Support multiple input jars (#553)

* Support multiple input jars

This is needed for FabricMC/fabric-loom#1354.

* Remove unnecessary null check in GuiController.reloadAll

* Remove outdated TODO

8 files changed, 68 insertions, 33 deletions

diff --git a/enigma-server/src/main/java/cuchaz/enigma/network/DedicatedEnigmaServer.java b/enigma-server/src/main/java/cuchaz/enigma/network/DedicatedEnigmaServer.java
index fbee40d0..f20a9d29 100644
--- a/enigma-server/src/main/java/cuchaz/enigma/network/DedicatedEnigmaServer.java
+++ b/enigma-server/src/main/java/cuchaz/enigma/network/DedicatedEnigmaServer.java
@@ -5,6 +5,7 @@ import java.io.PrintWriter;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.List;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.Executors;
 import java.util.concurrent.LinkedBlockingDeque;
@@ -55,7 +56,7 @@ public class DedicatedEnigmaServer extends EnigmaServer {
         public static void main(String[] args) {
                 OptionParser parser = new OptionParser();
 
-                OptionSpec<Path> jarOpt = parser.accepts("jar", "Jar file to open at startup").withRequiredArg().required().withValuesConvertedBy(PathConverter.INSTANCE);
+                OptionSpec<Path> jarOpt = parser.accepts("jar", "Jar file to open at startup; if there are multiple jars, the order must be the same between the server and all clients").withRequiredArg().required().withValuesConvertedBy(PathConverter.INSTANCE);
 
                 OptionSpec<Path> mappingsOpt = parser.accepts("mappings", "Mappings file to open at startup").withRequiredArg().required().withValuesConvertedBy(PathConverter.INSTANCE);
 
@@ -68,7 +69,7 @@ public class DedicatedEnigmaServer extends EnigmaServer {
                 OptionSpec<Path> logFileOpt = parser.accepts("log", "The log file to write to").withRequiredArg().withValuesConvertedBy(PathConverter.INSTANCE).defaultsTo(Paths.get("log.txt"));
 
                 OptionSet parsedArgs = parser.parse(args);
-                Path jar = parsedArgs.valueOf(jarOpt);
+                List<Path> jars = parsedArgs.valuesOf(jarOpt);
                 Path mappingsFile = parsedArgs.valueOf(mappingsOpt);
                 Path profileFile = parsedArgs.valueOf(profileOpt);
                 int port = parsedArgs.valueOf(portOpt);
@@ -85,12 +86,12 @@ public class DedicatedEnigmaServer extends EnigmaServer {
                 DedicatedEnigmaServer server;
 
                 try {
-                        byte[] checksum = Utils.zipSha1(parsedArgs.valueOf(jarOpt));
+                        byte[] checksum = Utils.zipSha1(jars.toArray(new Path[0]));
 
                         EnigmaProfile profile = EnigmaProfile.read(profileFile);
                         Enigma enigma = Enigma.builder().setProfile(profile).build();
                         System.out.println("Indexing Jar...");
-                        EnigmaProject project = enigma.openJar(jar, new ClasspathClassProvider(), ProgressListener.none());
+                        EnigmaProject project = enigma.openJars(jars, new ClasspathClassProvider(), ProgressListener.none());
 
                         MappingFormat mappingFormat = MappingFormat.ENIGMA_DIRECTORY;
                         EntryRemapper mappings;
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/Gui.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/Gui.java
index 05146d4a..21120b8a 100644
--- a/enigma-swing/src/main/java/cuchaz/enigma/gui/Gui.java
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/Gui.java
@@ -147,6 +147,7 @@ public class Gui {
 
         private void setupUi() {
                 this.jarFileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
+                this.jarFileChooser.setMultiSelectionEnabled(true);
 
                 this.exportSourceFileChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
                 this.exportSourceFileChooser.setAcceptAllFileFilterUsed(false);
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java
index ad10abfc..ece11b00 100644
--- a/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/GuiController.java
@@ -23,6 +23,7 @@ import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import javax.swing.JOptionPane;
@@ -119,20 +120,27 @@ public class GuiController implements ClientPacketHandler {
                 return project != null && project.getMapper().isDirty();
         }
 
-        public CompletableFuture<Void> openJar(final Path jarPath) {
+        public CompletableFuture<Void> openJar(final List<Path> jarPaths) {
                 this.gui.onStartOpenJar();
 
                 return ProgressDialog.runOffThread(gui.getFrame(), progress -> {
-                        project = enigma.openJar(jarPath, new ClasspathClassProvider(), progress);
+                        project = enigma.openJars(jarPaths, new ClasspathClassProvider(), progress);
                         indexTreeBuilder = new IndexTreeBuilder(project.getJarIndex());
                         chp = new ClassHandleProvider(project, UiConfig.getDecompiler().service);
                         SwingUtilities.invokeLater(() -> {
-                                gui.onFinishOpenJar(jarPath.getFileName().toString());
+                                gui.onFinishOpenJar(getFileNames(jarPaths));
                                 refreshClasses();
                         });
                 });
         }
 
