feat(obfuscator/transformers): Mixin Remapper for classes only

dev.skidfuscator.obfuscator/src/main/java/dev/skidfuscator/obfuscator/Skidfuscator.java

@@ -59,6 +59,7 @@
 import dev.skidfuscator.obfuscator.transform.impl.misc.AhegaoTransformer;
 import dev.skidfuscator.obfuscator.transform.impl.number.NumberTransformer;
 import dev.skidfuscator.obfuscator.transform.impl.pure.PureHashTransformer;
+import dev.skidfuscator.obfuscator.transform.impl.remapper.mixin.MixinTransformer;
 import dev.skidfuscator.obfuscator.transform.impl.sdk.SdkInjectorTransformer;
 import dev.skidfuscator.obfuscator.transform.impl.string.StringEncryptionType;
 import dev.skidfuscator.obfuscator.transform.impl.string.StringTransformerV2;
@@ -754,9 +755,10 @@ public List<Transformer> getTransformers() {
                     //new LoopConditionTransformer(this),
                 /*
                 new FlatteningFlowTransformer(this),*/
-                    new AhegaoTransformer(this)
-                    //new SimpleOutlinerTransformer()
+                    new AhegaoTransformer(this),
+                    //new SimpleOutlinerTransformer(),
                     //
+                    new MixinTransformer(this)
             ));
         } else {
             transformers.addAll(Arrays.asList(

dev.skidfuscator.obfuscator/src/main/java/dev/skidfuscator/obfuscator/transform/impl/remapper/mixin/MixinConfig.java

@@ -0,0 +1,23 @@
+package dev.skidfuscator.obfuscator.transform.impl.remapper.mixin;
+
+import com.typesafe.config.Config;
+import dev.skidfuscator.config.DefaultTransformerConfig;
+
+public class MixinConfig extends DefaultTransformerConfig {
+    public MixinConfig(Config config, String path) {
+        super(config, path);
+    }
+
+    @Override
+    public boolean isEnabled() {
+        return this.getBoolean("enabled", false);
+    }
+
+    public String getRefmapPath() {
+        return this.getString("refmap", "not_found");
+    }
+
+    public String getMixinPath() {
+        return this.getString("config", "not_found");
+    }
+}

dev.skidfuscator.obfuscator/src/main/java/dev/skidfuscator/obfuscator/transform/impl/remapper/mixin/MixinTransformer.java

