# Copyright (c) 2010-2020 Benjamin Peterson
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

"""Utilities for writing code that runs on Python 2 and 3"""

from __future__ import absolute_import

import functools
import itertools
import operator
import sys
import types

__author__ = "Benjamin Peterson <benjamin@python.org>"
__version__ = "1.16.0"


# Useful for very coarse version differentiation.
PY2 = sys.version_info[0] == 2
PY3 = sys.version_info[0] == 3
PY34 = sys.version_info[0:2] >= (3, 4)

if PY3:
    string_types = (str,)
    integer_types = (int,)
    class_types = (type,)
    text_type = str
    binary_type = bytes

    MAXSIZE = sys.maxsize
else:
    string_types = (basestring,)
    integer_types = (int, long)
    class_types = (type, types.ClassType)
    text_type = unicode
    binary_type = str

    if sys.platform.startswith("java"):
        # Jython always uses 32 bits.
        MAXSIZE = int((1 << 31) - 1)
    else:
        # It's possible to have sizeof(long) != sizeof(Py_ssize_t).
        class X(object):
            def __len__(self):
                return 1 << 31

        try:
            len(X())
        except OverflowError:
            # 32-bit
            MAXSIZE = int((1 << 31) - 1)
        else:
            # 64-bit
            MAXSIZE = int((1 << 63) - 1)
        del X

if PY34:
    from importlib.util import spec_from_loader
else:
    spec_from_loader = None


def _add_doc(func, doc):
    """Add documentation to a function."""
    func.__doc__ = doc


def _import_module(name):
    """Import module, returning the module after the last dot."""
    __import__(name)
    return sys.modules[name]


class _LazyDescr(object):
    def __init__(self, name):
        self.name = name

    def __get__(self, obj, tp):
        result = self._resolve()
        setattr(obj, self.name, result)  # Invokes __set__.
        try:
            # This is a bit ugly, but it avoids running this again by
            # removing this descriptor.
            delattr(obj.__class__, self.name)
        except AttributeError:
            pass
        return result


class MovedModule(_LazyDescr):
    def __init__(self, name, old, new=None):
        super(MovedModule, self).__init__(name)
        if PY3:
            if new is None:
                new = name
            self.mod = new
        else:
            self.mod = old

    def _resolve(self):
        return _import_module(self.mod)

    def __getattr__(self, attr):
        _module = self._resolve()
        value = getattr(_module, attr)
        setattr(self, attr, value)
        return value


class _LazyModule(types.ModuleType):
    def __init__(self, name):
        super(_LazyModule, self).__init__(name)
        self.__doc__ = self.__class__.__doc__

    def __dir__(self):
        attrs = ["__doc__", "__name__"]
        attrs += [attr.name for attr in self._moved_attributes]
        return attrs

    # Subclasses should override this
    _moved_attributes = []


class MovedAttribute(_LazyDescr):
    def __init__(self, name, old_mod, new_mod, old_attr=None, new_attr=None):
        super(MovedAttribute, self).__init__(name)
        if PY3:
            if new_mod is None:
                new_mod = name
            self.mod = new_mod
            if new_attr is None:
                if old_attr is None:
                    new_attr = name
                else:
                    new_attr = old_attr
            self.attr = new_attr
        else:
            self.mod = old_mod
            if old_attr is None:
                old_attr = name
            self.attr = old_attr

    def _resolve(self):
        module = _import_module(self.mod)
        return getattr(module, self.attr)


class _SixMetaPathImporter(object):

    """
    A meta path importer to import six.moves and its submodules.

    This class implements a PEP302 finder and loader. It should be compatible
    with Python 2.5 and all existing versions of Python3
    """

    def __init__(self, six_module_name):
        self.name = six_module_name
        self.known_modules = {}

    def _add_module(self, mod, *fullnames):
        for fullname in fullnames:
            self.known_modules[self.name + "." + fullname] = mod

    def _get_module(self, fullname):
        return self.known_modules[self.name + "." + fullname]

    def find_module(self, fullname, path=None):
        if fullname in self.known_modules:
            return self
        return None

    def find_spec(self, fullname, path, target=None):
        if fullname in self.known_modules:
            return spec_from_loader(fullname, self)
        return None

    def __get_module(self, fullname):
        try:
            return self.known_modules[fullname]
        except KeyError:
            raise ImportError("This loader does not know module " + fullname)

    def load_module(self, fullname):
        try:
            # in case of a reload
            return sys.modules[fullname]
        except KeyError:
            pass
        mod = self.__get_module(fullname)
        if isinstance(mod, MovedModule):
            mod = mod._resolve()
        else:
            mod.__loader__ = self
        sys.modules[fullname] = mod
        return mod

    def is_package(self, fullname):
        """
        Return true, if the named module is a package.

        We need this method to get correct spec objects with
        Python 3.4 (see PEP451)
        """
        return hasattr(self.__get_module(fullname), "__path__")

    def get_code(self, fullname):
        """Return None

        Required, if is_package is implemented"""
        self.__get_module(fullname)  # eventually raises ImportError
        return None

    get_source = get_code  # same as get_code

    def create_module(self, spec):
        return self.load_module(spec.name)

    def exec_module(self, module):
        pass


_importer = _SixMetaPathImporter(__name__)


class _MovedItems(_LazyModule):

    """Lazy loading of moved objects"""

