allow stand-alone remapper creation

Reviewed-on: #3
Reviewed-by: ender <ender@noreply.localhost>
Reviewed-by: Ecorous <ecorous@outlook.com>

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+tab_width = 4
+trim_trailing_whitespace = true
+indent_style = tab

.forgejo/workflows/publish.yml

@@ -0,0 +1,23 @@
+name: Publish to snapshot maven
+
+on:
+  push:
+    branches:
+        - 'main'
+
+jobs:
+  build:
+    runs-on: docker
+    steps:
+    - uses: actions/checkout@v4
+    - uses: https://github.com/actions/setup-java@v4
+      with:
+        distribution: 'temurin'
+        java-version: 21
+    - uses: https://github.com/gradle/actions/setup-gradle@v3
+    - name: Build
+      run: |
+        chmod +x ./gradlew
+        ./gradlew publishMavenJavaPublicationToFrogMCSnapshotsMavenRepository \
+        -PFrogMCSnapshotsMavenUsername=${{ secrets.MAVEN_PUSH_USER }} \
+        -PFrogMCSnapshotsMavenPassword=${{ secrets.MAVEN_PUSH_TOKEN }}

build.gradle.kts

@@ -1,21 +1,63 @@
+import java.util.Date
+
 plugins {
-    id("java")
+    java
+    `java-library`
     id("io.freefair.lombok").version("8.6+")
+    `maven-publish`
 }
 
-group = "org.example"
+group = "dev.frogmc"
-version = "1.0-SNAPSHOT"
+version = "0.0.1-alpha.18"
 
 repositories {
     mavenCentral()
 }
 
 dependencies {
-    implementation("com.google.code.gson:gson:2.10.1")
+    implementation("com.electronwill.night-config:json:3.8.1")
-    implementation("org.ow2.asm:asm-tree:9.7")
+    implementation("org.ow2.asm:asm:9.7")
     implementation("org.ow2.asm:asm-commons:9.7")
-    implementation("org.ow2.asm:asm-util:9.7")
+}
-
+
-    // Annotation Processor
+java {
-    annotationProcessor("org.ow2.asm:asm-tree:9.7")
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
+}
+
+tasks.jar {
+	manifest {
+		attributes("Implementation-Version" to version,
+			"Implementation-Name" to project.name,
+			"Implementation-Date" to Date(),
+			"Main-Class" to "dev.frogmc.thyroxine.Thyroxine")
+	}
+}
+
+publishing {
+    publications {
+        create<MavenPublication>("mavenJava") {
+            from(components["java"])
+        }
+    }
+
+    repositories {
+        maven {
+            name = "FrogMCSnapshotsMaven"
+            url = uri("https://maven.frogmc.dev/snapshots")
+            credentials(PasswordCredentials::class)
+            authentication {
+                create<BasicAuthentication>("basic")
+            }
+        }
+
+        maven {
+            name = "FrogMCReleasesMaven"
+            url = uri("https://maven.frogmc.dev/releases")
+            credentials(PasswordCredentials::class)
+            authentication {
+                create<BasicAuthentication>("basic")
+            }
+        }
+    }
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 #Sat Apr 27 20:33:54 CEST 2024
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.8-bin.zip
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStorePath=wrapper/dists

settings.gradle.kts

@@ -1,2 +1,2 @@
-rootProject.name = "mojmap-patcher"
+rootProject.name = "thyroxine"
 

src/main/java/dev/frogmc/thyroxine/Constants.java

@@ -0,0 +1,15 @@
+package dev.frogmc.thyroxine;
+
+import java.util.Objects;
+
+import com.electronwill.nightconfig.json.JsonParser;
+import org.objectweb.asm.Opcodes;
+
+public final class Constants {
+	public static final String USER_AGENT = "FrogMC Thyroxine/" +
+											Objects.requireNonNullElse(Constants.class.getPackage().getImplementationVersion(), "development") +
+											" <frogmc.dev>";
+	public static final String VERSION_MANIFEST = "https://piston-meta.mojang.com/mc/game/version_manifest_v2.json";
+	public static final JsonParser JSON_PARSER = new JsonParser();
+	public static final int ASM_VERSION = Opcodes.ASM9;
+}

src/main/java/dev/frogmc/thyroxine/HttpHelper.java

@@ -0,0 +1,44 @@
+package dev.frogmc.thyroxine;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.net.http.HttpClient.Redirect;
+import java.nio.file.Path;
+
+import com.electronwill.nightconfig.core.UnmodifiableConfig;
+import lombok.experimental.UtilityClass;
+
+import static dev.frogmc.thyroxine.Constants.JSON_PARSER;
+
+@UtilityClass
+public class HttpHelper {
+
+	public static UnmodifiableConfig getJson(String url) throws IOException {
+		return JSON_PARSER.parse(getString(url)).unmodifiable();
+	}
+
+	public static String getString(String url) throws IOException {
+		return request(url, HttpResponse.BodyHandlers.ofString()).body();
+	}
+
+	public static void download(String url, Path file) throws IOException {
+		request(url, HttpResponse.BodyHandlers.ofFile(file));
+	}
+
+	private static <T> HttpResponse<T> request(String url, HttpResponse.BodyHandler<T> handler) throws IOException {
+		try (HttpClient client = HttpClient.newBuilder().followRedirects(Redirect.NORMAL).build()) {
+			HttpRequest request = HttpRequest.newBuilder()
+				.header("User-Agent", Constants.USER_AGENT)
+				.header("Accept", "*/*")
+				.GET()
+				.uri(URI.create(url))
+				.build();
+			return client.send(request, handler);
+		} catch (InterruptedException e) {
+			throw new IOException(e);
+		}
+	}
+}

src/main/java/dev/frogmc/thyroxine/RemappingStep.java

@@ -0,0 +1,8 @@
+package dev.frogmc.thyroxine;
+
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.commons.Remapper;
+
+public interface RemappingStep {
+	ClassVisitor run(ClassVisitor previous, Remapper remapper);
+}

src/main/java/dev/frogmc/thyroxine/Thyroxine.java

@@ -0,0 +1,228 @@
+package dev.frogmc.thyroxine;
+
+import java.io.IOException;
+import java.nio.file.*;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.*;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import dev.frogmc.thyroxine.api.Mapper;
+import dev.frogmc.thyroxine.api.ParameterClassRemapper;
+import dev.frogmc.thyroxine.api.data.MappingBundle;
+import dev.frogmc.thyroxine.api.data.MappingData;
+import dev.frogmc.thyroxine.parser.ProguardParser;
+import dev.frogmc.thyroxine.parser.tiny.TinyV1Parser;
+import dev.frogmc.thyroxine.parser.tiny.TinyV2Parser;
+import dev.frogmc.thyroxine.provider.MojmapProvider;
+import dev.frogmc.thyroxine.provider.ParchmentProvider;
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.commons.ClassRemapper;
+import org.objectweb.asm.commons.Remapper;
+
+public class Thyroxine {
+
+	private static boolean SYSOUT = false;
+
+	public static void run(String minecraftVersion, Path inputJar, Path outputJar, boolean skipMetaInf, boolean renameParameters) throws IOException, InterruptedException {
+		Path out = outputJar.toAbsolutePath();
+		MappingBundle data = MojmapProvider.get(minecraftVersion,
+			out.resolveSibling("client-" + minecraftVersion + ".txt"),
+			out.resolveSibling("server-" + minecraftVersion + ".txt")).reverse();
+
+		MappingBundle parchment = null;
+		if (renameParameters) {
+			parchment = ParchmentProvider.getParchment(minecraftVersion, out.getParent());
+		}
+
+		MappingBundle result;
+		if (parchment != null) {
+			result = MappingBundle.merge(data, parchment);
+		} else {
+			result = data;
+		}
+
+		SYSOUT = true;
+		remap(result, inputJar, out, skipMetaInf, renameParameters, "official", "named");
+		SYSOUT = false;
+	}
+
+	public static void remap(MappingData data, Path inputJar, Path outputJar, boolean skipMetaInf, Path... context) throws IOException, InterruptedException {
+		remap(data, inputJar, outputJar, skipMetaInf, true, context);
+	}
+
+	public static void remap(MappingBundle bundle, Path inputJar, Path outputJar, boolean skipMetaInf, boolean renameParameters, String srcNamespace, String dstNamespace, Path... context) throws IOException, InterruptedException {
+		remap(bundle.forNamespaces(srcNamespace, dstNamespace), inputJar, outputJar, skipMetaInf, renameParameters, context);
+	}
+
+	public static void remap(MappingData data, Path inputJar, Path outputJar, boolean skipMetaInf, boolean renameParameters, Path... context) throws IOException, InterruptedException {
+		List<RemappingStep> steps = List.of(
+			ClassRemapper::new,
+			(cv, mapper) -> renameParameters ? new ParameterClassRemapper(cv, mapper, data) : cv
+		);
+		remap(data, inputJar, outputJar, skipMetaInf, steps, context);
+	}
+
+	public static void remap(MappingData data, Path inputJar, Path outputJar, boolean skipMetaInf, List<RemappingStep> steps, Path... context) throws IOException, InterruptedException {
+		Files.deleteIfExists(outputJar);
+
+		if (SYSOUT) {
+			System.out.println("Remapping...");
+		}
+
+		long startTime = System.currentTimeMillis();
+
+		try (ExecutorService exec = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
+			 FileSystem inFs = FileSystems.newFileSystem(inputJar);
+			 FileSystem outFs = FileSystems.newFileSystem(outputJar, Map.of("create", "true"))) {
+			List<Callable<Void>> tasks = new ArrayList<>();
+			Map<Path, FileSystem> contexts = new HashMap<>(context.length + 1);
+			contexts.put(inputJar, inFs);
+			for (Path p : context) {
+				if (!contexts.containsKey(p)) {
+					contexts.put(p, FileSystems.newFileSystem(p));
+				}
+			}
+
+			Remapper mapper = createMapper(data, contexts.values());
+
+			Files.walkFileTree(inFs.getPath("/"), new SimpleFileVisitor<>() {
+
+				@Override
+				public FileVisitResult visitFile(Path path, BasicFileAttributes basicFileAttributes) {
+					if (skipMetaInf) {
+						if (path.startsWith("/META-INF")) {
+							var name = path.getFileName().toString();
+							if (name.endsWith(".MF") || name.endsWith(".SF") || name.endsWith(".RSA")) {
+								return FileVisitResult.CONTINUE;
+							}
+						}
+					}
+
+					tasks.add(() -> {
+						try {
+							if (path.getFileName().toString().endsWith(".class")) {
+								String className = path.toString().substring(1, path.toString().lastIndexOf("."));
+								Path result = outFs.getPath(mapper.map(className) + ".class");
+								Path newClass = result.toAbsolutePath();
+								byte[] bytes = Files.readAllBytes(path);
+								ClassReader reader = new ClassReader(bytes);
+								ClassWriter writer = new ClassWriter(0);
+								ClassVisitor visitor = writer;
+								for (RemappingStep pass : steps) {
+									visitor = pass.run(visitor, mapper);
+								}
+								reader.accept(visitor, 0);
+
+								byte[] output = writer.toByteArray();
+								Files.createDirectories(result.getParent());
+								Files.write(newClass, output);
+
+							} else {
+								Path result = outFs.getPath(path.toString()).toAbsolutePath();
+								Files.createDirectories(result.getParent());
+								Files.copy(path, result);
+							}
+						} catch (IOException ex) {
+							throw new Error(ex);
+						}
+
+						return null;
+					});
+
+					return FileVisitResult.CONTINUE;
+				}
+			});
+
+			exec.invokeAll(tasks);
+
+			for (FileSystem fs : contexts.values()) {
+				fs.close();
+			}
+
+			if (SYSOUT) {
+				System.out.printf("Finished remapping (%.2fs)%n", (System.currentTimeMillis() - startTime) / 1000F);
+			}
+		}
+	}
+
+	public static Remapper createMapper(MappingData data, Collection<FileSystem> contexts) {
+		Map<String, List<String>> lazyParents = new ConcurrentHashMap<>();
+		MappingData reverseData = data.reverse();
+		return new Mapper(data, className -> lazyParents.computeIfAbsent(className, ignored ->
+			computeInheritances(className, reverseData, contexts)));
+	}
+
+	public static MappingBundle parse(Path mappings) throws IOException {
+		String data = Files.readString(mappings);
+		String header = data.split("\n", 2)[0];
+		if (header.matches("tiny\t+v2\t+.*")) {
+			return TinyV2Parser.parse(data);
+		} else if (TinyV1Parser.HEADER.matcher(header).matches()) {
+			return TinyV1Parser.parse(data);
+		} else {
+			return new MappingBundle(ProguardParser.read(data));
+		}
+	}
+
+	public static void main(String[] args) throws IOException, InterruptedException {
+		// temporary
+		if (args.length < 3 || args.length > 5) {
+			System.err.println("Usage: <minecraft-version> <minecraft.jar> <out.jar> [--remove-meta-inf] [--remap-parameters]");
+			return;
+		}
+
+		String minecraftVersion = args[0];
+		String minecraftJar = args[1];
+		String outJar = args[2];
+		boolean removeMetaInf = args.length > 3 && hasArg(args, "--remove-meta-inf");
+		boolean remapParams = args.length > 3 && hasArg(args, "--remap-parameters");
+
+		run(minecraftVersion, Paths.get(minecraftJar), Paths.get(outJar), removeMetaInf, remapParams);
+	}
+
+	private static boolean hasArg(String[] arguments, String arg) {
+		for (String s : arguments) {
+			if (arg.equals(s)) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	private static List<String> computeInheritances(String className, MappingData reverse, Collection<FileSystem> jars) {
+		try {
+			if (reverse.classes().containsKey(className)) {
+				className = reverse.classes().get(className);
+			}
+			List<String> superTypes = new ArrayList<>();
+			for (FileSystem fs : jars) {
+				Path path = fs.getPath("/" + className + ".class");
+				if (!Files.isRegularFile(path)) {
+					continue;
+				}
+
+				byte[] bytes = Files.readAllBytes(path);
+				ClassReader reader = new ClassReader(bytes);
+				reader.accept(new ClassVisitor(Constants.ASM_VERSION) {
+					@Override
+					public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+						if (interfaces != null) {
+							superTypes.addAll(Arrays.asList(interfaces));
+						}
+						if (!"java/lang/Object".equals(superName)) {
+							superTypes.add(superName);
+						}
+					}
+				}, ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES);
+			}
+			return superTypes;
+		} catch (IOException error) {
+			throw new Error(error); // not our problem :^) for now
+		}
+	}
+}

