#     Copyright 2018, Kay Hayen, mailto:kay.hayen@gmail.com
#
#     Part of "Nuitka", an optimizing Python compiler that is compatible and
#     integrates with CPython, but also works on its own.
#
#     Licensed under the Apache License, Version 2.0 (the "License");
#     you may not use this file except in compliance with the License.
#     You may obtain a copy of the License at
#
#        http://www.apache.org/licenses/LICENSE-2.0
#
#     Unless required by applicable law or agreed to in writing, software
#     distributed under the License is distributed on an "AS IS" BASIS,
#     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#     See the License for the specific language governing permissions and
#     limitations under the License.
#
""" Common test infrastructure functions. To be used by test runners. """

from __future__ import print_function

import ast
import atexit
import os
import re
import shutil
import subprocess
import sys
import tempfile
from contextlib import contextmanager

from nuitka.Tracing import my_print
from nuitka.utils.AppDirs import getAppDir, getCacheDir
from nuitka.utils.Execution import check_output, withEnvironmentVarOverriden
from nuitka.utils.FileOperations import makePath, removeDirectory

from .SearchModes import (
    SearchModeBase,
    SearchModeByPattern,
    SearchModeCoverage,
    SearchModeResume
)


def check_result(*popenargs, **kwargs):
    if "stdout" in kwargs:
        raise ValueError("stdout argument not allowed, it will be overridden.")

    process = subprocess.Popen(
        stdout = subprocess.PIPE,
        *popenargs,
        **kwargs
    )
    _unused_output, _unused_err = process.communicate()
    retcode = process.poll()

    if retcode:
        return False
    else:
        return True


def goMainDir():
    # Go its own directory, to have it easy with path knowledge.
    os.chdir(
        os.path.dirname(
            os.path.abspath(sys.modules[ "__main__" ].__file__)
        )
    )

_python_version = None
_python_arch = None
_python_executable = None

def setup(suite = "", needs_io_encoding = False, silent = False, go_main = True):
    if go_main:
        goMainDir()

    if "PYTHON" not in os.environ:
        os.environ["PYTHON"] = sys.executable

    # Allow test code to use this to make caching specific.
    os.environ["NUITKA_TEST_SUITE"] = suite

    # Allow providing 33, 27, and expand that to python2.7
    if len(os.environ["PYTHON"]) == 2 and \
       os.environ["PYTHON"].isdigit() and \
       os.name != "nt":

        os.environ["PYTHON"] = "python%s.%s" % (
            os.environ["PYTHON"][0],
            os.environ["PYTHON"][1]
        )

    if needs_io_encoding and "PYTHONIOENCODING" not in os.environ:
        os.environ["PYTHONIOENCODING"] = "utf-8"

    version_output = check_output(
        (
            os.environ["PYTHON"],
            "-c",
            """\
import sys, os;\
print(".".join(str(s) for s in list(sys.version_info)[:3]));\
print(("x86_64" if "AMD64" in sys.version else "x86") if os.name == "nt" else os.uname()[4]);\
print(sys.executable);\
""",
        ),
        stderr = subprocess.STDOUT
    )

    global _python_version, _python_arch, _python_executable # singleton, pylint: disable=global-statement

    _python_version = version_output.split(b"\n")[0].strip()
    _python_arch = version_output.split(b"\n")[1].strip()
    _python_executable = version_output.split(b"\n")[2].strip()

    if sys.version.startswith('3'):
        _python_arch = _python_arch.decode("utf-8")
        _python_version = _python_version.decode("utf-8")
        _python_executable = _python_executable.decode("utf-8")

    if not silent:
        my_print("Using concrete python", _python_version, "on", _python_arch)

    assert type(_python_version) is str, repr(_python_version)
    assert type(_python_arch) is str, repr(_python_arch)
    assert type(_python_executable) is str, repr(_python_executable)

    if "COVERAGE_FILE" not in os.environ:
        os.environ["COVERAGE_FILE"] = os.path.join(
            os.path.dirname(__file__),
            "..",
            "..",
            "..",
            ".coverage"
        )