    __path__ = []  # mark as package


_moved_attributes = [
    MovedAttribute("cStringIO", "cStringIO", "io", "StringIO"),
    MovedAttribute("filter", "itertools", "builtins", "ifilter", "filter"),
    MovedAttribute(
        "filterfalse", "itertools", "itertools", "ifilterfalse", "filterfalse"
    ),
    MovedAttribute("input", "__builtin__", "builtins", "raw_input", "input"),
    MovedAttribute("intern", "__builtin__", "sys"),
    MovedAttribute("map", "itertools", "builtins", "imap", "map"),
    MovedAttribute("getcwd", "os", "os", "getcwdu", "getcwd"),
    MovedAttribute("getcwdb", "os", "os", "getcwd", "getcwdb"),
    MovedAttribute("getoutput", "commands", "subprocess"),
    MovedAttribute("range", "__builtin__", "builtins", "xrange", "range"),
    MovedAttribute(
        "reload_module", "__builtin__", "importlib" if PY34 else "imp", "reload"
    ),
    MovedAttribute("reduce", "__builtin__", "functools"),
    MovedAttribute("shlex_quote", "pipes", "shlex", "quote"),
    MovedAttribute("StringIO", "StringIO", "io"),
    MovedAttribute("UserDict", "UserDict", "collections"),
    MovedAttribute("UserList", "UserList", "collections"),
    MovedAttribute("UserString", "UserString", "collections"),
    MovedAttribute("xrange", "__builtin__", "builtins", "xrange", "range"),
    MovedAttribute("zip", "itertools", "builtins", "izip", "zip"),
    MovedAttribute(
        "zip_longest", "itertools", "itertools", "izip_longest", "zip_longest"
    ),
    MovedModule("builtins", "__builtin__"),
    MovedModule("configparser", "ConfigParser"),
    MovedModule(
        "collections_abc",
        "collections",
        "collections.abc" if sys.version_info >= (3, 3) else "collections",
    ),
    MovedModule("copyreg", "copy_reg"),
    MovedModule("dbm_gnu", "gdbm", "dbm.gnu"),
    MovedModule("dbm_ndbm", "dbm", "dbm.ndbm"),
    MovedModule(
        "_dummy_thread",
        "dummy_thread",
        "_dummy_thread" if sys.version_info < (3, 9) else "_thread",
    ),
    MovedModule("http_cookiejar", "cookielib", "http.cookiejar"),
    MovedModule("http_cookies", "Cookie", "http.cookies"),
    MovedModule("html_entities", "htmlentitydefs", "html.entities"),
    MovedModule("html_parser", "HTMLParser", "html.parser"),
    MovedModule("http_client", "httplib", "http.client"),
    MovedModule("email_mime_base", "email.MIMEBase", "email.mime.base"),
    MovedModule("email_mime_image", "email.MIMEImage", "email.mime.image"),
    MovedModule("email_mime_multipart", "email.MIMEMultipart", "email.mime.multipart"),
    MovedModule(
        "email_mime_nonmultipart", "email.MIMENonMultipart", "email.mime.nonmultipart"
    ),
    MovedModule("email_mime_text", "email.MIMEText", "email.mime.text"),
    MovedModule("BaseHTTPServer", "BaseHTTPServer", "http.server"),
    MovedModule("CGIHTTPServer", "CGIHTTPServer", "http.server"),
    MovedModule("SimpleHTTPServer", "SimpleHTTPServer", "http.server"),
    MovedModule("cPickle", "cPickle", "pickle"),
    MovedModule("queue", "Queue"),
    MovedModule("reprlib", "repr"),
    MovedModule("socketserver", "SocketServer"),
    MovedModule("_thread", "thread", "_thread"),
    MovedModule("tkinter", "Tkinter"),
    MovedModule("tkinter_dialog", "Dialog", "tkinter.dialog"),
    MovedModule("tkinter_filedialog", "FileDialog", "tkinter.filedialog"),
    MovedModule("tkinter_scrolledtext", "ScrolledText", "tkinter.scrolledtext"),
    MovedModule("tkinter_simpledialog", "SimpleDialog", "tkinter.simpledialog"),
    MovedModule("tkinter_tix", "Tix", "tkinter.tix"),
    MovedModule("tkinter_ttk", "ttk", "tkinter.ttk"),
    MovedModule("tkinter_constants", "Tkconstants", "tkinter.constants"),
    MovedModule("tkinter_dnd", "Tkdnd", "tkinter.dnd"),
    MovedModule("tkinter_colorchooser", "tkColorChooser", "tkinter.colorchooser"),
    MovedModule("tkinter_commondialog", "tkCommonDialog", "tkinter.commondialog"),
    MovedModule("tkinter_tkfiledialog", "tkFileDialog", "tkinter.filedialog"),
    MovedModule("tkinter_font", "tkFont", "tkinter.font"),
    MovedModule("tkinter_messagebox", "tkMessageBox", "tkinter.messagebox"),
    MovedModule("tkinter_tksimpledialog", "tkSimpleDialog", "tkinter.simpledialog"),
    MovedModule("urllib_parse", __name__ + ".moves.urllib_parse", "urllib.parse"),
    MovedModule("urllib_error", __name__ + ".moves.urllib_error", "urllib.error"),
    MovedModule("urllib", __name__ + ".moves.urllib", __name__ + ".moves.urllib"),
    MovedModule("urllib_robotparser", "robotparser", "urllib.robotparser"),
    MovedModule("xmlrpc_client", "xmlrpclib", "xmlrpc.client"),
    MovedModule("xmlrpc_server", "SimpleXMLRPCServer", "xmlrpc.server"),
]
# Add windows specific modules.
if sys.platform == "win32":
    _moved_attributes += [
        MovedModule("winreg", "_winreg"),
    ]

for attr in _moved_attributes:
    setattr(_MovedItems, attr.name, attr)
    if isinstance(attr, MovedModule):
        _importer._add_module(attr, "moves." + attr.name)
del attr

_MovedItems._moved_attributes = _moved_attributes

moves = _MovedItems(__name__ + ".moves")
_importer._add_module(moves, "moves")


class Module_six_moves_urllib_parse(_LazyModule):

    """Lazy loading of moved objects in six.moves.urllib_parse"""


_urllib_parse_moved_attributes = [
    MovedAttribute("ParseResult", "urlparse", "urllib.parse"),
    MovedAttribute("SplitResult", "urlparse", "urllib.parse"),
    MovedAttribute("parse_qs", "urlparse", "urllib.parse"),
    MovedAttribute("parse_qsl", "urlparse", "urllib.parse"),
    MovedAttribute("urldefrag", "urlparse", "urllib.parse"),
    MovedAttribute("urljoin", "urlparse", "urllib.parse"),
    MovedAttribute("urlparse", "urlparse", "urllib.parse"),
    MovedAttribute("urlsplit", "urlparse", "urllib.parse"),
    MovedAttribute("urlunparse", "urlparse", "urllib.parse"),
    MovedAttribute("urlunsplit", "urlparse", "urllib.parse"),
    MovedAttribute("quote", "urllib", "urllib.parse"),
    MovedAttribute("quote_plus", "urllib", "urllib.parse"),
    MovedAttribute("unquote", "urllib", "urllib.parse"),
    MovedAttribute("unquote_plus", "urllib", "urllib.parse"),
    MovedAttribute(
        "unquote_to_bytes", "urllib", "urllib.parse", "unquote", "unquote_to_bytes"
    ),
    MovedAttribute("urlencode", "urllib", "urllib.parse"),
    MovedAttribute("splitquery", "urllib", "urllib.parse"),
    MovedAttribute("splittag", "urllib", "urllib.parse"),
    MovedAttribute("splituser", "urllib", "urllib.parse"),
    MovedAttribute("splitvalue", "urllib", "urllib.parse"),
    MovedAttribute("uses_fragment", "urlparse", "urllib.parse"),
    MovedAttribute("uses_netloc", "urlparse", "urllib.parse"),
    MovedAttribute("uses_params", "urlparse", "urllib.parse"),
    MovedAttribute("uses_query", "urlparse", "urllib.parse"),
    MovedAttribute("uses_relative", "urlparse", "urllib.parse"),
]
for attr in _urllib_parse_moved_attributes:
    setattr(Module_six_moves_urllib_parse, attr.name, attr)
del attr