src/main/java/dev/frogmc/thyroxine/api/Mapper.java

@@ -0,0 +1,63 @@
+package dev.frogmc.thyroxine.api;
+
+import dev.frogmc.thyroxine.api.data.MappingData;
+import dev.frogmc.thyroxine.api.data.Member;
+import org.objectweb.asm.commons.Remapper;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+public class Mapper extends Remapper {
+
+	private final MappingData data;
+	private final Function<String, List<String>> parentProvider;
+
+	public Mapper(MappingData data, Function<String, List<String>> parentProvider) {
+		this.data = data;
+		this.parentProvider = parentProvider;
+	}
+
+	@Override
+	public String map(String internalName) {
+		return data.classes().getOrDefault(internalName, internalName);
+	}
+
+	@Override
+	public String mapMethodName(String owner, String name, String descriptor) {
+		String result = map(0, data.methods(), owner, name, descriptor);
+		if (result != null)
+			return result;
+
+		return name;
+	}
+
+	@Override
+	public String mapFieldName(String owner, String name, String descriptor) {
+		String result = map(0, data.fields(), owner, name, descriptor);
+		if (result != null)
+			return result;
+
+		return name;
+	}
+
+	private String map(int depth, Map<Member, String> map, String owner, String name, String descriptor) {
+		if (owner.startsWith("["))
+			return null;
+
+		String result = map.get(new Member(owner, name, descriptor));
+		if (result != null)
+			return result;
+
+		if (depth >= 64)
+			return null;
+
+		for (String parent : parentProvider.apply(owner)) {
+			result = map(depth + 1, map, parent, name, descriptor);
+			if (result != null)
+				return result;
+		}
+
+		return null;
+	}
+}

src/main/java/dev/frogmc/thyroxine/api/ParameterClassRemapper.java

@@ -0,0 +1,40 @@
+package dev.frogmc.thyroxine.api;
+
+import java.util.Collections;
+import java.util.Map;
+
+import dev.frogmc.thyroxine.Constants;
+import dev.frogmc.thyroxine.api.data.MappingData;
+import dev.frogmc.thyroxine.api.data.Member;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.commons.Remapper;
+
+public class ParameterClassRemapper extends ClassVisitor {
+	private final MappingData data;
+	private final Remapper remapper;
+
+	private String className;
+	public ParameterClassRemapper(ClassVisitor classVisitor, Remapper remapper, MappingData data) {
+		super(Constants.ASM_VERSION, classVisitor);
+		this.remapper = remapper;
+		this.data = data;
+	}
+
+	@Override
+	public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+		this.className = name;
+		super.visit(version, access, name, signature, superName, interfaces);
+	}
+
+	@Override
+	public MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions) {
+		String remappedDescriptor = remapper.mapMethodDesc(descriptor);
+		MethodVisitor methodVisitor = cv.visitMethod(access, remapper.mapMethodName(className, name, descriptor), remappedDescriptor,
+			remapper.mapSignature(signature, false), exceptions == null ? null : remapper.mapTypes(exceptions));
+
+		Member member = new Member(remapper.map(className), remapper.mapMethodName(className, name, descriptor), remappedDescriptor);
+		Map<Integer, String> parameters = data != null ? data.parameters().getOrDefault(member, Collections.emptyMap()) : Collections.emptyMap();
+		return new ParameterMethodRemapper(methodVisitor, remapper, parameters);
+	}
+}

src/main/java/dev/frogmc/thyroxine/api/ParameterMethodRemapper.java

@@ -0,0 +1,105 @@
+package dev.frogmc.thyroxine.api;
+
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+
+import dev.frogmc.thyroxine.Constants;
+import org.objectweb.asm.Label;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Type;
+import org.objectweb.asm.commons.Remapper;
+
+public class ParameterMethodRemapper extends MethodVisitor {
+	private final Remapper remapper;
+	private final Map<Integer, String> parameters;
+	private final Set<String> usedLocalNames = new HashSet<>();
+
+	public ParameterMethodRemapper(MethodVisitor methodVisitor, Remapper remapper, Map<Integer, String> parameters) {
+		super(Constants.ASM_VERSION, methodVisitor);
+		this.remapper = remapper;
+		this.parameters = parameters;
+	}
+
+	@Override
+	public void visitLocalVariable(String name, String descriptor, String signature, Label start, Label end, int index) {
+		if (!name.equals("this")) {
+			if (parameters.containsKey(index)) {
+				name = parameters.get(index);
+			} else {
+				name = getNewName(descriptor, signature);
+			}
+		}
+		super.visitLocalVariable(name, descriptor, signature, start, end, index);
+	}
+
+	private String getNewName(String descriptor, String signature) {
+		descriptor = remapper.mapDesc(descriptor);
+		signature = remapper.mapSignature(signature, false);
+
+		String newName = convertDescriptor(descriptor);
+
+		int count = 1;
+		String nameCopy = newName;
+		while (usedLocalNames.contains(newName)) {
+			if (signature != null) {
+				String type = cleanType(signature);
+				if (!newName.toLowerCase(Locale.ROOT).contains(type.toLowerCase(Locale.ROOT))) {
+					newName = Character.toLowerCase(type.charAt(0)) + type.substring(1) +
+							  Character.toUpperCase(newName.charAt(0)) + newName.substring(1);
+					continue;
+				}
+			}
+			newName = nameCopy + ++count;
+		}
+		usedLocalNames.add(newName);
+		return newName;
+	}
+
+	private String convertDescriptor(String descriptor) {
+		return switch (descriptor.charAt(0)) {
+			case 'I' -> "i";
+			case 'B' -> "b";
+			case 'C' -> "c";
+			case 'S' -> "s";
+			case 'D' -> "d";
+			case 'F' -> "f";
+			case 'J' -> "l";
+			case 'Z' -> "bl";
+			case '[' -> {
+				Type type = Type.getType(descriptor).getElementType();
+				if (type.getSort() == Type.OBJECT) {
+					yield convertDescriptor(type.getInternalName()) + "s";
+				}
+				yield type.getClassName() + "s";
+			}
+			default -> {
+				String name = cleanType(descriptor);
+				name = Character.toLowerCase(name.charAt(0)) + name.substring(1);
+				yield name;
+			}
+		};
+	}
+
+	private String cleanType(String type) {
+		var cleaned = type;
+		if (cleaned.indexOf('<') != -1) {
+			cleaned = cleaned.substring(0, cleaned.indexOf('<'));
+		}
+
+		if (cleaned.indexOf('/') != -1) {
+			cleaned = cleaned.substring(cleaned.lastIndexOf('/') + 1);
+		}
+
+		cleaned = cleaned.replaceAll("\\$\\d+;", "");
+
+		if (cleaned.indexOf('$') != -1) {
+			cleaned = cleaned.substring(cleaned.lastIndexOf('$') + 1);
+		}
+
+		cleaned = cleaned.replace("[", "").replace("]", "").replaceAll("(.*)\\d", "$1").replace(";", "");
+
+		return cleaned;
+	}
+}

