Rafael Padilha

18 papers B 2Misc 2Journal 11Unranked 3
YearRankTypeTitle / Venue / Authors
2025 J jnl
CoRR
Yifei Xu, Tusher Chakraborty, Emre Kiciman, Bibek Aryal, Eduardo Rodrigues, Srinagesh Sharma, Roberto Estevão, Maria Angels de Luis Balaguer, Jessica Wolk, Rafael Padilha, Leonardo O. Nunes, Shobana Balakrishnan, Songwu Lu, Ranveer Chandra
2024 J jnl
CoRR
Somya Sharma, Swati Sharma, Rafael Padilha, Emre Kiciman, Ranveer Chandra
2024 J jnl
CoRR
Margaret Capetz, Swati Sharma, Rafael Padilha, Peder A. Olsen, Jessica Wolk, Emre Kiciman, Ranveer Chandra
2024 J jnl
CoRR
Maria Angels de Luis Balaguer, Vinamra Benara, Renato Luiz de Freitas Cunha, Roberto de M. Estevão Filho, Todd Hendry, Daniel Holstein, Jennifer Marsman, Nick Mecklenburg, Sara Malvar, Leonardo O. Nunes, Rafael Padilha, Morris Sharp, Bruno Silva, Swati Sharma, Vijay Aski, Ranveer Chandra
2023 J jnl
CoRR
João Phillipe Cardenuto, Jing Yang, Rafael Padilha, Renjie Wan, Daniel Moreira, Haoliang Li, Shiqi Wang, Fernanda A. Andaló, Sébastien Marcel, Anderson Rocha
2022 conf
ICAART (3)
Gabriel Bianchin de Oliveira, Lucas David, Rafael Padilha, Ana Paula da Silva, Francine de Paula, Lucas Infante, Lucio Jorge, Patricia Xavier, Zanoni Dias
2022 J jnl
IEEE Trans. Inf. Forensics Secur.
Rafael Padilha, Tawfiq Salem, Scott Workman, Fernanda A. Andaló, Anderson Rocha, Nathan Jacobs
2022 J jnl
J. Vis. Commun. Image Represent.
William Dias, Fernanda A. Andaló, Rafael Padilha, Gabriel Bertocco, Waldir R. de Almeida, Paula D. P. Costa, Anderson Rocha
2022 Misc conf
ICASSP
Antonio Theophilo, Rafael Padilha, Fernanda A. Andaló, Anderson Rocha
2021 J jnl
CoRR
Rafael Padilha, Tawfiq Salem, Scott Workman, Fernanda A. Andaló, Anderson Rocha, Nathan Jacobs
2021 conf
BSB
Daniel Ferber, Felipe Vieira, João Dalben, Mariana Ferraz, Nicholas Sato, Gabriel Bianchin de Oliveira, Rafael Padilha, Zanoni Dias
2021 J jnl
Pattern Recognit. Lett.
Rafael Padilha, Fernanda A. Andaló, Bahram Lavi, Luís A. M. Pereira, Anderson Rocha
2020 conf
BSB
Gabriel Bianchin de Oliveira, Rafael Padilha, André Dorte, Luis Cereda, Luiz Miyazaki, Maurício Lopes, Zanoni Dias
2020 J jnl
IEEE Secur. Priv.
Rafael Padilha, Caroline Mazini Rodrigues, Fernanda A. Andaló, Gabriel Bertocco, Zanoni Dias, Anderson Rocha
2020 Misc conf
ICASSP
Rafael Padilha, Fernanda A. Andaló, Anderson Rocha
2020 J jnl
IET Biom.
Rafael Padilha, Fernanda A. Andaló, Gabriel Bertocco, Waldir R. de Almeida, William Dias, Thiago Resek, Ricardo da Silva Torres, Jacques Wainer, Anderson Rocha
2017 B conf
IJCB
Zinelabdine Boulkenafet, Jukka Komulainen, Zahid Akhtar, Azeddine Benlamoudi, Djamel Samai, Salah Eddine Bekhouche, Abdelkrim Ouafi, Fadi Dornaika, Abdelmalik Taleb-Ahmed, Le Qin, Fei Peng, L. B. Zhang, Min Long, Shruti Bhilare, Vivek Kanhangad, Artur Costa-Pazo, Esteban Vázquez-Fernández, Daniel Pérez-Cabo, J. J. Moreira-Perez, Daniel González-Jiménez, Amir Mohammadi, Sushil Bhattacharjee, Sébastien Marcel, Svetlana Volkova, Y. Tang, N. Abe, L. Li, X. Feng, Z. Xia, X. Jiang, S. Liu, Rui Shao, Pong C. Yuen, Waldir R. de Almeida, Fernanda A. Andaló, Rafael Padilha, Gabriel Bertocco, William Dias, Jacques Wainer, Ricardo da Silva Torres, Anderson Rocha, Marcus A. Angeloni, Guilherme Folego, Alan Godoy, Abdenour Hadid
2012 B conf
CBMS
Herbert Franz Jelinek, Ramon Pires, Rafael Padilha, Siome Goldenstein, Jacques Wainer, Terry Bossomaier, Anderson Rocha
redb/extractors/decompiler/_archive/GhidraDecompilerScript.java
← Index redb/extractors/decompiler/_archive/GhidraDecompilerScript.java java
import ghidra.app.script.GhidraScript;
import ghidra.program.model.listing.*;
import ghidra.app.decompiler.*;
import ghidra.program.model.address.*;
import org.json.JSONObject;
import org.json.JSONArray;
import java.security.MessageDigest;
import java.nio.charset.StandardCharsets;
import ghidra.program.model.lang.OperandType;
import java.util.*;
import ghidra.program.model.block.*;
import ghidra.util.exception.CancelledException;
import ghidra.program.model.symbol.Reference;
import ghidra.program.model.symbol.Symbol;
import ghidra.program.model.symbol.SymbolTable;
import java.util.Arrays;
import com.sangupta.murmur.Murmur3;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.Executors;

public class GhidraDecompilerScript extends GhidraScript {
    private Listing listing;
    private BasicBlockModel basicBlockModel;
    private JSONArray errors;
    private DecompInterface decompInterface;  

    private enum InstructionType {
        // Data Movement
        GENERAL_DATA_MOVEMENT,    // mov, lea, xchg
        STACK_MANAGEMENT,         // push, pop, enter, leave
        STRING_MANIPULATION,      // movs, lods, stos, cmps
        
        // Arithmetic
        BASIC_ARITHMETIC,         // add, sub, inc, dec
        MULTIPLICATION_DIVISION,  // mul, div, imul, idiv
        CARRY_ARITHMETIC,         // adc, sbb
        
        // Logical
        BITWISE_LOGIC,           // and, or, xor, not
        CONDITIONAL_LOGIC,        // test, cmp, setX
        
        // Control Flow
        UNCONDITIONAL_JUMP,      // jmp
        CONDITIONAL_JUMP,        // je, jne, jl, jg, etc
        FUNCTION_CONTROL,        // call, ret
        LOOPING,                 // loop, loopz, loopnz
        
        // System
        SYSTEM_CALLS,            // syscall, int, sysenter
        PRIVILEGED_INSTRUCTIONS, // hlt, cli, sti
        CPU_FEATURES,            // cpuid, rdtsc
        
        // SIMD & FPU
        SSE_SIMD,               // SSE instructions
        AVX_SIMD,               // AVX instructions
        BASIC_FPU,              // fld, fst, fstp
        FPU_ARITHMETIC,         // fadd, fsub, etc
        
        // Bit Operations
        SHIFT_ROTATE,           // shl, shr, rol, ror
        BIT_TEST_MODIFY,        // bt, bts, btr, btc
        