Module_six_moves_urllib_parse._moved_attributes = _urllib_parse_moved_attributes

_importer._add_module(
    Module_six_moves_urllib_parse(__name__ + ".moves.urllib_parse"),
    "moves.urllib_parse",
    "moves.urllib.parse",
)


class Module_six_moves_urllib_error(_LazyModule):

    """Lazy loading of moved objects in six.moves.urllib_error"""


_urllib_error_moved_attributes = [
    MovedAttribute("URLError", "urllib2", "urllib.error"),
    MovedAttribute("HTTPError", "urllib2", "urllib.error"),
    MovedAttribute("ContentTooShortError", "urllib", "urllib.error"),
]
for attr in _urllib_error_moved_attributes:
    setattr(Module_six_moves_urllib_error, attr.name, attr)
del attr

Module_six_moves_urllib_error._moved_attributes = _urllib_error_moved_attributes

_importer._add_module(
    Module_six_moves_urllib_error(__name__ + ".moves.urllib.error"),
    "moves.urllib_error",
    "moves.urllib.error",
)


class Module_six_moves_urllib_request(_LazyModule):

    """Lazy loading of moved objects in six.moves.urllib_request"""


_urllib_request_moved_attributes = [
    MovedAttribute("urlopen", "urllib2", "urllib.request"),
    MovedAttribute("install_opener", "urllib2", "urllib.request"),
    MovedAttribute("build_opener", "urllib2", "urllib.request"),
    MovedAttribute("pathname2url", "urllib", "urllib.request"),
    MovedAttribute("url2pathname", "urllib", "urllib.request"),
    MovedAttribute("getproxies", "urllib", "urllib.request"),
    MovedAttribute("Request", "urllib2", "urllib.request"),
    MovedAttribute("OpenerDirector", "urllib2", "urllib.request"),
    MovedAttribute("HTTPDefaultErrorHandler", "urllib2", "urllib.request"),
    MovedAttribute("HTTPRedirectHandler", "urllib2", "urllib.request"),
    MovedAttribute("HTTPCookieProcessor", "urllib2", "urllib.request"),
    MovedAttribute("ProxyHandler", "urllib2", "urllib.request"),
    MovedAttribute("BaseHandler", "urllib2", "urllib.request"),
    MovedAttribute("HTTPPasswordMgr", "urllib2", "urllib.request"),
    MovedAttribute("HTTPPasswordMgrWithDefaultRealm", "urllib2", "urllib.request"),
    MovedAttribute("AbstractBasicAuthHandler", "urllib2", "urllib.request"),
    MovedAttribute("HTTPBasicAuthHandler", "urllib2", "urllib.request"),
    MovedAttribute("ProxyBasicAuthHandler", "urllib2", "urllib.request"),
    MovedAttribute("AbstractDigestAuthHandler", "urllib2", "urllib.request"),
    MovedAttribute("HTTPDigestAuthHandler", "urllib2", "urllib.request"),
    MovedAttribute("ProxyDigestAuthHandler", "urllib2", "urllib.request"),
    MovedAttribute("HTTPHandler", "urllib2", "urllib.request"),
    MovedAttribute("HTTPSHandler", "urllib2", "urllib.request"),
    MovedAttribute("FileHandler", "urllib2", "urllib.request"),
    MovedAttribute("FTPHandler", "urllib2", "urllib.request"),
    MovedAttribute("CacheFTPHandler", "urllib2", "urllib.request"),
    MovedAttribute("UnknownHandler", "urllib2", "urllib.request"),
    MovedAttribute("HTTPErrorProcessor", "urllib2", "urllib.request"),
    MovedAttribute("urlretrieve", "urllib", "urllib.request"),
    MovedAttribute("urlcleanup", "urllib", "urllib.request"),
    MovedAttribute("URLopener", "urllib", "urllib.request"),
    MovedAttribute("FancyURLopener", "urllib", "urllib.request"),
    MovedAttribute("proxy_bypass", "urllib", "urllib.request"),
    MovedAttribute("parse_http_list", "urllib2", "urllib.request"),
    MovedAttribute("parse_keqv_list", "urllib2", "urllib.request"),
]
for attr in _urllib_request_moved_attributes:
    setattr(Module_six_moves_urllib_request, attr.name, attr)
del attr

Module_six_moves_urllib_request._moved_attributes = _urllib_request_moved_attributes

_importer._add_module(
    Module_six_moves_urllib_request(__name__ + ".moves.urllib.request"),
    "moves.urllib_request",
    "moves.urllib.request",
)


class Module_six_moves_urllib_response(_LazyModule):

    """Lazy loading of moved objects in six.moves.urllib_response"""


_urllib_response_moved_attributes = [
    MovedAttribute("addbase", "urllib", "urllib.response"),
    MovedAttribute("addclosehook", "urllib", "urllib.response"),
    MovedAttribute("addinfo", "urllib", "urllib.response"),
    MovedAttribute("addinfourl", "urllib", "urllib.response"),
]
for attr in _urllib_response_moved_attributes:
    setattr(Module_six_moves_urllib_response, attr.name, attr)
del attr

Module_six_moves_urllib_response._moved_attributes = _urllib_response_moved_attributes

_importer._add_module(
    Module_six_moves_urllib_response(__name__ + ".moves.urllib.response"),
    "moves.urllib_response",
    "moves.urllib.response",
)


class Module_six_moves_urllib_robotparser(_LazyModule):

    """Lazy loading of moved objects in six.moves.urllib_robotparser"""


_urllib_robotparser_moved_attributes = [
    MovedAttribute("RobotFileParser", "robotparser", "urllib.robotparser"),
]
for attr in _urllib_robotparser_moved_attributes:
    setattr(Module_six_moves_urllib_robotparser, attr.name, attr)
del attr

Module_six_moves_urllib_robotparser._moved_attributes = (
    _urllib_robotparser_moved_attributes
)

_importer._add_module(
    Module_six_moves_urllib_robotparser(__name__ + ".moves.urllib.robotparser"),
    "moves.urllib_robotparser",
    "moves.urllib.robotparser",
)


class Module_six_moves_urllib(types.ModuleType):

    """Create a six.moves.urllib namespace that resembles the Python 3 namespace"""

    __path__ = []  # mark as package
    parse = _importer._get_module("moves.urllib_parse")
    error = _importer._get_module("moves.urllib_error")
    request = _importer._get_module("moves.urllib_request")
    response = _importer._get_module("moves.urllib_response")
    robotparser = _importer._get_module("moves.urllib_robotparser")

    def __dir__(self):
        return ["parse", "error", "request", "response", "robotparser"]


_importer._add_module(
    Module_six_moves_urllib(__name__ + ".moves.urllib"), "moves.urllib"
)


def add_move(move):
    """Add an item to six.moves."""
    setattr(_MovedItems, move.name, move)


def remove_move(name):
    """Remove item from six.moves."""
    try:
        delattr(_MovedItems, name)
    except AttributeError:
        try:
            del moves.__dict__[name]
        except KeyError:
            raise AttributeError("no such move, %r" % (name,))


if PY3:
    _meth_func = "__func__"
    _meth_self = "__self__"

