import atexit
import contextlib
import faulthandler
import math
import os.path
import random
import sys
import sysconfig
import tempfile
import textwrap

from test import support
from test.support import os_helper
from test.support import threading_helper


MS_WINDOWS = (sys.platform == 'win32')

# bpo-38203: Maximum delay in seconds to exit Python (call Py_Finalize()).
# Used to protect against threading._shutdown() hang.
# Must be smaller than buildbot "1200 seconds without output" limit.
EXIT_TIMEOUT = 120.0


# Types for types hints
StrPath = str
TestName = str
StrJSON = str
TestTuple = tuple[TestName, ...]
TestList = list[TestName]
# --match and --ignore options: list of patterns
# ('*' joker character can be used)
FilterTuple = tuple[TestName, ...]
FilterDict = dict[TestName, FilterTuple]


def format_duration(seconds):
    ms = math.ceil(seconds * 1e3)
    seconds, ms = divmod(ms, 1000)
    minutes, seconds = divmod(seconds, 60)
    hours, minutes = divmod(minutes, 60)

    parts = []
    if hours:
        parts.append('%s hour' % hours)
    if minutes:
        parts.append('%s min' % minutes)
    if seconds:
        if parts:
            # 2 min 1 sec
            parts.append('%s sec' % seconds)
        else:
            # 1.0 sec
            parts.append('%.1f sec' % (seconds + ms / 1000))
    if not parts:
        return '%s ms' % ms

    parts = parts[:2]
    return ' '.join(parts)


def strip_py_suffix(names: list[str]):
    if not names:
        return
    for idx, name in enumerate(names):
        basename, ext = os.path.splitext(name)
        if ext == '.py':
            names[idx] = basename


def count(n, word):
    if n == 1:
        return "%d %s" % (n, word)
    else:
        return "%d %ss" % (n, word)


def printlist(x, width=70, indent=4, file=None):
    """Print the elements of iterable x to stdout.

    Optional arg width (default 70) is the maximum line length.
    Optional arg indent (default 4) is the number of blanks with which to
    begin each line.
    """

    blanks = ' ' * indent
    # Print the sorted list: 'x' may be a '--random' list or a set()
    print(textwrap.fill(' '.join(str(elt) for elt in sorted(x)), width,
                        initial_indent=blanks, subsequent_indent=blanks),
          file=file)


def print_warning(msg):
    support.print_warning(msg)


orig_unraisablehook = None


def regrtest_unraisable_hook(unraisable):
    global orig_unraisablehook
    support.environment_altered = True
    support.print_warning("Unraisable exception")
    old_stderr = sys.stderr
    try:
        support.flush_std_streams()
        sys.stderr = support.print_warning.orig_stderr
        orig_unraisablehook(unraisable)
        sys.stderr.flush()
    finally:
        sys.stderr = old_stderr


def setup_unraisable_hook():
    global orig_unraisablehook
    orig_unraisablehook = sys.unraisablehook
    sys.unraisablehook = regrtest_unraisable_hook


orig_threading_excepthook = None


def regrtest_threading_excepthook(args):
    global orig_threading_excepthook
    support.environment_altered = True
    support.print_warning(f"Uncaught thread exception: {args.exc_type.__name__}")
    old_stderr = sys.stderr
    try:
        support.flush_std_streams()
        sys.stderr = support.print_warning.orig_stderr
        orig_threading_excepthook(args)
        sys.stderr.flush()
    finally:
        sys.stderr = old_stderr


def setup_threading_excepthook():
    global orig_threading_excepthook
    import threading
    orig_threading_excepthook = threading.excepthook
    threading.excepthook = regrtest_threading_excepthook


def clear_caches():
    # Clear the warnings registry, so they can be displayed again
    for mod in sys.modules.values():
        if hasattr(mod, '__warningregistry__'):
            del mod.__warningregistry__

    # Flush standard output, so that buffered data is sent to the OS and
    # associated Python objects are reclaimed.
    for stream in (sys.stdout, sys.stderr, sys.__stdout__, sys.__stderr__):
        if stream is not None:
            stream.flush()

    try:
        re = sys.modules['re']
    except KeyError:
        pass
    else:
        re.purge()

    try:
        _strptime = sys.modules['_strptime']
    except KeyError:
        pass
    else:
        _strptime._regex_cache.clear()

    try:
        urllib_parse = sys.modules['urllib.parse']
    except KeyError:
        pass
    else:
        urllib_parse.clear_cache()

    try:
        urllib_request = sys.modules['urllib.request']
    except KeyError:
        pass
    else:
        urllib_request.urlcleanup()

    try:
        linecache = sys.modules['linecache']
    except KeyError:
        pass
    else:
        linecache.clearcache()

    try:
        mimetypes = sys.modules['mimetypes']
    except KeyError:
        pass
    else:
        mimetypes._default_mime_types()

    try:
        filecmp = sys.modules['filecmp']
    except KeyError:
        pass
    else:
        filecmp._cache.clear()

    try:
        struct = sys.modules['struct']
    except KeyError:
        pass
    else:
        struct._clearcache()

