#!/usr/bin/env python3

import subprocess
import sys
import os
import shutil
import re
import stat
import tarfile

def get_executable_dynamic_libraries(filepath):
    libs = []
    process = subprocess.Popen(["ldd", filepath], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    (stdout, stderr) = process.communicate()
    if process.returncode != 0:
        raise RuntimeError("Failed to execute ldd on executable %s, error:\n%s" % (filepath, stderr))
    lines = stdout.splitlines()
    for line in lines:
        s = line.split()
        if b"=>" in s:
            if len(s) >= 3:
                libs.append(os.path.realpath(s[2].decode("UTF-8")))
    return libs

def make_executable(filepath):
    mode = os.stat(filepath).st_mode
    os.chmod(filepath, mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)

def main():
    if len(sys.argv) <= 2:
        print("usage: %s executable_path destination_path" % sys.argv[0])
        exit(1)

    os.makedirs(sys.argv[2], exist_ok=True)
    libs = get_executable_dynamic_libraries(sys.argv[1])

    so_loader_pattern = re.compile("ld-[0-9.]+\\.so.*")
    so_loader = None
    for lib in libs:
        lib_filename = os.path.basename(lib)
        if so_loader_pattern.match(lib_filename):
            if so_loader != None:
                print("Unexpected error: found multiple so loaders, unable to recover")
                exit(2)
            so_loader = lib_filename

    executable_filename = os.path.basename(sys.argv[1])
    new_executable_path = os.path.join(sys.argv[2], executable_filename)
    shutil.copyfile(sys.argv[1], new_executable_path)
    make_executable(new_executable_path)

    print("Patching executable")
    process = subprocess.Popen(["patchelf", "--set-interpreter", so_loader, new_executable_path], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    (stdout, stderr) = process.communicate()
    if process.returncode != 0:
        print("Failed to execute patchelf --set-interpreter on executable %s, error: %s" % (new_executable_path, stderr))
        exit(3)
    
    process = subprocess.Popen(["patchelf", "--set-rpath", ".", new_executable_path], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    (stdout, stderr) = process.communicate()
    if process.returncode != 0:
        print("Failed to execute patchelf --set-rpath on executable %s, error: %s" % (new_executable_path, stderr))
        exit(4)

    package_name = new_executable_path + ".tar.gz"
    print("Creating package %s" % os.path.basename(package_name))
    with tarfile.open(package_name, "w:gz") as tar:
        for lib in libs:
            print("Adding shared library %s to tar" % lib)
            tar.add(lib, arcname=os.path.basename(lib))
        print("Adding executable %s to tar" % sys.argv[1])
        tar.add(new_executable_path, arcname=os.path.basename(new_executable_path))
    
    print("Removing temporary file %s" % new_executable_path)
    os.remove(new_executable_path)
    print("Package has been created at %s" % package_name)

if __name__ == "__main__":
    main()