    _func_closure = "__closure__"
    _func_code = "__code__"
    _func_defaults = "__defaults__"
    _func_globals = "__globals__"
else:
    _meth_func = "im_func"
    _meth_self = "im_self"

    _func_closure = "func_closure"
    _func_code = "func_code"
    _func_defaults = "func_defaults"
    _func_globals = "func_globals"


try:
    advance_iterator = next
except NameError:

    def advance_iterator(it):
        return it.next()


next = advance_iterator


try:
    callable = callable
except NameError:

    def callable(obj):
        return any("__call__" in klass.__dict__ for klass in type(obj).__mro__)


if PY3:

    def get_unbound_function(unbound):
        return unbound

    create_bound_method = types.MethodType

    def create_unbound_method(func, cls):
        return func

    Iterator = object
else:

    def get_unbound_function(unbound):
        return unbound.im_func

    def create_bound_method(func, obj):
        return types.MethodType(func, obj, obj.__class__)

    def create_unbound_method(func, cls):
        return types.MethodType(func, None, cls)

    class Iterator(object):
        def next(self):
            return type(self).__next__(self)

    callable = callable
_add_doc(
    get_unbound_function, """Get the function out of a possibly unbound function"""
)


get_method_function = operator.attrgetter(_meth_func)
get_method_self = operator.attrgetter(_meth_self)
get_function_closure = operator.attrgetter(_func_closure)
get_function_code = operator.attrgetter(_func_code)
get_function_defaults = operator.attrgetter(_func_defaults)
get_function_globals = operator.attrgetter(_func_globals)


if PY3:

    def iterkeys(d, **kw):
        return iter(d.keys(**kw))

    def itervalues(d, **kw):
        return iter(d.values(**kw))

    def iteritems(d, **kw):
        return iter(d.items(**kw))

    def iterlists(d, **kw):
        return iter(d.lists(**kw))

    viewkeys = operator.methodcaller("keys")

    viewvalues = operator.methodcaller("values")

    viewitems = operator.methodcaller("items")
else:

    def iterkeys(d, **kw):
        return d.iterkeys(**kw)

    def itervalues(d, **kw):
        return d.itervalues(**kw)

    def iteritems(d, **kw):
        return d.iteritems(**kw)

    def iterlists(d, **kw):
        return d.iterlists(**kw)

    viewkeys = operator.methodcaller("viewkeys")

    viewvalues = operator.methodcaller("viewvalues")

    viewitems = operator.methodcaller("viewitems")

_add_doc(iterkeys, "Return an iterator over the keys of a dictionary.")
_add_doc(itervalues, "Return an iterator over the values of a dictionary.")
_add_doc(iteritems, "Return an iterator over the (key, value) pairs of a dictionary.")
_add_doc(
    iterlists, "Return an iterator over the (key, [values]) pairs of a dictionary."
)


if PY3:

    def b(s):
        return s.encode("latin-1")

    def u(s):
        return s

    unichr = chr
    import struct

    int2byte = struct.Struct(">B").pack
    del struct
    byte2int = operator.itemgetter(0)
    indexbytes = operator.getitem
    iterbytes = iter
    import io

    StringIO = io.StringIO
    BytesIO = io.BytesIO
    del io
    _assertCountEqual = "assertCountEqual"
    if sys.version_info[1] <= 1:
        _assertRaisesRegex = "assertRaisesRegexp"
        _assertRegex = "assertRegexpMatches"
        _assertNotRegex = "assertNotRegexpMatches"
    else:
        _assertRaisesRegex = "assertRaisesRegex"
        _assertRegex = "assertRegex"
        _assertNotRegex = "assertNotRegex"
else:

    def b(s):
        return s

    # Workaround for standalone backslash

    def u(s):
        return unicode(s.replace(r"\\", r"\\\\"), "unicode_escape")

    unichr = unichr
    int2byte = chr

    def byte2int(bs):
        return ord(bs[0])

    def indexbytes(buf, i):
        return ord(buf[i])

    iterbytes = functools.partial(itertools.imap, ord)
    import StringIO

    StringIO = BytesIO = StringIO.StringIO
    _assertCountEqual = "assertItemsEqual"
    _assertRaisesRegex = "assertRaisesRegexp"
    _assertRegex = "assertRegexpMatches"
    _assertNotRegex = "assertNotRegexpMatches"
_add_doc(b, """Byte literal""")
_add_doc(u, """Text literal""")


def assertCountEqual(self, *args, **kwargs):
    return getattr(self, _assertCountEqual)(*args, **kwargs)


def assertRaisesRegex(self, *args, **kwargs):
    return getattr(self, _assertRaisesRegex)(*args, **kwargs)


def assertRegex(self, *args, **kwargs):
    return getattr(self, _assertRegex)(*args, **kwargs)


def assertNotRegex(self, *args, **kwargs):
    return getattr(self, _assertNotRegex)(*args, **kwargs)


if PY3:
    exec_ = getattr(moves.builtins, "exec")

    def reraise(tp, value, tb=None):
        try:
            if value is None:
                value = tp()
            if value.__traceback__ is not tb:
                raise value.with_traceback(tb)
            raise value
        finally:
            value = None
            tb = None

else:

    def exec_(_code_, _globs_=None, _locs_=None):
        """Execute code in a namespace."""
        if _globs_ is None:
            frame = sys._getframe(1)
            _globs_ = frame.f_globals
            if _locs_ is None:
                _locs_ = frame.f_locals
            del frame
        elif _locs_ is None:
            _locs_ = _globs_
        exec ("""exec _code_ in _globs_, _locs_""")

    exec_(
        """def reraise(tp, value, tb=None):
    try:
        raise tp, value, tb
    finally:
        tb = None
"""
    )


if sys.version_info[:2] > (3,):
    exec_(
        """def raise_from(value, from_value):
    try:
        raise value from from_value
    finally:
        value = None
"""
    )
else:

    def raise_from(value, from_value):
        raise value


print_ = getattr(moves.builtins, "print", None)
if print_ is None:

    def print_(*args, **kwargs):
        """The new-style print function for Python 2.4 and 2.5."""
        fp = kwargs.pop("file", sys.stdout)
        if fp is None:
            return

        def write(data):
            if not isinstance(data, basestring):
                data = str(data)
            # If the file has an encoding, encode unicode with it.
            if (
                isinstance(fp, file)
                and isinstance(data, unicode)
                and fp.encoding is not None
            ):
                errors = getattr(fp, "errors", None)
                if errors is None:
                    errors = "strict"
                data = data.encode(fp.encoding, errors)
            fp.write(data)

