ns3

#! /usr/bin/env python3

import argparse
import atexit
import glob
import os
import re
import shutil
import subprocess
import sys

ns3_path = os.path.dirname(os.path.abspath(__file__))
out_dir = os.sep.join([ns3_path, "build"])
lock_file = os.sep.join([ns3_path, ".lock-ns3_%s_build" % sys.platform])

max_cpu_threads = max(1, os.cpu_count() - 1)
print_buffer = ""
run_verbose = True
# Windows uses ; as a PATH entry separator,
# but msys shell uses : just like most Unix-like systems
path_sep = ";" if ";" in os.environ["PATH"] else ":"
path_variable = "$PATH" if path_sep == ":" else "%PATH%"


# Prints everything in the print_buffer on exit
def exit_handler(dry_run):
    global print_buffer, run_verbose
    # We should not print anything in run except if dry_run or run_verbose
    if not dry_run and not run_verbose:
        return
    if print_buffer == "":
        return
    print_buffer = print_buffer.replace('\\', '/').replace('//', '/').replace('/', os.sep)
    if dry_run:
        print("The following commands would be executed:")
    elif run_verbose:
        print("Finished executing the following commands:")
    print(print_buffer[1:])


def on_off_argument(parser, option_name, help_on, help_off=None):
    parser.add_argument('--enable-%s' % option_name,
                        help=('Enable %s' % help_on) if help_off is None else help_on,
                        action="store_true", default=None)
    parser.add_argument('--disable-%s' % option_name,
                        help=('Disable %s' % help_on) if help_off is None else help_off,
                        action="store_true", default=None)
    return parser


def on_off(condition):
    return "ON" if condition else "OFF"


def on_off_condition(args, cmake_flag, option_name):
    enable_option = args.__getattribute__("enable_" + option_name)
    disable_option = args.__getattribute__("disable_" + option_name)
    cmake_arg = None
    if enable_option is not None or disable_option is not None:
        cmake_arg = "-DNS3_%s=%s" % (cmake_flag, on_off(enable_option and not disable_option))
    return cmake_arg


def add_argument_to_subparsers(parsers: list,
                               arguments: list,
                               help_msg: str,
                               dest: str,
                               action="store_true",
                               default_value=None):
    # Instead of copying and pasting repeated arguments for each parser, we add them here
    for subparser in parsers:
        subparser_name = subparser.prog.replace("ns3", "").strip()
        destination = ("%s_%s" % (subparser_name, dest)) if subparser_name else dest
        subparser.add_argument(*arguments,
                               help=help_msg,
                               action=action,
                               default=default_value,
                               dest=destination)


def parse_args(argv):
    parser = argparse.ArgumentParser(description="ns-3 wrapper for the CMake build system", add_help=False)

    sub_parser = parser.add_subparsers()

    parser.add_argument('-h', '--help',
                        help="Print a summary of available commands",
                        action="store_true", default=None, dest="main_help")
    parser_help = sub_parser.add_parser('help',
                                        help='Print a summary of available commands')
    parser_help.add_argument('help',
                             help='Print a summary of available commands',
                             action="store_true", default=False)
    # parser.add_argument('--docset',
    #               help=(
    #                   'Create Docset, without building. This requires the docsetutil tool from Xcode 9.2 or earlier.'
    #                   'See Bugzilla 2196 for more details.'),
    #               action="store_true", default=None,
    #               dest="docset_build")

    parser_build = sub_parser.add_parser('build',
                                         help=('Accepts a list of targets to build,'
                                               ' or builds the entire project if no target is given'),
                                         formatter_class=argparse.RawTextHelpFormatter)
    parser_build.add_argument('build',
                              help=('Build the entire project or the specified target and its dependencies.\n'
                                    'To get the list of targets, use:\n'
                                    './ns3 show targets\n'),
                              action="store", nargs='*', default=None, metavar='target')

    parser_configure = sub_parser.add_parser('configure',
                                             help='Try "./ns3 configure --help" for more configuration options')
    parser_configure.add_argument('configure',
                                  action='store_true', default=False)
    parser_configure.add_argument('-d', '--build-profile',
                                  help='Build profile',
                                  dest='build_profile',
                                  choices=["debug", "default", "release", "optimized", "minsizerel"],
                                  action="store", type=str, default=None)

    parser_configure.add_argument('-G',
                                  help=('CMake generator '
                                        '(e.g. https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html)'),
                                  action="store", type=str, default=None)

    parser_configure.add_argument('--cxx-standard',
                                  help='Compile NS-3 with the given C++ standard',
                                  type=str, default=None)

    # On-Off options
    # First positional is transformed into --enable-option --disable-option
    # Second positional is used for description "Enable %s" % second positional/"Disable %s" % second positional
    # When an optional third positional is given, the second is used as is as the 'enable' description
    # and the third is used as is as the 'disable' description
    on_off_options = [
        ("asserts", "the asserts regardless of the compile mode"),
        ("des-metrics", "Logging all events in a json file with the name of the executable "
                        "(which must call CommandLine::Parse(argc, argv))"
         ),
        ("build-version", "embedding git changes as a build version during build"),
        ("clang-tidy", "clang-tidy static analysis"),
        ("dpdk", "the fd-net-device DPDK features"),
        ("eigen", "Eigen3 library support"),
        ("examples", "the ns-3 examples"),
        ("gcov", "code coverage analysis"),
        ("gsl", "GNU Scientific Library (GSL) features"),
        ("gtk", "GTK support in ConfigStore"),
        ("logs", "the logs regardless of the compile mode"),
        ("monolib", "a single shared library with all ns-3 modules"),
        ("mpi", "the MPI support for distributed simulation"),
        ("ninja-tracing", "the conversion of the Ninja generator log file into about://tracing format"),
        ("precompiled-headers", "precompiled headers"),
        ("python-bindings", "python bindings"),
        ("tests", "the ns-3 tests"),
        ("sanitizers", "address, memory leaks and undefined behavior sanitizers"),
        ("static", "Build a single static library with all ns-3",
         "Restore the shared libraries"
         ),
        ("sudo", "use of sudo to setup suid bits on ns3 executables."),
        ("verbose", "printing of additional build system messages"),
        ("warnings", "compiler warnings"),
        ("werror", "Treat compiler warnings as errors",
         "Treat compiler warnings as warnings"
         ),
    ]
    for on_off_option in on_off_options:
        parser_configure = on_off_argument(parser_configure, *on_off_option)

    parser_configure.add_argument('--enable-modules',
                                  help='List of modules to build (e.g. \"core;network;internet\")',
                                  action="store", type=str, default=None)
    parser_configure.add_argument('--disable-modules',
                                  help='List of modules not to build (e.g. \"lte;wimax\")',
                                  action="store", type=str, default=None)
    parser_configure.add_argument('--filter-module-examples-and-tests',
                                  help=('List of modules that should have their examples '
                                        'and tests built (e.g. \"lte;wifi\")'),
                                  action="store", type=str, default=None)
    parser_configure.add_argument('--lcov-report',
                                  help=('Generate a code coverage report '
                                        '(use this option after configuring with --enable-gcov and running a program)'),
                                  action="store_true", default=None)
    parser_configure.add_argument('--lcov-zerocounters',
                                  help=('Zero the lcov counters'
                                        ' (use this option before rerunning a program'
                                        ' when generating repeated lcov reports)'),
                                  action="store_true", default=None)

