Avoid split package issue when packaging EMI API classes

emi-bridge/build.gradle.kts

@@ -1,3 +1,7 @@
+import net.fabricmc.loom.util.FileSystemUtil
+import java.nio.file.Files
+import java.nio.file.StandardCopyOption
+
 plugins {
     id("dev.architectury.loom")
 }
@@ -34,3 +38,17 @@ dependencies {
 
     modImplementation(group = "dev.emi", name = "emi-forge", version = "1.0.19+1.20.1")
 }
+
+tasks.remapJar {
+    // Painfully move dev/emi into relocate/dev/emi - gradle does NOT make this easy ...
+    doLast {
+        FileSystemUtil.getJarFileSystem(archiveFile.get().asFile.toPath(), false).use { fs ->
+            val from = fs.getPath("dev/emi")
+            val to = fs.getPath("relocate/dev/emi")
+            Files.walk(from).forEach {
+                Files.move(it, to.resolve(from.relativize(it)).also { Files.createDirectories(it.parent) }, StandardCopyOption.COPY_ATTRIBUTES)
+            }
+            Files.walk(from).sorted(Comparator.reverseOrder()).forEach(Files::delete)
+        }
+    }
+}

emi-bridge/src/main/java/dev/su5ed/sinytra/connectorextras/emibridge/EMIBridge.java

@@ -1,7 +1,99 @@
 package dev.su5ed.sinytra.connectorextras.emibridge;
 
+import com.mojang.logging.LogUtils;
+import cpw.mods.jarhandling.SecureJar;
+import cpw.mods.modlauncher.Launcher;
+import cpw.mods.modlauncher.api.IModuleLayerManager;
 import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.unsafe.UnsafeHacks;
+import org.slf4j.Logger;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.module.ModuleDescriptor;
+import java.lang.module.ModuleReference;
+import java.lang.module.ResolvedModule;
+import java.lang.reflect.Field;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.nio.file.FileSystem;
+import java.nio.file.FileSystems;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.security.CodeSigner;
+import java.util.Map;
+import java.util.Optional;
+import java.util.jar.Manifest;
 
 @Mod("connectorextras_emi_bridge")
 public class EMIBridge {
+    private static final Logger LOGGER = LogUtils.getLogger();
+
+    public static void injectModule() {
+        try {
+            ModuleLayer layer = Launcher.INSTANCE.findLayerManager().orElseThrow().getLayer(IModuleLayerManager.Layer.GAME).orElseThrow();
+            ResolvedModule emiModule = layer.configuration().findModule("emi").orElse(null);
+            if (emiModule == null) {
+                LOGGER.debug("EMI is not present, skipping class injection");
+                return;
+            }
+
+            Class<?> jarModuleReference = Class.forName("cpw.mods.cl.JarModuleFinder$JarModuleReference");
+            ModuleReference reference = emiModule.reference();
+            if (!jarModuleReference.isInstance(reference)) {
+                LOGGER.error("EMI module does not contain a jar module reference");
+                return;
+            }
+
+            Field jarField = jarModuleReference.getDeclaredField("jar");
+            SecureJar.ModuleDataProvider originalProvider = UnsafeHacks.getField(jarField, reference);
+            Path relocatePath = getRelocatedClassesPath();
+            if (relocatePath == null) {
+                LOGGER.error("EMI API relocated path not found");
+                return;
+            }
+            SecureJar.ModuleDataProvider wrappedProvider = new ModuleDataProviderWrapper(originalProvider, relocatePath);
+            UnsafeHacks.setField(jarField, reference, wrappedProvider);
+
+            LOGGER.debug("Successfully injected EMI Fabric API classes");
+        } catch (Throwable t) {
+            LOGGER.error("Error injecting EMI Fabric API classes", t);
+        }
+    }
+
+    public static Path getRelocatedClassesPath() throws URISyntaxException, IOException {
+        URL relocateUrl = EMIBridge.class.getResource("/relocate");
+        if (relocateUrl != null) {
+            Path relocatePath = Path.of(relocateUrl.toURI());
+            URI pathFsUri = new URI("path://" + relocateUrl.getPath());
+            FileSystem pathFS = FileSystems.newFileSystem(pathFsUri, Map.of("packagePath", relocatePath));
+            return pathFS.getPath("/");
+        }
+        return null;
+    }
+
+    public record ModuleDataProviderWrapper(SecureJar.ModuleDataProvider provider, Path relocatePath) implements SecureJar.ModuleDataProvider {
+        @Override
+        public Optional<InputStream> open(String name) {
+            return provider.open(name)
+                .or(() -> {
+                    try {
+                        Path path = relocatePath.resolve(name);
+                        return Optional.of(Files.newInputStream(path));
+                    } catch (Exception ignored) {
+                    }
+                    return Optional.empty();
+                });
+        }
+
+        //@formatter:off
+        @Override public String name() {return provider.name();}
+        @Override public ModuleDescriptor descriptor() {return provider.descriptor();}
+        @Override public URI uri() {return provider.uri();}
+        @Override public Optional<URI> findFile(String name) {return provider.findFile(name);}
+        @Override public Manifest getManifest() {return provider.getManifest();}
+        @Override public CodeSigner[] verifyAndGetSigners(String cname, byte[] bytes) {return provider.verifyAndGetSigners(cname, bytes);}
+        //@formatter:on
+    }
 }

emi-bridge/src/main/java/dev/su5ed/sinytra/connectorextras/emibridge/mixin/EmiAgnosForgeMixin.java

@@ -15,10 +15,10 @@ public class EmiAgnosForgeMixin {
     @ModifyVariable(method = "getPluginsAgnos", at = @At("RETURN"), remap = false)
     private List<EmiPluginContainer> connectorextras_emi_bridge$addFabricPlugins(List<EmiPluginContainer> orig) {
         orig.addAll(FabricLoader.getInstance()
-                .getEntrypointContainers("emi", EmiPlugin.class)
-                .stream()
-                .map(p -> new EmiPluginContainer(p.getEntrypoint(), p.getProvider().getMetadata().getId()))
-                .toList());
+            .getEntrypointContainers("emi", EmiPlugin.class)
+            .stream()
+            .map(p -> new EmiPluginContainer(p.getEntrypoint(), p.getProvider().getMetadata().getId()))
+            .toList());
         return orig;
     }
 }

emi-bridge/src/main/java/dev/su5ed/sinytra/connectorextras/emibridge/mixin/MainEntrypointMixin.java

@@ -0,0 +1,15 @@
+package dev.su5ed.sinytra.connectorextras.emibridge.mixin;
+
+import dev.su5ed.sinytra.connectorextras.emibridge.EMIBridge;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin({net.minecraft.client.main.Main.class, net.minecraft.server.Main.class})
+public class MainEntrypointMixin {
+    @Inject(method = "main", at = @At("HEAD"), remap = false)
+    private static void beforeGameLaunch(String[] strings, CallbackInfo ci) {
+        EMIBridge.injectModule();
+    }
+}

emi-bridge/src/main/resources/mixins.emibridge.json

@@ -4,6 +4,7 @@
   "required": true,
   "package": "dev.su5ed.sinytra.connectorextras.emibridge.mixin",
   "mixins": [
-    "EmiAgnosForgeMixin"
+    "EmiAgnosForgeMixin",
+    "MainEntrypointMixin"
   ]
 }