    return _python_version


tmp_dir = None

def getTempDir():
    # Create a temporary directory to work in, automatically remove it in case
    # it is empty in the end.
    global tmp_dir  # singleton, pylint: disable=global-statement

    if tmp_dir is None:
        tmp_dir = tempfile.mkdtemp(
            prefix = os.path.basename(
                os.path.dirname(
                    os.path.abspath(sys.modules[ "__main__" ].__file__)
                )
            ) + '-',
            dir    = tempfile.gettempdir() if
                         not os.path.exists("/var/tmp") else
                    "/var/tmp"
        )

        def removeTempDir():
            removeDirectory(
                path          = tmp_dir,
                ignore_errors = True
            )

        atexit.register(removeTempDir)

    return tmp_dir


def convertUsing2to3(path, force = False):
    command = [
        os.environ["PYTHON"],
        "-m",
        "py_compile",
        path
    ]

    if not force:
        with open(path) as source_file:
            if "xrange" not in source_file.read():
                with open(os.devnull, 'w') as stderr:
                    if check_result(command, stderr = stderr):
                        return path, False

    filename = os.path.basename(path)

    new_path = os.path.join(getTempDir(), filename)

    # This may already be a temp file, e.g. because of construct creation.
    try:
        shutil.copy(path, new_path)
    except shutil.Error:
        pass

    # For Python2.6 and 3.2 the -m lib2to3 was not yet supported.
    use_binary = sys.version_info[:2] in ((2,6), (3,2))

    if use_binary:
        # On Windows, we cannot rely on 2to3 to be in the path.
        if os.name == "nt":
            command = [
                sys.executable,
                os.path.join(
                    os.path.dirname(sys.executable),
                    "Tools/Scripts/2to3.py"
                )
            ]
        else:
            command = [
                "2to3"
            ]
    else:
        command = [
            sys.executable,
            "-m",
            "lib2to3",
        ]

    command += [
        "-w",
        "-n",
        "--no-diffs",
        new_path
    ]

    with open(os.devnull, 'w') as devnull:
        check_output(
            command,
            stderr = devnull
        )

    with open(new_path) as result_file:
        data = result_file.read()

    with open(new_path, 'w') as result_file:
        result_file.write("__file__ = %r\n" % os.path.abspath(path))
        result_file.write(data)

    return new_path, True


def decideFilenameVersionSkip(filename):
    """ Make decision whether to skip based on filename and Python version.

    This codifies certain rules that files can have as suffixes or prefixes
    to make them be part of the set of tests executed for a version or not.

    Generally, an ening of "<major><minor>.py" indicates that it must be that
    Python version or higher. There is no need for ending in "26.py" as this
    is the minimum version anyway.

    The "_2.py" indicates a maxmimum version of 2.7, i.e. not Python 3.x, for
    language syntax no more supported.
    """

    # This will make many decisions with immediate returns.
    # pylint: disable=too-many-return-statements

    assert type(filename) is str
    assert type(_python_version) is str

    # Skip runner scripts by default.
    if filename.startswith("run_"):
        return False

    # Skip tests that require Python 2.7 at least.
    if filename.endswith("27.py") and _python_version.startswith("2.6"):
        return False

    if filename.endswith("_2.py") and _python_version.startswith('3'):
        return False

    # Skip tests that require Python 3.2 at least.
    if filename.endswith("32.py") and _python_version < "3.2":
        return False

    # Skip tests that require Python 3.3 at least.
    if filename.endswith("33.py") and _python_version < "3.3":
        return False

    # Skip tests that require Python 3.4 at least.
    if filename.endswith("34.py") and _python_version < "3.4":
        return False

    # Skip tests that require Python 3.5 at least.
    if filename.endswith("35.py") and _python_version < "3.5":
        return False

    # Skip tests that require Python 3.6 at least.
    if filename.endswith("36.py") and _python_version < "3.6":
        return False

    return True


def _removeCPythonTestSuiteDir():
    # Cleanup, some tests apparently forget that.
    try:
        if os.path.isdir("@test"):
            removeDirectory("@test", ignore_errors = False)
        elif os.path.isfile("@test"):
            os.unlink("@test")
    except OSError:
        # TODO: Move this into removeDirectory maybe. Doing an external
        # call as last resort could be a good idea.