        // Special
        CRYPTOGRAPHIC_OPS,      // aesenc, aesdec, sha1rnds4
        MISC_OPS               // nop, ud2, etc
    }

    private enum BranchType {
        DIRECT, CONDITIONAL, CALL, RETURN, FALLTHROUGH, UNKNOWN
    }

    private enum ApiCategory {
        FILE_OP(Arrays.asList("CreateFile", "ReadFile", "WriteFile", "DeleteFile", "SetFilePointer", "CopyFile", "MoveFile", "FindFirstFile", "FindNextFile")),
        MEMORY_OP(Arrays.asList("VirtualAlloc", "VirtualFree", "HeapAlloc", "HeapFree", "LocalAlloc", "GlobalAlloc", "MapViewOfFile", "VirtualProtect")),
        NETWORK_OP(Arrays.asList("socket", "connect", "bind", "send", "recv", "WSAStartup", "InternetOpen", "InternetConnect", "HttpOpenRequest", "HttpSendRequest", "InternetReadFile", "URLDownloadToFile")),
        REGISTRY_OP(Arrays.asList("RegOpenKey", "RegCreateKey", "RegSetValue", "RegQueryValue", "RegDeleteKey", "RegEnumKey", "RegFlushKey")),
        PROCESS_OP(Arrays.asList("CreateProcess", "OpenProcess", "TerminateProcess", "GetProcessId", "CreateProcessAsUser", "NtCreateProcess")),
        THREAD_OP(Arrays.asList("CreateThread", "SuspendThread", "ResumeThread", "CreateRemoteThread", "SetThreadContext", "GetThreadContext")),
        INJECTION_OP(Arrays.asList("WriteProcessMemory", "VirtualAllocEx", "NtWriteVirtualMemory", "SetWindowsHookEx", "QueueUserAPC", "NtMapViewOfSection")),
        EVASION_OP(Arrays.asList("IsDebuggerPresent", "CheckRemoteDebuggerPresent", "NtQueryInformationProcess", "GetTickCount", "OutputDebugString", "Sleep", "QueryPerformanceCounter")),
        SPYING_OP(Arrays.asList("GetAsyncKeyState", "GetKeyboardState", "GetKeyState", "GetForegroundWindow", "SetWindowsHookEx", "BitBlt", "GetClipboardData")),
        SYSTEM_OP(Arrays.asList("CreateToolhelp32Snapshot", "EnumDeviceDrivers", "EnumProcesses", "GetSystemDirectoryA", "GetLogicalDrives")),
        SERVICE_OP(Arrays.asList("CreateServiceA", "OpenServiceA", "StartServiceA", "DeleteService", "OpenSCManagerA", "ControlService")),
        CRYPTO_OP(Arrays.asList("CryptAcquireContext", "CryptGenKey", "CryptEncrypt", "CryptDecrypt", "CryptCreateHash", "CryptHashData", "CryptGenRandom")),
        DLL_OP(Arrays.asList("LoadLibrary", "GetProcAddress", "FreeLibrary", "LdrLoadDll")),
        UNKNOWN_OP(Collections.emptyList());

        private final List<String> apis;

        ApiCategory(List<String> apis) {
            this.apis = apis;
        }

        public static ApiCategory fromApi(String apiName) {
            for (ApiCategory category : values()) {
                if (category.apis.stream().anyMatch(api -> apiName.startsWith(api))) {
                    return category;
                }
            }
            return UNKNOWN_OP;
        }
    }

    private static final String[] COMMON_OPCODES = {
        // Core instructions (tracked individually)
        "MOV", "PUSH", "POP", "LEA", "CALL", "RET",         // Data movement and control
        "ADD", "SUB", "MUL", "DIV",                         // Basic arithmetic
        "AND", "OR", "XOR", "NOT",                          // Logical operations
        "JMP", "JE", "JNE",                                 // Basic jumps
        "TEST", "CMP",                                      // Comparisons
        
        // Grouped categories (aggregated tracking)
        "SIMD_MOVE",      // MOVAPS, MOVDQA, MOVDQU, etc.
        "COND_JUMP_EXT",  // Other conditional jumps (JG, JL, JGE, etc.)
        "STRING_OP",      // MOVS, STOS, LODS, SCAS, CMPS
        "STACK_ADV",      // ENTER, LEAVE, PUSHA, POPA
        "ARITHMETIC_ADV", // IMUL, IDIV, ADC, SBB
        "BIT_OP",        // SHL, SHR, SAR, ROL, ROR, etc.
        "FPU_OP",        // FLD, FST, FADD, etc.
        "SYSTEM_OP",     // SYSCALL, INT, SYSENTER
        "CRYPTO_OP",     // AES*, SHA* instructions
        "MISC_OP"        // Rare but interesting (CPUID, RDTSC, etc.)
    };
    private Map<String, Integer> opcodeIndex;
    private Map<String, String> opcodeCategories;

    private void initializeOpcodeMaps() {
        opcodeIndex = new HashMap<>();
        opcodeCategories = new HashMap<>();
        
        for (int i = 0; i < COMMON_OPCODES.length; i++) {
            opcodeIndex.put(COMMON_OPCODES[i], i);
            
            // Categorize opcodes
            String opcode = COMMON_OPCODES[i];
            
            // String Operations (checking these first to avoid MOV confusion)
            if (opcode.matches("MOVS.*|STOS.*|LODS.*|SCAS.*|CMPS.*|REP.*") && 
                !opcode.startsWith("MOVSX") && !opcode.startsWith("MOVZX")) {
                opcodeCategories.put(opcode, "STRING_MANIPULATION");
            }
            
            // Data Movement (after string ops to avoid MOVS confusion)
            else if ((opcode.startsWith("MOV")) || 
                     opcode.equals("LEA") || opcode.equals("XCHG")) {
                opcodeCategories.put(opcode, "DATA_MOVEMENT");
            }
            
            // Stack Operations
            else if (opcode.matches("PUSH|POP|ENTER|LEAVE|PUSHA|POPA")) {
                opcodeCategories.put(opcode, "STACK_MANAGEMENT");
            }
            
            // Control Flow (non-conditional)
            else if (opcode.matches("JMP|CALL|RET")) {
                opcodeCategories.put(opcode, "CONTROL_FLOW");
            }
            
            // Conditional Jumps and Loops
            else if (opcode.startsWith("J") || opcode.startsWith("LOOP")) {
                opcodeCategories.put(opcode, "CONDITIONAL_JUMP");
            }
            
            // Arithmetic
            else if (opcode.matches("ADD|SUB|MUL|DIV|I?MUL|I?DIV|ADC|SBB|INC|DEC|NEG")) {
                opcodeCategories.put(opcode, "ARITHMETIC");
            }
            
            // Logical
            else if (opcode.matches("AND|OR|XOR|NOT|TEST|CMP")) {
                opcodeCategories.put(opcode, "LOGICAL");
            }
            
            // Shifts & Rotates
            else if (opcode.matches("SHL|SHR|SAR|SAL|ROL|ROR|RCL|RCR")) {
                opcodeCategories.put(opcode, "SHIFT_ROTATE");
            }
            
            // System & Interrupts
            else if (opcode.matches("SYSCALL|INT.*|SYSENTER|SYSEXIT|SGDT|SIDT|SLDT|WRMSR|RDMSR")) {
                opcodeCategories.put(opcode, "SYSTEM_CALLS");
            }
            
            // Floating Point
            else if (opcode.matches("F.*")) {
                opcodeCategories.put(opcode, "FPU_ARITHMETIC");
            }
            
            // System Information and Random Number Generation
            else if (opcode.matches("PUSHF|POPF|CPUID|RDTSC|RDRAND|RDSEED")) {
                opcodeCategories.put(opcode, "CPU_FEATURES");
            }
            
            // Cryptography
            else if (opcode.startsWith("AES") || opcode.startsWith("SHA")) {
                opcodeCategories.put(opcode, "CRYPTOGRAPHIC");
            }
            
            // Miscellaneous (including flag operations)
            else {
                opcodeCategories.put(opcode, "MISC");
            }
        }
    }

    private static final int MIN_FUNCTION_SIZE = 10;  // instructions
    private static final int MIN_BLOCK_SIZE = 4;      // instructions
    private static final int INVALID_STACK_SIZE = -1;

    private void logError(String message, String functionName, String address, Exception e, String errorLocation) {
        String errorMsg = String.format("Error in function %s at %s: %s%s", 
            functionName, 
            address, 
            message,
            e != null ? " - " + e.getMessage() : ""  // Only add exception message if e is not null
        );
        println(errorMsg);
        
        // Add to errors array
        JSONObject error = new JSONObject();
        error.put("function_name", functionName);
        error.put("function_address", address);
        error.put("error_location", errorLocation);
        error.put("error_message", message);
        error.put("error_details", e != null ? e.getMessage() : "");
        error.put("error_type", e != null ? e.getClass().getSimpleName() : "Unknown");
        error.put("timestamp", System.currentTimeMillis());
        errors.put(error);
    }

    private String calculateSha256(String input) throws Exception {
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        byte[] hash = digest.digest(input.getBytes(StandardCharsets.UTF_8));
        StringBuilder hexString = new StringBuilder();
        for (byte b : hash) {
            String hex = Integer.toHexString(0xff & b);
            if (hex.length() == 1) hexString.append('0');
            hexString.append(hex);
        }
        return hexString.toString();
    }