    try:
        doctest = sys.modules['doctest']
    except KeyError:
        pass
    else:
        doctest.master = None

    try:
        ctypes = sys.modules['ctypes']
    except KeyError:
        pass
    else:
        ctypes._reset_cache()

    try:
        typing = sys.modules['typing']
    except KeyError:
        pass
    else:
        for f in typing._cleanups:
            f()

    try:
        fractions = sys.modules['fractions']
    except KeyError:
        pass
    else:
        fractions._hash_algorithm.cache_clear()

    try:
        inspect = sys.modules['inspect']
    except KeyError:
        pass
    else:
        inspect._shadowed_dict_from_mro_tuple.cache_clear()


def get_build_info():
    # Get most important configure and build options as a list of strings.
    # Example: ['debug', 'ASAN+MSAN'] or ['release', 'LTO+PGO'].

    config_args = sysconfig.get_config_var('CONFIG_ARGS') or ''
    cflags = sysconfig.get_config_var('PY_CFLAGS') or ''
    cflags_nodist = sysconfig.get_config_var('PY_CFLAGS_NODIST') or ''
    ldflags_nodist = sysconfig.get_config_var('PY_LDFLAGS_NODIST') or ''

    build = []

    # --disable-gil
    if sysconfig.get_config_var('Py_NOGIL'):
        build.append("nogil")

    if hasattr(sys, 'gettotalrefcount'):
        # --with-pydebug
        build.append('debug')

        if '-DNDEBUG' in (cflags + cflags_nodist):
            build.append('without_assert')
    else:
        build.append('release')

        if '--with-assertions' in config_args:
            build.append('with_assert')
        elif '-DNDEBUG' not in (cflags + cflags_nodist):
            build.append('with_assert')

    # --enable-framework=name
    framework = sysconfig.get_config_var('PYTHONFRAMEWORK')
    if framework:
        build.append(f'framework={framework}')

    # --enable-shared
    shared = int(sysconfig.get_config_var('PY_ENABLE_SHARED') or '0')
    if shared:
        build.append('shared')

    # --with-lto
    optimizations = []
    if '-flto=thin' in ldflags_nodist:
        optimizations.append('ThinLTO')
    elif '-flto' in ldflags_nodist:
        optimizations.append('LTO')

    # --enable-optimizations
    pgo_options = (
        # GCC
        '-fprofile-use',
        # clang: -fprofile-instr-use=code.profclangd
        '-fprofile-instr-use',
        # ICC
        "-prof-use",
    )
    if any(option in cflags_nodist for option in pgo_options):
        optimizations.append('PGO')
    if optimizations:
        build.append('+'.join(optimizations))

    # --with-address-sanitizer
    sanitizers = []
    if support.check_sanitizer(address=True):
        sanitizers.append("ASAN")
    # --with-memory-sanitizer
    if support.check_sanitizer(memory=True):
        sanitizers.append("MSAN")
    # --with-undefined-behavior-sanitizer
    if support.check_sanitizer(ub=True):
        sanitizers.append("UBSAN")
    if sanitizers:
        build.append('+'.join(sanitizers))

    # --with-trace-refs
    if hasattr(sys, 'getobjects'):
        build.append("TraceRefs")
    # --enable-pystats
    if hasattr(sys, '_stats_on'):
        build.append("pystats")
    # --with-valgrind
    if sysconfig.get_config_var('WITH_VALGRIND'):
        build.append("valgrind")
    # --with-dtrace
    if sysconfig.get_config_var('WITH_DTRACE'):
        build.append("dtrace")

    return build


def get_temp_dir(tmp_dir):
    if tmp_dir:
        tmp_dir = os.path.expanduser(tmp_dir)
    else:
        # When tests are run from the Python build directory, it is best practice
        # to keep the test files in a subfolder.  This eases the cleanup of leftover
        # files using the "make distclean" command.
        if sysconfig.is_python_build():
            tmp_dir = sysconfig.get_config_var('abs_builddir')
            if tmp_dir is None:
                # bpo-30284: On Windows, only srcdir is available. Using
                # abs_builddir mostly matters on UNIX when building Python
                # out of the source tree, especially when the source tree
                # is read only.
                tmp_dir = sysconfig.get_config_var('srcdir')
            tmp_dir = os.path.join(tmp_dir, 'build')
        else:
            tmp_dir = tempfile.gettempdir()

    return os.path.abspath(tmp_dir)


def fix_umask():
    if support.is_emscripten:
        # Emscripten has default umask 0o777, which breaks some tests.
        # see https://github.com/emscripten-core/emscripten/issues/17269
        old_mask = os.umask(0)
        if old_mask == 0o777:
            os.umask(0o027)
        else:
            os.umask(old_mask)


def get_work_dir(*, parent_dir: StrPath = '', worker: bool = False):
    # Define a writable temp dir that will be used as cwd while running
    # the tests. The name of the dir includes the pid to allow parallel
    # testing (see the -j option).
    # Emscripten and WASI have stubbed getpid(), Emscripten has only
    # milisecond clock resolution. Use randint() instead.
    if sys.platform in {"emscripten", "wasi"}:
        nounce = random.randint(0, 1_000_000)
    else:
        nounce = os.getpid()

    if worker:
        work_dir = 'test_python_worker_{}'.format(nounce)
    else:
        work_dir = 'test_python_{}'.format(nounce)
    work_dir += os_helper.FS_NONASCII
    if parent_dir:
        work_dir = os.path.join(parent_dir, work_dir)
    return work_dir