+        private static String getFileNames(List<Path> jarPaths) {
+                return jarPaths.stream()
+                                .map(Path::getFileName)
+                                .map(Object::toString)
+                                .collect(Collectors.joining(", "));
+        }
+
         public void closeJar() {
                 this.chp.destroy();
                 this.chp = null;
@@ -241,17 +249,15 @@ public class GuiController implements ClientPacketHandler {
         }
 
         public void reloadAll() {
-                Path jarPath = this.project.getJarPath();
+                List<Path> jarPaths = this.project.getJarPaths();
                 MappingFormat loadedMappingFormat = this.loadedMappingFormat;
                 Path loadedMappingPath = this.loadedMappingPath;
 
-                if (jarPath != null) {
-                        this.closeJar();
-                        CompletableFuture<Void> f = this.openJar(jarPath);
+                this.closeJar();
+                CompletableFuture<Void> f = this.openJar(jarPaths);
 
-                        if (loadedMappingFormat != null && loadedMappingPath != null) {
-                                f.whenComplete((v, t) -> this.openMappings(loadedMappingFormat, loadedMappingPath));
-                        }
+                if (loadedMappingFormat != null && loadedMappingPath != null) {
+                        f.whenComplete((v, t) -> this.openMappings(loadedMappingFormat, loadedMappingPath));
                 }
         }
 
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/Main.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/Main.java
index 213a5fea..43b16cd9 100644
--- a/enigma-swing/src/main/java/cuchaz/enigma/gui/Main.java
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/Main.java
@@ -38,7 +38,7 @@ public class Main {
         public static void main(String[] args) throws IOException {
                 OptionParser parser = new OptionParser();
 
-                OptionSpec<Path> jar = parser.accepts("jar", "Jar file to open at startup").withRequiredArg().withValuesConvertedBy(PathConverter.INSTANCE);
+                OptionSpec<Path> jar = parser.accepts("jar", "Jar file to open at startup; if there are multiple jars, the order must be the same between all collab session members").withRequiredArg().withValuesConvertedBy(PathConverter.INSTANCE);
 
                 OptionSpec<Path> mappings = parser.accepts("mappings", "Mappings file to open at startup").withRequiredArg().withValuesConvertedBy(PathConverter.INSTANCE);
 
@@ -137,8 +137,8 @@ public class Main {
                         }
 
                         if (options.has(jar)) {
-                                Path jarPath = options.valueOf(jar);
-                                controller.openJar(jarPath).whenComplete((v, t) -> {
+                                List<Path> jarPaths = options.valuesOf(jar);
+                                controller.openJar(jarPaths).whenComplete((v, t) -> {
                                         if (options.has(mappings)) {
                                                 Path mappingsPath = options.valueOf(mappings);
 
diff --git a/enigma-swing/src/main/java/cuchaz/enigma/gui/elements/MenuBar.java b/enigma-swing/src/main/java/cuchaz/enigma/gui/elements/MenuBar.java
index d7054f78..78050bb3 100644
--- a/enigma-swing/src/main/java/cuchaz/enigma/gui/elements/MenuBar.java
+++ b/enigma-swing/src/main/java/cuchaz/enigma/gui/elements/MenuBar.java
@@ -7,6 +7,7 @@ import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.stream.Collectors;
@@ -235,15 +236,15 @@ public class MenuBar {
                         return;
                 }
 
-                File file = d.getSelectedFile();
+                File[] files = d.getSelectedFiles();
 
                 // checks if the file name is not empty
-                if (file != null) {
-                        Path path = file.toPath();
+                if (files.length >= 1) {
+                        List<Path> paths = Arrays.stream(files).map(File::toPath).toList();
 
                         // checks if the file name corresponds to an existing file
-                        if (Files.exists(path)) {
-                                this.gui.getController().openJar(path);
+                        if (paths.stream().allMatch(Files::exists)) {
+                                this.gui.getController().openJar(paths);
                         }
 
                         UiConfig.setLastSelectedDir(d.getCurrentDirectory().getAbsolutePath());
diff --git a/enigma/src/main/java/cuchaz/enigma/Enigma.java b/enigma/src/main/java/cuchaz/enigma/Enigma.java
index 414285d7..315b5f63 100644
--- a/enigma/src/main/java/cuchaz/enigma/Enigma.java
+++ b/enigma/src/main/java/cuchaz/enigma/Enigma.java
@@ -57,15 +57,33 @@ public class Enigma {
         }
 
         public EnigmaProject openJar(Path path, ClassProvider libraryClassProvider, ProgressListener progress) throws IOException {
-                JarClassProvider jarClassProvider = new JarClassProvider(path);
+                return openJars(List.of(path), libraryClassProvider, progress);
+        }
+
+        public EnigmaProject openJars(List<Path> paths, ClassProvider libraryClassProvider, ProgressListener progress) throws IOException {
+                ClassProvider jarClassProvider = getJarClassProvider(paths);
                 ClassProvider classProvider = new CachingClassProvider(new CombiningClassProvider(jarClassProvider, libraryClassProvider));
-                Set<String> scope = jarClassProvider.getClassNames();
+                Set<String> scope = Set.copyOf(jarClassProvider.getClassNames());
 