        # This seems to work for broken "lnk" files.
        if os.name == "nt":
            os.system("rmdir /S /Q @test")

        if os.path.exists("@test"):
            raise

def compareWithCPython(dirname, filename, extra_flags, search_mode, needs_2to3):
    """ Call the comparison tool. For a given directory filename.

    The search mode decides if the test case aborts on error or gets extra
    flags that are exceptions.

    """

    if dirname is None:
        path = filename
    else:
        path = os.path.join(dirname, filename)

    # Apply 2to3 conversion if necessary.
    if needs_2to3:
        path, converted = convertUsing2to3(path)
    else:
        converted = False

    command = [
        sys.executable,
        os.path.join("..", "..", "bin", "compare_with_cpython"),
        path,
        "silent"
    ]

    if extra_flags is not None:
        command += extra_flags

    command += search_mode.getExtraFlags(dirname, filename)

    # Cleanup before and after test stage directory.
    _removeCPythonTestSuiteDir()

    try:
        result = subprocess.call(
            command
        )
    except KeyboardInterrupt:
        result = 2

    # Cleanup before and after test stage directory.
    _removeCPythonTestSuiteDir()

    if result != 0 and \
       result != 2 and \
       search_mode.abortOnFinding(dirname, filename):
        my_print("Error exit!", result)
        sys.exit(result)

    if converted:
        os.unlink(path)

    if result == 2:
        sys.stderr.write("Interrupted, with CTRL-C\n")
        sys.exit(2)


def checkCompilesNotWithCPython(dirname, filename, search_mode):
    if dirname is None:
        path = filename
    else:
        path = os.path.join(dirname, filename)

    command = [
        _python_executable,
        "-mcompileall",
        path
    ]

    try:
        result = subprocess.call(
            command
        )
    except KeyboardInterrupt:
        result = 2

    if result != 1 and \
       result != 2 and \
       search_mode.abortOnFinding(dirname, filename):
        my_print("Error exit!", result)
        sys.exit(result)


def checkSucceedsWithCPython(filename):
    command = [
        _python_executable,
        filename
    ]

    result = subprocess.call(
        command,
        stdout = open(os.devnull,'w'),
        stderr = subprocess.STDOUT
    )

    return result == 0


def hasDebugPython():
    # On Debian systems, these work.
    debug_python = os.path.join("/usr/bin/", os.environ["PYTHON"] + "-dbg")
    if os.path.exists(debug_python):
        return True

    # On Windows systems, these work.
    debug_python = os.environ["PYTHON"]
    if debug_python.lower().endswith(".exe"):
        debug_python = debug_python[:-4]
    debug_python = debug_python + "_d.exe"
    if os.path.exists(debug_python):
        return True

    # For other Python, if it's the one also executing the runner, which is
    # very probably the case, we check that. We don't check the provided
    # binary here, this could be done as well.
    if sys.executable == os.environ["PYTHON"] and \
       hasattr(sys, "gettotalrefcount"):
        return True

    # Otherwise no.
    return False


def getArchitecture():
    if os.name == "nt":
        if "AMD64" in sys.version:
            return "x86_64"
        else:
            return "x86"
    else:
        return os.uname()[4]  # @UndefinedVariable


def getDependsExePath():
    if "APPDATA" not in os.environ:
        sys.exit("Error, standalone mode cannot find 'APPDATA' environment.")