    @Override
    public void run() throws Exception {
        ExecutorService mainExecutor = null;
        final int FUNCTION_TIMEOUT_SECONDS = 90;  // 1.5 minutes per function
        final int GLOBAL_TIMEOUT_SECONDS = 1080 ;    // 18 minutes global, 20 is the total timeout from Python

        try {
            // Initialize listing
            listing = currentProgram.getListing();
            initializeOpcodeMaps();
            
            // // Validate input arguments (expecting SHA256 of binary)
            String[] args = getScriptArgs();
            if (args.length < 1) {
                println("Error: SHA256 argument is required");
                return;
            }
            String binarySha256 = args[0];
            
            // Initialize decompiler interface
            decompInterface = new DecompInterface();
            DecompileOptions options = new DecompileOptions();
            // DecompInterface decompInterface = new DecompInterface();
            decompInterface.setOptions(options);
            
            // Open the current program
            if (!decompInterface.openProgram(currentProgram)) {
                println("Error: Could not open program for decompilation");
                return;
            }
            
            basicBlockModel = new BasicBlockModel(currentProgram);

            // Create main executor for the whole analysis
            mainExecutor = Executors.newSingleThreadExecutor();

            Future<?> analysisTask = mainExecutor.submit(() -> {
                try {

                    // Create main JSON object
                    JSONObject outputJson = new JSONObject();
                    outputJson.put("sha256", binarySha256);
                    JSONArray decompiled = new JSONArray();
                    outputJson.put("decompiled", decompiled);
                    JSONArray disassembled = new JSONArray();
                    outputJson.put("disassembled", disassembled);
                    JSONArray cfg = new JSONArray();
                    outputJson.put("cfg", cfg);

                    // Initialize the errors array
                    errors = new JSONArray();
                    outputJson.put("errors", errors);

                    // Iterate through all functions
                    FunctionIterator functions = currentProgram.getFunctionManager().getFunctions(true);
                    for (Function function : functions) {
                        try {
                            // Create executor service for timeouts
                            ExecutorService executor = Executors.newSingleThreadExecutor();
                            // final int TIMEOUT_SECONDS = 60;  // 1 minute timeout

                            // 1. Decompile block with timeout
                            Future<?> decompileFuture = executor.submit(() -> {
                                try {
                                    DecompileResults results = decompInterface.decompileFunction(function, 30, monitor);
                                    if (results.decompileCompleted()) {
                                        String decompiledCode = results.getDecompiledFunction().getC();
                                        JSONObject functionJson = new JSONObject();
                                        String contentHash = calculateSha256(decompiledCode);
                                        functionJson.put("decompiled_content_hash", contentHash);
                                        functionJson.put("decompiled_function", decompiledCode);
                                        functionJson.put("decompiled_function_name", function.getName());
                                        functionJson.put("decompiled_function_address", function.getEntryPoint().toString());
                                        functionJson.put("function_type", determineFunctionType(function));
                                        decompiled.put(functionJson);
                                    }
                                } catch (Exception e) {
                                    logError("Failed in decompilation block", function.getName(), 
                                            function.getEntryPoint().toString(), e, "decompile");
                                }
                            });

                            try {
                                decompileFuture.get(FUNCTION_TIMEOUT_SECONDS, TimeUnit.SECONDS);
                            } catch (TimeoutException e) {
                                logError("Timeout in decompilation block", function.getName(), 
                                        function.getEntryPoint().toString(), null, "decompile");
                                decompileFuture.cancel(true);
                            }

                            // 2. Disassembly block with timeout
                            Future<?> disassemblyFuture = executor.submit(() -> {
                                try {
                                    JSONObject disassemblyJson = extractDisassembly(function);
                                    if (disassemblyJson != null) {
                                        disassemblyJson.put("function_type", determineFunctionType(function));
                                        disassembled.put(disassemblyJson);
                                    }
                                } catch (Exception e) {
                                    logError("Failed in disassembly block", function.getName(), 
                                            function.getEntryPoint().toString(), e, "disassembly");
                                }
                            });

                            try {
                                disassemblyFuture.get(FUNCTION_TIMEOUT_SECONDS, TimeUnit.SECONDS);
                            } catch (TimeoutException e) {
                                logError("Timeout in disassembly block", function.getName(), 
                                        function.getEntryPoint().toString(), null, "disassembly");
                                disassemblyFuture.cancel(true);
                            }

                            // 3. CFG block with timeout
                            Future<?> cfgFuture = executor.submit(() -> {
                                try {
                                    CodeBlockIterator blocks = basicBlockModel.getCodeBlocksContaining(function.getBody(), monitor);
                                    while (blocks.hasNext()) {
                                        CodeBlock block = blocks.next();
                                        JSONObject blockJson = extractBasicBlock(block, function);
                                        if (blockJson != null) {
                                            cfg.put(blockJson);
                                        }
                                    }
                                } catch (Exception e) {
                                    logError("Failed in CFG block", function.getName(), 
                                            function.getEntryPoint().toString(), e, "cfg");
                                }
                            });

                            try {
                                cfgFuture.get(FUNCTION_TIMEOUT_SECONDS, TimeUnit.SECONDS);
                            } catch (TimeoutException e) {
                                logError("Timeout in CFG block", function.getName(), 
                                        function.getEntryPoint().toString(), null, "cfg");
                                cfgFuture.cancel(true);
                            }

                            // Shutdown executor
                            executor.shutdownNow();

                        } catch (Exception e) {
                            logError("Failed to process function", function.getName(), 
                                    function.getEntryPoint().toString(), e, "unknown");
                            // Continue with next function
                        }
                    }
                    
                    try {
                        // Print the final JSON to stdout for Python to capture
                        System.out.println(outputJson.toString());
                    } catch (Exception e) {
                        System.out.println("Error: Failed to output final JSON: " + e.getMessage()); 
                    }
                } catch (Exception e) {
                        System.out.println("Fatal error in analysis: " + e.getMessage());
                }
            });

            // Wait for completion with a global timeout
            try {
                analysisTask.get(GLOBAL_TIMEOUT_SECONDS, TimeUnit.SECONDS); // 5 minute global timeout
            } catch (TimeoutException e) {
                println("Global analysis timeout reached");
                Thread.sleep(5000);  // 5 second grace period
            }
        } finally {
            // Cleanup section
            println("Starting cleanup process...");
            if (mainExecutor != null) {
                mainExecutor.shutdownNow(); // Force shutdown of all tasks
                try {
                    if (!mainExecutor.awaitTermination(5, TimeUnit.SECONDS)) {
                        println("Warning: Some tasks did not terminate");
                    }
                } catch (InterruptedException ie) {
                    Thread.currentThread().interrupt();
                }
            }

            cleanup();

            // // Print thread state for debugging
            // println("Active threads after cleanup:");
            // Thread.getAllStackTraces().forEach((thread, stackTrace) -> {
            //     println("Thread: " + thread.getName() + " - State: " + thread.getState());
            // });
            
            // Force exit if we're still hanging
            println("Analysis complete, forcing exit...");
            System.exit(0);  // This is a bit aggressive but will ensure termination
        }
    }

    private void cleanup() {
        println("Executing cleanup...");
        try {
            // Force cleanup of any remaining resources
            if (decompInterface != null) {
                println("Closing decompiler interface...");
                decompInterface.closeProgram();
                decompInterface.dispose();
            }
            
            // Clear any thread locals or static resources
            decompInterface = null;
            listing = null;
            basicBlockModel = null;
            errors = null;
            
            // Request garbage collection
            // System.gc();
            
            println("Cleanup completed successfully");
        } catch (Exception e) {
            println("Error during cleanup: " + e.getMessage());
        }
    }

    private JSONObject extractDisassembly(Function function) throws Exception {
        if (function.isExternal() || 
            function.isThunk() || 
            function.getSymbol().isExternal() ||
            function.getEntryPoint().toString().startsWith("00105")) {  // Your external functions all start with 00105
            return null;
        }
        // Add debug for non-external functions that fail
        if (!function.isExternal() && listing.getInstructionAt(function.getEntryPoint()) == null) {
            println(String.format("Debug: Function %s at %s has no instructions but is not external", 
                function.getName(), function.getEntryPoint().toString()));
            return null;
        }