src/main/java/dev/frogmc/thyroxine/api/data/DocumentationData.java

@@ -0,0 +1,123 @@
+package dev.frogmc.thyroxine.api.data;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+public record DocumentationData(String namespace, List<Package> packages, List<Class> classes) {
+
+	public DocumentationData(String namespace) {
+		this(namespace, new ArrayList<>(), new ArrayList<>());
+	}
+
+	public DocumentationData insert(DocumentationData other) {
+		other.classes().forEach(c -> {
+			Optional<Class> opt = getClass(c.name);
+			if (opt.isPresent()) {
+				opt.get().merge(c);
+			} else {
+				classes.add(c);
+			}
+		});
+
+		other.packages().forEach(p -> {
+			Optional<Package> opt = getPackage(p.name);
+			if (opt.isPresent()) {
+				opt.get().merge(p);
+			} else {
+				packages.add(p);
+			}
+		});
+
+		return this;
+	}
+
+	public Optional<Class> getClass(String name) {
+		if (classes == null){
+			return Optional.empty();
+		}
+		return classes.stream().filter(c -> c.name().equals(name)).findFirst();
+	}
+
+	public Optional<Package> getPackage(String name) {
+		if (packages == null){
+			return Optional.empty();
+		}
+		return packages().stream().filter(p -> p.name().equals(name)).findFirst();
+	}
+
+	public record Package(String name, List<String> javadoc) {
+
+		public void merge(Package other) {
+			if (other.javadoc() != null && !String.join("\n", other.javadoc()).equals(String.join("\n", javadoc()))) {
+				javadoc().addAll(other.javadoc());
+			}
+		}
+	}
+
+	public record Class(String name, List<String> javadoc, List<Field> fields, List<Method> methods) {
+		public Optional<Field> getField(String name, String descriptor) {
+			if (fields == null){
+				return Optional.empty();
+			}
+			return fields.stream()
+					.filter(f -> f.name.equals(name) &&
+								 f.descriptor.equals(descriptor))
+					.findFirst();
+		}
+
+		public Optional<Method> getMethod(String name, String descriptor) {
+			if (methods == null){
+				return Optional.empty();
+			}
+			return methods.stream()
+					.filter(method -> method.name.equals(name) &&
+									  method.descriptor.equals(descriptor))
+					.findFirst();
+		}
+
+		public void merge(Class other) {
+			if (other.javadoc() != null && !String.join("\n", other.javadoc()).equals(String.join("\n", javadoc()))) {
+				if (!other.javadoc().isEmpty()) {
+					javadoc().addAll(other.javadoc());
+				}
+			}
+
+			other.fields.forEach(f -> {
+				Optional<Field> opt = getField(f.name, f.descriptor);
+				if (opt.isPresent()) {
+					opt.get().merge(f);
+				} else {
+					fields.add(f);
+				}
+			});
+
+			other.methods.forEach(m -> {
+				Optional<Method> opt = getMethod(m.name, m.descriptor);
+				if (opt.isPresent()) {
+					opt.get().merge(m);
+				} else {
+					methods.add(m);
+				}
+			});
+
+		}
+	}
+
+	public record Field(String name, String descriptor, List<String> javadoc) {
+		public void merge(Field other) {
+			if (other.javadoc() != null && !String.join("\n", other.javadoc()).equals(String.join("\n", javadoc()))) {
+				javadoc().addAll(other.javadoc());
+			}
+		}
+	}
+
+	public record Method(String name, String descriptor, List<String> javadoc) {
+		public void merge(Method other) {
+			if (other.javadoc() != null && !String.join("\n", other.javadoc()).equals(String.join("\n", javadoc()))) {
+				javadoc().addAll(other.javadoc());
+			}
+		}
+	}
+}
+

src/main/java/dev/frogmc/thyroxine/api/data/MappingBundle.java

@@ -0,0 +1,358 @@
+package dev.frogmc.thyroxine.api.data;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+import dev.frogmc.thyroxine.api.Mapper;
+
+public record MappingBundle(List<MappingData> data, List<DocumentationData> documentation) {
+
+	public MappingBundle() {
+		this((MappingData) null);
+	}
+
+	public MappingBundle(MappingData data) {
+		this(data, null);
+	}
+
+	public MappingBundle(DocumentationData data) {
+		this(null, data);
+	}
+
+	public MappingBundle(MappingData data, DocumentationData documentation) {
+		this(list(data), list(documentation));
+	}
+
+	private static <T> List<T> list(T element) { // create a mutable list populated with a single element
+		List<T> list = new ArrayList<>();
+		if (element != null) {
+			list.add(element);
+		}
+		return list;
+	}
+
+	public static MappingBundle merge(MappingBundle... bundles) {
+		List<MappingData> mergedData = new ArrayList<>();
+		List<DocumentationData> mergedDocs = new ArrayList<>();
+
+		for (MappingBundle bundle : bundles) {
+			mergedData.addAll(bundle.data());
+			mergedDocs.addAll(bundle.documentation());
+		}
+
+		return new MappingBundle(mergedData, mergedDocs);
+	}
+
+	public MappingBundle insert(MappingData data) {
+		this.data.add(data);
+		return this;
+	}
+
+	public MappingBundle insert(DocumentationData data) {
+		for (DocumentationData d : documentation) {
+			if (d.namespace().equals(data.namespace())) {
+				d.insert(data);
+				return this;
+			}
+		}
+
+		documentation.add(data);
+		return this;
+	}
+
+	public List<String> srcNamespaces() {
+		return data.stream().map(MappingData::srcNamespace).toList();
+	}
+
+	public List<String> dstNamespaces() {
+		return data.stream().map(MappingData::dstNamespace).toList();
+	}
+
+	public MappingData forNamespaces(String src, String dst) {
+		return flattenInternal(src, dst, false);
+	}
+
+	public MappingData forNamespaces(String src, String dst, boolean allowIncomplete) {
+		return flattenInternal(src, dst, allowIncomplete);
+	}
+
+	public MappingBundle flatten(String src, String dst) {
+		return flatten(src, dst, false);
+	}
+
+	public MappingBundle flatten(String src, String dst, boolean allowIncomplete) {
+		MappingData data = flattenInternal(src, dst, allowIncomplete);
+		return new MappingBundle(data, get(data.dstNamespace()));
+	}
+
+	public DocumentationData docsForNamespace(String ns) {
+		DocumentationData result = new DocumentationData(ns);
+		for (DocumentationData d : documentation) {
+			if (d.namespace().equals(ns)) {
+				result.insert(d);
+			} else {
+				Mapper mappings = new Mapper(forNamespaces(d.namespace(), ns, false), a -> Collections.emptyList());
+				DocumentationData remapped = new DocumentationData(ns);
+				// TODO is there something we can do about the packages...? (don't think so)
+				d.classes().forEach(c -> {
+					String name = mappings.map(c.name());
+					List<DocumentationData.Method> methods = c.methods().stream().map(m ->
+						new DocumentationData.Method(mappings.mapMethodName(c.name(), m.name(), m.descriptor()),
+							mappings.mapMethodDesc(m.descriptor()), m.javadoc())).toList();
+					List<DocumentationData.Field> fields = c.fields().stream().map(f ->
+						new DocumentationData.Field(mappings.mapFieldName(c.name(), f.name(), f.descriptor()),
+							mappings.mapDesc(f.descriptor()), f.javadoc())).collect(Collectors.toCollection(ArrayList::new));
+					remapped.classes().add(new DocumentationData.Class(name, c.javadoc(), fields, methods));
+				});
+				result.insert(remapped);
+			}
+		}
+		return result;
+	}
+
+	public MappingBundle flatten() {
+		return flatten(false);
+	}
+
+	public MappingBundle flatten(boolean allowIncomplete) {
+		MappingData data = flattenData(allowIncomplete);
+		return new MappingBundle(data, get(data.dstNamespace()));
+	}
+
+	public MappingData flattenData(boolean allowIncomplete) {
+		Set<String> overlayNs = new HashSet<>();
+		for (MappingData d : data()) {
+			if (d.srcNamespace().equals(d.dstNamespace())) {
+				overlayNs.add(d.srcNamespace());
+			}
+		}
+		List<String> srcNs = srcNamespaces();
+		List<String> dstNs = dstNamespaces();
+		List<String> srcNsCandidates = srcNs.stream().distinct().filter(s -> !dstNs.contains(s) && !overlayNs.contains(s)).toList();
+		List<String> dstNsCandidates = dstNs.stream().distinct().filter(s -> !srcNs.contains(s) || overlayNs.contains(s)).toList();
+		if (srcNsCandidates.size() > 1) {
+			throw new IllegalStateException("Not a linear graph, cannot flatten! Got possible roots: " + String.join(", ", srcNsCandidates));
+		} else if (srcNsCandidates.isEmpty()) {
+			throw new IllegalStateException("Not a linear graph, cannot flatten! Got no possible roots! SrcNamespaces: " + String.join(", ", srcNs) + " Overlays: " + String.join(", ", overlayNs));
+		}
+		if (dstNsCandidates.size() > 1) {
+			throw new IllegalStateException("Not a linear graph, cannot flatten! Got possible ends: " + String.join(", ", dstNsCandidates));
+		} else if (dstNsCandidates.isEmpty()) {
+			throw new IllegalStateException("Not a linear graph, cannot flatten! Got no possible roots! DstNamespaces: " + String.join(", ", dstNs));
+		}
+		String srcRoot = srcNsCandidates.getFirst();
+		String dstRoot = dstNsCandidates.getFirst();
+		return flattenInternal(srcRoot, dstRoot, allowIncomplete);
+	}
+
+	private MappingData flattenInternal(String srcRoot, String dstRoot, boolean allowIncomplete) {
+		Deque<MappingData> path = computePath(srcRoot, dstRoot).reversed();
+
+		MappingData result = new MappingData(srcRoot, dstRoot);
+
+		MappingData first = path.pop();
+
+		Map<String, Map<String, Mapper>> mappers = new HashMap<>();
+		Mapper start = mappers.computeIfAbsent(first.srcNamespace(),
+			a -> new HashMap<>()).computeIfAbsent(first.dstNamespace(),
+			a -> new Mapper(first, b -> Collections.emptyList()));
+
+		first.classes().forEach((s, s2) -> {
+			String res = s2;
+			for (MappingData d : path) {
+				String w = res;
+				res = d.classes().get(res);
+				if (res == null) {
+					int dollar = w.indexOf("$");
+					if (dollar != -1) {
+						String prefix = d.classes().get(w.substring(0, dollar));
+						if (prefix != null) {
+							res = prefix + w.substring(dollar);
+							break;
+						}
+					}
+					if (!allowIncomplete) {
+						/*
+						 * The mapping set is incomplete at this point.
+						 * We're using the last available value to prevent incompleteness
+						 * in the resulting set.
+						 */
+						res = w;
+					}
+					break;
+				}
+			}
+			if (res != null) {
+				result.classes().put(s, res);
+			}
+		});
+
+		first.methods().forEach((member, s) -> {
+			String res = s;
+			String owner = start.map(member.owner());
+			String desc = start.mapMethodDesc(member.descriptor());
+			for (MappingData d : path) {
+				Mapper mapper = mappers.computeIfAbsent(d.srcNamespace(),
+					a -> new HashMap<>()).computeIfAbsent(d.dstNamespace(),
+					a -> new Mapper(d, b -> Collections.emptyList()));
+				String w = res;
+				res = d.methods().get(new Member(owner, res, desc));
+				owner = mapper.map(owner);
+				desc = mapper.mapMethodDesc(desc);
+				if (res == null) {
+					if (!allowIncomplete) {
+						/*
+						 * The mapping set is incomplete at this point.
+						 * We're using the last available value to prevent incompleteness
+						 * in the resulting set.
+						 */
+						res = w;
+					}
+					break;
+				}
+			}
+			if (res != null) {
+				result.methods().put(member, res);
+			}
+		});
+
+		first.fields().forEach((member, s) -> {
+			String res = s;
+			String owner = start.map(member.owner());
+			String desc = start.mapDesc(member.descriptor());
+			for (MappingData d : path) {
+				Mapper mapper = mappers.computeIfAbsent(d.srcNamespace(),
+					a -> new HashMap<>()).computeIfAbsent(d.dstNamespace(),
+					a -> new Mapper(d, b -> Collections.emptyList()));
+				String w = res;
+				res = d.fields().get(new Member(owner, res, desc));
+				owner = mapper.map(owner);
+				desc = mapper.mapDesc(desc);
+				if (res == null) {
+					if (!allowIncomplete) {
+						/*
+						 * The mapping set is incomplete at this point.
+						 * We're using the last available value to prevent incompleteness
+						 * in the resulting set.
+						 */
+						res = w;
+					}
+					break;
+				}
+			}
+			if (res != null) {
+				result.fields().put(member, res);
+			}
+		});
+
+		{
+			List<MappingData> all = new ArrayList<>(path);
+			all.addFirst(first);
+			Map<Member, Map<Integer, String>> queue = new HashMap<>();
+			for (MappingData d : all) {
+				queue.putAll(d.parameters());
+				Mapper mapper = mappers.computeIfAbsent(d.srcNamespace(),
+					a -> new HashMap<>()).computeIfAbsent(d.dstNamespace(),
+					a -> new Mapper(d, b -> Collections.emptyList()));
+				Map<Member, Map<Integer, String>> map = new HashMap<>(queue);
+				queue.clear();
+				map.forEach((member, param) -> queue.put(new Member(mapper.map(member.owner()),
+						mapper.mapMethodName(member.owner(), member.name(), member.descriptor()),
+						mapper.mapMethodDesc(member.descriptor())),
+					param));
+			}
+			result.parameters().putAll(queue);
+		}
+
+		return result;
+	}
+
+	private Deque<MappingData> computePath(String srcRoot, String dstRoot) {
+
+		Deque<MappingData> path = new ArrayDeque<>();
+		List<MappingData> available = new ArrayList<>(data);
+		for (MappingData d : data) {
+			if (d.srcNamespace().equals(srcRoot)) {
+				path.push(d);
+				available.remove(d);
+				break;
+			} else if (d.dstNamespace().equals(srcRoot)) {
+				path.push(d.reverse());
+				available.remove(d);
+				break;
+			}
+		}
+
+		while (!path.getFirst().dstNamespace().equals(dstRoot)) {
+			MappingData last = path.getFirst();
+
+			String needed = last.dstNamespace();
+			for (MappingData d : new ArrayList<>(available)) {
+				if (d.srcNamespace().equals(needed)) {
+					available.remove(d);
+					path.push(d);
+				} else if (d.dstNamespace().equals(needed)) {
+					available.remove(d);
+					path.push(d.reverse());
+				}
+			}
+		}
+
+		for (MappingData d : available) {
+			if (d.srcNamespace().equals(d.dstNamespace()) && d.srcNamespace().equals(dstRoot)) {
+				path.push(d);
+			}
+		}
+
+		return path;
+	}
+
+	public MappingBundle insert(MappingData data, DocumentationData documentation) {
+		return insert(data).insert(documentation);
+	}
+
+	public MappingBundle insert(MappingBundle other) {
+		return insert(other.data, other.documentation);
+	}
+
+	public MappingBundle insert(List<MappingData> data, List<DocumentationData> documentation) {
+		data.forEach(this::insert);
+		documentation.forEach(this::insert);
+		return this;
+	}
+
+	public DocumentationData get(String namespace) {
+		DocumentationData result = null;
+		for (DocumentationData d : documentation) {
+			if (d.namespace().equals(namespace)) {
+				if (result == null) {
+					result = new DocumentationData(namespace);
+				}
+				result.insert(d);
+			}
+		}
+		return result;
+	}
+
+	public MappingData getWithSrcNamespace(String namespace) {
+		return data.stream().filter(d -> d.srcNamespace().equals(namespace)).findFirst().orElse(null);
+	}
+
+	public MappingData getWithDstNamespace(String namespace) {
+		return data.stream().filter(d -> d.dstNamespace().equals(namespace)).findFirst().orElse(null);
+	}
+
+	public MappingBundle reverse() {
+		MappingBundle reversed = new MappingBundle();
+		for (MappingData d : data) {
+			reversed.data().addFirst(d.reverse());
+		}
+
+		reversed.documentation.addAll(documentation);
+		return reversed;
+	}
+
+	public MappingData flattenData() {
+		return flattenData(false);
+	}
+}