@@ -0,0 +1,306 @@
+package dev.skidfuscator.obfuscator.transform.impl.remapper.mixin;
+
+import com.google.gson.*;
+import dev.skidfuscator.config.DefaultTransformerConfig;
+import dev.skidfuscator.obfuscator.Skidfuscator;
+import dev.skidfuscator.obfuscator.event.EventPriority;
+import dev.skidfuscator.obfuscator.event.annotation.Listen;
+import dev.skidfuscator.obfuscator.event.impl.transform.clazz.InitClassTransformEvent;
+import dev.skidfuscator.obfuscator.event.impl.transform.skid.FinalSkidTransformEvent;
+import dev.skidfuscator.obfuscator.event.impl.transform.skid.InitSkidTransformEvent;
+import dev.skidfuscator.obfuscator.skidasm.SkidClassNode;
+import dev.skidfuscator.obfuscator.transform.AbstractTransformer;
+import dev.skidfuscator.obfuscator.util.MiscUtil;
+import dev.skidfuscator.obfuscator.util.misc.Pair;
+import lombok.NonNull;
+import org.topdank.byteengineer.commons.data.JarResource;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * Transforms mixin config files that contain remapped Mixin classes
+ * <p>
+ * TODO: Support Mixin Plugin transformation.
+ * TODO: In theory, it is possible to transform methods & fields found within Mixin classes, would require a lot more work though.
+ * TODO: ^ ideally, it would require for the Method, Field (and Class, to remove the requirement of the transformer holding the changes) nodes to keep track of the initial & updated name
+ *
+ * @author Trol
+ */
+public class MixinTransformer extends AbstractTransformer {
+
+    private final Gson gson = new GsonBuilder().create();
+
+    /**
+     * A mixin configuration file should contain the following paths in order to be valid.
+     */
+    private final String[] mixinConfigPathsToCheck = new String[]{"mixins", "client", "server"};
+    /**
+     * A mixin refmap file should contain the following paths in order to be valid.
+     */
+    private final String[] refmapPathsToCheck = new String[]{"data", "mappings"};
+
+    /**
+     * Lazily loaded mixin refmap as a json object
+     */
+    private JsonObject mixinRefmap;
+
+    /**
+     * Lazily loaded mixin configuration as a json object
+     */
+    private JsonObject mixinConfig;
+
+    /**
+     * We store classes that are marked with @Mixin annotation within our own list, together with their original name.
+     * Then, we check if any of them have been modified by comparing with the original name with {@link SkidClassNode#getName()}
+     */
+    private final List<Pair<String, SkidClassNode>> mixinsToCheck = new ArrayList<>();
+
+
+    public MixinTransformer(Skidfuscator skidfuscator) {
+        super(skidfuscator, "Mixin Config Transformer");
+    }
+
+    /**
+     * The initialization phase we validate the files, if they are invalid, then there's no need for the program to run.
+     */
+    @Listen
+    void initConfigs(InitSkidTransformEvent event) {
+        final String refmapPath = this.getConfig().getRefmapPath();
+        final String mixinConfigPath = this.getConfig().getMixinPath();
+        if (!validatePath(refmapPath, "refmap") || !validatePath(mixinConfigPath, "config")
+                || !parseAndGetFile(refmapPath, "refmap") || !parseAndGetFile(mixinConfigPath, "config")) {
+            Skidfuscator.LOGGER.warn("Mixin Transformer is disabled, due to reasons above.");
+            return;
+        }
+    }
+
+    /**
+     * Upon the initialization of the jar paths, we obtain the Mixin classes and configuration/refmap files.
+     */
+    @Listen(EventPriority.MONITOR)
+    void gatherMixins(InitClassTransformEvent event) {
+        if (getFailed() > 0) {
+            return;
+        }
+        SkidClassNode classNode = event.getClassNode();
+        if (classNode.isMixin()) {
+            mixinsToCheck.add(new Pair<>(classNode.getName(), classNode));
+        }
+
+        if (mixinConfig.size() == 0) {
+            Skidfuscator.LOGGER.warn("Mixin Remapper found 0 Mixin classes. Aborting mission.");
+            this.fail();
+        }
+    }
+
+    /**
+     * Validates the remapped count, by checking against the original list, it's either all of them, or none of them.
+     * Afterward we update the files.
+     * NOTE: Remapper needs to not remap mixins into their own each separate package, otherwise it will fail too!
+     */
+    @Listen(EventPriority.FINALIZER)
+    void transformMixins(FinalSkidTransformEvent event) {
+        if (getFailed() > 0) {
+            return;
+        }
+        // Ask if StreamAPI is usable for speed or nah.
+        int remappedCount = mixinsToCheck.stream().filter(it -> !it.getA().equals(it.getB().getName())).toList().size();
+        if (remappedCount != mixinConfig.size()) {
+            this.fail();
+            Skidfuscator.LOGGER.warn("Mixin Remapper remapping class mismatch: [got: " + remappedCount + ", expected: " + mixinsToCheck.size() + "]. Aborting mission.");
+            return;
+        }
+        String firstNodeName = mixinsToCheck.get(0).getB().getName();
+        String firstQualifiedPackage = firstNodeName.substring(0, firstNodeName.lastIndexOf('.'));
+        for (Pair<String, SkidClassNode> stringSkidClassNodePair : mixinsToCheck.subList(1, mixinsToCheck.size())) {
+            String fullyQualifiedName = stringSkidClassNodePair.getB().getName();
+            String qualifiedPackage = fullyQualifiedName.substring(0, fullyQualifiedName.lastIndexOf('.'));
+            if (!firstQualifiedPackage.equals(qualifiedPackage)) {
+                this.fail();
+                Skidfuscator.LOGGER.warn("Mixin Remapper found two Mixin classes in two different directories. Aborting mission!");
+                return;
+            }
+        }
+        if (getFailed() > 0) {
+            return;
+        }
+        for (Pair<String, SkidClassNode> pair : mixinsToCheck) {
+            // Maybe the remapper has support for only confusing the package name?
+            // i.e if it was in com.test.mixins, then it would support the following:
+            // com.test.mixins.client.MinecraftClientMixin
+            // com.test.mixins.SharedConstantsMixin
+            String oldName = pair.getA().substring(firstQualifiedPackage.length());
+            String newName = pair.getB().getName().substring(firstQualifiedPackage.length());
+            if (!updateMixinConfig(oldName.replace("/", "."), newName.replace("/", "."))) {
+                this.fail();