    parser_configure.add_argument('--out', '--output-directory',
                                  help=('Directory to store build artifacts'),
                                  type=str, default=None, dest="output_directory")
    parser_configure.add_argument('--with-brite',
                                  help=('Use BRITE integration support, given by the indicated path,'
                                        ' to allow the use of the BRITE topology generator'),
                                  type=str, default=None)
    parser_configure.add_argument('--with-click',
                                  help='Path to Click source or installation prefix for NS-3 Click Integration support',
                                  type=str, default=None)
    parser_configure.add_argument('--with-openflow',
                                  help='Path to OFSID source for NS-3 OpenFlow Integration support',
                                  type=str, default=None)
    parser_configure.add_argument('--force-refresh',
                                  help='Force refresh the CMake cache by deleting'
                                       ' the cache and reconfiguring the project',
                                  action="store_true", default=None)
    parser_configure.add_argument('--prefix',
                                  help='Target output directory to install',
                                  action="store", default=None)
    parser_configure.add_argument('--trace-performance',
                                  help="Generate a performance trace log for the CMake configuration",
                                  action="store_true", default=None, dest="trace_cmake_perf")

    parser_clean = sub_parser.add_parser('clean', help='Removes files created by ns3')
    parser_clean.add_argument('clean', action="store_true", default=False)

    parser_distclean = sub_parser.add_parser('distclean', help='Removes files created by ns3, tests and documentation')
    parser_distclean.add_argument('distclean', action="store_true", default=False)

    parser_install = sub_parser.add_parser('install', help='Install ns-3')
    parser_install.add_argument('install', action="store_true", default=False)

    parser_uninstall = sub_parser.add_parser('uninstall', help='Uninstall ns-3')
    parser_uninstall.add_argument('uninstall', action="store_true", default=False)

    parser_run = sub_parser.add_parser('run',
                                       help='Try "./ns3 run --help" for more runtime options',
                                       formatter_class=argparse.RawTextHelpFormatter)
    parser_run.add_argument('run',
                            help=('Build and run the target executable.\n'
                                  'If --no-build is present, the build step is skipped.\n'
                                  'To get the list of targets, use:\n'
                                  './ns3 show targets\n'
                                  'Arguments can be passed down to a program in one of the following ways:\n'
                                  './ns3 run "target --help"\n'
                                  './ns3 run target -- --help\n'
                                  './ns3 run target --command-template="%%s --help"\n'),
                            default='', nargs='?', metavar='target')
    parser_run.add_argument('--no-build',
                            help='Skip build step.',
                            action="store_true", default=False)
    parser_run.add_argument('--command-template',
                            help=('Template of the command used to run the program given by run;'
                                  ' It should be a shell command string containing %%s inside,'
                                  ' which will be replaced by the actual program.'),
                            type=str, default=None)
    parser_run.add_argument('--cwd',
                            help='Set the working directory for a program.',
                            action="store", type=str, default=None)
    parser_run.add_argument('--gdb',
                            help='Change the default command template to run programs with gdb',
                            action="store_true", default=None)
    parser_run.add_argument('--lldb',
                            help='Change the default command template to run programs with lldb',
                            action="store_true", default=None)
    parser_run.add_argument('-g', '--valgrind',
                            help='Change the default command template to run programs with valgrind',
                            action="store_true", default=None)
    parser_run.add_argument('--memray',
                            help='Use Memray memory profiler for Python scripts. Output will be saved to memray.output',
                            action="store_true", default=None)
    parser_run.add_argument('--heaptrack',
                            help='Use Heaptrack memory profiler for C++',
                            action="store_true", default=None)
    parser_run.add_argument('--perf',
                            help='Use Linux\'s perf to profile a program',
                            action="store_true", default=None)
    parser_run.add_argument('--vis', '--visualize',
                            help='Modify --run arguments to enable the visualizer',
                            action="store_true", dest="visualize", default=None)
    parser_run.add_argument('--enable-sudo',
                            help='Use sudo to setup suid bits on ns3 executables.',
                            dest='enable_sudo', action='store_true',
                            default=False)

    parser_shell = sub_parser.add_parser('shell',
                                         help='Try "./ns3 shell --help" for more shell options')
    parser_shell.add_argument('shell',
                              help='Export necessary environment variables and open a shell',
                              action="store_true", default=False)

    parser_docs = sub_parser.add_parser('docs',
                                        help='Try "./ns3 docs --help" for more documentation options')
    parser_docs.add_argument('docs',
                             help='Build project documentation',
                             choices=["contributing", "installation", "manual", "models", "tutorial",
                                      "sphinx", "doxygen-no-build", "doxygen", "all"],
                             action="store", type=str, default=None)

    parser_show = sub_parser.add_parser('show',
                                        help='Try "./ns3 show --help" for more show options')
    parser_show.add_argument('show',
                             help=('Print the current ns-3 build profile type, configuration or version, '
                                   'or a list of buildable/runnable targets'),
                             choices=["profile", "version", "config", "targets", "all"],
                             action="store", type=str, nargs="?", default="all")

    add_argument_to_subparsers(
        [parser, parser_build, parser_configure, parser_clean, parser_distclean, parser_docs, parser_run, parser_show],
        ["--dry-run"],
        help_msg="Do not execute the commands.",
        dest="dry_run")

    add_argument_to_subparsers([parser, parser_build, parser_run],
                               ['-j', '--jobs'],
                               help_msg="Set number of parallel jobs.",
                               dest="jobs",
                               action="store",
                               default_value=max_cpu_threads)

    add_argument_to_subparsers([parser, parser_build, parser_configure, parser_run, parser_show],
                               ["--quiet"],
                               help_msg="Don't print task lines, i.e. messages saying which tasks are being executed.",
                               dest="quiet")

    add_argument_to_subparsers([parser, parser_build, parser_configure, parser_docs, parser_run],
                               ['-v', '--verbose'],
                               help_msg='Print which commands were executed',
                               dest='verbose',
                               default_value=False)

    # Try to split -- separated arguments into two lists for ns3 and for the runnable target
    try:
        args_separator_index = argv.index('--')
        ns3_args = argv[:args_separator_index]
        runnable_args = argv[args_separator_index + 1:]
    except ValueError:
        ns3_args = argv
        runnable_args = []

    # Parse known arguments and separate from unknown arguments
    args, unknown_args = parser.parse_known_args(ns3_args)

    # If run doesn't have a target, print the help message of the run parser
    if "run" in args and args.run == '':
        parser_run.print_help()
        exit(-1)

    # Merge attributes
    attributes_to_merge = ["dry_run", "help", "verbose", "quiet"]
    filtered_attributes = list(
        filter(lambda x: x if ("disable" not in x and "enable" not in x) else None, args.__dir__()))
    for attribute in attributes_to_merge:
        merging_attributes = list(
            map(lambda x: args.__getattribute__(x) if attribute in x else None, filtered_attributes))
        setattr(args, attribute, merging_attributes.count(True) > 0)

    if args.help:
        print(parser.description)
        print("")
        print(parser.format_usage())

        # retrieve subparsers from parser
        subparsers_actions = [
            action for action in parser._actions
            if isinstance(action, argparse._SubParsersAction)]
        # there will probably only be one subparser_action,
        # but better safe than sorry
        for subparsers_action in subparsers_actions:
            # get all subparsers and print help
            for choice, subparser in subparsers_action.choices.items():
                subcommand = subparser.format_usage()[:-1].replace("usage: ", "   or: ")
                if len(subcommand) > 1:
                    print(subcommand)

        print(parser.format_help().replace(parser.description, "").replace(parser.format_usage(), ""))
        exit(0)

    attributes_to_merge = ["jobs"]
    filtered_attributes = list(filter(lambda x: x if ("disable" not in x and "enable" not in x) else 0, args.__dir__()))
    for attribute in attributes_to_merge:
        merging_attributes = list(
            map(lambda x: int(args.__getattribute__(x)) if attribute in x else max_cpu_threads, filtered_attributes))
        setattr(args, attribute, min(merging_attributes))