src/main/java/dev/frogmc/thyroxine/api/data/MappingData.java

@@ -0,0 +1,73 @@
+package dev.frogmc.thyroxine.api.data;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.objectweb.asm.Type;
+
+public record MappingData(String srcNamespace, String dstNamespace, Map<String, String> classes, Map<Member, String> methods,
+						  Map<Member, String> fields, Map<Member, Map<Integer, String>> parameters) {
+
+	public MappingData(String srcNs, String dstNs) {
+		this(srcNs, dstNs, new HashMap<>(), new HashMap<>(), new HashMap<>(), new HashMap<>());
+	}
+
+	public MappingData reverse() {
+		Map<String, String> classesReversed = new HashMap<>();
+		Map<Member, String> methodsReversed = new HashMap<>();
+		Map<Member, String> fieldsReversed = new HashMap<>();
+		Map<Member, Map<Integer, String>> parametersReversed = new HashMap<>();
+
+		for (Map.Entry<String, String> clazz : classes.entrySet())
+			classesReversed.put(clazz.getValue(), clazz.getKey());
+
+		for (Map.Entry<Member, String> method : methods.entrySet()) {
+			methodsReversed.put(
+				new Member(
+					classes.getOrDefault(method.getKey().owner(), method.getKey().owner()),
+					method.getValue(),
+					remapType(Type.getType(method.getKey().descriptor())).getDescriptor()
+				),
+				method.getKey().name()
+			);
+		}
+
+		for (Map.Entry<Member, String> field : fields.entrySet()) {
+			fieldsReversed.put(
+				new Member(
+					classes.getOrDefault(field.getKey().owner(), field.getKey().owner()),
+					field.getValue(),
+					remapType(Type.getType(field.getKey().descriptor())).getDescriptor()
+				),
+				field.getKey().name()
+			);
+		}
+
+		for (Map.Entry<Member, Map<Integer, String>> param : parameters.entrySet()) {
+			parametersReversed.put(new Member(
+				classes.getOrDefault(param.getKey().owner(), param.getKey().owner()),
+				fields.getOrDefault(param.getKey(), param.getKey().name()),
+				remapType(Type.getType(param.getKey().descriptor())).getDescriptor()
+			), param.getValue());
+		}
+
+		return new MappingData(dstNamespace, srcNamespace, classesReversed, methodsReversed, fieldsReversed, parametersReversed);
+	}
+
+	private Type remapType(Type type) {
+		return switch (type.getSort()) {
+			case Type.OBJECT ->
+				Type.getObjectType(classes.getOrDefault(type.getInternalName(), type.getInternalName()));
+			case Type.ARRAY -> Type.getObjectType(
+				"[".repeat(type.getDimensions()) + remapType(type.getElementType()).getDescriptor()
+			);
+			case Type.METHOD -> Type.getMethodType(
+				remapType(type.getReturnType()),
+				Arrays.stream(type.getArgumentTypes()).map(this::remapType).toArray(Type[]::new)
+			);
+			default -> type;
+		};
+	}
+
+}

src/main/java/dev/frogmc/thyroxine/api/data/Member.java

@@ -0,0 +1,4 @@
+package dev.frogmc.thyroxine.api.data;
+
+public record Member(String owner, String name, String descriptor) {
+}