                 JarIndex index = JarIndex.empty();
                 ClassProvider classProviderWithFrames = index.indexJar(scope, classProvider, progress);
                 services.get(JarIndexerService.TYPE).forEach(indexer -> indexer.acceptJar(scope, classProviderWithFrames, index));
 
-                return new EnigmaProject(this, path, classProvider, index, Utils.zipSha1(path));
+                return new EnigmaProject(this, paths, classProvider, index, Utils.zipSha1(paths.toArray(new Path[0])));
+        }
+
+        private ClassProvider getJarClassProvider(List<Path> jars) throws IOException {
+                if (jars.size() == 1) {
+                        return new JarClassProvider(jars.get(0));
+                }
+
+                var classProviders = new ClassProvider[jars.size()];
+
+                for (int i = 0; i < jars.size(); i++) {
+                        classProviders[i] = new JarClassProvider(jars.get(i));
+                }
+
+                return new CombiningClassProvider(classProviders);
         }
 
         public EnigmaProfile getProfile() {
diff --git a/enigma/src/main/java/cuchaz/enigma/EnigmaProject.java b/enigma/src/main/java/cuchaz/enigma/EnigmaProject.java
index f9db4d18..1051f452 100644
--- a/enigma/src/main/java/cuchaz/enigma/EnigmaProject.java
+++ b/enigma/src/main/java/cuchaz/enigma/EnigmaProject.java
@@ -48,17 +48,17 @@ import cuchaz.enigma.utils.I18n;
 public class EnigmaProject {
         private final Enigma enigma;
 
-        private final Path jarPath;
+        private final List<Path> jarPaths;
         private final ClassProvider classProvider;
         private final JarIndex jarIndex;
         private final byte[] jarChecksum;
 
         private EntryRemapper mapper;
 
-        public EnigmaProject(Enigma enigma, Path jarPath, ClassProvider classProvider, JarIndex jarIndex, byte[] jarChecksum) {
+        public EnigmaProject(Enigma enigma, List<Path> jarPaths, ClassProvider classProvider, JarIndex jarIndex, byte[] jarChecksum) {
                 Preconditions.checkArgument(jarChecksum.length == 20);
                 this.enigma = enigma;
-                this.jarPath = jarPath;
+                this.jarPaths = List.copyOf(jarPaths);
                 this.classProvider = classProvider;
                 this.jarIndex = jarIndex;
                 this.jarChecksum = jarChecksum;
@@ -78,8 +78,8 @@ public class EnigmaProject {
                 return enigma;
         }
 
-        public Path getJarPath() {
-                return jarPath;
+        public List<Path> getJarPaths() {
+                return jarPaths;
         }
 
         public ClassProvider getClassProvider() {
diff --git a/enigma/src/main/java/cuchaz/enigma/utils/Utils.java b/enigma/src/main/java/cuchaz/enigma/utils/Utils.java
index 081c9410..a1926a8b 100644
--- a/enigma/src/main/java/cuchaz/enigma/utils/Utils.java
+++ b/enigma/src/main/java/cuchaz/enigma/utils/Utils.java
@@ -28,6 +28,7 @@ import java.util.function.Supplier;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
+import com.google.common.base.Preconditions;
 import com.google.common.io.CharStreams;
 
 public class Utils {
@@ -53,7 +54,8 @@ public class Utils {
                 }
         }
 
-        public static byte[] zipSha1(Path path) throws IOException {
+        public static byte[] zipSha1(Path... paths) throws IOException {
+                Preconditions.checkArgument(paths.length >= 1, "Must provide at least one zip");
                 MessageDigest digest;
 
                 try {
@@ -63,6 +65,14 @@ public class Utils {
                         throw new RuntimeException(e);
                 }
 
+                for (Path path : paths) {
+                        appendZipSha1(digest, path);
+                }
+
+                return digest.digest();
+        }
+
+        private static void appendZipSha1(MessageDigest digest, Path path) throws IOException {
                 try (ZipFile zip = new ZipFile(path.toFile())) {
                         List<? extends ZipEntry> entries = Collections.list(zip.entries());
                         // only compare classes (some implementations may not generate directory entries)
@@ -83,8 +93,6 @@ public class Utils {
                                 }
                         }
                 }
-
-                return digest.digest();
         }
 
         public static void withLock(Lock l, Runnable op) {