    # If some positional options are not in args, set them to false.
    for option in ["clean", "configure", "docs", "install", "run", "shell", "uninstall", "show", "distclean"]:
        if option not in args:
            setattr(args, option, False)

    if args.run and args.enable_sudo is None:
        args.enable_sudo = True

    # Save runnable target arguments
    setattr(args, "program_args", runnable_args)

    # Emit error in case of unknown arguments
    if unknown_args:
        msg = ("Unknown options were given: {options}.\n"
               "To see the allowed options add the `--help` option.\n"
               "To forward configuration or runtime options, put them after '--'.\n")
        if args.run:
            msg += "Try: ./ns3 run {target} -- {options}\n"
        if args.configure:
            msg += "Try: ./ns3 configure -- {options}\n"
        msg = msg.format(options=", ".join(unknown_args), target=args.run)
        raise Exception(msg)
    return args


def check_lock_data(output_directory):
    # Check the .lock-ns3 for the build type (in case there are multiple cmake cache folders
    ns3_modules_tests = []
    ns3_modules = None

    build_info = {"NS3_ENABLED_MODULES": [],
                  "BUILD_PROFILE": None,
                  "VERSION": None,
                  "ENABLE_EXAMPLES": False,
                  "ENABLE_SUDO": False,
                  "ENABLE_TESTS": False,
                  "BUILD_VERSION_STRING": None
                  }
    if output_directory and os.path.exists(lock_file):
        exec(open(lock_file).read(), globals(), build_info)
        ns3_modules = build_info["NS3_ENABLED_MODULES"]
        if ns3_modules:
            ns3_modules.extend(build_info["NS3_ENABLED_CONTRIBUTED_MODULES"])
            if build_info["ENABLE_TESTS"]:
                ns3_modules_tests = [x + "-test" for x in ns3_modules]
            ns3_modules = ns3_modules + ns3_modules_tests
    return build_info, ns3_modules


def print_and_buffer(message):
    global print_buffer
    # print(message)
    print_buffer += "\n" + message


def remove_dir(dir_to_remove, dry_run, directory_qualifier=""):
    dir_to_remove = os.path.abspath(dir_to_remove)
    if os.path.exists(dir_to_remove):
        if (".." in os.path.relpath(dir_to_remove, ns3_path)
            or os.path.abspath(dir_to_remove) == os.path.abspath(ns3_path)):
            # In case the directory to remove isn't within
            # the current ns-3 directory, print an error
            # message for the dry-run case
            # Or throw an exception in a normal run
            error_message = (f"The {directory_qualifier} directory '{dir_to_remove}' "
                             "is not within the current ns-3 directory. "
                             "Deleting it can cause data loss.")
            if dry_run:
                print_and_buffer(error_message)
                return
            else:
                raise Exception(error_message)

        # Remove directories that are within the current ns-3 directory
        print_and_buffer("rm -R %s" % os.path.relpath(dir_to_remove, ns3_path))
        if not dry_run:
            shutil.rmtree(dir_to_remove, ignore_errors=True)


def remove_file(file_to_remove, dry_run):
    if os.path.exists(file_to_remove):
        print_and_buffer("rm -R %s" % os.path.relpath(file_to_remove, ns3_path))
        if not dry_run:
            os.remove(file_to_remove)


def clean_cmake_artifacts(dry_run=False):
    remove_dir(out_dir, dry_run, "output")

    cmake_cache_files = glob.glob("%s/**/CMakeCache.txt" % ns3_path, recursive=True)
    for cmake_cache_file in cmake_cache_files:
        dirname = os.path.dirname(cmake_cache_file)
        remove_dir(dirname, dry_run, "CMake cache")

    dirs_to_remove = [os.path.join(ns3_path, "testpy-output"),
                      os.path.join(ns3_path, "__pycache__")
                      ]
    for dir_to_remove in dirs_to_remove:
        remove_dir(dir_to_remove, dry_run)

    remove_file(lock_file, dry_run)


def clean_docs_and_tests_artifacts(dry_run=False):
    docs_dir = os.path.join(ns3_path, 'doc')

    file_artifacts = ["doxygen.log",
                      "doxygen.warnings.log",
                      "introspected-command-line.h",
                      "introspected-doxygen.h",
                      "ns3-object.txt"]
    docs_files = [os.path.join(docs_dir, filename) for filename in file_artifacts]

    docs_and_tests_dirs = [os.path.join(docs_dir, "html"),
                           os.path.join(docs_dir, "html-warn"),
                           ]
    docs_and_tests_dirs.extend(glob.glob(f"{docs_dir}/**/build", recursive=True))
    docs_and_tests_dirs.extend(glob.glob(f"{docs_dir}/**/source-temp", recursive=True))

    for directory in docs_and_tests_dirs:
        remove_dir(directory, dry_run)

    for file in docs_files:
        remove_file(file, dry_run)


def clean_pip_packaging_artifacts(dry_run=False):
    pip_dirs = [os.path.join(ns3_path, "dist"),
                os.path.join(ns3_path, "nsnam.egg-info"),
                os.path.join(ns3_path, "wheelhouse")
                ]
    for directory in pip_dirs:
        remove_dir(directory, dry_run)


def clean_vcpkg_artifacts(dry_run=False):
    remove_dir(os.path.join(ns3_path, "vcpkg"), dry_run)


def search_cmake_cache(build_profile):
    # Search for the CMake cache
    cmake_cache_files = glob.glob("%s/**/CMakeCache.txt" % ns3_path, recursive=True)
    current_cmake_cache_folder = None
    current_cmake_generator = None

    if cmake_cache_files:
        # In case there are multiple cache files, get the correct one
        for cmake_cache_file in cmake_cache_files:
            # We found the right cache folder
            if current_cmake_cache_folder and current_cmake_generator:
                break

            # Still looking for it
            current_cmake_cache_folder = None
            current_cmake_generator = None
            with open(cmake_cache_file, "r") as f:
                lines = f.read().split("\n")

            while len(lines):
                line = lines[0]
                lines.pop(0)

                # Check for EOF
                if current_cmake_cache_folder and current_cmake_generator:
                    break

                # Check the build profile
                if "build_profile:INTERNAL" in line:
                    if build_profile:
                        if build_profile == line.split("=")[-1]:
                            current_cmake_cache_folder = os.path.dirname(cmake_cache_file)
                    else:
                        current_cmake_cache_folder = os.path.dirname(cmake_cache_file)

                # Check the generator
                if "CMAKE_GENERATOR:" in line:
                    current_cmake_generator = line.split("=")[-1]

    if not current_cmake_generator:
        # Search for available generators
        cmake_generator_map = {"ninja": "Ninja",
                               "make": "Unix Makefiles",
                               "xcodebuild": "Xcode"
                               }
        available_generators = []
        for generator in cmake_generator_map.keys():
            if shutil.which(generator):
                available_generators.append(generator)

        # Select the first one
        if len(available_generators) == 0:
            raise Exception("No generator available.")

        current_cmake_generator = cmake_generator_map[available_generators[0]]

    return current_cmake_cache_folder, current_cmake_generator


def project_not_configured(config_msg=""):
    print("You need to configure ns-3 first: try ./ns3 configure%s" % config_msg)
    exit(1)


def check_config(current_cmake_cache_folder):
    if current_cmake_cache_folder is None:
        project_not_configured()
    config_table = current_cmake_cache_folder + os.sep + "ns3config.txt"
    if not os.path.exists(config_table):
        project_not_configured()
    with open(config_table, "r") as f:
        print(f.read())


def project_configured(current_cmake_cache_folder):
    if not current_cmake_cache_folder:
        return False
    if not os.path.exists(current_cmake_cache_folder):
        return False
    if not os.path.exists(os.sep.join([current_cmake_cache_folder, "CMakeCache.txt"])):
        return False
    return True


def configure_cmake(cmake, args, current_cmake_cache_folder, current_cmake_generator, output, dry_run=False):
    # Aggregate all flags to configure CMake
    cmake_args = [cmake]

    if not project_configured(current_cmake_cache_folder):
        # Create a new cmake_cache folder if one does not exist
        current_cmake_cache_folder = os.sep.join([ns3_path, "cmake-cache"])
        if not os.path.exists(current_cmake_cache_folder):
            print_and_buffer("mkdir %s" % os.path.relpath(current_cmake_cache_folder, ns3_path))
            if not dry_run:
                os.makedirs(current_cmake_cache_folder, exist_ok=True)