        want_unicode = False
        sep = kwargs.pop("sep", None)
        if sep is not None:
            if isinstance(sep, unicode):
                want_unicode = True
            elif not isinstance(sep, str):
                raise TypeError("sep must be None or a string")
        end = kwargs.pop("end", None)
        if end is not None:
            if isinstance(end, unicode):
                want_unicode = True
            elif not isinstance(end, str):
                raise TypeError("end must be None or a string")
        if kwargs:
            raise TypeError("invalid keyword arguments to print()")
        if not want_unicode:
            for arg in args:
                if isinstance(arg, unicode):
                    want_unicode = True
                    break
        if want_unicode:
            newline = unicode("\n")
            space = unicode(" ")
        else:
            newline = "\n"
            space = " "
        if sep is None:
            sep = space
        if end is None:
            end = newline
        for i, arg in enumerate(args):
            if i:
                write(sep)
            write(arg)
        write(end)


if sys.version_info[:2] < (3, 3):
    _print = print_

    def print_(*args, **kwargs):
        fp = kwargs.get("file", sys.stdout)
        flush = kwargs.pop("flush", False)
        _print(*args, **kwargs)
        if flush and fp is not None:
            fp.flush()


_add_doc(reraise, """Reraise an exception.""")

if sys.version_info[0:2] < (3, 4):
    # This does exactly the same what the :func:`py3:functools.update_wrapper`
    # function does on Python versions after 3.2. It sets the ``__wrapped__``
    # attribute on ``wrapper`` object and it doesn't raise an error if any of
    # the attributes mentioned in ``assigned`` and ``updated`` are missing on
    # ``wrapped`` object.
    def _update_wrapper(
        wrapper,
        wrapped,
        assigned=functools.WRAPPER_ASSIGNMENTS,
        updated=functools.WRAPPER_UPDATES,
    ):
        for attr in assigned:
            try:
                value = getattr(wrapped, attr)
            except AttributeError:
                continue
            else:
                setattr(wrapper, attr, value)
        for attr in updated:
            getattr(wrapper, attr).update(getattr(wrapped, attr, {}))
        wrapper.__wrapped__ = wrapped
        return wrapper

    _update_wrapper.__doc__ = functools.update_wrapper.__doc__

    def wraps(
        wrapped,
        assigned=functools.WRAPPER_ASSIGNMENTS,
        updated=functools.WRAPPER_UPDATES,
    ):
        return functools.partial(
            _update_wrapper, wrapped=wrapped, assigned=assigned, updated=updated
        )

    wraps.__doc__ = functools.wraps.__doc__

else:
    wraps = functools.wraps


def with_metaclass(meta, *bases):
    """Create a base class with a metaclass."""
    # This requires a bit of explanation: the basic idea is to make a dummy
    # metaclass for one level of class instantiation that replaces itself with
    # the actual metaclass.
    class metaclass(type):
        def __new__(cls, name, this_bases, d):
            if sys.version_info[:2] >= (3, 7):
                # This version introduced PEP 560 that requires a bit
                # of extra care (we mimic what is done by __build_class__).
                resolved_bases = types.resolve_bases(bases)
                if resolved_bases is not bases:
                    d["__orig_bases__"] = bases
            else:
                resolved_bases = bases
            return meta(name, resolved_bases, d)

        @classmethod
        def __prepare__(cls, name, this_bases):
            return meta.__prepare__(name, bases)

    return type.__new__(metaclass, "temporary_class", (), {})


def add_metaclass(metaclass):
    """Class decorator for creating a class with a metaclass."""

    def wrapper(cls):
        orig_vars = cls.__dict__.copy()
        slots = orig_vars.get("__slots__")
        if slots is not None:
            if isinstance(slots, str):
                slots = [slots]
            for slots_var in slots:
                orig_vars.pop(slots_var)
        orig_vars.pop("__dict__", None)
        orig_vars.pop("__weakref__", None)
        if hasattr(cls, "__qualname__"):
            orig_vars["__qualname__"] = cls.__qualname__
        return metaclass(cls.__name__, cls.__bases__, orig_vars)

    return wrapper


def ensure_binary(s, encoding="utf-8", errors="strict"):
    """Coerce **s** to six.binary_type.

    For Python 2:
      - `unicode` -> encoded to `str`
      - `str` -> `str`

    For Python 3:
      - `str` -> encoded to `bytes`
      - `bytes` -> `bytes`
    """
    if isinstance(s, binary_type):
        return s
    if isinstance(s, text_type):
        return s.encode(encoding, errors)
    raise TypeError("not expecting type '%s'" % type(s))


def ensure_str(s, encoding="utf-8", errors="strict"):
    """Coerce *s* to `str`.

    For Python 2:
      - `unicode` -> encoded to `str`
      - `str` -> `str`

    For Python 3:
      - `str` -> `str`
      - `bytes` -> decoded to `str`
    """
    # Optimization: Fast return for the common case.
    if type(s) is str:
        return s
    if PY2 and isinstance(s, text_type):
        return s.encode(encoding, errors)
    elif PY3 and isinstance(s, binary_type):
        return s.decode(encoding, errors)
    elif not isinstance(s, (text_type, binary_type)):
        raise TypeError("not expecting type '%s'" % type(s))
    return s


def ensure_text(s, encoding="utf-8", errors="strict"):
    """Coerce *s* to six.text_type.

    For Python 2:
      - `unicode` -> `unicode`
      - `str` -> `unicode`

    For Python 3:
      - `str` -> `str`
      - `bytes` -> decoded to `str`
    """
    if isinstance(s, binary_type):
        return s.decode(encoding, errors)
    elif isinstance(s, text_type):
        return s
    else:
        raise TypeError("not expecting type '%s'" % type(s))


def python_2_unicode_compatible(klass):
    """
    A class decorator that defines __unicode__ and __str__ methods under Python 2.
    Under Python 3 it does nothing.

    To support Python 2 and 3 with a single code base, define a __str__ method
    returning text and apply this decorator to the class.
    """
    if PY2:
        if "__str__" not in klass.__dict__:
            raise ValueError(
                "@python_2_unicode_compatible cannot be applied "
                "to %s because it doesn't define __str__()." % klass.__name__
            )
        klass.__unicode__ = klass.__str__
        klass.__str__ = lambda self: self.__unicode__().encode("utf-8")
    return klass