src/main/java/dev/frogmc/thyroxine/parser/ProguardParser.java

@@ -0,0 +1,97 @@
+package dev.frogmc.thyroxine.parser;
+
+import dev.frogmc.thyroxine.api.data.MappingData;
+import dev.frogmc.thyroxine.api.data.Member;
+
+public class ProguardParser {
+
+	public static MappingData read(String mappings) {
+		String[] lines = mappings.split("\n");
+
+		MappingData data = new MappingData("named", "official");
+		String currentClass = null;
+		for (String line : lines) {
+			if (line.contains("#")) {
+				line = line.substring(0, line.indexOf('#'));
+			}
+
+			line = line.trim();
+
+			if (line.isEmpty()) {
+				continue;
+			}
+
+			int arrowIndex = line.indexOf("->");
+			if (arrowIndex == -1) {
+				throw new IllegalStateException("Missing arrow in mapping");
+			}
+
+			String obf = line.substring(0, arrowIndex).trim();
+			String deobf = line.substring(arrowIndex + 2).trim();
+
+			if (line.endsWith(":")) {
+				deobf = deobf.substring(0, deobf.length() - 1);
+				currentClass = obf.replace('.', '/');
+				data.classes().put(currentClass, deobf.replace('.', '/'));
+			} else {
+				if (currentClass == null) {
+					throw new IllegalStateException("Member mapping specified before a class");
+				}
+
+				int spaceIndex = obf.indexOf(' ');
+				if (spaceIndex == -1) {
+					throw new IllegalStateException("Missing member signature");
+				}
+
+				String type = obf.substring(0, spaceIndex);
+				String signature = obf.substring(spaceIndex + 1);
+
+				int colonIndex = type.lastIndexOf(':');
+				if (colonIndex != -1)
+					type = type.substring(colonIndex + 1);
+
+				if (signature.contains("(") && signature.endsWith(")")) {
+					// method
+					String name = signature.substring(0, signature.indexOf('('));
+					String args = signature.substring(signature.indexOf('(') + 1, signature.length() - 1);
+					StringBuilder descriptor = new StringBuilder();
+					descriptor.append('(');
+					if (!args.isEmpty()) {
+						for (String arg : args.split(",")) {
+							descriptor.append(convertType(arg));
+						}
+					}
+					descriptor.append(')');
+					descriptor.append(convertType(type));
+
+					data.methods().put(new Member(currentClass, name, descriptor.toString()), deobf);
+				} else
+					data.fields().put(new Member(currentClass, signature, convertType(type)), deobf);
+			}
+		}
+		return data;
+	}
+
+	private static String convertType(String type) {
+		int dimensions = 0;
+		while (type.endsWith("[]")) {
+			type = type.substring(0, type.length() - 2);
+			++dimensions;
+		}
+
+		String result = switch (type) {
+			case "void" -> "V";
+			case "boolean" -> "Z";
+			case "byte" -> "B";
+			case "short" -> "S";
+			case "int" -> "I";
+			case "long" -> "J";
+			case "float" -> "F";
+			case "double" -> "D";
+			case "char" -> "C";
+			default -> 'L' + type.replace('.', '/') + ';';
+		};
+
+		return "[".repeat(dimensions) + result;
+	}
+}

src/main/java/dev/frogmc/thyroxine/parser/tiny/TinyV1Parser.java

@@ -0,0 +1,82 @@
+package dev.frogmc.thyroxine.parser.tiny;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import dev.frogmc.thyroxine.api.data.MappingBundle;
+import dev.frogmc.thyroxine.api.data.MappingData;
+import dev.frogmc.thyroxine.api.data.Member;
+
+public class TinyV1Parser {
+
+	public static final Pattern HEADER = Pattern.compile("v(?<majorVer>[12]+)\\s\\w*\\s?(?<srcns>\\S+)\\s(?<dstns>\\S+)");
+
+	public static MappingBundle parse(String mappings) {
+		String[] lines = mappings.split("\n");
+		int length = lines.length;
+
+		Matcher header = HEADER.matcher(lines[0]);
+		if (!header.matches()) {
+			throw new IllegalStateException("Not a valid tiny file");
+		}
+
+		MappingData data = new MappingData(header.group("srcns"), header.group("dstns"));
+		//DocumentationData documentation = new DocumentationData();
+		for (int i = 1; i < length; i++) {
+			String[] line = lines[i].split("\\s");
+
+			String type = line[0];
+
+			if ("CLASS".equals(type)) {
+				data.classes().put(line[1], line[2]);
+				//documentation.classes().add(new DocumentationData.Class(line[1], new ArrayList<>(0), new ArrayList<>(), new ArrayList<>()));
+				continue;
+			}
+
+
+			if ("FIELD".equals(type)) {
+				String desc = line[2];
+				String obf = line[line.length - 2]; // aaa these files can contain more than two namespaces, we *should* be fine by just using the last two
+				String deobf = line[line.length - 1];
+				data.fields().put(new Member(line[1], obf, desc), deobf);
+				//documentation.getClass(line[1]).ifPresent(c -> c.fields().add(new DocumentationData.Field(obf, desc, new ArrayList<>())));
+				//continue;
+			} else if ("METHOD".equals(type)) {
+				String desc = line[2];
+				String obf = line[line.length - 2]; // aaa these files can contain more than two namespaces, we *should* be fine by just using the last two
+				String deobf = line[line.length - 1];
+
+				data.methods().put(new Member(line[1], obf, desc), deobf);
+				//documentation.getClass(line[1]).ifPresent(c -> c.methods().add(new DocumentationData.Method(obf, desc, new ArrayList<>(), new ArrayList<>())));
+				//continue;
+			}
+			// TODO Observe if there are any tinyv1 files with javadocs and/or parameter mappings
+			/* else if ("c".equals(type)) {
+				currentC.javadoc().addAll(Arrays.asList(line[2].split("\n")));
+				continue;
+			}
+
+
+			if (currentF == null && currentM == null) {
+				throw new IllegalStateException("Field javadoc/Method parameter mapping/javadoc specified before a declaration");
+			}
+
+
+			if (currentM != null) {
+				if ("p".equals(type)) {
+					currentM.parameters().add(new DocumentationData.Parameter(Integer.parseInt(line[3]), line[5]));
+				} else if ("c".equals(type)) {
+					currentM.javadoc().addAll(Arrays.asList(line[2].split("\n")));
+				}
+			} else {
+				if ("c".equals(type)) {
+					currentF.javadoc().addAll(Arrays.asList(line[2].split("\n")));
+				}
+			}*/
+
+
+		}
+
+		return new MappingBundle(data);
+	}
+}

src/main/java/dev/frogmc/thyroxine/parser/tiny/TinyV2Parser.java

@@ -0,0 +1,135 @@
+package dev.frogmc.thyroxine.parser.tiny;
+
+import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import dev.frogmc.thyroxine.api.Mapper;
+import dev.frogmc.thyroxine.api.data.DocumentationData;
+import dev.frogmc.thyroxine.api.data.MappingBundle;
+import dev.frogmc.thyroxine.api.data.MappingData;
+import dev.frogmc.thyroxine.api.data.Member;
+
+public class TinyV2Parser {
+
+	private static final Pattern HEADER = Pattern.compile("tiny\t(?<majorVer>\\d+)\t(?<minorVer>\\d+)\t(?<namespaces>(?:\t?[^\t]+){2,})");
+
+	public static MappingBundle parse(String mappings) {
+		String[] lines = mappings.split("\n");
+		int length = lines.length;
+
+		Matcher header = HEADER.matcher(lines[0]);
+		if (!header.matches()) {
+			throw new IllegalStateException("Not a valid tiny file! (header: "+lines[0]+")");
+		}
+
+		List<String> namespaces = Arrays.asList(header.group("namespaces").split("\t"));
+		int count = namespaces.size();
+		MappingBundle bundle = new MappingBundle();
+		List<Mapper> mappers = new ArrayList<>();
+
+		for (int ns = 1;ns<count;ns++) {
+			String srcNs = namespaces.get(ns-1);
+			String dstNs = namespaces.get(ns);
+
+			MappingData data = new MappingData(srcNs, dstNs);
+			String currentClass = null;
+			DocumentationData.Class currentC = null;
+			DocumentationData.Method currentM = null;
+			DocumentationData.Field currentF = null;
+			DocumentationData documentation = new DocumentationData(dstNs);
+			for (int i = 1; i < length; i++) {
+				String[] line = lines[i].split("\t");
+
+				if ("c".equals(line[0])) {
+					if (1+ns >= line.length) {
+						while (lines[i + 1].startsWith("\t")) {
+							i++;
+						}
+						continue;
+					}
+					currentClass = line[ns];
+					data.classes().put(currentClass, line[1+ns]);
+					documentation.classes().add(currentC = new DocumentationData.Class(line[1+ns], new ArrayList<>(0), new ArrayList<>(), new ArrayList<>()));
+					currentM = null;
+					currentF = null;
+					continue;
+				}
+
+				if (currentClass == null) {
+					throw new IllegalStateException("Member mapping specified before a class");
+				}
+
+				{
+					String type = line[1];
+					if ("f".equals(type)) {
+						if (3+ns >= line.length) {
+							continue;
+						}
+						String desc = line[2];
+						String obf = line[2+ns];
+						String deobf = line[3+ns];
+
+						if (ns > 1) {
+							for (Mapper mapper : mappers) {
+								desc = mapper.mapDesc(desc);
+							}
+						}
+
+						data.fields().put(new Member(currentClass, obf, desc), deobf);
+						currentC.fields().add(currentF = new DocumentationData.Field(deobf, desc, new ArrayList<>()));
+						continue;
+					} else if ("m".equals(type)) {
+						if (3+ns >= line.length) {
+							continue;
+						}
+						String desc = line[2];
+						String obf = line[2+ns];
+						String deobf = line[3+ns];
+
+						if (ns > 1) {
+							for (Mapper mapper : mappers) {
+								desc = mapper.mapMethodDesc(desc);
+							}
+						}
+
+						data.methods().put(new Member(currentClass, obf, desc), deobf);
+						currentC.methods().add(currentM = new DocumentationData.Method(deobf, desc, new ArrayList<>()));
+						continue;
+					} else if ("c".equals(type)) {
+						currentC.javadoc().addAll(Arrays.asList(line[2].split("\n")));
+						continue;
+					}
+				}
+
+				if (currentF == null && currentM == null) {
+					continue;
+				}
+
+				{
+					String type = line[2];
+					if (currentM != null) {
+						if ("p".equals(type)) {
+							if (4+ns >= line.length) {
+								continue;
+							}
+							data.parameters().computeIfAbsent(new Member(currentClass, currentM.name(), currentM.descriptor()), a -> new HashMap<>())
+									.put(Integer.parseInt(line[3]), line[4+ns]);
+						} else if ("c".equals(type)) {
+							currentM.javadoc().addAll(Arrays.asList(line[3].split("\n")));
+						}
+					} else {
+						if ("c".equals(type)) {
+							currentF.javadoc().addAll(Arrays.asList(line[3].split("\n")));
+						}
+					}
+				}
+			}
+			mappers.add(new Mapper(data, s -> Collections.emptyList()));
+			bundle.insert(data, documentation);
+
+		}
+
+		return bundle;
+	}
+}

