_Rename.java

import java.nio.file.*;
import java.nio.charset.*;
import java.io.*;
import java.util.regex.*;

/**
 * Renames all classes greater than wy
 */
public class Rename {
	public static final String LAST_OBF_NAME = "wy";
	public static final char ORIG_CHAR_1 = LAST_OBF_NAME.charAt(0), ORIG_CHAR_2 = LAST_OBF_NAME.charAt(1);
	public static final Charset CHARSET = Charset.forName("UTF-8");
	public static final Pattern SIGNATURE_PATTERN = Pattern.compile("L(.+?);");
	
	public static void main(String[] args) throws Exception {
		handleClasses();
		handleMethods();
		handleFields();
	}
	
	public static void handleClasses() throws Exception {
		System.out.println("classes.csv");
		Path outFile = FileSystems.getDefault().getPath("classes.csv");
		Path inFile = FileSystems.getDefault().getPath("classes.original.csv");
		try (BufferedReader reader = Files.newBufferedReader(inFile, CHARSET)) {
			try (BufferedWriter writer = Files.newBufferedWriter(outFile, CHARSET)) {
				String line;
				while ((line = reader.readLine()) != null) {
					String[] parts = line.split(",");
					String oldName = parts[1].replace("\"", "");
					if (oldName.equals(LAST_OBF_NAME)) {
						// Remove this line
						System.out.println("Removed " + line);
						continue;
					}
					String newName = decrementClassNameIfNecessary(oldName);
					
					parts[1] = "\"" + newName + "\"";
					String newLine = String.join(",", parts);
					
					if (!newLine.equals(line)) {
						System.out.println(line + " -> " + newLine);
					}
					
					writer.write(newLine, 0, newLine.length());
					writer.write("\r\n", 0, 2);
				}
			}
		}
	}
	
	public static void handleMethods() throws Exception {
		System.out.println("methods.csv");
		Path outFile = FileSystems.getDefault().getPath("methods.csv");
		Path inFile = FileSystems.getDefault().getPath("methods.original.csv");
		try (BufferedReader reader = Files.newBufferedReader(inFile, CHARSET)) {
			try (BufferedWriter writer = Files.newBufferedWriter(outFile, CHARSET)) {
				String line;
				while ((line = reader.readLine()) != null) {
					String[] parts = line.split(",");
					
					String oldClassNotch = parts[6].replace("\"", "");
					if (oldClassNotch.equals(LAST_OBF_NAME)) {
						// Remove this line
						System.out.println("Removed " + line);
						continue;
					}
					String newClassNotch = decrementClassNameIfNecessary(oldClassNotch);
					parts[6] = "\"" + newClassNotch + "\"";
					
					parts[4] = updateSignature(parts[4]);

					String newLine = String.join(",", parts);
					
					if (!newLine.equals(line)) {
						System.out.println(line + " -> " + newLine);
					}
					
					writer.write(newLine, 0, newLine.length());
					writer.write("\r\n", 0, 2);
				}
			}
		}
	}
	
	
	public static void handleFields() throws Exception {
		System.out.println("fields.csv");
		Path outFile = FileSystems.getDefault().getPath("fields.csv");
		Path inFile = FileSystems.getDefault().getPath("fields.original.csv");
		try (BufferedReader reader = Files.newBufferedReader(inFile, CHARSET)) {
			try (BufferedWriter writer = Files.newBufferedWriter(outFile, CHARSET)) {
				String line;
				while ((line = reader.readLine()) != null) {
					String[] parts = line.split(",");
					
					String oldClassNotch = parts[6].replace("\"", "");
					if (oldClassNotch.equals(LAST_OBF_NAME)) {
						// Remove this line
						System.out.println("Removed " + line);
						continue;
					}
					String newClassNotch = decrementClassNameIfNecessary(oldClassNotch);
					parts[6] = "\"" + newClassNotch + "\"";
					
					parts[4] = updateSignature(parts[4]);

					String newLine = String.join(",", parts);
					
					if (!newLine.equals(line)) {
						System.out.println(line + " -> " + newLine);
					}
					
					writer.write(newLine, 0, newLine.length());
					writer.write("\r\n", 0, 2);
				}
			}
		}
	}
	
	public static String updateSignature(String signature) {
		Matcher matcher = SIGNATURE_PATTERN.matcher(signature);
		if (matcher.find()) {
			String name = matcher.group(1);
			String newName = decrementClassNameIfNecessary(name);
			return signature.substring(0, matcher.start(1)) + newName + updateSignature(signature.substring(matcher.end(1)));
		} else {
			return signature;
		}
	}
	
	public static String decrementClassNameIfNecessary(String name) {
		if (name.length() == 2) {
			char char1 = name.charAt(0);
			char char2 = name.charAt(1);
			if ((char1 > ORIG_CHAR_1) || (char1 == ORIG_CHAR_1 && char2 >= ORIG_CHAR_2)) {
				char2--;
				if (char2 == 'a' - 1) {
					char2 = 'z';
					char1--;
				}
				return char1 + "" + char2;
			}
		}
		return name;
	}
}

classes.csv

fields.csv

methods.csv