        # Set default build type to default if a previous cache doesn't exist
        if args.build_profile is None:
            args.build_profile = "default"

        # Set generator if a previous cache doesn't exist
        if args.G is None:
            args.G = current_cmake_generator

        # Get the current Python information to supply
        # CMake with the respective installation
        if args.enable_python_bindings is True:
            import sysconfig
            cmake_args.append(f"-DPython3_LIBRARY_DIRS={sysconfig.get_config_var('LIBDIR')}")
            cmake_args.append(f"-DPython3_INCLUDE_DIRS={sysconfig.get_config_var('INCLUDEPY')}")
            cmake_args.append(f"-DPython3_EXECUTABLE={sys.executable}")

    # C++ standard
    if args.cxx_standard is not None:
        cmake_args.append("-DCMAKE_CXX_STANDARD=%s" % args.cxx_standard)

    # Build type
    if args.build_profile is not None:
        args.build_profile = args.build_profile.lower()
        if args.build_profile not in ["debug", "default", "release", "optimized", "minsizerel", "relwithdebinfo"]:
            raise Exception("Unknown build type")
        else:
            if args.build_profile == "debug":
                cmake_args.extend(
                    "-DCMAKE_BUILD_TYPE=debug -DNS3_ASSERT=ON -DNS3_LOG=ON -DNS3_WARNINGS_AS_ERRORS=ON".split())
            elif args.build_profile in ["default", "relwithdebinfo"]:
                cmake_args.extend(
                    "-DCMAKE_BUILD_TYPE=default -DNS3_ASSERT=ON -DNS3_LOG=ON -DNS3_WARNINGS_AS_ERRORS=OFF".split())
            elif args.build_profile in ["release", "optimized"]:
                cmake_args.extend(
                    "-DCMAKE_BUILD_TYPE=release -DNS3_ASSERT=OFF -DNS3_LOG=OFF -DNS3_WARNINGS_AS_ERRORS=OFF".split())
            else:
                cmake_args.extend(
                    "-DCMAKE_BUILD_TYPE=minsizerel -DNS3_ASSERT=OFF -DNS3_LOG=OFF -DNS3_WARNINGS_AS_ERRORS=OFF".split()
                )
            cmake_args.append("-DNS3_NATIVE_OPTIMIZATIONS=%s" % on_off((args.build_profile == "optimized")))

    options = (("ASSERT", "asserts"),
               ("CLANG_TIDY", "clang_tidy"),
               ("COVERAGE", "gcov"),
               ("DES_METRICS", "des_metrics"),
               ("DPDK", "dpdk"),
               ("EIGEN", "eigen"),
               ("ENABLE_BUILD_VERSION", "build_version"),
               ("ENABLE_SUDO", "sudo"),
               ("EXAMPLES", "examples"),
               ("GSL", "gsl"),
               ("GTK3", "gtk"),
               ("LOG", "logs"),
               ("MONOLIB", "monolib"),
               ("MPI", "mpi"),
               ("NINJA_TRACING", "ninja_tracing"),
               ("PRECOMPILE_HEADERS", "precompiled_headers"),
               ("PYTHON_BINDINGS", "python_bindings"),
               ("SANITIZE", "sanitizers"),
               ("STATIC", "static"),
               ("TESTS", "tests"),
               ("VERBOSE", "verbose"),
               ("WARNINGS", "warnings"),
               ("WARNINGS_AS_ERRORS", "werror"),
               )
    for (cmake_flag, option_name) in options:
        arg = on_off_condition(args, cmake_flag, option_name)
        if arg:
            is_on = "=ON" in arg
            reverse = arg.replace("=ON" if is_on else "=OFF",
                                  "=OFF" if is_on else "=ON")
            if reverse in cmake_args:
                cmake_args.remove(reverse)
            cmake_args.append(arg)

    if args.lcov_zerocounters is not None:
        cmake_args.append("-DNS3_COVERAGE_ZERO_COUNTERS=%s" % on_off(args.lcov_zerocounters))

    # Output, Brite, Click and Openflow dirs
    if args.output_directory is not None:
        cmake_args.append("-DNS3_OUTPUT_DIRECTORY=%s" % args.output_directory)

    if args.with_brite is not None:
        cmake_args.append("-DNS3_WITH_BRITE=%s" % args.with_brite)

    if args.with_click is not None:
        cmake_args.append("-DNS3_WITH_CLICK=%s" % args.with_click)

    if args.with_openflow is not None:
        cmake_args.append("-DNS3_WITH_OPENFLOW=%s" % args.with_openflow)

    if args.prefix is not None:
        cmake_args.append("-DCMAKE_INSTALL_PREFIX=%s" % args.prefix)

    # Process enabled/disabled modules
    if args.enable_modules is not None:
        cmake_args.append("-DNS3_ENABLED_MODULES=%s" % args.enable_modules)

    if args.disable_modules is not None:
        cmake_args.append("-DNS3_DISABLED_MODULES=%s" % args.disable_modules)

    if args.filter_module_examples_and_tests is not None:
        cmake_args.append("-DNS3_FILTER_MODULE_EXAMPLES_AND_TESTS=%s" % args.filter_module_examples_and_tests)

    # Try to set specified generator (will probably fail if there is an old cache)
    if args.G:
        cmake_args.extend(["-G", args.G])

    if args.trace_cmake_perf:
        cmake_performance_trace = os.path.join(os.path.relpath(ns3_path, current_cmake_cache_folder),
                                               "cmake_performance_trace.log")
        cmake_args.extend(["--profiling-format=google-trace",
                           "--profiling-output=" + cmake_performance_trace])

    # Append CMake flags passed using the -- separator
    cmake_args.extend(args.program_args)

    # Configure cmake
    cmake_args.append("..")  # for now, assuming the cmake_cache directory is inside the ns-3-dev folder

    # Echo out the configure command
    print_and_buffer("cd %s; %s ; cd %s" % (os.path.relpath(current_cmake_cache_folder, ns3_path),
                                            " ".join(cmake_args),
                                            os.path.relpath(ns3_path, current_cmake_cache_folder)
                                            )
                     )

    # Run cmake
    if not dry_run:
        proc_env = os.environ.copy()
        ret = subprocess.run(cmake_args, cwd=current_cmake_cache_folder, stdout=output, env=proc_env)
        if ret.returncode != 0:
            exit(ret.returncode)

        update_scratches_list(current_cmake_cache_folder)


def update_scratches_list(current_cmake_cache_folder):
    # Store list of scratches to trigger a reconfiguration step if needed
    current_scratch_sources = glob.glob(os.path.join(ns3_path, "scratch", "**", "*.cc"), recursive=True)
    with open(os.path.join(current_cmake_cache_folder, "ns3scratches"), "w") as f:
        f.write("\n".join(current_scratch_sources))


def refresh_cmake(current_cmake_cache_folder, output):
    cmake, _ = cmake_check_version()
    ret = subprocess.run([cmake, ".."], cwd=current_cmake_cache_folder, stdout=output)
    if ret.returncode != 0:
        exit(ret.returncode)
    update_scratches_list(current_cmake_cache_folder)


def get_program_shortcuts(build_profile, ns3_version):
    # Import programs from .lock-ns3
    programs_dict = {}
    exec(open(lock_file).read(), globals(), programs_dict)