# Complete the moves implementation.
# This code is at the end of this module to speed up module loading.
# Turn this module into a package.
__path__ = []  # required for PEP 302 and PEP 451
__package__ = __name__  # see PEP 366 @ReservedAssignment
if globals().get("__spec__") is not None:
    __spec__.submodule_search_locations = []  # PEP 451 @UndefinedVariable
# Remove other six meta path importers, since they cause problems. This can
# happen if six is removed from sys.modules and then reloaded. (Setuptools does
# this for some reason.)
if sys.meta_path:
    for i, importer in enumerate(sys.meta_path):
        # Here's some real nastiness: Another "instance" of the six module might
        # be floating around. Therefore, we can't use isinstance() to check for
        # the six meta path importer, since the other six instance will have
        # inserted an importer with different class.
        if (
            type(importer).__name__ == "_SixMetaPathImporter"
            and importer.name == __name__
        ):
            del sys.meta_path[i]
            break
    del i, importer
# Finally, add the importer to the meta path import hook.
sys.meta_path.append(_importer)

from __future__ import absolute_import

import datetime
import logging
import os
import re
import socket
import warnings
from socket import error as SocketError
from socket import timeout as SocketTimeout

from .packages import six
from .packages.six.moves.http_client import HTTPConnection as _HTTPConnection
from .packages.six.moves.http_client import HTTPException  # noqa: F401
from .util.proxy import create_proxy_ssl_context

try:  # Compiled with SSL?
    import ssl

    BaseSSLError = ssl.SSLError
except (ImportError, AttributeError):  # Platform-specific: No SSL.
    ssl = None

    class BaseSSLError(BaseException):
        pass


try:
    # Python 3: not a no-op, we're adding this to the namespace so it can be imported.
    ConnectionError = ConnectionError
except NameError:
    # Python 2
    class ConnectionError(Exception):
        pass


try:  # Python 3:
    # Not a no-op, we're adding this to the namespace so it can be imported.
    BrokenPipeError = BrokenPipeError
except NameError:  # Python 2:

    class BrokenPipeError(Exception):
        pass


from ._collections import HTTPHeaderDict  # noqa (historical, removed in v2)
from ._version import __version__
from .exceptions import (
    ConnectTimeoutError,
    NewConnectionError,
    SubjectAltNameWarning,
    SystemTimeWarning,
)
from .util import SKIP_HEADER, SKIPPABLE_HEADERS, connection
from .util.ssl_ import (
    assert_fingerprint,
    create_urllib3_context,
    is_ipaddress,
    resolve_cert_reqs,
    resolve_ssl_version,
    ssl_wrap_socket,
)
from .util.ssl_match_hostname import CertificateError, match_hostname

log = logging.getLogger(__name__)

port_by_scheme = {"http": 80, "https": 443}

# When it comes time to update this value as a part of regular maintenance
# (ie test_recent_date is failing) update it to ~6 months before the current date.
RECENT_DATE = datetime.date(2024, 1, 1)

_CONTAINS_CONTROL_CHAR_RE = re.compile(r"[^-!#$%&'*+.^_`|~0-9a-zA-Z]")


class HTTPConnection(_HTTPConnection, object):
    """
    Based on :class:`http.client.HTTPConnection` but provides an extra constructor
    backwards-compatibility layer between older and newer Pythons.

    Additional keyword parameters are used to configure attributes of the connection.
    Accepted parameters include:

    - ``strict``: See the documentation on :class:`urllib3.connectionpool.HTTPConnectionPool`
    - ``source_address``: Set the source address for the current connection.
    - ``socket_options``: Set specific options on the underlying socket. If not specified, then
      defaults are loaded from ``HTTPConnection.default_socket_options`` which includes disabling
      Nagle's algorithm (sets TCP_NODELAY to 1) unless the connection is behind a proxy.

      For example, if you wish to enable TCP Keep Alive in addition to the defaults,
      you might pass:

      .. code-block:: python

         HTTPConnection.default_socket_options + [
             (socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1),
         ]

      Or you may want to disable the defaults by passing an empty list (e.g., ``[]``).
    """

    default_port = port_by_scheme["http"]

    #: Disable Nagle's algorithm by default.
    #: ``[(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)]``
    default_socket_options = [(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)]

    #: Whether this connection verifies the host's certificate.
    is_verified = False

    #: Whether this proxy connection (if used) verifies the proxy host's
    #: certificate.
    proxy_is_verified = None

    def __init__(self, *args, **kw):
        if not six.PY2:
            kw.pop("strict", None)

        # Pre-set source_address.
        self.source_address = kw.get("source_address")

        #: The socket options provided by the user. If no options are
        #: provided, we use the default options.
        self.socket_options = kw.pop("socket_options", self.default_socket_options)

        # Proxy options provided by the user.
        self.proxy = kw.pop("proxy", None)
        self.proxy_config = kw.pop("proxy_config", None)

        _HTTPConnection.__init__(self, *args, **kw)

    @property
    def host(self):
        """
        Getter method to remove any trailing dots that indicate the hostname is an FQDN.

        In general, SSL certificates don't include the trailing dot indicating a
        fully-qualified domain name, and thus, they don't validate properly when
        checked against a domain name that includes the dot. In addition, some
        servers may not expect to receive the trailing dot when provided.

        However, the hostname with trailing dot is critical to DNS resolution; doing a
        lookup with the trailing dot will properly only resolve the appropriate FQDN,
        whereas a lookup without a trailing dot will search the system's search domain
        list. Thus, it's important to keep the original host around for use only in
        those cases where it's appropriate (i.e., when doing DNS lookup to establish the
        actual TCP connection across which we're going to send HTTP requests).
        """
        return self._dns_host.rstrip(".")

    @host.setter
    def host(self, value):
        """
        Setter for the `host` property.

        We assume that only urllib3 uses the _dns_host attribute; httplib itself
        only uses `host`, and it seems reasonable that other libraries follow suit.
        """
        self._dns_host = value

    def _new_conn(self):
        """Establish a socket connection and set nodelay settings on it.

        :return: New socket connection.
        """
        extra_kw = {}
        if self.source_address:
            extra_kw["source_address"] = self.source_address

        if self.socket_options:
            extra_kw["socket_options"] = self.socket_options

        try:
            conn = connection.create_connection(
                (self._dns_host, self.port), self.timeout, **extra_kw
            )

        except SocketTimeout:
            raise ConnectTimeoutError(
                self,
                "Connection to %s timed out. (connect timeout=%s)"
                % (self.host, self.timeout),
            )

        except SocketError as e:
            raise NewConnectionError(
                self, "Failed to establish a new connection: %s" % e
            )

        return conn

    def _is_using_tunnel(self):
        # Google App Engine's httplib does not define _tunnel_host
        return getattr(self, "_tunnel_host", None)

    def _prepare_conn(self, conn):
        self.sock = conn
        if self._is_using_tunnel():
            # TODO: Fix tunnel so it doesn't depend on self.sock state.
            self._tunnel()
            # Mark this connection as not reusable
            self.auto_open = 0

    def connect(self):
        conn = self._new_conn()
        self._prepare_conn(conn)

    def putrequest(self, method, url, *args, **kwargs):
        """ """
        # Empty docstring because the indentation of CPython's implementation
        # is broken but we don't want this method in our documentation.
        match = _CONTAINS_CONTROL_CHAR_RE.search(method)
        if match:
            raise ValueError(
                "Method cannot contain non-token characters %r (found at least %r)"
                % (method, match.group())
            )

        return _HTTPConnection.putrequest(self, method, url, *args, **kwargs)