src/main/java/dev/frogmc/thyroxine/provider/MojmapProvider.java

@@ -0,0 +1,64 @@
+package dev.frogmc.thyroxine.provider;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Map;
+
+import com.electronwill.nightconfig.core.UnmodifiableConfig;
+import dev.frogmc.thyroxine.Constants;
+import dev.frogmc.thyroxine.HttpHelper;
+import dev.frogmc.thyroxine.api.data.MappingBundle;
+import dev.frogmc.thyroxine.api.data.MappingData;
+import dev.frogmc.thyroxine.parser.ProguardParser;
+
+public class MojmapProvider {
+
+	public static MappingBundle get(String gameVersion, Path clientCacheFile, Path serverCacheFile) throws IOException {
+		MappingData client = ProguardParser.read(getMappings(gameVersion, "client", clientCacheFile));
+		MappingData server = ProguardParser.read(getMappings(gameVersion, "server", serverCacheFile));
+		client.classes().putAll(server.classes());
+		client.fields().putAll(server.fields());
+		client.methods().putAll(server.methods());
+		client.parameters().putAll(server.parameters());
+		return new MappingBundle(client);
+	}
+
+	public static MappingBundle get(String gameVersion, String env, Path cacheFile) throws IOException {
+		return new MappingBundle(ProguardParser.read(getMappings(gameVersion, env, cacheFile)));
+	}
+
+	@SuppressWarnings("unchecked")
+	private static String getMappings(String gameVersion, String env, Path cacheFile) throws IOException {
+		if (Files.exists(cacheFile)) {
+			return Files.readString(cacheFile, StandardCharsets.UTF_8);
+		}
+		UnmodifiableConfig manifest = HttpHelper.getJson(Constants.VERSION_MANIFEST);
+		String versionName;
+		if (gameVersion.startsWith("latest-")) {
+			versionName = (String) ((Map<?, ?>) manifest.get("latest")).get(gameVersion.split("-")[1]);
+		} else {
+			versionName = gameVersion;
+		}
+
+		System.out.println("Loading version: " + versionName);
+
+		for (UnmodifiableConfig version : (List<UnmodifiableConfig>) manifest.get("versions")) {
+			if (version.get("id").equals(versionName)) {
+
+				UnmodifiableConfig versionManifest = HttpHelper.getJson(version.get("url"));
+				String mappingsUrl = ((UnmodifiableConfig) ((UnmodifiableConfig) versionManifest
+					.get("downloads")).get(env+"_mappings")).get("url");
+
+				String s = HttpHelper.getString(mappingsUrl);
+				Files.createDirectories(cacheFile.getParent());
+				Files.writeString(cacheFile, s);
+				return s;
+			}
+		}
+		throw new IllegalArgumentException("Could not find mojmap for the specified version: " + gameVersion + "/"+env+"!");
+	}
+
+}

src/main/java/dev/frogmc/thyroxine/provider/ParchmentProvider.java

@@ -0,0 +1,138 @@
+package dev.frogmc.thyroxine.provider;
+
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+import java.nio.file.FileSystem;
+import java.nio.file.FileSystems;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.*;
+
+import com.electronwill.nightconfig.core.UnmodifiableConfig;
+import dev.frogmc.thyroxine.Constants;
+import dev.frogmc.thyroxine.HttpHelper;
+import dev.frogmc.thyroxine.api.data.DocumentationData;
+import dev.frogmc.thyroxine.api.data.MappingBundle;
+import dev.frogmc.thyroxine.api.data.MappingData;
+import dev.frogmc.thyroxine.api.data.Member;
+import org.w3c.dom.Document;
+import org.xml.sax.SAXException;
+
+public class ParchmentProvider {
+
+	private static final String PARCHMENT_URL = "https://maven.parchmentmc.org/org/parchmentmc/data";
+
+	private static String getParchmentUrl(String gameVersion) {
+		return PARCHMENT_URL + "/parchment-" + gameVersion;
+	}
+
+	private static String findParchmentVersion(String gameVersion) throws IOException {
+		String url = getParchmentUrl(gameVersion) + "/maven-metadata.xml";
+		try (InputStream
+				 stream = URI.create(url).toURL().openStream()) {
+			Document document = DocumentBuilderFactory.newInstance()
+				.newDocumentBuilder().parse(stream);
+			return document.getElementsByTagName("release").item(0).getTextContent();
+		} catch (IOException | SAXException | ParserConfigurationException e) {
+			throw new IOException(e);
+		}
+	}
+
+	public static MappingBundle getParchment(String gameVersion, Path cacheDir) throws IOException {
+		return getParchment(gameVersion, findParchmentVersion(gameVersion), cacheDir);
+	}
+
+	public static MappingBundle getParchment(String gameVersion, String parchmentVer, Path cacheDir) throws IOException {
+		return getParchment(gameVersion, parchmentVer, cacheDir, false);
+	}
+
+	public static MappingBundle getParchment(String gameVersion, String parchmentVer, Path cacheDir, boolean forceDownload) throws IOException {
+		long time = System.currentTimeMillis();
+		System.out.println("Loading Parchment mappings..");
+		var cachePath = cacheDir.resolve("parchment-" + gameVersion + "-" + parchmentVer + ".zip");
+		Files.createDirectories(cachePath.getParent());
+
+		var url = "%s/%s/parchment-%s-%s.zip".formatted(getParchmentUrl(gameVersion), parchmentVer, gameVersion, parchmentVer);
+		if (forceDownload || Files.notExists(cachePath)) {
+			HttpHelper.download(url, cachePath);
+		}
+
+		{
+			try {
+				var hash = HttpHelper.getString(url + ".sha512").split("\n", 2)[0];
+				MessageDigest digest = MessageDigest.getInstance("SHA-512");
+				byte[] out = digest.digest(Files.readAllBytes(cachePath));
+				StringBuilder sb = new StringBuilder();
+				for (byte b : out) {
+					sb.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
+				}
+				String local = sb.toString();
+				if (!hash.equals(local)) {
+					System.out.println("Hashes do not match for " + cachePath + ": " + local + " != " + hash + "; redownloading!");
+					return getParchment(gameVersion, parchmentVer, cacheDir, true);
+				}
+			} catch (NoSuchAlgorithmException e) {
+				throw new IOException(e);
+			}
+		}
+		MappingBundle parchment = new MappingBundle();
+		MappingData parameters = new MappingData("named", "named");
+		try (FileSystem fs = FileSystems.newFileSystem(cachePath)) {
+			var mappings = Files.readString(fs.getPath("parchment.json"));
+			UnmodifiableConfig c = Constants.JSON_PARSER.parse(mappings);
+			// String version = c.get("version"); // currently unused
+			List<UnmodifiableConfig> packagesList = Objects.requireNonNullElse(c.get("packages"), Collections.emptyList());
+			List<DocumentationData.Package> packages = new ArrayList<>();
+			packagesList.forEach(config ->
+				packages.add(new DocumentationData.Package(config.get("name"), new ArrayList<>(Objects.requireNonNullElse(c.get("javadoc"),
+					Collections.emptyList())))));
+
+			List<DocumentationData.Class> classes = new ArrayList<>();
+			List<UnmodifiableConfig> classesList = Objects.requireNonNullElse(c.get("classes"), Collections.emptyList());
+			classesList.forEach(config -> {
+				List<DocumentationData.Method> methods = new ArrayList<>();
+				List<DocumentationData.Field> fields = new ArrayList<>();
+
+				List<UnmodifiableConfig> methodsList = Objects.requireNonNullElse(config.get("methods"), Collections.emptyList());
+				methodsList.forEach(uc -> {
+					List<String> javadoc = uc.get("javadoc");
+					List<UnmodifiableConfig> parametersList = Objects.requireNonNullElse(uc.get("parameters"), Collections.emptyList());
+					for (UnmodifiableConfig puC : parametersList) {
+						parameters.parameters().computeIfAbsent(new Member(config.get("name"), uc.get("name"), uc.get("descriptor")),
+							a -> new HashMap<>()).put(puC.get("index"), puC.get("name"));
+						String doc = puC.get("javadoc");
+						if (doc != null) {
+							if (javadoc == null) {
+								javadoc = new ArrayList<>();
+							}
+							javadoc.add("@parameter " + puC.get("name") + " " + doc);
+						}
+					}
+					methods.add(new DocumentationData.Method(uc.get("name"), uc.get("descriptor"), Objects.requireNonNullElse(javadoc, new ArrayList<>())));
+				});
+
+				List<UnmodifiableConfig> fieldsList = Objects.requireNonNullElse(config.get("fields"), Collections.emptyList());
+				fieldsList.forEach(uc -> {
+					List<String> javadoc = new ArrayList<>(uc.get("javadoc"));
+					fields.add(new DocumentationData.Field(uc.get("name"), uc.get("descriptor"), javadoc));
+				});
+
+				classes.add(new DocumentationData.Class(config.get("name"), new ArrayList<>(Objects.requireNonNullElse(config.get("javadoc"),
+					Collections.emptyList())), fields, methods));
+			});
+			parchment.insert(parameters, new DocumentationData("named", packages, classes));
+		}
+
+		System.out.printf("Finished loading (%.2fs)\n", (System.currentTimeMillis() - time) / 1000F);
+		return parchment;
+	}
+
+	public static String findForMinecraftVersion(String minecraftVersion) throws IOException {
+		return findParchmentVersion(minecraftVersion);
+	}
+}

src/main/java/dev/frogmc/thyroxine/writer/ProguardWriter.java

@@ -0,0 +1,51 @@
+package dev.frogmc.thyroxine.writer;
+
+import java.io.PrintWriter;
+import java.io.Writer;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import dev.frogmc.thyroxine.api.data.MappingBundle;
+import dev.frogmc.thyroxine.api.data.MappingData;
+import dev.frogmc.thyroxine.api.data.Member;
+import org.objectweb.asm.Type;
+
+public class ProguardWriter {
+
+	/**
+	 * WARNING: This format should probably not be used.
+	 * <strong>The Proguard format does not support parameter mappings or javadocs.
+	 * This means that this process is likely to be lossy!</strong>
+	 *
+	 * @param bundle the data
+	 * @param writer a writer for the mappings to be written to
+	 */
+	public static void write(MappingBundle bundle, Writer writer) {
+		MappingData data = bundle.flattenData(); // we can only have 2 namespaces.
+		Map<String, Map<Member, String>> methods = new HashMap<>();
+		Map<String, Map<Member, String>> fields = new HashMap<>();
+
+		data.methods().forEach((member, s) -> methods.computeIfAbsent(member.owner(), a -> new HashMap<>()).put(member, s));
+		data.fields().forEach((member, s) -> fields.computeIfAbsent(member.owner(), a -> new HashMap<>()).put(member, s));
+
+		PrintWriter print = new PrintWriter(writer, true);
+		print.println("# Generated by FrogMC/Thyroxine.");
+		print.println("# src-ns: " + data.srcNamespace() + " dst-ns: " + data.dstNamespace());
+
+		data.classes().keySet().stream().sorted().toList().forEach(s -> {
+			String s2 = data.classes().get(s);
+			print.println(s.replace("/", ".") + " -> " + s2.replace("/", "."));
+			fields.getOrDefault(s, Collections.emptyMap()).forEach((member, s1) ->
+				print.println("    " + Type.getType(member.descriptor()).getClassName() +
+							  " " + member.name() + " -> " + s1));
+			methods.getOrDefault(s, Collections.emptyMap()).forEach((member, s1) -> {
+				Type type = Type.getMethodType(member.descriptor());
+				print.println("    ::" + type.getReturnType().getClassName() + " " +
+							  member.name() + "(" + String.join(",", Arrays.stream(type.getArgumentTypes())
+					.map(Type::getClassName).toList()) + ") -> " + s1);
+			});
+		});
+	}
+}