    nuitka_app_dir = getAppDir()

    depends_dir = os.path.join(
        nuitka_app_dir,
        _python_arch,
    )
    depends_exe = os.path.join(
        depends_dir,
        "depends.exe"
    )

    assert os.path.exists(depends_exe), depends_exe

    return depends_exe

def isExecutableCommand(command):
    path = os.environ["PATH"]

    suffixes = (".exe",) if os.name == "nt" else ("",)

    for part in path.split(os.pathsep):
        if not part:
            continue

        for suffix in suffixes:
            if os.path.isfile(os.path.join(part, command + suffix)):
                return True

    return False


def getRuntimeTraceOfLoadedFiles(path, trace_error = True):
    """ Returns the files loaded when executing a binary. """

    # This will make a crazy amount of work, pylint: disable=too-many-branches,too-many-statements

    result = []

    if os.name == "posix":
        if sys.platform == "darwin" or \
           sys.platform.startswith("freebsd"):
            if not isExecutableCommand("dtruss"):
                sys.exit(
                    """\
Error, needs 'dtruss' on your system to scan used libraries."""
                )

            if not isExecutableCommand("sudo"):
                sys.exit(
                    """\
Error, needs 'sudo' on your system to scan used libraries."""
                )

            args = (
                "sudo",
                "dtruss",
                "-t",
                "open",
                path
            )
        else:
            if not isExecutableCommand("strace"):
                sys.exit(
                    """\
Error, needs 'strace' on your system to scan used libraries."""
                )

            args = (
                "strace",
                "-e", "file",
                "-s4096", # Some paths are truncated otherwise.
                path
            )

        # Ensure executable is not polluted with third party stuff,
        # tests may fail otherwise due to unexpected libs being loaded
        with withEnvironmentVarOverriden("LD_PRELOAD", None):
            process = subprocess.Popen(
                args   = args,
                stdout = subprocess.PIPE,
                stderr = subprocess.PIPE
            )

            _stdout_strace, stderr_strace = process.communicate()
            exit_strace = process.returncode

            if exit_strace != 0:
                if str is not bytes:
                    stderr_strace = stderr_strace.decode("utf8")

                my_print(stderr_strace, file = sys.stderr)
                sys.exit("Failed to run strace.")

            open(path+".strace","wb").write(stderr_strace)

            for line in stderr_strace.split(b"\n"):
                if process.returncode != 0 and trace_error:
                    my_print(line)

                if not line:
                    continue

                # Don't consider files not found. The "site" module checks lots
                # of things.
                if b"ENOENT" in line:
                    continue

                if line.startswith(b"stat(") and b"S_IFDIR" in line:
                    continue

                # Allow stats on the python binary, and stuff pointing to the
                # standard library, just not uses of it. It will search there
                # for stuff.
                if line.startswith(b"lstat(") or \
                   line.startswith(b"stat(") or \
                   line.startswith(b"readlink("):
                    filename = line[line.find(b"(")+2:line.find(b", ")-1]

                    # At least Python3.7 considers the default Python3 path.
                    if filename == b"/usr/bin/python3":
                        continue

                    if filename in (b"/usr/bin/python3." + version for version in (b"5", b"6", b"7")):
                        continue

                    binary_path = _python_executable
                    if str is not bytes:
                        binary_path = binary_path.encode("utf-8")

                    found = False
                    while binary_path:
                        if filename == binary_path:
                            found = True
                            break

                        if binary_path == os.path.dirname(binary_path):
                            break

                        binary_path = os.path.dirname(binary_path)

                        if filename == os.path.join(binary_path, b"python" + _python_version[:3].encode("utf8")):
                            found = True
                            continue


                    if found:
                        continue

                result.extend(
                    os.path.abspath(match)
                    for match in
                    re.findall(b'"(.*?)(?:\\\\0)?"', line)
                )

            if sys.version.startswith('3'):
                result = [s.decode("utf-8") for s in result]
    elif os.name == "nt":
        subprocess.call(
            (
                getDependsExePath(),
                "-c",
                "-ot%s" % path + ".depends",
                "-f1",
                "-pa1",
                "-ps1",
                "-pp0",
                "-pl1",
                path
            )
        )

        inside = False
        for line in open(path + ".depends"):
            if "| Module Dependency Tree |" in line:
                inside = True
                continue

            if not inside:
                continue

            if "| Module List |" in line:
                break

            if ']' not in line:
                continue

            # Skip missing DLLs, apparently not needed anyway.
            if '?' in line[:line.find(']')]:
                continue

            dll_filename = line[line.find(']')+2:-1]
            assert os.path.isfile(dll_filename), dll_filename