    def putheader(self, header, *values):
        """ """
        if not any(isinstance(v, str) and v == SKIP_HEADER for v in values):
            _HTTPConnection.putheader(self, header, *values)
        elif six.ensure_str(header.lower()) not in SKIPPABLE_HEADERS:
            raise ValueError(
                "urllib3.util.SKIP_HEADER only supports '%s'"
                % ("', '".join(map(str.title, sorted(SKIPPABLE_HEADERS))),)
            )

    def request(self, method, url, body=None, headers=None):
        # Update the inner socket's timeout value to send the request.
        # This only triggers if the connection is re-used.
        if getattr(self, "sock", None) is not None:
            self.sock.settimeout(self.timeout)

        if headers is None:
            headers = {}
        else:
            # Avoid modifying the headers passed into .request()
            headers = headers.copy()
        if "user-agent" not in (six.ensure_str(k.lower()) for k in headers):
            headers["User-Agent"] = _get_default_user_agent()
        super(HTTPConnection, self).request(method, url, body=body, headers=headers)

    def request_chunked(self, method, url, body=None, headers=None):
        """
        Alternative to the common request method, which sends the
        body with chunked encoding and not as one block
        """
        headers = headers or {}
        header_keys = set([six.ensure_str(k.lower()) for k in headers])
        skip_accept_encoding = "accept-encoding" in header_keys
        skip_host = "host" in header_keys
        self.putrequest(
            method, url, skip_accept_encoding=skip_accept_encoding, skip_host=skip_host
        )
        if "user-agent" not in header_keys:
            self.putheader("User-Agent", _get_default_user_agent())
        for header, value in headers.items():
            self.putheader(header, value)
        if "transfer-encoding" not in header_keys:
            self.putheader("Transfer-Encoding", "chunked")
        self.endheaders()

        if body is not None:
            stringish_types = six.string_types + (bytes,)
            if isinstance(body, stringish_types):
                body = (body,)
            for chunk in body:
                if not chunk:
                    continue
                if not isinstance(chunk, bytes):
                    chunk = chunk.encode("utf8")
                len_str = hex(len(chunk))[2:]
                to_send = bytearray(len_str.encode())
                to_send += b"\r\n"
                to_send += chunk
                to_send += b"\r\n"
                self.send(to_send)

        # After the if clause, to always have a closed body
        self.send(b"0\r\n\r\n")


class HTTPSConnection(HTTPConnection):
    """
    Many of the parameters to this constructor are passed to the underlying SSL
    socket by means of :py:func:`urllib3.util.ssl_wrap_socket`.
    """

    default_port = port_by_scheme["https"]

    cert_reqs = None
    ca_certs = None
    ca_cert_dir = None
    ca_cert_data = None
    ssl_version = None
    assert_fingerprint = None
    tls_in_tls_required = False

    def __init__(
        self,
        host,
        port=None,
        key_file=None,
        cert_file=None,
        key_password=None,
        strict=None,
        timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
        ssl_context=None,
        server_hostname=None,
        **kw
    ):

        HTTPConnection.__init__(self, host, port, strict=strict, timeout=timeout, **kw)

        self.key_file = key_file
        self.cert_file = cert_file
        self.key_password = key_password
        self.ssl_context = ssl_context
        self.server_hostname = server_hostname

        # Required property for Google AppEngine 1.9.0 which otherwise causes
        # HTTPS requests to go out as HTTP. (See Issue #356)
        self._protocol = "https"

    def set_cert(
        self,
        key_file=None,
        cert_file=None,
        cert_reqs=None,
        key_password=None,
        ca_certs=None,
        assert_hostname=None,
        assert_fingerprint=None,
        ca_cert_dir=None,
        ca_cert_data=None,
    ):
        """
        This method should only be called once, before the connection is used.
        """
        # If cert_reqs is not provided we'll assume CERT_REQUIRED unless we also
        # have an SSLContext object in which case we'll use its verify_mode.
        if cert_reqs is None:
            if self.ssl_context is not None:
                cert_reqs = self.ssl_context.verify_mode
            else:
                cert_reqs = resolve_cert_reqs(None)

        self.key_file = key_file
        self.cert_file = cert_file
        self.cert_reqs = cert_reqs
        self.key_password = key_password
        self.assert_hostname = assert_hostname
        self.assert_fingerprint = assert_fingerprint
        self.ca_certs = ca_certs and os.path.expanduser(ca_certs)
        self.ca_cert_dir = ca_cert_dir and os.path.expanduser(ca_cert_dir)
        self.ca_cert_data = ca_cert_data

    def connect(self):
        # Add certificate verification
        self.sock = conn = self._new_conn()
        hostname = self.host
        tls_in_tls = False

        if self._is_using_tunnel():
            if self.tls_in_tls_required:
                self.sock = conn = self._connect_tls_proxy(hostname, conn)
                tls_in_tls = True

            # Calls self._set_hostport(), so self.host is
            # self._tunnel_host below.
            self._tunnel()
            # Mark this connection as not reusable
            self.auto_open = 0

            # Override the host with the one we're requesting data from.
            hostname = self._tunnel_host

        server_hostname = hostname
        if self.server_hostname is not None:
            server_hostname = self.server_hostname

        is_time_off = datetime.date.today() < RECENT_DATE
        if is_time_off:
            warnings.warn(
                (
                    "System time is way off (before {0}). This will probably "
                    "lead to SSL verification errors"
                ).format(RECENT_DATE),
                SystemTimeWarning,
            )

        # Wrap socket using verification with the root certs in
        # trusted_root_certs
        default_ssl_context = False
        if self.ssl_context is None:
            default_ssl_context = True
            self.ssl_context = create_urllib3_context(
                ssl_version=resolve_ssl_version(self.ssl_version),
                cert_reqs=resolve_cert_reqs(self.cert_reqs),
            )

        context = self.ssl_context
        context.verify_mode = resolve_cert_reqs(self.cert_reqs)

        # Try to load OS default certs if none are given.
        # Works well on Windows (requires Python3.4+)
        if (
            not self.ca_certs
            and not self.ca_cert_dir
            and not self.ca_cert_data
            and default_ssl_context
            and hasattr(context, "load_default_certs")
        ):
            context.load_default_certs()

        self.sock = ssl_wrap_socket(
            sock=conn,
            keyfile=self.key_file,
            certfile=self.cert_file,
            key_password=self.key_password,
            ca_certs=self.ca_certs,
            ca_cert_dir=self.ca_cert_dir,
            ca_cert_data=self.ca_cert_data,
            server_hostname=server_hostname,
            ssl_context=context,
            tls_in_tls=tls_in_tls,
        )