src/main/java/dev/frogmc/thyroxine/writer/tiny/TinyV1Writer.java

@@ -0,0 +1,34 @@
+package dev.frogmc.thyroxine.writer.tiny;
+
+import java.io.PrintWriter;
+import java.io.Writer;
+
+import dev.frogmc.thyroxine.api.data.MappingBundle;
+import dev.frogmc.thyroxine.api.data.MappingData;
+
+public class TinyV1Writer {
+
+	/**
+	 * WARNING: This format should probably not be used.
+	 * <strong>Tiny V1 does not support parameter mappings or javadocs.
+	 * This means that this process is likely to be lossy!</strong>
+	 *
+	 * @param bundle the data
+	 * @param writer a writer for the mappings to be written to
+	 */
+	public static void write(MappingBundle bundle, Writer writer) {
+		MappingData data;
+		if (bundle.srcNamespaces().size() > 1 || bundle.dstNamespaces().size() > 1) {
+			data = bundle.flattenData(); // we can only have 2 namespaces.
+		} else {
+			data = bundle.data().getFirst();
+		}
+
+		PrintWriter print = new PrintWriter(writer, true);
+		print.println("v1\t" + data.srcNamespace() + "\t" + data.dstNamespace());
+
+		data.classes().forEach((s, s2) -> print.println("CLASS\t" + s + "\t" + s2));
+		data.fields().forEach((member, s) -> print.println("FIELD\t" + member.owner() + "\t" + member.descriptor() + "\t" + member.name() + "\t" + s));
+		data.methods().forEach((member, s) -> print.println("METHOD\t" + member.owner() + "\t" + member.descriptor() + "\t" + member.name() + "\t" + s));
+	}
+}

src/main/java/dev/frogmc/thyroxine/writer/tiny/TinyV2Writer.java

@@ -0,0 +1,188 @@
+package dev.frogmc.thyroxine.writer.tiny;
+
+import java.io.*;
+import java.util.*;
+import java.util.stream.Collectors;
+
+import dev.frogmc.thyroxine.api.Mapper;
+import dev.frogmc.thyroxine.api.data.DocumentationData;
+import dev.frogmc.thyroxine.api.data.MappingBundle;
+import dev.frogmc.thyroxine.api.data.MappingData;
+import dev.frogmc.thyroxine.api.data.Member;
+
+public class TinyV2Writer {
+
+	public static void write(MappingBundle bundle, Writer writer) {
+
+		Set<String> overlayNs = new HashSet<>();
+		for (MappingData d : bundle.data()) {
+			if (d.srcNamespace().equals(d.dstNamespace())) {
+				overlayNs.add(d.srcNamespace());
+			}
+		}
+		List<String> srcNs = bundle.srcNamespaces();
+		List<String> dstNs = bundle.dstNamespaces();
+		List<String> srcNamespaces = srcNs.stream().distinct().filter(s -> !dstNs.contains(s) && !overlayNs.contains(s)).toList();
+		if (srcNamespaces.size() > 1) {
+			throw new IllegalStateException("Mapping Data cannot be reduced to a single source namespace, " +
+											"please use .flatten(...) to obtain a mappings set with defined namespaces");
+		}
+		String srcNamespace = srcNamespaces.getFirst();
+
+		Map<String, Map<Integer, String>> classes = new HashMap<>();
+		Map<String, Map<Member, Map<Integer, String>>> methods = new HashMap<>();
+		Map<String, Map<Member, Map<Integer, String>>> fields = new HashMap<>();
+		Map<Member, Map<Integer, Map<Integer, String>>> parameters = new HashMap<>();
+		Map<String, String> javadocs = new HashMap<>();
+
+		List<Mapper> reverseMappers = new ArrayList<>();
+
+		String src = srcNamespace;
+
+		MappingData data = bundle.getWithSrcNamespace(src);
+		DocumentationData docs;
+		int indent = 0;
+		while (data != null) {
+			reverseMappers.addFirst(new Mapper(data.reverse(), s -> Collections.emptyList()));
+			docs = bundle.get(data.dstNamespace());
+			Map<String, DocumentationData.Class> docsClasses = null;
+			Mapper selfMap = new Mapper(data, s -> Collections.emptyList());
+			if (docs != null) {
+				docsClasses = docs.classes().stream().collect(Collectors.toMap(DocumentationData.Class::name, c -> c));
+			}
+			for (Map.Entry<String, String> e : data.classes().entrySet()) {
+				String k = e.getKey();
+				String s2 = e.getValue();
+				String root = k;
+				for (Mapper mapper : reverseMappers) {
+					root = mapper.map(root);
+				}
+				classes.computeIfAbsent(root, a -> new HashMap<>()).put(indent, s2);
+				if (docs != null) {
+					DocumentationData.Class c = docsClasses.get(k);
+					if (c != null) {
+						if (c.javadoc() != null && !c.javadoc().isEmpty()) {
+							javadocs.put(root, String.join("\\n", c.javadoc()));
+						}
+					}
+				}
+			}
+			for (Map.Entry<Member, String> entry : data.methods().entrySet()) {
+				Member key = entry.getKey();
+				String value = entry.getValue();
+				Member root = key;
+				for (Mapper mapper : reverseMappers) {
+					root = new Member(mapper.map(root.owner()),
+						mapper.mapMethodName(root.owner(), root.name(), root.descriptor()),
+						mapper.mapMethodDesc(root.descriptor()));
+				}
+				methods.computeIfAbsent(root.owner(), a -> new HashMap<>()).computeIfAbsent(root, a -> new HashMap<>()).put(indent, value);
+				if (docs != null) {
+					Member rt = root;
+					DocumentationData.Class c = docsClasses.get(data.classes().get(key.owner()));
+					if (c != null) {
+						c.getMethod(data.methods().get(key), selfMap.mapMethodDesc(key.descriptor()))
+							.ifPresent(m -> {
+								if (m.javadoc() != null && !m.javadoc().isEmpty()) {
+									javadocs.put(rt.owner() + rt.descriptor() + rt.name(), String.join("\\n", m.javadoc()));
+								}
+							});
+					}
+				}
+			}
+			for (Map.Entry<Member, String> entry : data.fields().entrySet()) {
+				Member member = entry.getKey();
+				String value = entry.getValue();
+				Member root = member;
+				for (Mapper mapper : reverseMappers) {
+					root = new Member(mapper.map(root.owner()),
+						mapper.mapFieldName(root.owner(), root.name(), root.descriptor()),
+						mapper.mapDesc(root.descriptor()));
+				}
+				fields.computeIfAbsent(root.owner(), a -> new HashMap<>()).computeIfAbsent(root, a -> new HashMap<>()).put(indent, value);
+				if (docs != null) {
+					String id = root.owner() + root.descriptor() + root.name();
+					DocumentationData.Class c = docsClasses.get(data.classes().get(member.owner()));
+					if (c != null) {
+						c.getField(data.fields().get(member), selfMap.mapDesc(member.descriptor()))
+							.ifPresent(f -> {
+								if (f.javadoc() != null && !f.javadoc().isEmpty()) {
+									javadocs.put(id, String.join("\\n", f.javadoc()));
+								}
+							});
+					}
+				}
+			}
+			for (Map.Entry<Member, Map<Integer, String>> entry : data.parameters().entrySet()) {
+				Member member = entry.getKey();
+				Map<Integer, String> integerStringMap = entry.getValue();
+				Member root = member;
+				for (Mapper mapper : reverseMappers) {
+					root = new Member(mapper.map(root.owner()),
+						mapper.mapFieldName(root.owner(), root.name(), root.descriptor()),
+						mapper.mapDesc(root.descriptor()));
+				}
+				Map<Integer, Map<Integer, String>> map = parameters.computeIfAbsent(root, a -> new HashMap<>());
+				for (Map.Entry<Integer, String> e : integerStringMap.entrySet()) {
+					Integer integer = e.getKey();
+					String s = e.getValue();
+					map.computeIfAbsent(integer, a -> new HashMap<>()).put(indent, s);
+				}
+			}
+			indent++;
+			src = data.dstNamespace();
+			data = bundle.getWithSrcNamespace(src);
+		}
+		PrintWriter print = new PrintWriter(writer, true);
+		print.println("tiny\t2\t0\t" + srcNamespace + "\t" + String.join("\t", dstNs));
+
+		classes.keySet().stream().sorted().forEach(s -> {
+			Map<Integer, String> strings = classes.get(s);
+			print.println("c\t" + s + "\t" + printWithIndent(strings));
+			if (javadocs.containsKey(s)) {
+				print.println("\tc\t" + javadocs.get(s));
+			}
+			Map<Member, Map<Integer, String>> fmap = fields.getOrDefault(s, Collections.emptyMap());
+			fmap.keySet().stream().sorted(Comparator.comparing(Member::name)).forEach(m -> {
+				Map<Integer, String> map = fmap.get(m);
+				print.println("\tf\t" + m.descriptor() + "\t" + m.name() + "\t" + printWithIndent(map));
+				String id = m.owner() + m.descriptor() + m.name();
+				if (javadocs.containsKey(id)) {
+					print.println("\t\tc\t" + javadocs.get(id));
+				}
+			});
+			Map<Member, Map<Integer, String>> mmap = methods.getOrDefault(s, Collections.emptyMap());
+			mmap.keySet().stream().sorted(Comparator.comparing(Member::name)).forEach(m -> {
+				Map<Integer, String> map = mmap.get(m);
+				print.println("\tm\t" + m.descriptor() + "\t" + m.name() + "\t" + printWithIndent(map));
+				String id = m.owner() + m.descriptor() + m.name();
+				if (javadocs.containsKey(id) && !javadocs.get(id).isEmpty()) {
+					print.println("\t\tc\t" + javadocs.get(id));
+				}
+				if (parameters.containsKey(m)) {
+					parameters.get(m).forEach((integer, ps) -> {
+						if (ps.values().stream().anyMatch(pname -> !pname.isEmpty())) {
+							print.println("\t\tp\t" + integer + "\t\t" + printWithIndent(ps));
+						}
+					});
+				}
+			});
+		});
+	}
+
+	private static String printWithIndent(Map<Integer, String> map) {
+		int max = map.keySet().stream().max(Comparator.comparingInt(i -> i)).orElse(0);
+		StringBuilder builder = new StringBuilder();
+		for (int current = 0; current <= max; current++) {
+			if (current > 0) {
+				builder.append("\t");
+			}
+			builder.append(map.getOrDefault(current, ""));
+		}
+		String line = builder.toString();
+		while (line.endsWith("\t")) {
+			line = line.substring(0, line.length()-1);
+		}
+		return line;
+	}
+}