    # We can now build a map to simplify things for users (at this point we could remove versioning prefix/suffix)
    ns3_program_map = {}
    longest_shortcut_map = {}

    for program in programs_dict["ns3_runnable_programs"]:
        if "pch_exec" in program:
            continue
        temp_path = program.replace(out_dir, "")
        # Sometimes Windows uses \\, sometimes /
        # quite the mess
        temp_path = temp_path.split(os.sep if os.sep in temp_path else '/')
        temp_path.pop(0)  # remove first path separator

        # Remove version prefix and build type suffix from shortcuts (or keep them too?)
        temp_path[-1] = temp_path[-1].replace("-" + build_profile, "").replace("ns" + ns3_version + "-", "")

        # Deal with scratch subdirs
        if "scratch" in temp_path and len(temp_path) > 3:
            subdir = "_".join([*temp_path[2:-1], ""])
            temp_path[-1] = temp_path[-1].replace(subdir, "")

        # Check if there is a .cc file for that specific program
        source_file_path = os.sep.join(temp_path) + ".cc"
        source_shortcut = False
        if os.path.exists(os.path.join(ns3_path, source_file_path)):
            source_shortcut = True

        program = program.strip()
        longest_shortcut = None
        while len(temp_path):
            # Shortcuts: /src/aodv/examples/aodv can be accessed with aodv/examples/aodv, examples/aodv, aodv
            shortcut_path = os.sep.join(temp_path)
            if not longest_shortcut:
                longest_shortcut = shortcut_path

            # Store longest shortcut path for collisions
            if shortcut_path not in longest_shortcut_map:
                longest_shortcut_map[shortcut_path] = [longest_shortcut]
            else:
                longest_shortcut_map[shortcut_path].append(longest_shortcut)

            ns3_program_map[shortcut_path] = [program]

            # Add a shortcut with .exe suffix when running on Windows
            if sys.platform == "win32":
                ns3_program_map[shortcut_path.replace("\\", "/")] = [program]
                ns3_program_map[shortcut_path + ".exe"] = [program]
                ns3_program_map[shortcut_path.replace("\\", "/") + ".exe"] = [program]

            if source_shortcut:
                cc_shortcut_path = shortcut_path + ".cc"
                ns3_program_map[cc_shortcut_path] = [program]
                if sys.platform == "win32":
                    ns3_program_map[cc_shortcut_path] = [program]
                    ns3_program_map[cc_shortcut_path.replace("\\", "/")] = [program]

                # Store longest shortcut path for collisions
                if cc_shortcut_path not in longest_shortcut_map:
                    longest_shortcut_map[cc_shortcut_path] = [longest_shortcut]
                else:
                    longest_shortcut_map[cc_shortcut_path].append(longest_shortcut)
            temp_path.pop(0)

    # Filter collisions
    collisions = list(filter(lambda x: x if len(x[1]) > 1 else None, longest_shortcut_map.items()))
    for (colliding_shortcut, longest_shortcuts) in collisions:
        ns3_program_map[colliding_shortcut] = longest_shortcuts

    if programs_dict["ns3_runnable_scripts"]:
        scratch_scripts = glob.glob(os.path.join(ns3_path, "scratch", "*.py"), recursive=True)
        programs_dict["ns3_runnable_scripts"].extend(scratch_scripts)

    for program in programs_dict["ns3_runnable_scripts"]:
        temp_path = program.replace(ns3_path, "").split(os.sep)
        program = program.strip()
        while len(temp_path):
            shortcut_path = os.sep.join(temp_path)
            ns3_program_map[shortcut_path] = [program]
            temp_path.pop(0)
    return ns3_program_map


def parse_version(version_str):
    version = version_str.split(".")
    version = tuple(map(int, version))
    return version


def cmake_check_version():
    # Check CMake version
    cmake3 = shutil.which("cmake3")
    cmake = cmake3 if cmake3 else shutil.which("cmake")
    if not cmake:
        print("Error:  CMake not found; please install version 3.10 or greater, or modify", path_variable)
        exit(1)
    cmake = cmake.replace(".EXE", "").replace(".exe", "")  # Trim cmake executable extension
    cmake_output = subprocess.check_output([cmake, "--version"]).decode("utf-8")
    version = re.findall("version (.*)", cmake_output)[0]
    if parse_version(version) < parse_version("3.10.0"):
        print("Error:  CMake found at %s but version %s is older than 3.10" % (cmake, version))
        exit(1)
    return cmake, version


def cmake_build(current_cmake_cache_folder, output, jobs, target=None, dry_run=False, build_verbose=False):
    cmake, version = cmake_check_version()

    # Older CMake versions don't accept the number of jobs directly
    jobs_part = ("-j %d" % jobs) if parse_version(version) >= parse_version("3.12.0") else ""
    target_part = (" --target %s" % target) if target else ""
    cmake_build_command = "%s --build . %s%s" % (cmake, jobs_part, target_part)

    print_and_buffer("cd %s; %s ; cd %s" % (os.path.relpath(current_cmake_cache_folder, ns3_path),
                                            cmake_build_command,
                                            os.path.relpath(ns3_path, current_cmake_cache_folder)
                                            )
                     )
    if not dry_run:
        # Assume quiet is not enabled, and print things normally
        kwargs = {"stdout": None,
                  "stderr": None}

        proc_env = os.environ.copy()
        if build_verbose:
            # If verbose is enabled, we print everything to the terminal
            # and set the environment variable
            proc_env.update({"VERBOSE": "1"})

        if output is not None:
            # If quiet is enabled, we pipe the output of the
            # build and only print in case of failure
            kwargs["stdout"] = subprocess.PIPE
            kwargs["stderr"] = subprocess.PIPE

        ret = subprocess.run(cmake_build_command.split(),
                             cwd=current_cmake_cache_folder,
                             env=proc_env,
                             **kwargs,
                             )

        # Print errors in case compilation fails and output != None (quiet)
        if ret.returncode != 0 and output is not None:
            print(ret.stdout.decode())
            print(ret.stderr.decode())

        # In case of failure, exit prematurely with the return code from the build
        if ret.returncode != 0:
            exit(ret.returncode)


def extract_cmakecache_settings(current_cmake_cache_folder):
    try:
        with open(current_cmake_cache_folder + os.sep + "CMakeCache.txt", "r", encoding="utf-8") as f:
            contents = f.read()
    except FileNotFoundError as e:
        raise e
    current_settings = re.findall("(NS3_.*):.*=(.*)", contents)  # extract NS3 specific settings
    current_settings.extend(re.findall("(CMAKE_BUILD_TYPE):.*=(.*)", contents))  # extract build type
    current_settings.extend(re.findall("(CMAKE_GENERATOR):.*=(.*)", contents))  # extract generator
    current_settings.extend(re.findall("(CMAKE_CXX_COMPILER):.*=(.*)", contents))  # C++ compiler
    current_settings.extend(re.findall("(CMAKE_CXX_FLAGS):.*=(.*)", contents))  # C++ flags
    current_settings.extend(re.findall("(CMAKE_C_COMPILER):.*=(.*)", contents))  # C compiler
    current_settings.extend(re.findall("(CMAKE_C_FLAGS):.*=(.*)", contents))  # C flags
    current_settings.extend(re.findall("(CMAKE_INSTALL_PREFIX):.*=(.*)", contents))  # installation directory

    # Transform list into dictionary
    settings_dictionary = dict(current_settings)
    del settings_dictionary["NS3_INT64X64-STRINGS"]  # remove cached options or CMake will warn you