        # If we're using all defaults and the connection
        # is TLSv1 or TLSv1.1 we throw a DeprecationWarning
        # for the host.
        if (
            default_ssl_context
            and self.ssl_version is None
            and hasattr(self.sock, "version")
            and self.sock.version() in {"TLSv1", "TLSv1.1"}
        ):  # Defensive:
            warnings.warn(
                "Negotiating TLSv1/TLSv1.1 by default is deprecated "
                "and will be disabled in urllib3 v2.0.0. Connecting to "
                "'%s' with '%s' can be enabled by explicitly opting-in "
                "with 'ssl_version'" % (self.host, self.sock.version()),
                DeprecationWarning,
            )

        if self.assert_fingerprint:
            assert_fingerprint(
                self.sock.getpeercert(binary_form=True), self.assert_fingerprint
            )
        elif (
            context.verify_mode != ssl.CERT_NONE
            and not getattr(context, "check_hostname", False)
            and self.assert_hostname is not False
        ):
            # While urllib3 attempts to always turn off hostname matching from
            # the TLS library, this cannot always be done. So we check whether
            # the TLS Library still thinks it's matching hostnames.
            cert = self.sock.getpeercert()
            if not cert.get("subjectAltName", ()):
                warnings.warn(
                    (
                        "Certificate for {0} has no `subjectAltName`, falling back to check for a "
                        "`commonName` for now. This feature is being removed by major browsers and "
                        "deprecated by RFC 2818. (See https://github.com/urllib3/urllib3/issues/497 "
                        "for details.)".format(hostname)
                    ),
                    SubjectAltNameWarning,
                )
            _match_hostname(cert, self.assert_hostname or server_hostname)

        self.is_verified = (
            context.verify_mode == ssl.CERT_REQUIRED
            or self.assert_fingerprint is not None
        )

    def _connect_tls_proxy(self, hostname, conn):
        """
        Establish a TLS connection to the proxy using the provided SSL context.
        """
        proxy_config = self.proxy_config
        ssl_context = proxy_config.ssl_context
        if ssl_context:
            # If the user provided a proxy context, we assume CA and client
            # certificates have already been set
            return ssl_wrap_socket(
                sock=conn,
                server_hostname=hostname,
                ssl_context=ssl_context,
            )

        ssl_context = create_proxy_ssl_context(
            self.ssl_version,
            self.cert_reqs,
            self.ca_certs,
            self.ca_cert_dir,
            self.ca_cert_data,
        )

        # If no cert was provided, use only the default options for server
        # certificate validation
        socket = ssl_wrap_socket(
            sock=conn,
            ca_certs=self.ca_certs,
            ca_cert_dir=self.ca_cert_dir,
            ca_cert_data=self.ca_cert_data,
            server_hostname=hostname,
            ssl_context=ssl_context,
        )

        if ssl_context.verify_mode != ssl.CERT_NONE and not getattr(
            ssl_context, "check_hostname", False
        ):
            # While urllib3 attempts to always turn off hostname matching from
            # the TLS library, this cannot always be done. So we check whether
            # the TLS Library still thinks it's matching hostnames.
            cert = socket.getpeercert()
            if not cert.get("subjectAltName", ()):
                warnings.warn(
                    (
                        "Certificate for {0} has no `subjectAltName`, falling back to check for a "
                        "`commonName` for now. This feature is being removed by major browsers and "
                        "deprecated by RFC 2818. (See https://github.com/urllib3/urllib3/issues/497 "
                        "for details.)".format(hostname)
                    ),
                    SubjectAltNameWarning,
                )
            _match_hostname(cert, hostname)

        self.proxy_is_verified = ssl_context.verify_mode == ssl.CERT_REQUIRED
        return socket


def _match_hostname(cert, asserted_hostname):
    # Our upstream implementation of ssl.match_hostname()
    # only applies this normalization to IP addresses so it doesn't
    # match DNS SANs so we do the same thing!
    stripped_hostname = asserted_hostname.strip("u[]")
    if is_ipaddress(stripped_hostname):
        asserted_hostname = stripped_hostname

    try:
        match_hostname(cert, asserted_hostname)
    except CertificateError as e:
        log.warning(
            "Certificate did not match expected hostname: %s. Certificate: %s",
            asserted_hostname,
            cert,
        )
        # Add cert to exception and reraise so client code can inspect
        # the cert when catching the exception, if they want to
        e._peer_cert = cert
        raise


def _get_default_user_agent():
    return "python-urllib3/%s" % __version__


class DummyConnection(object):
    """Used to detect a failed ConnectionCls import."""

    pass


if not ssl:
    HTTPSConnection = DummyConnection  # noqa: F811


VerifiedHTTPSConnection = HTTPSConnection

import contextlib
import os
import re
import ssl
import typing

# candidates based on https://github.com/tiran/certifi-system-store by Christian Heimes
_CA_FILE_CANDIDATES = [
    # Alpine, Arch, Fedora 34+, OpenWRT, RHEL 9+, BSD
    "/etc/ssl/cert.pem",
    # Fedora <= 34, RHEL <= 9, CentOS <= 9
    "/etc/pki/tls/cert.pem",
    # Debian, Ubuntu (requires ca-certificates)
    "/etc/ssl/certs/ca-certificates.crt",
    # SUSE
    "/etc/ssl/ca-bundle.pem",
]

_HASHED_CERT_FILENAME_RE = re.compile(r"^[0-9a-fA-F]{8}\.[0-9]$")


@contextlib.contextmanager
def _configure_context(ctx: ssl.SSLContext) -> typing.Iterator[None]:
    # First, check whether the default locations from OpenSSL
    # seem like they will give us a usable set of CA certs.
    # ssl.get_default_verify_paths already takes care of:
    # - getting cafile from either the SSL_CERT_FILE env var
    #   or the path configured when OpenSSL was compiled,
    #   and verifying that that path exists
    # - getting capath from either the SSL_CERT_DIR env var
    #   or the path configured when OpenSSL was compiled,
    #   and verifying that that path exists
    # In addition we'll check whether capath appears to contain certs.
    defaults = ssl.get_default_verify_paths()
    if defaults.cafile or (defaults.capath and _capath_contains_certs(defaults.capath)):
        ctx.set_default_verify_paths()
    else:
        # cafile from OpenSSL doesn't exist
        # and capath from OpenSSL doesn't contain certs.
        # Let's search other common locations instead.
        for cafile in _CA_FILE_CANDIDATES:
            if os.path.isfile(cafile):
                ctx.load_verify_locations(cafile=cafile)
                break

    yield


def _capath_contains_certs(capath: str) -> bool:
    """Check whether capath exists and contains certs in the expected format."""
    if not os.path.isdir(capath):
        return False
    for name in os.listdir(capath):
        if _HASHED_CERT_FILENAME_RE.match(name):
            return True
    return False


def _verify_peercerts_impl(
    ssl_context: ssl.SSLContext,
    cert_chain: list[bytes],
    server_hostname: str | None = None,
) -> None:
    # This is a no-op because we've enabled SSLContext's built-in
    # verification via verify_mode=CERT_REQUIRED, and don't need to repeat it.
    pass