        JSONObject disassemblyJson = new JSONObject();
        try {
            // Check minimum function size first
            int instructionCount = 0;
            AddressSetView functionBody = function.getBody();
            Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                instructionCount++;
                instruction = instruction.getNext();
            }
            
            if (instructionCount < MIN_FUNCTION_SIZE) {
                return null;  // Skip functions that are too small
            }

            StringBuilder disassemblyBuilder = new StringBuilder();
            StringBuilder[] normalizedBuilders = new StringBuilder[3];  // One for each normalization level
            for (int i = 0; i < 3; i++) {
                normalizedBuilders[i] = new StringBuilder();
            }
            // int instructionCount = 0;

            // Get function body
            instruction = null;
            // AddressSetView functionBody = function.getBody();
            // Instruction instruction = null;

            // Iterate through instructions
            try {
                instruction = listing.getInstructionAt(function.getEntryPoint());
            } catch (Exception e) {
                logError("Failed to get first instruction", function.getName(), 
                        function.getEntryPoint().toString(), e, "extractDisassembly");
                return null;
            }

            if (instruction == null) {
                // Don't log error for external functions
                if (!function.isExternal()) {
                    logError("Failed to get first instruction", function.getName(),
                            function.getEntryPoint().toString(), null, "extractDisassembly");
                }
                return null;
            }

            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                try {
                    // Original disassembly with addresses
                    disassemblyBuilder.append(instruction.getAddress().toString())
                                    .append(": ")
                                    .append(instruction.toString())
                                    .append("\n");
                    
                    // Normalized disassembly (just mnemonics and generic operands)
                    try {
                        String[] normalizedVersions = normalizeInstructionAllLevels(instruction);
                        for (int i = 0; i < 3; i++) {
                            normalizedBuilders[i].append(normalizedVersions[i]);
                            if (isControlFlowInstruction(instruction)) {
                                normalizedBuilders[i].append(" <TARGET>");
                            }
                            normalizedBuilders[i].append("\n");
                        }
                        // normalizedBuilder.append(normalizeInstruction(instruction));
                        // if (isControlFlowInstruction(instruction)) {
                        //     normalizedBuilder.append(" <TARGET>");  // Abstract away specific targets
                        // }
                        // normalizedBuilder.append("\n");
                    } catch (Exception e) {
                        logError("Failed to normalize instruction", function.getName(), 
                                instruction.getAddress().toString(), e, "extractDisassembly");
                        // Continue with next instruction
                    }

                    // instructionCount++;
                    instruction = instruction.getNext();
                } catch (Exception e) {
                    logError("Failed processing instruction", function.getName(), 
                            instruction.getAddress().toString(), e, "extractDisassembly");
                    break; // Exit loop if we can't process further instructions
                }
            }

            String disassemblyStr = disassemblyBuilder.toString();
            try {
                disassemblyJson.put("disassembled_content_hash", calculateSha256(disassemblyStr));
                disassemblyJson.put("fully_normalized_content_hash", calculateSha256(normalizedBuilders[0].toString()));
                disassemblyJson.put("api_normalized_content_hash", calculateSha256(normalizedBuilders[1].toString()));
                disassemblyJson.put("category_normalized_content_hash", calculateSha256(normalizedBuilders[2].toString()));
                disassemblyJson.put("disassembled_function", disassemblyStr);
                disassemblyJson.put("fully_normalized_disassembly", normalizedBuilders[0].toString());
                disassemblyJson.put("api_normalized_disassembly", normalizedBuilders[1].toString());
                disassemblyJson.put("category_normalized_disassembly", normalizedBuilders[2].toString());
                disassemblyJson.put("disassembled_function_name", function.getName());
                disassemblyJson.put("disassembled_function_address", function.getEntryPoint().toString());
                disassemblyJson.put("instruction_count", instructionCount);
                Map<String, Integer> typeFrequencies = collectInstructionTypes(function);
                disassemblyJson.put("instruction_types", new JSONArray(typeFrequencies.keySet()));

                disassemblyJson.put("control_flow_count", countControlFlowInstructions(function));
                disassemblyJson.put("memory_access_pattern", new JSONArray(collectMemoryPatterns(function)));
                disassemblyJson.put("register_usage", new JSONArray(collectRegisterUsage(function)));
                disassemblyJson.put("data_references_count", countDataReferences(function));
                // disassemblyJson.put("opcode_frequency_vector", new JSONArray(computeOpcodeFrequency(function)));
                // disassemblyJson.put("api_calls_vector", new JSONArray(computeApiCallsVector(function)));
                // disassemblyJson.put("minhash_signature", new JSONArray(computeMinHash(function, 16)));  // 16 hashes
                disassemblyJson.put("max_block_size", computeMaxBlockSize(function));
                disassemblyJson.put("num_calls", computeNumCalls(function));
                disassemblyJson.put("stack_size", estimateStackSize(function));
                // Map<String, Double> ratios = calculateInstructionTypeRatios(typeFrequencies);
                // disassemblyJson.put("instruction_type_ratios", new JSONArray(convertRatiosToArray(ratios)));

                // String picHash = calculatePicHash(function);
                // if (picHash != null) {
                //     disassemblyJson.put("pic_hash", picHash);
                // }
  
            } catch (Exception e) {
                logError("Failed to create JSON object", function.getName(), 
                        function.getEntryPoint().toString(), e, "extractDisassembly");
                return null;
            }
            
            return disassemblyJson;
        } catch (Exception e) {
            logError("Fatal error in disassembly extraction", function.getName(), 
                    function.getEntryPoint().toString(), e, "extractDisassembly");
            return null;
        }
    }


    private String[] normalizeInstructionAllLevels(Instruction instruction) {
        StringBuilder[] normalized = new StringBuilder[3];
        for (int i = 0; i < 3; i++) {
            normalized[i] = new StringBuilder();
        }

        try {
            String mnemonic = instruction.getMnemonicString();
            for (int i = 0; i < 3; i++) {
                normalized[i].append(mnemonic);
            }

            for (int i = 0; i < instruction.getNumOperands(); i++) {
                String operand = instruction.getDefaultOperandRepresentation(i);
                String[] normalizedOps = normalizeOperandAllLevels(operand, instruction, i);
                
                for (int level = 0; level < 3; level++) {
                    normalized[level].append(" ").append(normalizedOps[level]);
                }
            }
        } catch (Exception e) {
            // If normalization fails, return simple mnemonic
            String fallback = instruction.getMnemonicString() + " op";
            return new String[]{fallback, fallback, fallback};
        }

        return new String[]{
            normalized[0].toString(),
            normalized[1].toString(),
            normalized[2].toString()
        };
    }

    private String[] normalizeOperandAllLevels(String operand, Instruction instruction, int opIndex) {
        // Returns [fullyNormalized, apiNormalized, categoryNormalized]
        String[] normalizations = new String[3];
        
        operand = operand.trim().toUpperCase();
        
        // Handle API calls
        if (instruction.getOperandType(opIndex) == OperandType.ADDRESS || 
            (operand.startsWith("0X") && isLikelyApi(operand))) {
            
            String apiName = resolveApiName(operand, instruction);
            if (apiName != null) {
                normalizations[0] = "DATA_REF";  // Most abstract
                normalizations[1] = "API_" + apiName;  // Preserve exact API
                normalizations[2] = "API_" + ApiCategory.fromApi(apiName).name();  // Use category
                return normalizations;
            }
        }

        // Handle immediate values
        if (instruction.getOperandType(opIndex) == OperandType.SCALAR) {
            // Level 0: Most abstract
            normalizations[0] = "CONST";
            
            // Level 1: Keep small constants, normalize large ones
            try {
                long value = Long.decode(operand);
                if (value >= -16 && value <= 16) {
                    normalizations[1] = "CONST_" + value;
                } else {
                    normalizations[1] = "CONST_LARGE";
                }
            } catch (NumberFormatException e) {
                normalizations[1] = "CONST";
            }
            
            // Level 2: Distinguish between different types of constants
            if (operand.startsWith("0X")) {
                normalizations[2] = "CONST_HEX";
            } else {
                normalizations[2] = "CONST_DEC";
            }
            return normalizations;
        }
        
        // Handle registers
        if (instruction.getOperandType(opIndex) == OperandType.REGISTER) {
            // Level 0: Most abstract - just register type
            normalizations[0] = normalizeRegister(operand);
            