    # Return dictionary with NS3-related CMake settings
    return settings_dictionary


def reconfigure_cmake_to_force_refresh(cmake, current_cmake_cache_folder, output, dry_run=False):
    import json
    settings_bak_file = "settings.json"

    # Extract settings or recover from the backup
    if not os.path.exists(settings_bak_file):
        settings = extract_cmakecache_settings(current_cmake_cache_folder)
    else:
        with open(settings_bak_file, "r", encoding="utf-8") as f:
            settings = json.load(f)

    # Delete cache folder and then recreate it
    cache_path = os.path.relpath(current_cmake_cache_folder, ns3_path)
    print_and_buffer("rm -R %s; mkdir %s" % (cache_path, cache_path))
    if not dry_run:
        shutil.rmtree(current_cmake_cache_folder)
        os.mkdir(current_cmake_cache_folder)

    # Save settings backup to prevent loss
    with open(settings_bak_file, "w", encoding="utf-8") as f:
        json.dump(settings, f, indent=2)

    # Reconfigure CMake preserving previous NS3 settings
    cmake_args = [cmake]
    for setting in settings.items():
        if setting[1]:
            cmake_args.append("-D%s=%s" % setting)
    cmake_args.append("..")

    # Echo out the configure command
    print_and_buffer("cd %s; %s ; cd %s" % (os.path.relpath(ns3_path, current_cmake_cache_folder),
                                            " ".join(cmake_args),
                                            os.path.relpath(current_cmake_cache_folder, ns3_path)
                                            )
                     )

    # Call cmake
    if not dry_run:
        ret = subprocess.run(cmake_args, cwd=current_cmake_cache_folder, stdout=output)

        # If it succeeds, delete backup, otherwise raise exception
        if ret.returncode == 0:
            os.remove(settings_bak_file)
        else:
            raise Exception("Reconfiguring CMake to force refresh failed. "
                            "A backup of the settings was saved in %s" % settings_bak_file)

        update_scratches_list(current_cmake_cache_folder)


def get_target_to_build(program_path, ns3_version, build_profile):
    if ".py" in program_path:
        return None

    build_profile_suffix = "" if build_profile in ["release"] else "-" + build_profile
    program_name = ""

    try:
        program_name = "".join(*re.findall("(.*)ns%s-(.*)%s" % (ns3_version, build_profile_suffix), program_path))
    except TypeError:
        print("Target to build does not exist: %s" % program_path)
        exit(1)

    if "scratch" in program_path:
        # Get the path to the program and replace slashes with underlines
        # to get unique targets for CMake, preventing collisions with modules examples
        return program_name.replace(out_dir, "").replace("/", "_")[1:]
    else:
        # Other programs just use their normal names (without version prefix and build_profile suffix) as targets
        return program_name.split("/")[-1]


def configuration_step(current_cmake_cache_folder, current_cmake_generator, args,
                       output, dry_run=False):
    # Search for the CMake binary
    cmake, _ = cmake_check_version()

    # If --force-refresh, we load settings from the CMakeCache, delete it, then reconfigure CMake to
    #   force refresh cached packages/libraries that were installed/removed, without losing the current settings
    if args.force_refresh:
        reconfigure_cmake_to_force_refresh(cmake, current_cmake_cache_folder, output, dry_run)
        exit(0)

    # Call cmake to configure/reconfigure/refresh the project
    configure_cmake(cmake,
                    args,
                    current_cmake_cache_folder,
                    current_cmake_generator,
                    output,
                    dry_run
                    )

    # If manually configuring, we end the script earlier
    exit(0)


def build_step(args,
               build_and_run,
               target_to_run,
               current_cmake_cache_folder,
               ns3_modules,
               ns3_version,
               build_profile,
               output):
    # There is one scenario where we build everything: ./ns3 build
    if "build" in args and len(args.build) == 0:
        cmake_build(current_cmake_cache_folder,
                    jobs=args.jobs,
                    output=output,
                    dry_run=args.dry_run,
                    build_verbose=args.verbose
                    )

    # If we are building specific targets, we build them one by one
    if "build" in args:
        non_executable_targets = ["assemble-introspected-command-line",
                                  "check-version",
                                  "cmake-format",
                                  "coverage_gcc",
                                  "docs",
                                  "doxygen",
                                  "doxygen-no-build",
                                  "installation",
                                  "sphinx",
                                  "manual",
                                  "models",
                                  "ninjaTrace",
                                  "timeTraceReport",
                                  "tutorial",
                                  "contributing",
                                  "install",
                                  "uninstall",
                                  ]
        # Build targets in the list
        for target in args.build:
            if target in ns3_modules:
                target = "lib" + target
            elif target not in non_executable_targets:
                target = get_target_to_build(target, ns3_version, build_profile)
            else:
                # Sphinx target should have the sphinx prefix
                if target in ["contributing", "installation", "manual", "models", "tutorial"]:
                    target = "sphinx_%s" % target

                # Docs should build both doxygen and sphinx based docs
                if target == "docs":
                    target = "sphinx"
                    args.build.append("doxygen")

                if target == "check-version":
                    global run_verbose
                    run_verbose = False  # Do not print the equivalent cmake command

            cmake_build(current_cmake_cache_folder,
                        jobs=args.jobs,
                        target=target,
                        output=output,
                        dry_run=args.dry_run,
                        build_verbose=args.verbose)

    # The remaining case is when we want to build something to run
    if build_and_run:
        cmake_build(current_cmake_cache_folder,
                    jobs=args.jobs,
                    target=get_target_to_build(target_to_run, ns3_version, build_profile),
                    output=output,
                    dry_run=args.dry_run,
                    build_verbose=args.verbose
                    )


def check_program_installed(program_name: str) -> str:
    program_path = shutil.which(program_name)
    if program_path is None:
        print("Executable '{program}' was not found".format(program=program_name.capitalize()))
        exit(-1)
    return program_path


def check_module_installed(module_name: str):
    import importlib
    try:
        importlib.import_module(module_name)
    except ImportError:
        print("Python module '{module}' was not found".format(module=module_name))
        exit(-1)


def run_step(args, target_to_run, target_args):
    libdir = "%s/lib" % out_dir

    custom_env = {"PATH": libdir,
                  "PYTHONPATH": "%s/bindings/python" % out_dir,
                  }
    if sys.platform != "win32":
        custom_env["LD_LIBRARY_PATH"] = libdir

    proc_env = os.environ.copy()
    for (key, value) in custom_env.items():
        if key in proc_env:
            proc_env[key] += path_sep + value
        else:
            proc_env[key] = value

    debugging_software = []
    working_dir = ns3_path
    use_shell = False
    target_args += args.program_args

    if args.shell:
        target_to_run = "bash"
        use_shell = True
    else:
        # running a python script?
        if ".py" in target_to_run:
            target_args = [target_to_run] + target_args
            target_to_run = "python3"

            # running with memray?
            if args.memray:
                check_module_installed("memray")
                target_args = ["-m", "memray", "run", "-o", "memray.output", "--native"] + target_args

        # running from ns-3-dev (ns3_path) or cwd
        if args.cwd:
            working_dir = args.cwd

        # running with heaptrack?
        if args.heaptrack:
            debugging_software.append(check_program_installed("heaptrack"))

        # running valgrind?
        if args.valgrind:
            debugging_software.extend(
                [check_program_installed("valgrind"), "--leak-check=full", "--show-leak-kinds=all"])

        # running gdb?
        if args.gdb:
            gdb_eval_command = []
            if os.getenv("gdb_eval"):
                gdb_eval_command.append("--eval-command=quit")
            debugging_software.extend([check_program_installed("gdb"), *gdb_eval_command, "--args"])