src/main/java/io/github/moehreag/mojmap_patcher/Constants.java

@@ -1,12 +0,0 @@
-package io.github.moehreag.mojmap_patcher;
-
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-
-import java.util.regex.Pattern;
-
-public final class Constants {
-    public static final String VERSION_MANIFEST = "https://piston-meta.mojang.com/mc/game/version_manifest_v2.json";
-    public static final Gson GSON = new GsonBuilder().create();
-    public static final Pattern METHOD_PATTERN = Pattern.compile("\\d+:\\d+:.*");
-}

src/main/java/io/github/moehreag/mojmap_patcher/HttpHelper.java

@@ -1,39 +0,0 @@
-package io.github.moehreag.mojmap_patcher;
-
-import com.google.gson.JsonObject;
-import lombok.experimental.UtilityClass;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.nio.charset.StandardCharsets;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Optional;
-
-import static io.github.moehreag.mojmap_patcher.Constants.GSON;
-
-@UtilityClass
-public class HttpHelper {
-
-    private static final Map<String, String> requestCache = new HashMap<>();
-
-    public static Optional<JsonObject> getJson(String url) {
-        return getString(url).map(s -> GSON.fromJson(s, JsonObject.class));
-    }
-
-    public static Optional<String> getString(String url) {
-        return Optional.ofNullable(requestCache.computeIfAbsent(url, s -> {
-            try (InputStream in = URI.create(url).parseServerAuthority().toURL().openStream()) {
-                return new String(in.readAllBytes(), StandardCharsets.UTF_8);
-            } catch (IOException | URISyntaxException e) {
-                e.printStackTrace();
-                // TODO
-            }
-            return null;
-        }));
-    }
-}

src/main/java/io/github/moehreag/mojmap_patcher/MojMapPatcher.java

@@ -1,20 +0,0 @@
-package io.github.moehreag.mojmap_patcher;
-
-import io.github.moehreag.mojmap_patcher.provider.MojmapProvider;
-import io.github.moehreag.mojmap_patcher.parser.ProguardParser;
-
-public class MojMapPatcher {
-
-    public static void main(String[] args) {
-        String version;
-        if (args.length == 0) {
-            version = "latest-release";
-        } else {
-            version = args[0];
-        }
-        MojmapProvider.get(version).map(ProguardParser::read).ifPresent(s -> {
-            //s.getClassFields().keySet().forEach(System.out::println);
-            s.classFields().get("net.minecraft.client.Minecraft").forEach((s1, s2) -> System.out.println(s1 + " -> " + s2));
-        });
-    }
-}

src/main/java/io/github/moehreag/mojmap_patcher/api/Mapper.java

@@ -1,70 +0,0 @@
-package io.github.moehreag.mojmap_patcher.api;
-
-import io.github.moehreag.mojmap_patcher.api.data.MappingData;
-import io.github.moehreag.mojmap_patcher.api.data.Field;
-import io.github.moehreag.mojmap_patcher.api.data.Method;
-import org.objectweb.asm.commons.Remapper;
-
-import java.util.Collections;
-import java.util.Map;
-import java.util.Optional;
-
-public class Mapper extends Remapper {
-
-    private MappingData data;
-
-    public static Mapper load() {
-        throw new UnsupportedOperationException("TODO");
-    }
-
-    public String mapClass(String name) {
-        return data.classes().getOrDefault(name, name);
-    }
-
-    private Optional<Method> mapMethodInternal(String owner, String name, String descriptor) {
-        for (Map.Entry<Method, Method> entry : data.classMethods().getOrDefault(owner, Collections.emptyMap()).entrySet()) {
-            Method from = entry.getKey();
-            Method to = entry.getValue();
-
-            if (from.name().equals(name) && from.descriptor().equals(descriptor)) {
-                return Optional.of(to);
-            }
-        }
-        return Optional.empty();
-    }
-
-    public Method mapMethod(String owner, String name, String descriptor) {
-        return mapMethodInternal(owner, name, descriptor).orElse(null);
-    }
-
-    private Optional<Field> mapFieldInternal(String owner, String name, String descriptor) {
-        for (Map.Entry<Field, Field> entry : data.classFields().getOrDefault(owner, Collections.emptyMap()).entrySet()) {
-            Field from = entry.getKey();
-            Field to = entry.getValue();
-
-            if (from.name().equals(name) && from.descriptor().equals(descriptor)) {
-                return Optional.of(to);
-            }
-        }
-        return Optional.empty();
-    }
-
-    public Field mapField(String owner, String name, String descriptor) {
-        return mapFieldInternal(owner, name, descriptor).orElse(null);
-    }
-
-    @Override
-    public String map(String internalName) {
-        return mapClass(internalName);
-    }
-
-    @Override
-    public String mapMethodName(String owner, String name, String descriptor) {
-        return mapMethodInternal(owner, name, descriptor).map(Method::name).orElse(name);
-    }
-
-    @Override
-    public String mapFieldName(String owner, String name, String descriptor) {
-        return mapFieldInternal(owner, name, descriptor).map(Field::name).orElse(name);
-    }
-}

src/main/java/io/github/moehreag/mojmap_patcher/api/Remapper.java

@@ -1,18 +0,0 @@
-package io.github.moehreag.mojmap_patcher.api;
-
-public class Remapper {
-
-    private final Mapper mapper;
-
-    public Remapper(Mapper mapper) {
-        this.mapper = mapper;
-    }
-
-    public static Remapper of(Mapper mapper) {
-        return new Remapper(mapper);
-    }
-
-    public void apply() {
-
-    }
-}

src/main/java/io/github/moehreag/mojmap_patcher/api/data/Field.java

@@ -1,4 +0,0 @@
-package io.github.moehreag.mojmap_patcher.api.data;
-
-public record Field(String name, String descriptor) {
-}

src/main/java/io/github/moehreag/mojmap_patcher/api/data/MappingData.java

@@ -1,17 +0,0 @@
-package io.github.moehreag.mojmap_patcher.api.data;
-
-import java.util.HashMap;
-import java.util.Map;
-
-public record MappingData(
-        // IntelliJank, stop putting 8 spaces >:(
-        Map<String, String> classes,
-        Map<String, Map<Method, Method>> classMethods,
-        Map<String, Map<Field, Field>> classFields
-) {
-
-    public MappingData() {
-        this(new HashMap<>(), new HashMap<>(), new HashMap<>());
-    }
-
-}

src/main/java/io/github/moehreag/mojmap_patcher/api/data/Method.java

@@ -1,4 +0,0 @@
-package io.github.moehreag.mojmap_patcher.api.data;
-
-public record Method(int startLine, int endLine, String returnType, String name, String descriptor) {
-}

src/main/java/io/github/moehreag/mojmap_patcher/parser/ProguardParser.java

@@ -1,46 +0,0 @@
-package io.github.moehreag.mojmap_patcher.parser;
-
-import io.github.moehreag.mojmap_patcher.Constants;
-import io.github.moehreag.mojmap_patcher.api.data.Field;
-import io.github.moehreag.mojmap_patcher.api.data.MappingData;
-import io.github.moehreag.mojmap_patcher.api.data.Method;
-
-import java.util.HashMap;
-
-public class ProguardParser {
-
-    public static MappingData read(String mappings) {
-        String[] lines = mappings.split("\n");
-
-        MappingData data = new MappingData();
-        String currentClass = null;
-        for (String line : lines) {
-            if (line.startsWith("#")) { // Filter out comments
-                continue;
-            }
-
-            String[] mapping = line.split("->");
-            String deobf = mapping[0].trim();
-            String obf = mapping[1].trim();
-            if (line.startsWith("    ")) { // It's a field/method mapping
-                if (currentClass == null) {
-                    throw new IllegalStateException("Field/Method mapping outside a class");
-                }
-                if (Constants.METHOD_PATTERN.matcher(deobf).matches()) {
-                    String[] method = deobf.split(":");
-                    String[] descriptor = method[2].split(" ");
-                    int bracket = descriptor[1].indexOf("(");
-                    data.classMethods().computeIfAbsent(currentClass, s -> new HashMap<>()).put(new Method(Integer.parseInt(method[0]), Integer.parseInt(method[1]), obf, descriptor[1].substring(0, bracket), descriptor[1].substring(bracket + 1)),
-                            new Method(Integer.parseInt(method[0]), Integer.parseInt(method[1]), descriptor[0], descriptor[1].substring(0, bracket), descriptor[1].substring(bracket + 1)));
-                } else {
-                    String[] field = deobf.split(" ");
-                    data.classFields().computeIfAbsent(currentClass, s -> new HashMap<>()).put(new Field(field[1], obf), new Field(field[1], field[0]));
-                }
-            } else { // It's a class mapping
-                currentClass = deobf;
-                data.classes().put(obf, deobf);
-            }
-        }
-        return data;
-    }
-}

src/main/java/io/github/moehreag/mojmap_patcher/provider/MojmapProvider.java

@@ -1,37 +0,0 @@
-package io.github.moehreag.mojmap_patcher.provider;
-
-import com.google.gson.*;
-import io.github.moehreag.mojmap_patcher.Constants;
-import io.github.moehreag.mojmap_patcher.HttpHelper;
-
-import java.util.Optional;
-
-public class MojmapProvider {
-
-    public static Optional<String> get(String gameVersion) {
-        return HttpHelper.getJson(Constants.VERSION_MANIFEST).map(manifest -> {
-            String versionName;
-            if (gameVersion.startsWith("latest-")) {
-                versionName = manifest.get("latest").getAsJsonObject().get(gameVersion.split("-")[1]).getAsString();
-            } else {
-                versionName = gameVersion;
-            }
-
-            System.out.println("Loading version: " + versionName);
-
-            for (JsonElement element : manifest.get("versions").getAsJsonArray()) {
-                JsonObject version = element.getAsJsonObject();
-                if (version.get("id").getAsString().equals(versionName)) {
-
-                    JsonObject versionManifest = HttpHelper.getJson(version.get("url").getAsString()).orElseThrow();
-                    String mappingsUrl = versionManifest
-                            .get("downloads").getAsJsonObject().get("client_mappings").getAsJsonObject().get("url").getAsString();
-
-                    return HttpHelper.getString(mappingsUrl).orElseThrow();
-                }
-            }
-            return null;
-        });
-    }
-
-}