            # The executable itself is of course exempted.
            if os.path.normcase(dll_filename) == \
                os.path.normcase(os.path.abspath(path)):
                continue

            dll_filename = os.path.normcase(dll_filename)

            result.append(dll_filename)

        os.unlink(path + ".depends")

    result = list(sorted(set(result)))

    return result


def checkRuntimeLoadedFilesForOutsideAccesses(loaded_filenames, white_list):
    # A lot of special white listing is required.
    # pylint: disable=too-many-branches,too-many-statements

    result = []

    for loaded_filename in loaded_filenames:
        loaded_filename = os.path.normpath(loaded_filename)
        loaded_filename = os.path.normcase(loaded_filename)
        loaded_basename = os.path.basename(loaded_filename)

        ok = False
        for entry in white_list:
            if loaded_filename.startswith(entry):
                ok = True

            while entry:
                old_entry = entry
                entry = os.path.dirname(entry)

                if old_entry == entry:
                    break

                if loaded_filename == entry:
                    ok = True
                    break
        if ok:
            continue

        if loaded_filename.startswith("/etc/"):
            continue

        if loaded_filename.startswith("/proc/") or loaded_filename == "/proc":
            continue

        if loaded_filename.startswith("/dev/"):
            continue

        if loaded_filename.startswith("/tmp/"):
            continue

        if loaded_filename.startswith("/run/"):
            continue

        if loaded_filename.startswith("/sys/"):
            continue

        if loaded_filename.startswith("/usr/lib/locale/"):
            continue

        if loaded_filename.startswith("/usr/share/locale/"):
            continue

        if loaded_filename.startswith("/usr/share/X11/locale/"):
            continue

        # Themes may of course be loaded.
        if loaded_filename.startswith("/usr/share/themes"):
            continue
        if "gtk" in loaded_filename and "/engines/" in loaded_filename:
            continue

        # Terminal info files are OK too.
        if loaded_filename.startswith("/lib/terminfo/"):
            continue

        # System C libraries are to be expected.
        if loaded_basename.startswith((
            "ld-linux-x86-64.so",
            "libc.so.",
            "libpthread.so.",
            "libm.so.",
            "libdl.so.",
            "libBrokenLocale.so.",
            "libSegFault.so",
            "libanl.so.",
            "libcidn.so.",
            "libcrypt.so.",
            "libmemusage.so",
            "libmvec.so.",
            "libnsl.so.",
            "libnss_compat.so.",
            "libnss_db.so.",
            "libnss_dns.so.",
            "libnss_files.so.",
            "libnss_hesiod.so.",
            "libnss_nis.so.",
            "libnss_nisplus.so.",
            "libpcprofile.so",
            "libresolv.so.",
            "librt.so.",
            "libthread_db-1.0.so",
            "libthread_db.so.",
            "libutil.so."
        )):
            continue

        # Taking these from system is harmless and desirable
        if loaded_basename.startswith((
            "libz.so",
            "libgcc_s.so",
        )):
            continue

        # TODO: Unclear, loading gconv from filesystem of installed system
        # may be OK or not. I think it should be.
        if loaded_basename == "gconv-modules.cache":
            continue
        if "/gconv/" in loaded_filename:
            continue
        if loaded_basename.startswith("libicu"):
            continue