            // Level 1: Preserve register class but normalize within class
            if (operand.matches("E?[ABCD]X|R\\d+")) {
                normalizations[1] = "GPR_DATA";
            } else if (operand.matches("E?SI|E?DI")) {
                normalizations[1] = "GPR_INDEX";
            } else if (operand.matches("E?[BS]P|R?SP")) {
                normalizations[1] = "GPR_STACK";
            } else if (operand.matches("XMM\\d+")) {
                normalizations[1] = "XMM_REG";
            } else if (operand.matches("ST\\d+")) {
                normalizations[1] = "FPU_REG";
            } else {
                normalizations[1] = "OTHER_REG";
            }
            
            // Level 2: More specific register categorization
            if (operand.startsWith("R")) {
                normalizations[2] = "REG_64";
            } else if (operand.startsWith("E")) {
                normalizations[2] = "REG_32";
            } else if (operand.matches("[ABCD][XHL]|SI|DI|SP|BP")) {
                normalizations[2] = "REG_16_8";
            } else {
                normalizations[2] = "REG_SPECIAL";
            }
            return normalizations;
        }
        
        // Handle memory references
        if (operand.contains("[")) {
            // Level 0: Most abstract
            normalizations[0] = operand.matches(".*\\[.*[+-].*\\]") ? "MEM_OFF" : "MEM";
            
            // Level 1: Distinguish base register types
            String memContent = operand.replaceAll(".*\\[(.*?)\\].*", "$1");
            if (memContent.contains("ESP") || memContent.contains("EBP")) {
                normalizations[1] = "MEM_STACK";
            } else if (memContent.contains("ESI") || memContent.contains("EDI")) {
                normalizations[1] = "MEM_STRING";
            } else {
                normalizations[1] = "MEM_GENERAL";
            }
            
            // Level 2: More detailed memory access pattern
            if (memContent.contains("+") && memContent.contains("*")) {
                normalizations[2] = "MEM_SCALED_INDEX";
            } else if (memContent.contains("+") || memContent.contains("-")) {
                normalizations[2] = "MEM_BASE_OFFSET";
            } else {
                normalizations[2] = "MEM_DIRECT";
            }
            return normalizations;
        }
        
        // Handle string/data references that aren't APIs
        if (instruction.getOperandType(opIndex) == OperandType.ADDRESS || 
            operand.startsWith("0X") || 
            operand.matches(".*_.*")) {
            normalizations[0] = "DATA_REF";
            normalizations[1] = "DATA_" + (operand.startsWith("0X") ? "ADDR" : "SYM");
            normalizations[2] = "DATA_" + (operand.contains("str") || operand.contains("STR") ? "STRING" : "OTHER");
            return normalizations;
        }
        
        // Default case - keep original for all levels if we can't categorize
        normalizations[0] = normalizations[1] = normalizations[2] = operand;
        return normalizations;
    }

    private boolean isLikelyApi(String operand) {
        // Check for common API function patterns
        return operand.matches(".*_[A-Za-z].*") ||  // Has underscore followed by letters
            operand.matches("^[A-Z][a-z]+[A-Z].*") || // PascalCase pattern typical of Win32 APIs
            operand.matches(".*@.*") ||  // Has @ symbol (common in decorated names)
            operand.matches("^_.*[A-Z].*"); // Starts with underscore and has uppercase
    }

    // Helper method to resolve API names
    private String resolveApiName(String operand, Instruction instruction) {
        // Try to get symbol name if available
        Reference[] refs = instruction.getReferencesFrom();
        if (refs != null && refs.length > 0) {
            for (Reference ref : refs) {
                Address toAddr = ref.getToAddress();
                SymbolTable symbolTable = currentProgram.getSymbolTable();
                Symbol[] symbols = symbolTable.getSymbols(toAddr);
                if (symbols != null && symbols.length > 0) {
                    // First try to find a symbol that matches our API patterns
                    for (Symbol sym : symbols) {
                        String name = sym.getName();
                        if (isLikelyApi(name)) {  // reuse your existing API detection
                            name = name.replaceAll("^_*", "")  // Remove leading underscores
                                    .replaceAll("@.*$", "");  // Remove @ decorations
                            return name;
                        }
                    }
                    // If no API-like symbol found, fall back to first symbol
                    String name = symbols[0].getName()
                        .replaceAll("^_*", "")
                        .replaceAll("@.*$", "");
                    return name;
                }
            }
        }
        return null;
    }

    private String normalizeRegister(String register) {
        // Convert to uppercase for consistent matching
        register = register.toUpperCase();
        
        // General purpose registers
        if (register.matches("E?[ABCD]X|E?SI|E?DI|R\\d+")) {
            return "GPR";
        }
        // Stack/base pointers
        if (register.matches("E?[BS]P|R?SP")) {
            return "PTR";
        }
        // SIMD registers
        if (register.matches("XMM\\d+")) {
            return "XMM";
        }
        // FPU registers
        if (register.matches("ST\\d+")) {
            return "FPU";
        }
        // Any other register
        return "REG";
    }

    private boolean isControlFlowInstruction(Instruction instruction) {
        String mnemonic = instruction.getMnemonicString().toUpperCase();
        return mnemonic.startsWith("J") ||
               mnemonic.equals("CALL") ||
               mnemonic.equals("RET") ||
               mnemonic.equals("LOOP");
    }

    private Map<String, Integer> collectInstructionTypes(Function function) {
        Map<String, Integer> typeFrequencies = new HashMap<>();
        try {
            AddressSetView functionBody = function.getBody();
            Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
            
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                try {
                    String mnemonic = instruction.getMnemonicString().toUpperCase();
                    
                    // Data Movement Categories
                    if (mnemonic.matches("MOV|LEA|XCHG")) {
                        incrementFrequency(typeFrequencies, InstructionType.GENERAL_DATA_MOVEMENT.name());
                    }
                    else if (mnemonic.matches("PUSH|POP|ENTER|LEAVE|PUSHA|POPA")) {
                        incrementFrequency(typeFrequencies, InstructionType.STACK_MANAGEMENT.name());
                    }
                    else if (mnemonic.matches("MOVS|LODS|STOS|CMPS|SCAS|REP.*")) {
                        incrementFrequency(typeFrequencies, InstructionType.STRING_MANIPULATION.name());
                    }
                    
                    // Arithmetic Categories
                    else if (mnemonic.matches("ADD|SUB|INC|DEC")) {
                        incrementFrequency(typeFrequencies, InstructionType.BASIC_ARITHMETIC.name());
                    }
                    else if (mnemonic.matches("MUL|DIV|IMUL|IDIV")) {
                        incrementFrequency(typeFrequencies, InstructionType.MULTIPLICATION_DIVISION.name());
                    }
                    else if (mnemonic.matches("ADC|SBB")) {
                        incrementFrequency(typeFrequencies, InstructionType.CARRY_ARITHMETIC.name());
                    }
                    
                    // Logical Categories
                    else if (mnemonic.matches("AND|OR|XOR|NOT")) {
                        incrementFrequency(typeFrequencies, InstructionType.BITWISE_LOGIC.name());
                    }
                    else if (mnemonic.matches("TEST|CMP|SET[A-Z]+")) {
                        incrementFrequency(typeFrequencies, InstructionType.CONDITIONAL_LOGIC.name());
                    }
                    
                    // Control Flow Categories
                    else if (mnemonic.equals("JMP")) {
                        incrementFrequency(typeFrequencies, InstructionType.UNCONDITIONAL_JUMP.name());
                    }
                    else if (mnemonic.matches("J[A-Z]+") && !mnemonic.equals("JMP")) {
                        incrementFrequency(typeFrequencies, InstructionType.CONDITIONAL_JUMP.name());
                    }
                    else if (mnemonic.matches("CALL|RET")) {
                        incrementFrequency(typeFrequencies, InstructionType.FUNCTION_CONTROL.name());
                    }
                    else if (mnemonic.matches("LOOP.*")) {
                        incrementFrequency(typeFrequencies, InstructionType.LOOPING.name());
                    }
                    
                    // System Categories
                    else if (mnemonic.matches("SYSCALL|SYSENTER|INT")) {
                        incrementFrequency(typeFrequencies, InstructionType.SYSTEM_CALLS.name());
                    }
                    else if (mnemonic.matches("HLT|CLI|STI")) {
                        incrementFrequency(typeFrequencies, InstructionType.PRIVILEGED_INSTRUCTIONS.name());
                    }
                    else if (mnemonic.matches("CPUID|RDTSC|RDTSCP")) {
                        incrementFrequency(typeFrequencies, InstructionType.CPU_FEATURES.name());
                    }
                    