        # running lldb?
        if args.lldb:
            debugging_software.extend([check_program_installed("lldb"), "--"])

        # running with perf?
        if args.perf:
            debugging_software.extend([
                check_program_installed("perf"),
                "record", "--call-graph", "dwarf", "-e",
                "cache-misses,branch-misses,cpu-cycles,stalled-cycles-frontend,stalled-cycles-backend"
            ])

        # running with the visualizer?
        if args.visualize:
            target_args.append("--SimulatorImplementationType=ns3::VisualSimulatorImpl")

        # running with command template?
        if args.command_template:
            commands = (args.command_template % target_to_run).split()
            check_program_installed(commands[0])
            target_to_run = commands[0]
            target_args = commands[1:] + target_args

            # running mpi on the CI?
            if target_to_run in ["mpiexec", "mpirun"] and os.getenv("MPI_CI"):
                if shutil.which("ompi_info"):
                    target_args = ["--oversubscribe"] + target_args
                target_args = ["--allow-run-as-root"] + target_args

    program_arguments = [*debugging_software, target_to_run, *target_args]

    if run_verbose or args.dry_run:
        exported_variables = "export "
        for (variable, value) in custom_env.items():
            if variable == "PATH":
                value = path_variable + path_sep + libdir
            exported_variables += "%s=%s " % (variable, value)
        print_and_buffer("cd %s; %s; %s" % (os.path.relpath(ns3_path, working_dir),
                                            exported_variables,
                                            " ".join(program_arguments)
                                            )
                         )

    if not args.dry_run:
        try:
            subprocess.run(program_arguments, env=proc_env, cwd=working_dir, shell=use_shell, check=True)
        except subprocess.CalledProcessError as e:
            # Replace list of arguments with a single string
            e.cmd = " ".join(e.cmd)
            # Replace full path to binary to relative path
            e.cmd = e.cmd.replace(os.path.abspath(target_to_run), os.path.relpath(target_to_run, ns3_path))
            # Print error message and forward the return code
            print(e)
            exit(e.returncode)
        except KeyboardInterrupt:
            print("Process was interrupted by the user")

        # Exit normally
        exit(0)


def non_ambiguous_program_target_list(programs: dict) -> list:
    # Assembles a dictionary of all the possible shortcuts a program have
    list_of_shortcuts = {}
    for (shortcut, possible_programs) in programs.items():
        if len(possible_programs) == 1:
            if possible_programs[0] not in list_of_shortcuts:
                list_of_shortcuts[possible_programs[0]] = [shortcut]
            else:
                list_of_shortcuts[possible_programs[0]].append(shortcut)
    # Select the shortest non-ambiguous shortcut for each program
    final_list = []
    for shortcuts in list_of_shortcuts.values():
        final_list.append(sorted(shortcuts, key=lambda x: len(x))[0])
    return final_list


def print_targets_list(ns3_modules: list, ns3_programs: dict) -> None:
    def list_to_table(targets_list: list) -> str:
        # Set column width and check how much is space is left at the end
        columnwidth = 30
        try:
            terminal_width = os.get_terminal_size().columns
        except OSError:
            terminal_width = 80  # assume 80 columns when grepping
        dead_space = terminal_width % columnwidth

        # Filter the targets with names longer than the column width
        large_items = list(filter(lambda x: len(x) >= columnwidth, targets_list))

        # Then filter the targets with names shorter than the column width
        small_items = sorted(list(set(targets_list) - set(large_items)))

        prev_new_line = 0
        output = "\n"
        for item in small_items:
            current_end = len(output)
            # If the terminal width minus the written columns is smaller than the dead space,
            # we add a new line and start counting the width of the new line from it
            if terminal_width - (current_end - prev_new_line) < dead_space:
                prev_new_line = len(output)
                output += "\n"
            # After the new line or space, add the item plus some spacing
            output += item + " " * (columnwidth - len(item))
        # Add a new line in case we did not fill all the columns
        # of the last small item line
        if len(output) - prev_new_line > 0:
            output += "\n"

        # The list of large items is printed next
        for large_item in sorted(large_items):
            output += large_item + "\n"
        return output

    print("""Buildable targets:{buildables}\n\nRunnable/Buildable targets:{runnables}
                  """.format(buildables=list_to_table(sorted(ns3_modules)),
                             runnables=list_to_table(non_ambiguous_program_target_list(ns3_programs))
                             )
          )
    return


def show_profile(build_profile, exit_early=True):
    if build_profile:
        print("Build profile: %s" % build_profile)
    else:
        project_not_configured()

    if exit_early:
        exit(0)


def show_build_version(build_version_string, exit_early=True):
    if build_version_string is None:
        project_not_configured()

    if build_version_string == '' and shutil.which("git") and os.path.exists(os.path.join(ns3_path, ".git")):
        try:
            build_version_string = subprocess.check_output(["git", "describe", "--dirty"], cwd=ns3_path).decode()
            build_version_string += ("Reconfigure with './ns3 configure --enable-build-version' "
                                     "to bake the version into the libraries.")
        except subprocess.CalledProcessError:
            pass

    if build_version_string == '':
        print("Build version feature disabled. Reconfigure ns-3 with ./ns3 configure --enable-build-version")
    else:
        print("ns-3 version: %s" % build_version_string)

    if exit_early:
        exit(0)


# Debugging this with PyCharm is a no no. It refuses to work hanging indefinitely
def sudo_command(command: list, password: str):
    # Run command and feed the sudo password
    proc = subprocess.Popen(['sudo', '-S', *command],
                            stdin=subprocess.PIPE,
                            stdout=subprocess.PIPE,
                            stderr=subprocess.PIPE
                            ).communicate(input=password.encode() + b'\n')
    stdout, stderr = proc[0].decode(), proc[1].decode()

    # Clean sudo password after each command
    subprocess.Popen(["sudo", "-k"],
                     stdin=subprocess.PIPE,
                     stdout=subprocess.PIPE,
                     stderr=subprocess.PIPE).communicate()

    # Check if the password is wrong
    if "try again" in stderr:
        raise Exception("Incorrect sudo password")

    return stdout, stderr


def sudo_step(args, target_to_run, configure_post_build: set):
    # Check if sudo exists
    sudo = shutil.which("sudo")
    if not sudo:
        raise Exception("Sudo is required by --enable-sudo, but it was not found")

    # We do this for specified targets if --enable-sudo was set in the run sub-parser
    # And to all executables if set in the 'configure' sub-parser
    targets_to_sudo = configure_post_build
    if target_to_run:
        targets_to_sudo.add(target_to_run)

    password = os.getenv("SUDO_PASSWORD", None)
    if not args.dry_run:
        if password is None:
            from getpass import getpass
            password = getpass(prompt="Sudo password:")

    import stat
    for target in targets_to_sudo:
        # Check if the file was already built
        if not os.path.exists(target):
            continue

        # Check if we need to set anything
        fstat = os.stat(target)
        if (fstat.st_mode & stat.S_ISUID) == stat.S_ISUID:
            continue

        # Log commands
        relative_path_to_target = os.path.relpath(target, ns3_path)
        chown_command = "chown root {}".format(relative_path_to_target)
        chmod_command = "chmod u+s {}".format(relative_path_to_target)
        print_and_buffer("; ".join([chown_command, chmod_command]))

        # Change permissions
        if not args.dry_run:
            out, err = sudo_command(chown_command.split(), password)
            if len(out) > 0:
                raise Exception("Failed to chown: ", relative_path_to_target)

            out, err = sudo_command(chmod_command.split(), password)
            if len(out) > 0:
                raise Exception("Failed to chmod: ", relative_path_to_target)
    return


def refuse_run_as_root():
    # Check if the user is root and refuse to run
    username = os.getenv("USER", "")
    if username == "root":
        raise Exception("Refusing to run as root. --enable-sudo will request your password when needed")


def main():
    global out_dir, run_verbose

    # Refuse to run with sudo
    refuse_run_as_root()

    # Enable colorized output for CMake and GCC/Clang
    if os.getenv("CLICOLOR") is None:
        os.environ["CLICOLOR"] = "1"