@contextlib.contextmanager
def exit_timeout():
    try:
        yield
    except SystemExit as exc:
        # bpo-38203: Python can hang at exit in Py_Finalize(), especially
        # on threading._shutdown() call: put a timeout
        if threading_helper.can_start_thread:
            faulthandler.dump_traceback_later(EXIT_TIMEOUT, exit=True)
        sys.exit(exc.code)


def remove_testfn(test_name: TestName, verbose: int) -> None:
    # Try to clean up os_helper.TESTFN if left behind.
    #
    # While tests shouldn't leave any files or directories behind, when a test
    # fails that can be tedious for it to arrange.  The consequences can be
    # especially nasty on Windows, since if a test leaves a file open, it
    # cannot be deleted by name (while there's nothing we can do about that
    # here either, we can display the name of the offending test, which is a
    # real help).
    name = os_helper.TESTFN
    if not os.path.exists(name):
        return

    if os.path.isdir(name):
        import shutil
        kind, nuker = "directory", shutil.rmtree
    elif os.path.isfile(name):
        kind, nuker = "file", os.unlink
    else:
        raise RuntimeError(f"os.path says {name!r} exists but is neither "
                           f"directory nor file")

    if verbose:
        print_warning(f"{test_name} left behind {kind} {name!r}")
        support.environment_altered = True

    try:
        import stat
        # fix possible permissions problems that might prevent cleanup
        os.chmod(name, stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO)
        nuker(name)
    except Exception as exc:
        print_warning(f"{test_name} left behind {kind} {name!r} "
                      f"and it couldn't be removed: {exc}")


def abs_module_name(test_name: TestName, test_dir: StrPath | None) -> TestName:
    if test_name.startswith('test.') or test_dir:
        return test_name
    else:
        # Import it from the test package
        return 'test.' + test_name


# gh-90681: When rerunning tests, we might need to rerun the whole
# class or module suite if some its life-cycle hooks fail.
# Test level hooks are not affected.
_TEST_LIFECYCLE_HOOKS = frozenset((
    'setUpClass', 'tearDownClass',
    'setUpModule', 'tearDownModule',
))

def normalize_test_name(test_full_name, *, is_error=False):
    short_name = test_full_name.split(" ")[0]
    if is_error and short_name in _TEST_LIFECYCLE_HOOKS:
        if test_full_name.startswith(('setUpModule (', 'tearDownModule (')):
            # if setUpModule() or tearDownModule() failed, don't filter
            # tests with the test file name, don't use use filters.
            return None

        # This means that we have a failure in a life-cycle hook,
        # we need to rerun the whole module or class suite.
        # Basically the error looks like this:
        #    ERROR: setUpClass (test.test_reg_ex.RegTest)
        # or
        #    ERROR: setUpModule (test.test_reg_ex)
        # So, we need to parse the class / module name.
        lpar = test_full_name.index('(')
        rpar = test_full_name.index(')')
        return test_full_name[lpar + 1: rpar].split('.')[-1]
    return short_name


def replace_stdout():
    """Set stdout encoder error handler to backslashreplace (as stderr error
    handler) to avoid UnicodeEncodeError when printing a traceback"""
    stdout = sys.stdout
    try:
        fd = stdout.fileno()
    except ValueError:
        # On IDLE, sys.stdout has no file descriptor and is not a TextIOWrapper
        # object. Leaving sys.stdout unchanged.
        #
        # Catch ValueError to catch io.UnsupportedOperation on TextIOBase
        # and ValueError on a closed stream.
        return

    sys.stdout = open(fd, 'w',
        encoding=stdout.encoding,
        errors="backslashreplace",
        closefd=False,
        newline='\n')

    def restore_stdout():
        sys.stdout.close()
        sys.stdout = stdout
    atexit.register(restore_stdout)


def adjust_rlimit_nofile():
    """
    On macOS the default fd limit (RLIMIT_NOFILE) is sometimes too low (256)
    for our test suite to succeed. Raise it to something more reasonable. 1024
    is a common Linux default.
    """
    try:
        import resource
    except ImportError:
        return

    fd_limit, max_fds = resource.getrlimit(resource.RLIMIT_NOFILE)

    desired_fds = 1024

    if fd_limit < desired_fds and fd_limit < max_fds:
        new_fd_limit = min(desired_fds, max_fds)
        try:
            resource.setrlimit(resource.RLIMIT_NOFILE,
                               (new_fd_limit, max_fds))
            print(f"Raised RLIMIT_NOFILE: {fd_limit} -> {new_fd_limit}")
        except (ValueError, OSError) as err:
            print_warning(f"Unable to raise RLIMIT_NOFILE from {fd_limit} to "
                          f"{new_fd_limit}: {err}.")