        # GTK may access X files.
        if loaded_basename == ".Xauthority":
            continue

        result.append(loaded_filename)

    return result


def hasModule(module_name):
    result = subprocess.call(
        (
            os.environ["PYTHON"],
            "-c"
            "import %s" % module_name
        ),
        stdout = open(os.devnull,'w'),
        stderr = subprocess.STDOUT
    )

    return result == 0


m1 = {}
m2 = {}

def snapObjRefCntMap(before):
    import gc

    if before:
        m = m1
    else:
        m = m2

    for x in gc.get_objects():
        if x is m1:
            continue

        if x is m2:
            continue

        m[ str(x) ] = sys.getrefcount(x)


def checkReferenceCount(checked_function, max_rounds = 10):
    assert sys.exc_info() == (None, None, None), sys.exc_info()

    print(checked_function.__name__ + ": ", end = "")
    sys.stdout.flush()

    ref_count1 = 17
    ref_count2 = 17

    explain = False

    import gc

    assert max_rounds > 0
    for count in range(max_rounds):
        gc.collect()
        ref_count1 = sys.gettotalrefcount()  # @UndefinedVariable

        if explain and count == max_rounds - 1:
            snapObjRefCntMap(True)

        checked_function()

        # Not allowed, but happens when bugs occur.
        assert sys.exc_info() == (None, None, None), sys.exc_info()

        gc.collect()

        if explain and count == max_rounds - 1:
            snapObjRefCntMap(False)

        ref_count2 = sys.gettotalrefcount()  # @UndefinedVariable

        if ref_count1 == ref_count2:
            result = True
            print("PASSED")
            break

        # print count, ref_count1, ref_count2
    else:
        result = False
        print("FAILED", ref_count1, ref_count2, "leaked", ref_count2 - ref_count1)

        if explain:
            assert m1
            assert m2

            for key in m1:
                if key not in m2:
                    print('*' * 80)
                    print("extra", key)
                elif m1[key] != m2[key]:
                    print('*' * 80)
                    print(m1[key], "->", m2[key], key)
                else:
                    pass
                    # print m1[key]

    assert sys.exc_info() == (None, None, None), sys.exc_info()

    gc.collect()
    sys.stdout.flush()

    return result



def createSearchMode():
    search_mode = len(sys.argv) > 1 and sys.argv[1] == "search"
    resume_mode = len(sys.argv) > 1 and sys.argv[1] == "resume"
    start_at = sys.argv[2] if len(sys.argv) > 2 else None
    coverage_mode = len(sys.argv) > 1 and sys.argv[1] == "coverage"


    if coverage_mode:

        return SearchModeCoverage()
    elif resume_mode:
        return SearchModeResume(
            sys.modules["__main__"].__file__
        )
    elif search_mode and start_at:
        start_at = start_at.replace('/', os.path.sep)
        return SearchModeByPattern(start_at)
    else:
        class SearchModeImmediate(SearchModeBase):
            def abortOnFinding(self, dirname, filename):
                return search_mode and \
                       SearchModeBase.abortOnFinding(self, dirname, filename)

        return SearchModeImmediate()

def reportSkip(reason, dirname, filename):
    case = os.path.join(dirname, filename)
    case = os.path.normpath(case)

    my_print("Skipped, %s (%s)." % (case, reason))


def executeReferenceChecked(prefix, names, tests_skipped, tests_stderr):
    import gc
    gc.disable()

    extract_number = lambda name: int(name.replace(prefix, ""))

    # Find the function names.
    matching_names = tuple(
        name
        for name in names
        if name.startswith(prefix) and name[-1].isdigit()
    )

    old_stderr = sys.stderr

    # Everything passed
    result = True

    for name in sorted(matching_names, key = extract_number):
        number = extract_number(name)

        # print(tests_skipped)
        if number in tests_skipped:
            my_print(name + ": SKIPPED (%s)" % tests_skipped[number])
            continue

        # Avoid unraisable output.
        try:
            if number in tests_stderr:
                sys.stderr = open(os.devnull, "wb")
        except OSError: # Windows
            if not checkReferenceCount(names[name]):
                result = False
        else:
            if not checkReferenceCount(names[name]):
                result = False

            if number in tests_stderr:
                new_stderr = sys.stderr
                sys.stderr = old_stderr
                new_stderr.close()

    gc.enable()
    return result


def checkDebugPython():
    if not hasattr(sys, "gettotalrefcount"):
        my_print("Warning, using non-debug Python makes this test ineffective.")
        sys.gettotalrefcount = lambda : 0
    elif sys.version_info >= (3,7,0) and sys.version_info < (3,7,1):
        my_print("Warning, bug of CPython 3.7.0/1 breaks reference counting and makes this test ineffective.")
        sys.gettotalrefcount = lambda : 0


def addToPythonPath(python_path):
    if type(python_path) in (tuple, list):
        python_path = os.pathsep.join(python_path)

    if python_path:
        if "PYTHONPATH" in os.environ:
            os.environ["PYTHONPATH"] += os.pathsep + python_path
        else:
            os.environ["PYTHONPATH"] = python_path