                    // SIMD & FPU Categories
                    else if (mnemonic.startsWith("V") && (
                        mnemonic.contains("PS") || mnemonic.contains("PD") || 
                        mnemonic.contains("SS") || mnemonic.contains("SD"))) {
                        incrementFrequency(typeFrequencies, InstructionType.AVX_SIMD.name());
                    }
                    else if (mnemonic.matches(".*(?:PS|PD|SS|SD).*") || 
                            mnemonic.startsWith("MM") || mnemonic.startsWith("P")) {
                        incrementFrequency(typeFrequencies, InstructionType.SSE_SIMD.name());
                    }
                    else if (mnemonic.matches("FLD|FST|FSTP")) {
                        incrementFrequency(typeFrequencies, InstructionType.BASIC_FPU.name());
                    }
                    else if (mnemonic.matches("FADD|FSUB|FMUL|FDIV|FSQRT")) {
                        incrementFrequency(typeFrequencies, InstructionType.FPU_ARITHMETIC.name());
                    }
                    
                    // Bit Operation Categories
                    else if (mnemonic.matches("SHL|SHR|SAR|SAL|ROR|ROL|RCR|RCL")) {
                        incrementFrequency(typeFrequencies, InstructionType.SHIFT_ROTATE.name());
                    }
                    else if (mnemonic.matches("BT|BTS|BTR|BTC|BSF|BSR")) {
                        incrementFrequency(typeFrequencies, InstructionType.BIT_TEST_MODIFY.name());
                    }
                    
                    // Special Categories
                    else if (mnemonic.matches("AES.*|SHA.*|RDRAND|RDSEED")) {
                        incrementFrequency(typeFrequencies, InstructionType.CRYPTOGRAPHIC_OPS.name());
                    }
                    else if (mnemonic.matches("NOP|UD2|INT3")) {
                        incrementFrequency(typeFrequencies, InstructionType.MISC_OPS.name());
                    }
                    
                    instruction = instruction.getNext();
                } catch (Exception e) {
                    logError("Failed to process instruction type", function.getName(), 
                            instruction.getAddress().toString(), e, "collectInstructionTypes");
                }
            }
        } catch (Exception e) {
            logError("Failed to collect instruction types", function.getName(), 
                    function.getEntryPoint().toString(), e, "collectInstructionTypes");
        }
        
        return typeFrequencies;
    }

    private void incrementFrequency(Map<String, Integer> frequencies, String type) {
        frequencies.put(type, frequencies.getOrDefault(type, 0) + 1);
    }

    /**
     * Collect memory access patterns in the function
     */
    private List<String> collectMemoryPatterns(Function function) {
        Set<String> patterns = new HashSet<>();
        try {
            AddressSetView functionBody = function.getBody();
            Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
            
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                try {
                    for (int i = 0; i < instruction.getNumOperands(); i++) {
                        String opRep = instruction.getDefaultOperandRepresentation(i);
                        // Check if operand uses memory (indicated by square brackets)
                        if (opRep.contains("[")) {
                            if (opRep.contains("+") || opRep.contains("-")) {
                                patterns.add("BASE_PLUS_OFFSET");
                            } else if (opRep.contains("*")) {
                                patterns.add("SCALED_INDEX");
                            } else {
                                patterns.add("DIRECT_MEMORY");
                            }
                        }
                    }
                    instruction = instruction.getNext();
                } catch (Exception e) {
                    logError("Failed to process memory pattern", function.getName(), 
                            instruction.getAddress().toString(), e, "collectMemoryPatterns");
                }
            }
        } catch (Exception e) {
            logError("Failed to collect memory patterns", function.getName(), 
                    function.getEntryPoint().toString(), e, "collectMemoryPatterns");
        }
        return new ArrayList<>(patterns);
    }

    /**
     * Collect register usage information
     */
    private List<String> collectRegisterUsage(Function function) {
        Set<String> registers = new HashSet<>();
        try {
            AddressSetView functionBody = function.getBody();
            Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
            
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                try {
                    for (int i = 0; i < instruction.getNumOperands(); i++) {
                        if ((instruction.getOperandType(i) & OperandType.REGISTER) != 0) {
                            String reg = instruction.getDefaultOperandRepresentation(i).toUpperCase();
                            // Categorize register type
                            if (reg.matches("E?[ABCD]X|R\\d+")) registers.add("GPR");
                            else if (reg.matches("E?[BS]P|R?SP")) registers.add("STACK_PTR");
                            else if (reg.matches("E?[SD]I")) registers.add("INDEX_PTR");
                            else if (reg.matches("XMM\\d+")) registers.add("SIMD");
                            else if (reg.matches("ST\\d+")) registers.add("FPU");
                            else registers.add("OTHER");
                        }
                    }
                    instruction = instruction.getNext();
                } catch (Exception e) {
                    logError("Failed to process register usage", function.getName(), 
                            instruction.getAddress().toString(), e, "collectRegisterUsage");
                }
            }
        } catch (Exception e) {
            logError("Failed to collect register usage", function.getName(), 
                    function.getEntryPoint().toString(), e, "collectRegisterUsage");
        }
        return new ArrayList<>(registers);
    }

    /**
     * Count references to data section
     */
    private int countDataReferences(Function function) {
        int count = 0;
        try {
            AddressSetView functionBody = function.getBody();
            Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
            
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                try {
                    // Count operands that access data
                    for (int i = 0; i < instruction.getNumOperands(); i++) {
                        String opRep = instruction.getDefaultOperandRepresentation(i);
                        // Look for data references like symbols, constants
                        if (instruction.getOperandType(i) == OperandType.SCALAR || 
                            opRep.matches(".*_[A-Za-z].*") ||  // Named references
                            (opRep.startsWith("0x") && !opRep.contains("[")) // Direct address without memory indirection
                        ) {
                            count++;
                        }
                    }
                    instruction = instruction.getNext();
                } catch (Exception e) {
                    logError("Failed to process data reference", function.getName(), 
                            instruction.getAddress().toString(), e, "countDataReferences");
                }
            }
        } catch (Exception e) {
            logError("Failed to count data references", function.getName(), 
                    function.getEntryPoint().toString(), e, "countDataReferences");
        }
        return count;
    }

    /**
     * Count control flow instructions (jumps, calls, returns)
     */
    private int countControlFlowInstructions(Function function) {
        int count = 0;
        try {
            AddressSetView functionBody = function.getBody();
            Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
            
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                try {
                    String mnemonic = instruction.getMnemonicString().toUpperCase();
                    // Check for jumps, calls, returns
                    if (mnemonic.startsWith("J") ||     // All jumps
                        mnemonic.equals("CALL") ||      // Calls
                        mnemonic.equals("RET") ||       // Returns
                        mnemonic.equals("LOOP")) {      // Loop instructions
                        count++;
                    }
                    instruction = instruction.getNext();
                } catch (Exception e) {
                    logError("Failed to process control flow instruction", function.getName(), 
                            instruction.getAddress().toString(), e, "countControlFlowInstructions");
                }
            }
        } catch (Exception e) {
            logError("Failed to count control flow instructions", function.getName(), 
                    function.getEntryPoint().toString(), e, "countControlFlowInstructions");
        }
        return count;
    }

    private JSONObject extractBasicBlock(CodeBlock block, Function function) {
        try {
            // Check minimum block size first
            int blockSize = 0;
            AddressIterator addrs = block.getAddresses(true);
            while (addrs.hasNext()) {
                Address addr = addrs.next();
                if (listing.getInstructionAt(addr) != null) {
                    blockSize++;
                }
            }
            
            if (blockSize < MIN_BLOCK_SIZE) {
                return null;  // Skip blocks that are too small
            }

            JSONObject blockJson = new JSONObject();
            String blockInstructions = getBlockInstructions(block);
            
            // Calculate block_id
            String blockIdInput = blockInstructions + 
                                block.getMinAddress().toString() +
                                block.getMaxAddress().toString() +
                                function.getEntryPoint().toString();
            String blockId = calculateSha256(blockIdInput);

            blockJson.put("block_id", blockId);
            blockJson.put("function_address", function.getEntryPoint().toString());
            blockJson.put("block_start_address", block.getMinAddress().toString());
            blockJson.put("block_end_address", block.getMaxAddress().toString());
            blockJson.put("block_instructions", blockInstructions);
            blockJson.put("block_size", blockSize);
            
