContext context)
-            throws IOException {
+    private void unpick(final Path definitionsPath, final List<ZipFile> zips) throws IOException {
         IClassResolver classResolver = new IClassResolver() {
             @Override
             public @Nullable ClassReader resolveClass(final String internalName) {
@@ -128,7 +132,45 @@ private void unpick(final Path definitionsPath, final List<ZipFile> zips, final
             this.uninliner = ConstantUninliner.builder()
                     .grouper(ConstantGroupers.dataDriven()
                             .classResolver(classResolver)
-                            .mappingSource(definitionsReader)
+                            .mappingSource(visitor -> {
+                                try {
+                                    new UnpickV3Reader(definitionsReader)
+                                            .accept(new ForwardingUnpickV3Visitor(visitor) {
+                                                // Filter out any groups where all constants reference missing classes
+                                                // (client classes when applying to the server)
+                                                // This may need further refinement to handle applying outdated definitions leniently
+                                                @Override
+                                                public void visitGroupDefinition(
+                                                        final GroupDefinition groupDefinition) {
+                                                    final List<Expression> constants =
+                                                            new ArrayList<>(groupDefinition.constants());
+                                                    for (final Expression constant : groupDefinition.constants()) {
+                                                        if (constant instanceof final FieldExpression field) {
+                                                            try {
+                                                                final @Nullable ClassData clsData = UnpickPage.this
+                                                                        .context
+                                                                        .getContextProvider()
+                                                                        .findClass(field.className);
+                                                                if (clsData == null) {
+                                                                    constants.remove(constant);
+                                                                }
+                                                            } catch (final IOException e) {
+                                                                throw new UncheckedIOException(e);
+                                                            }
+                                                        }
+                                                    }
+                                                    if (!constants.isEmpty()) {
+                                                        super.visitGroupDefinition(
+                                                                GroupDefinition.Builder.from(groupDefinition)
+                                                                        .setConstants(constants)
+                                                                        .build());
+                                                    }
+                                                }
+                                            });
+                                } catch (final IOException e) {
+                                    throw new UncheckedIOException(e);
+                                }
+                            })
                             .build())
                     .classResolver(classResolver)
                     .build();