@contextmanager
def withPythonPathChange(python_path):
    if python_path:
        if type(python_path) not in (tuple, list):
            python_path = python_path.split(os.pathsep)

        python_path = [
            os.path.normpath(os.path.abspath(element))
            for element in
            python_path
        ]

        python_path = os.pathsep.join(python_path)

        if "PYTHONPATH" in os.environ:
            old_path = os.environ["PYTHONPATH"]
            os.environ["PYTHONPATH"] += os.pathsep + python_path
        else:
            old_path = None
            os.environ["PYTHONPATH"] = python_path

#     print(
#         "Effective PYTHONPATH in %s is %r" % (
#             sys.modules["__main__"],
#             os.environ.get("PYTHONPATH", "")
#         )
#     )

    yield

    if python_path:
        if old_path is None:
            del os.environ["PYTHONPATH"]
        else:
            os.environ["PYTHONPATH"] = old_path


@contextmanager
def withExtendedExtraOptions(*args):
    assert args
    old_value = os.environ.get("NUITKA_EXTRA_OPTIONS", None)

    value = old_value

    for arg in args:
        if value is None:
            value = arg
        else:
            value += ' ' + arg

    os.environ[ "NUITKA_EXTRA_OPTIONS" ] = value

    yield

    if old_value is None:
        del os.environ[ "NUITKA_EXTRA_OPTIONS" ]
    else:
        os.environ[ "NUITKA_EXTRA_OPTIONS" ] = old_value


def indentedCode(codes, count):
    """ Indent code, used for generating test codes.

    """
    return '\n'.join( ' ' * count + line if line else "" for line in codes )


def convertToPython(doctests, line_filter = None):
    """ Convert give doctest string to static Python code.

    """
    # This is convoluted, but it just needs to work, pylint: disable=too-many-branches

    import doctest
    code = doctest.script_from_examples(doctests)

    if code.endswith('\n'):
        code += "#\n"
    else:
        assert False

    output = []
    inside = False

    def getPrintPrefixed(evaluated, line_number):
        try:
            node = ast.parse(evaluated.lstrip(), "eval")
        except SyntaxError:
            return evaluated

        if node.body[0].__class__.__name__ == "Expr":
            count = 0

            while evaluated.startswith(' ' * count):
                count += 1

            if sys.version_info < (3,):
                modified = (count-1) * ' ' + "print " + evaluated
                return (count-1) * ' ' + ("print 'Line %d'" % line_number) + '\n' + modified
            else:
                modified = (count-1) * ' ' + "print(" + evaluated + "\n)\n"
                return (count-1) * ' ' + ("print('Line %d'" % line_number) + ")\n" + modified
        else:
            return evaluated

    def getTried(evaluated, line_number):
        if sys.version_info < (3,):
            return """
try:
%(evaluated)s
except Exception as __e:
    print "Occurred", type(__e), __e
""" % { "evaluated" : indentedCode(getPrintPrefixed(evaluated, line_number).split('\n'), 4) }
        else:
            return """
try:
%(evaluated)s
except Exception as __e:
    print("Occurred", type(__e), __e)
""" % { "evaluated" : indentedCode(getPrintPrefixed(evaluated, line_number).split('\n'), 4) }

    def isOpener(evaluated):
        evaluated = evaluated.lstrip()

        if evaluated == "":
            return False

        return evaluated.split()[0] in (
            "def", "class", "for", "while", "try:", "except", "except:",
            "finally:", "else:"
        )