            // Get predecessor blocks
            JSONArray predecessors = new JSONArray();
            CodeBlockReferenceIterator preds = block.getSources(monitor);
            while (preds.hasNext()) {
                CodeBlockReference ref = preds.next();
                predecessors.put(ref.getSourceAddress().toString());
            }
            if (predecessors.length() > 0) {
                blockJson.put("predecessor_blocks", predecessors);
            }

            // Get successor blocks
            JSONArray successors = new JSONArray();
            CodeBlockReferenceIterator succs = block.getDestinations(monitor);
            while (succs.hasNext()) {
                CodeBlockReference ref = succs.next();
                successors.put(ref.getDestinationAddress().toString());
            }
            if (successors.length() > 0) {
                blockJson.put("successor_blocks", successors);
            }

            // Determine if entry/exit block
            blockJson.put("is_entry_block", block.getMinAddress().equals(function.getEntryPoint()));
            blockJson.put("is_exit_block", successors.length() == 0);

            BranchType branchType = determineBranchType(block);
            blockJson.put("branch_type", branchType.name());

            // Add normalized instructions
            StringBuilder[] normalizedBuilders = new StringBuilder[3];  // One for each level
            for (int i = 0; i < 3; i++) {
                normalizedBuilders[i] = new StringBuilder();
            }

            addrs = block.getAddresses(true);
            while (addrs.hasNext()) {
                Address addr = addrs.next();
                Instruction instr = listing.getInstructionAt(addr);
                if (instr != null) {
                    String[] normalizedVersions = normalizeInstructionAllLevels(instr);
                    for (int i = 0; i < 3; i++) {
                        normalizedBuilders[i].append(normalizedVersions[i]);
                        if (isControlFlowInstruction(instr)) {
                            normalizedBuilders[i].append(" <TARGET>");
                        }
                        normalizedBuilders[i].append("\n");
                    }
                }
            }

            blockJson.put("fully_normalized_instructions", normalizedBuilders[0].toString());
            blockJson.put("api_normalized_instructions", normalizedBuilders[1].toString());
            blockJson.put("category_normalized_instructions", normalizedBuilders[2].toString());

            Set<String> constants = extractConstantReferences(block);
            if (!constants.isEmpty()) {
                blockJson.put("referenced_constants", new JSONArray(constants));
            }
            
            return blockJson;
        } catch (Exception e) {
            logError("Failed to process basic block", function.getName(), 
                    block.getMinAddress().toString(), e, "extractBasicBlock");
            return null;
        }
    }

    private String getBlockInstructions(CodeBlock block) {
        StringBuilder instructions = new StringBuilder();
        AddressIterator addresses = block.getAddresses(true);
        while (addresses.hasNext()) {
            Address addr = addresses.next();
            Instruction instr = listing.getInstructionAt(addr);
            if (instr != null) {
                instructions.append(addr.toString())
                        .append(": ")
                        .append(instr.toString())
                        .append("\n");
            }
        }
        return instructions.toString();
    }

    private BranchType determineBranchType(CodeBlock block) {
        try {
            Address lastInstrAddr = block.getMaxAddress();
            Instruction lastInstr = listing.getInstructionAt(lastInstrAddr);
            if (lastInstr == null) {
                return BranchType.UNKNOWN;
            }

            String mnemonic = lastInstr.getMnemonicString().toUpperCase();
            
            // Check for return instructions
            if (mnemonic.equals("RET") || mnemonic.equals("RETN")) {
                return BranchType.RETURN;
            }
            
            // Check for call instructions
            if (mnemonic.equals("CALL")) {
                return BranchType.CALL;
            }
            
            // Check for jumps
            if (mnemonic.startsWith("J")) {
                // Unconditional jumps
                if (mnemonic.equals("JMP")) {
                    return BranchType.DIRECT;
                }
                // Conditional jumps (JE, JNE, JG, JLE, etc.)
                return BranchType.CONDITIONAL;
            }
            
            // Check number of successors
            CodeBlockReferenceIterator succs = block.getDestinations(monitor);
            if (succs.hasNext()) {
                return BranchType.FALLTHROUGH;
            }
            
            return BranchType.UNKNOWN;
        } catch (Exception e) {
            logError("Failed to determine branch type", "", block.getMinAddress().toString(), e, "determineBranchType");
            return BranchType.UNKNOWN;
        }
    }

    private Set<String> extractConstantReferences(CodeBlock block) {
        Set<String> constants = new HashSet<>();
        try {
            AddressIterator addresses = block.getAddresses(true);
            while (addresses.hasNext()) {
                Address addr = addresses.next();
                Instruction instr = listing.getInstructionAt(addr);
                if (instr == null) continue;

                // Process each operand
                for (int i = 0; i < instr.getNumOperands(); i++) {
                    int opType = instr.getOperandType(i);
                    String opRep = instr.getDefaultOperandRepresentation(i);
                    
                    // Immediate values
                    if ((opType & OperandType.SCALAR) != 0) {
                        constants.add("IMM:" + opRep);
                    }
                    
                    // Memory offsets
                    if (opRep.contains("[")) {
                        String offset = opRep.replaceAll(".*\\[(.*?)\\].*", "$1");
                        if (offset.matches("^[+-]?\\d+$") || offset.startsWith("0x")) {
                            constants.add("OFF:" + offset);
                        }
                    }
                    
                    // Data references
                    Reference[] refs = instr.getOperandReferences(i);
                    if (refs != null) {
                        for (Reference ref : refs) {
                            if (ref.getReferenceType().isData()) {
                                constants.add("DATA:" + ref.getToAddress());
                            }
                        }
                    }
                }
            }
        } catch (Exception e) {
            logError("Failed to extract constants", "", block.getMinAddress().toString(), e, "extractConstantReferences");
        }
        return constants;
    }

    private String determineFunctionType(Function function) {
        try {
            if (function.isExternal()) {
                return "EXTERNAL";
            }
            if (function.isThunk()) {
                return "THUNK";
            }
            // Check if it's a library function by name pattern or location
            String name = function.getName();
            if (name.startsWith("__") || 
                name.contains("@") || 
                function.getEntryPoint().toString().startsWith("00105")) {
                return "LIBRARY";
            }
            return "USER";
        } catch (Exception e) {
            logError("Failed to determine function type", function.getName(), 
                    function.getEntryPoint().toString(), e, "determineFunctionType");
            return "UNKNOWN";
        }
    }

    private float[] computeOpcodeFrequency(Function function) {
        float[] frequencies = new float[COMMON_OPCODES.length];
        int totalInstructions = 0;
        
        try {
            AddressSetView functionBody = function.getBody();
            Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
            
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                String mnemonic = instruction.getMnemonicString();
                String normalized = normalizeOpcode(mnemonic);
                
                Integer index = opcodeIndex.get(normalized);
                if (index != null) {
                    frequencies[index]++;
                }
                
                totalInstructions++;
                instruction = instruction.getNext();
            }
            
            // Normalize
            if (totalInstructions > 0) {
                for (int i = 0; i < frequencies.length; i++) {
                    frequencies[i] /= totalInstructions;
                }
            }
            
        } catch (Exception e) {
            logError("Failed to compute opcode frequencies", function.getName(), 
                function.getEntryPoint().toString(), e, "computeOpcodeFrequency");
        }
        
        return frequencies;
    }


    private String normalizeOpcode(String mnemonic) {
        String normalized = mnemonic.trim().toUpperCase();
        
        // Handle prefixes
        if (normalized.startsWith("REP") || normalized.startsWith("REPE") || normalized.startsWith("REPNE")) {
            normalized = normalized.substring(normalized.indexOf(' ') + 1);
        }
        
        // Direct matches first
        if (opcodeIndex.containsKey(normalized)) {
            return normalized;
        }
        