    # If pybindgen exists in the parent directory
    # (e.g. ns3-all-in-one), add it to the PYTHONPATH
    pybindgen_dir = glob.glob(os.path.abspath(os.path.join(ns3_path, "..", "pybindgen*")))
    if pybindgen_dir:
        if "PYTHONPATH" not in os.environ:
            os.environ["PYTHONPATH"] = ""
        os.environ["PYTHONPATH"] += path_sep + pybindgen_dir[0]

    # Parse arguments
    args = parse_args(sys.argv[1:])
    atexit.register(exit_handler, dry_run=args.dry_run)
    output = subprocess.DEVNULL if args.quiet else None

    # no arguments were passed, so can't possibly be reconfiguring anything, then we refresh and rebuild
    if len(sys.argv) == 1:
        args.build = []

    # Read contents from lock (output directory is important)
    if os.path.exists(lock_file):
        exec(open(lock_file).read(), globals())

    # Clean project if needed
    if args.clean:
        clean_cmake_artifacts(dry_run=args.dry_run)
        # We end things earlier when cleaning
        return

    if args.distclean:
        clean_cmake_artifacts(dry_run=args.dry_run)
        clean_docs_and_tests_artifacts(dry_run=args.dry_run)
        clean_pip_packaging_artifacts(dry_run=args.dry_run)
        clean_vcpkg_artifacts(dry_run=args.dry_run)
        # We end things earlier when cleaning
        return

    # Installation and uninstallation options become cmake targets
    if args.install:
        args.build = ['install']
    if args.uninstall:
        args.build = ['uninstall']

    # Get build profile and other settings
    build_info, ns3_modules = check_lock_data(out_dir)
    build_profile = build_info["BUILD_PROFILE"]
    build_version_string = build_info["BUILD_VERSION_STRING"]
    enable_sudo = build_info["ENABLE_SUDO"]
    ns3_version = build_info["VERSION"]

    # Docs subparser options become cmake targets
    if args.docs:
        args.build = [args.docs] if args.docs != "all" else ["sphinx", "doxygen"]
        if "doxygen" in args.build and (not build_info["ENABLE_EXAMPLES"] or not build_info["ENABLE_TESTS"]):
            print('The "./ns3 docs doxygen" and "./ns3 docs all" commands,\n'
                  'requires examples and tests to generate introspected documentation.\n'
                  'Try "./ns3 docs doxygen-no-build" or enable examples and tests.')
            exit(1)

    if args.show == "profile":
        show_profile(build_profile)

    if args.show == "version":
        show_build_version(build_version_string)

    # Check if running something or reconfiguring ns-3
    run_only = False
    build_and_run = False
    if args.run:
        # Only print "Finished running..." if verbose is set
        run_verbose = not (args.run_verbose is not True)

        # Check whether we are only running or we need to build first
        if args.no_build:
            run_only = True
        else:
            build_and_run = True
    target_to_run = None
    target_args = []
    current_cmake_cache_folder = None
    if run_only or build_and_run:
        target_to_run = args.run
        if len(target_to_run) > 0:
            # While testing a weird case appeared where the target to run is between quotes,
            # so we remove in case they exist
            if target_to_run[0] in ["\"", "'"] and target_to_run[-1] in ["\"", "'"]:
                target_to_run = target_to_run[1:-1]
            target_to_run = target_to_run.split()
            target_to_run, target_args = target_to_run[0], target_to_run[1:]
        else:
            raise Exception("You need to specify a program to run")

    if not run_only:
        # Get current CMake cache folder and CMake generator (used when reconfiguring)
        current_cmake_cache_folder, current_cmake_generator = search_cmake_cache(build_profile)

        if args.show == "config":
            check_config(current_cmake_cache_folder)
            # We end things earlier if only checking the current project configuration
            exit(0)

        # Check for changes in scratch sources and trigger a reconfiguration if sources changed
        if current_cmake_cache_folder:
            current_scratch_sources = glob.glob(os.path.join(ns3_path, "scratch", "**", "*.cc"),
                                                recursive=True)
            scratches_file = os.path.join(current_cmake_cache_folder, "ns3scratches")
            if os.path.exists(scratches_file):
                with open(scratches_file, "r") as f:
                    previous_scratches_sources = f.read().split('\n')
                    if previous_scratches_sources != current_scratch_sources:
                        refresh_cmake(current_cmake_cache_folder, output)

        if args.configure:
            configuration_step(current_cmake_cache_folder,
                               current_cmake_generator,
                               args,
                               output,
                               args.dry_run,
                               )

        if not project_configured(current_cmake_cache_folder):
            project_not_configured()

    if ns3_modules is None:
        project_not_configured()

    # We could also replace the "ns3-" prefix used in .lock-ns3 with the "lib" prefix currently used in cmake
    ns3_modules = [module.replace("ns3-", "") for module in ns3_modules]

    # Now that CMake is configured, we can look for c++ targets in .lock-ns3
    ns3_programs = get_program_shortcuts(build_profile, ns3_version)

    if args.show == "targets":
        print_targets_list(ns3_modules, ns3_programs)
        exit(0)

    if args.show == "all":
        show_profile(build_profile, exit_early=False)
        show_build_version(build_version_string, exit_early=False)
        check_config(current_cmake_cache_folder)
        print("---- Summary of buildable targets:")
        print("Buildable targets:          %4.d" % len(ns3_modules))
        print("Runnable/Buildable targets: %4.d" % len(non_ambiguous_program_target_list(ns3_programs)))

        exit(0)

    def check_ambiguous_target(target_type, target_to_check, programs):
        if len(programs[target_to_check]) > 1:
            print('%s target "%s" is ambiguous. Try one of these: "%s"'
                  % (target_type, target_to_check, '", "'.join(programs[target_to_check])))
            exit(1)
        return programs[target_to_check][0]

    # If we have a target to run, replace shortcut with full path or raise exception
    if run_only or build_and_run:
        if target_to_run in ns3_programs:
            target_to_run = check_ambiguous_target("Run", target_to_run, ns3_programs)
        elif ".py" in target_to_run and os.path.exists(target_to_run):
            # We let python scripts pass to be able to run ./utils/python-unit-tests.py
            pass
        else:
            raise Exception("Couldn't find the specified program: %s" % target_to_run)

    if "build" in args:
        complete_targets = []
        for target in args.build:
            build_target = check_ambiguous_target("Build", target, ns3_programs) if target in ns3_programs else target
            complete_targets.append(build_target)
        args.build = complete_targets
        del complete_targets

    if not run_only:
        build_step(args,
                   build_and_run,
                   target_to_run,
                   current_cmake_cache_folder,
                   ns3_modules,
                   ns3_version,
                   build_profile,
                   output
                   )

    if not args.shell and target_to_run and ".py" not in target_to_run:
        if sys.platform == "win32":
            target_to_run += ".exe"

        # If we're only trying to run the target, we need to check if it actually exists first
        if (run_only or build_and_run) and ".py" not in target_to_run and not os.path.exists(target_to_run):
            raise Exception("Executable has not been built yet")

    # Setup program as sudo
    if enable_sudo or (args.run and args.enable_sudo):
        sudo_step(args, target_to_run, set(map(lambda x: x[0], ns3_programs.values())) if enable_sudo else set())

    # Finally, we try to run it
    if args.shell or run_only or build_and_run:
        run_step(args, target_to_run, target_args)

    return


main()