    chunk = None
    for line_number, line in enumerate(code.split('\n')):
        # print "->", inside, line

        if line_filter is not None and line_filter(line):
            continue

        if inside and line and line[0].isalnum() and not isOpener(line):
            output.append(getTried('\n'.join(chunk), line_number))  # @UndefinedVariable

            chunk = []
            inside = False

        if inside and not (line.startswith('#') and line.find("SyntaxError:") != -1):
            chunk.append(line)
        elif line.startswith('#'):
            if line.find("SyntaxError:") != -1:
                # print "Syntax error detected"

                if inside:
                    # print "Dropping chunk", chunk

                    chunk = []
                    inside = False
                else:
                    del output[-1]
        elif isOpener(line):
            inside = True
            chunk = [line]
        elif line.strip() == "":
            output.append(line)
        else:
            output.append(getTried(line, line_number))

    return '\n'.join(output).rstrip() + '\n'


def compileLibraryPath(search_mode, path, stage_dir, decide, action):
    my_print("Checking standard library path:", path)

    for root, dirnames, filenames in os.walk(path):
        dirnames_to_remove = [
            dirname
            for dirname in dirnames
            if '-' in dirname
        ]

        for dirname in dirnames_to_remove:
            dirnames.remove(dirname)

        dirnames.sort()

        filenames = [
            filename
            for filename in filenames
            if decide(root, filename)
        ]

        for filename in sorted(filenames):
            if not search_mode.consider(root, filename):
                continue

            full_path = os.path.join(root, filename)

            my_print(full_path, ':', end = ' ')
            sys.stdout.flush()

            action(stage_dir, path, full_path)


def compileLibraryTest(search_mode, stage_dir, decide, action):
    if not os.path.exists(stage_dir):
        os.makedirs(stage_dir)

    my_dirname = os.path.join(os.path.dirname(__file__), "../../..")
    my_dirname = os.path.normpath(my_dirname)

    paths = [
        path
        for path in
        sys.path
        if not path.startswith(my_dirname)
    ]

    my_print("Using standard library paths:")
    for path in paths:
        my_print(path)

    for path in paths:
        print("Checking path:", path)
        compileLibraryPath(
            search_mode = search_mode,
            path        = path,
            stage_dir   = stage_dir,
            decide      = decide,
            action      = action
        )

    search_mode.finish()


def run_async(coro):
    """ Execute a coroutine until it's done. """

    values = []
    result = None
    while True:
        try:
            values.append(coro.send(None))
        except StopIteration as ex:
            result = ex.args[0] if ex.args else None
            break
    return values, result


def async_iterate(g):
    """ Execute async generator until it's done. """

    # Test code for Python3, catches all kinds of exceptions.
    # pylint: disable=broad-except

    # Also Python3 only, pylint: disable=I0021,undefined-variable

    res = []
    while True:
        try:
            g.__anext__().__next__()
        except StopAsyncIteration:  # @UndefinedVariable
            res.append("STOP")
            break
        except StopIteration as ex:
            if ex.args:
                res.append("ex arg %s" % ex.args[0])
            else:
                res.append("EMPTY StopIteration")
                break
        except Exception as ex:
            res.append(str(type(ex)))

    return res


def getTestingCacheDir():
    cache_dir = getCacheDir()

    result = os.path.join(cache_dir, "tests_state")
    makePath(result)
    return result


def getTestingCPythonOutputsCacheDir():
    cache_dir = getCacheDir()

    result = os.path.join(cache_dir, "cpython_outputs", os.environ.get("NUITKA_TEST_SUITE", ""))

    makePath(result)
    return result

@contextmanager
def withDirectoryChange(path, allow_none = False):
    if path is not None or not allow_none:
        old_cwd = os.getcwd()
        os.chdir(path)

    yield

    if path is not None or not allow_none:
        os.chdir(old_cwd)


def someGenerator():
    yield 1
    yield 2
    yield 3

def someGeneratorRaising():
    yield 1
    raise TypeError(2)