        // Group categorization
        if (normalized.matches("MOV[AU]PS|MOVDQ[AU]|VMOVDQ[AU]|VMOV[AU]PS")) {
            return "SIMD_MOVE";
        }
        
        if (normalized.matches("J[GLABE][E]?|JG?[EZSC]|JN[GLABE][E]?|JN[EZSC]")) {
            return "COND_JUMP_EXT";
        }
        
        if (normalized.matches("MOVS|STOS|LODS|SCAS|CMPS|MOVSB|MOVSW|MOVSD")) {
            return "STRING_OP";
        }
        
        if (normalized.matches("ENTER|LEAVE|PUSHA|POPA")) {
            return "STACK_ADV";
        }
        
        if (normalized.matches("IMUL|IDIV|ADC|SBB|NEG|BSWAP")) {
            return "ARITHMETIC_ADV";
        }
        
        if (normalized.matches("SHL|SHR|SAR|SAL|ROL|ROR|RCL|RCR|BT[SR]?|BSF|BSR")) {
            return "BIT_OP";
        }
        
        if (normalized.startsWith("F")) {
            return "FPU_OP";
        }
        
        if (normalized.matches("SYSCALL|INT|SYSENTER|SYSEXIT")) {
            return "SYSTEM_OP";
        }
        
        if (normalized.matches("AES.*|SHA.*|RDRAND|RDSEED")) {
            return "CRYPTO_OP";
        }
        
        if (normalized.matches("CPUID|RDTSC|UD2|HLT|PAUSE")) {
            return "MISC_OP";
        }
        
        return normalized;  // Keep as is if no categorization matches
    }


    // method for API calls vector
    private float[] computeApiCallsVector(Function function) {
        // Initialize vector with one position per API category
        float[] apiVector = new float[ApiCategory.values().length];
        int totalCalls = 0;
        
        AddressSetView functionBody = function.getBody();
        Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
        
        while (instruction != null && functionBody.contains(instruction.getAddress())) {
            if (instruction.getMnemonicString().equals("CALL")) {
                for (int i = 0; i < instruction.getNumOperands(); i++) {
                    String apiName = resolveApiName(
                        instruction.getDefaultOperandRepresentation(i), 
                        instruction
                    );
                    if (apiName != null) {
                        ApiCategory category = ApiCategory.fromApi(apiName);
                        apiVector[category.ordinal()]++;
                        totalCalls++;
                    }
                }
            }
            instruction = instruction.getNext();
        }
        
        // Normalize to frequencies
        if (totalCalls > 0) {
            for (int i = 0; i < apiVector.length; i++) {
                apiVector[i] /= totalCalls;
            }
        }
        
        return apiVector;
    }

    private long[] computeMinHash(Function function, int numHashes) {
        long[] signature = new long[numHashes];
        Arrays.fill(signature, Long.MAX_VALUE);
        
        AddressSetView functionBody = function.getBody();
        Instruction instruction = listing.getInstructionAt(function.getEntryPoint());

        while (instruction != null && functionBody.contains(instruction.getAddress())) {
            String[] normalizedVersions = normalizeInstructionAllLevels(instruction);
            String token = normalizedVersions[0];  // Fully normalized instruction
            
            // Hash token using numHashes different hash functions
            for (int i = 0; i < numHashes; i++) {
                long hash = murmurHash64(token, i) & Long.MAX_VALUE;  // Ensure non-negative
                signature[i] = Math.min(signature[i], hash);
            }

            instruction = instruction.getNext();
        }

        return signature;
    }

    // MurmurHash3 function for better MinHashing
    private long murmurHash64(String token, int seed) {
        return Murmur3.hash_x64_128(token.getBytes(StandardCharsets.UTF_8), token.length(), seed)[0];
    }

    private long calculateTokenHash(String token, long seed) {
        // MurmurHash3-like hashing
        long h = seed;
        
        for (char c : token.toCharArray()) {
            h ^= c;
            h *= 0x5bd1e995;
            h ^= h >>> 13;
        }
        
        return h;
    }

    /*
    PicHash calculation which:
    - Uses the fully normalized instruction representation
    - Creates a position-independent hash by normalizing addresses
    - Takes first 64 bits (16 chars) of SHA-256
    */
    private String calculatePicHash(Function function) {
        try {
            StringBuilder normalizedFunction = new StringBuilder();
            AddressSetView functionBody = function.getBody();
            Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
            
            // Check minimum size threshold
            int instructionCount = 0;
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                instructionCount++;
                instruction = instruction.getNext();
            }
            if (instructionCount < MIN_FUNCTION_SIZE) {
                return null;
            }
            
            // Reset to start of function for actual processing
            instruction = listing.getInstructionAt(function.getEntryPoint());
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                String[] normalizedVersions = normalizeInstructionAllLevels(instruction);
                // Use fully normalized version (index 0) for PicHash
                normalizedFunction.append(normalizedVersions[0]).append("\n");
                instruction = instruction.getNext();
            }
            
            // Calculate SHA-256 and take first 16 characters (64 bits)
            return calculateSha256(normalizedFunction.toString()).substring(0, 16);
        } catch (Exception e) {
            logError("Failed to calculate PicHash", function.getName(), 
                    function.getEntryPoint().toString(), e, "calculatePicHash");
            return null;
        }
    }

    private int computeMaxBlockSize(Function function) {
        try {
            int maxSize = 0;
            CodeBlockIterator blocks = basicBlockModel.getCodeBlocksContaining(function.getBody(), monitor);
            while (blocks.hasNext()) {
                CodeBlock block = blocks.next();
                int blockSize = 0;
                AddressIterator addrs = block.getAddresses(true);
                while (addrs.hasNext()) {
                    Address addr = addrs.next();
                    if (listing.getInstructionAt(addr) != null) {
                        blockSize++;
                    }
                }
                maxSize = Math.max(maxSize, blockSize);
            }
            return maxSize;
        } catch (Exception e) {
            logError("Failed to compute max block size", function.getName(), 
                    function.getEntryPoint().toString(), e, "computeMaxBlockSize");
            return 0;
        }
    }

    private int computeNumCalls(Function function) {
        try {
            int callCount = 0;
            AddressSetView functionBody = function.getBody();
            Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
            
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                if (instruction.getMnemonicString().toUpperCase().equals("CALL")) {
                    callCount++;
                }
                instruction = instruction.getNext();
            }
            return callCount;
        } catch (Exception e) {
            logError("Failed to compute call count", function.getName(), 
                    function.getEntryPoint().toString(), e, "computeNumCalls");
            return 0;
        }
    }

    private int estimateStackSize(Function function) {
        try {
            // Look for stack adjustment in function prologue
            Instruction instruction = listing.getInstructionAt(function.getEntryPoint());
            AddressSetView functionBody = function.getBody();
            boolean foundProlog = false;
            int stackSize = INVALID_STACK_SIZE;
            
            // Look for common prolog patterns
            while (instruction != null && functionBody.contains(instruction.getAddress())) {
                String mnemonic = instruction.getMnemonicString().toUpperCase();
                
                // Look for PUSH EBP/RBP followed by MOV EBP/RBP, ESP/RSP
                if (mnemonic.equals("PUSH") && 
                    instruction.getDefaultOperandRepresentation(0).toUpperCase().matches(".*BP")) {
                    foundProlog = true;
                }
                // Look for SUB ESP/RSP, immediate
                else if (foundProlog && mnemonic.equals("SUB") && 
                        instruction.getDefaultOperandRepresentation(0).toUpperCase().matches(".*SP")) {
                    String immValue = instruction.getDefaultOperandRepresentation(1);
                    try {
                        // Handle hex values
                        if (immValue.startsWith("0x")) {
                            stackSize = Integer.parseInt(immValue.substring(2), 16);
                        } else {
                            stackSize = Integer.parseInt(immValue);
                        }
                        break;
                    } catch (NumberFormatException nfe) {
                        // If we can't parse the value, continue
                        continue;
                    }
                }
                instruction = instruction.getNext();
            }
            return stackSize;
        } catch (Exception e) {
            logError("Failed to estimate stack size", function.getName(), 
                    function.getEntryPoint().toString(), e, "estimateStackSize");
            return INVALID_STACK_SIZE;
        }
    }

    // Helper method to calculate instruction type ratios
    private Map<String, Double> calculateInstructionTypeRatios(Map<String, Integer> typeFrequencies) {
        Map<String, Double> ratios = new HashMap<>();
        if (typeFrequencies.isEmpty()) return ratios;
        
        // Calculate total instructions
        int total = typeFrequencies.values().stream().mapToInt(Integer::intValue).sum();
        
        // Calculate ratios
        for (Map.Entry<String, Integer> entry : typeFrequencies.entrySet()) {
            ratios.put(entry.getKey(), entry.getValue() / (double)total);
        }
        
        return ratios;
    }

    // Method to convert ratios to array format for storage
    private float[] convertRatiosToArray(Map<String, Double> ratios) {
        float[] array = new float[InstructionType.values().length];
        for (InstructionType type : InstructionType.values()) {
            array[type.ordinal()] = ratios.getOrDefault(type.name(), 0.0).floatValue();
        }
        return array;
    }
}