+                Skidfuscator.LOGGER.warn("Mixin Remapper did not find " + oldName.replace("/", ".") + " within the Mixin configuration file");
+                break;
+            }
+            if (!updateRefmapConfig(pair.getA(), pair.getB().getName())) {
+                this.fail();
+                Skidfuscator.LOGGER.warn("Mixin Remapper did not find " + pair.getA() + " within the Mixin refmap file");
+                break;
+            }
+            this.success();
+        }
+    }
+
+    /**
+     * Updates the old class name to the new one within the Mixin configuration name
+     *
+     * @param oldName The initial name of the class
+     * @param newName The remapped name of the class
+     * @return status of the name being updated within the file
+     */
+    private Boolean updateMixinConfig(String oldName, String newName) {
+        boolean flag = false;
+        // It should only appear in one path, if it does in multiple - skill issue
+        // Client / Server mixins are supposed to be separated, common - for both.
+        for (String path : mixinConfigPathsToCheck) {
+            JsonArray mixins = (JsonArray) this.mixinConfig.get(path);
+            for (int i = 0; i < mixins.size(); i++) {
+                String mixin = mixins.get(i).getAsString();
+                if (mixin.equals(oldName)) {
+                    mixins.set(i, new JsonPrimitive(newName));
+                    flag = true;
+                    break;
+                }
+            }
+        }
+        return flag;
+    }
+
+    /**
+     * Updates the "mappings" and "data" of oldName to newName
+     * TODO: Attempt to see if any specific Mixin version uses different identifications of this, but seeing as Mixin never went out of beta, this isn't the case.
+     *
+     * @param oldName The initial name of the class
+     * @param newName The remapped name of the class
+     * @return status of the name being updated within the file
+     */
+    private Boolean updateRefmapConfig(String oldName, String newName) {
+        JsonObject mappings = mixinRefmap.get("mappings").getAsJsonObject();
+        if (!mappings.has(oldName)) {
+            return false;
+        }
+        JsonObject clazzMappings = mappings.get(oldName).getAsJsonObject();
+        mappings.add(newName, clazzMappings);
+        mappings.remove(oldName);
+
+        JsonObject data = mixinRefmap.get("data").getAsJsonObject();
+        for (Map.Entry<String, JsonElement> entry : data.entrySet()) {
+            JsonObject clazzData = entry.getValue().getAsJsonObject();
+
+            if (!clazzData.has(oldName)){
+                return false;
+            }
+            JsonObject mappedData = clazzData.get(oldName).getAsJsonObject();
+            clazzData.add(newName, mappedData);
+            clazzData.remove(oldName);
+            break;
+        }
+        return true;
+    }
+
+    /**
+     * Failsafe to check if the mixin config is populated
+     *
+     * @param path the given path of the provided type
+     * @param type the type of file it is currently checking
+     * @return result of it checking if it is populated and valid.
+     */
+    private boolean validatePath(@NonNull String path, @NonNull String type) {
+        if (path.equals("not_found")) {
+            this.fail();
+            // TODO: Is there a way to show an error message? This is critically important.
+            Skidfuscator.LOGGER.warn("Mixin " + type + " file is not set");
+            return false;
+        }
+
+        if (this.skidfuscator.getJarContents().getResourceContents().namedMap().containsKey(path)) {
+            this.fail();
+            Skidfuscator.LOGGER.warn("Mixin " + type + " at " + path + " does not exist.");
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * Validates the given file if it is indeed a mixin file, for specific types it is looking for, see (mixinConfigs|refMap)pathsToCheck
+     *
+     * @param path the resource path given
+     * @param type the type it is currently checking
+     * @return parsed file as a JsonObject, or empty.
+     */
+    private Optional<JsonObject> isValidFormatAndParse(@NonNull String path, @NonNull String type) {
+        JarResource jarResource = this.skidfuscator.getJarContents().getResourceContents().namedMap().get(path);
+
+        try {
+            final ByteArrayInputStream bais = new ByteArrayInputStream(jarResource.getData());
+
+            final InputStreamReader isr = new InputStreamReader(bais);
+
+            JsonObject jsonObject = gson.fromJson(isr, JsonObject.class);
+
+            String[] paths = type.equals("refmap") ? refmapPathsToCheck : mixinConfigPathsToCheck;
+            boolean flag = true;
+            for (String jsonElementPath : paths) {
+                if (jsonObject.has(jsonElementPath)) {
+                    flag = false;
+                }
+            }
+
+            if (flag) {
+                // Maybe it should support plugins? But for the first revision, it should be fine I think.
+                Skidfuscator.LOGGER.warn("Provided mixin " + type + " does not have any valid paths to remap.");
+                return Optional.empty();
+            }
+
+
+            isr.close();
+            bais.close();
+
+            return Optional.of(jsonObject);
+        } catch (IOException e) {
+            Skidfuscator.LOGGER.warn("Failed to close the file reading of " + path);
+            return Optional.empty();
+        }
+    }
+
+    /**
+     * Parses the file {@link #isValidFormatAndParse} and updates the fields mixin(Refmap|Config)
+     *
+     * @param path the path to the file
+     * @param type the type of file being currently parsed
+     * @return if it succeeded in parsing or not.
+     */
+    private boolean parseAndGetFile(String path, String type) {
+        Optional<JsonObject> parsedData = isValidFormatAndParse(path, type);
+
+        if (parsedData.isEmpty()) {
+            return false;
+        }
+        if (type.equals("refmap")) {
+            this.mixinRefmap = parsedData.get();
+        } else {
+            this.mixinConfig = parsedData.get();
+        }
+        return true;
+    }
+
+    @Override
+    protected <T extends DefaultTransformerConfig> T createConfig() {
+        return (T) new MixinConfig(skidfuscator.getTsConfig(), MiscUtil.toCamelCase(name));
+    }
+
+    @Override
+    public MixinConfig getConfig() {
+        return (MixinConfig) super.getConfig();
+    }
+}