"""
requests.exceptions
~~~~~~~~~~~~~~~~~~~

This module contains the set of Requests' exceptions.
"""
from pip._vendor.urllib3.exceptions import HTTPError as BaseHTTPError

from .compat import JSONDecodeError as CompatJSONDecodeError


class RequestException(IOError):
    """There was an ambiguous exception that occurred while handling your
    request.
    """

    def __init__(self, *args, **kwargs):
        """Initialize RequestException with `request` and `response` objects."""
        response = kwargs.pop("response", None)
        self.response = response
        self.request = kwargs.pop("request", None)
        if response is not None and not self.request and hasattr(response, "request"):
            self.request = self.response.request
        super().__init__(*args, **kwargs)


class InvalidJSONError(RequestException):
    """A JSON error occurred."""


class JSONDecodeError(InvalidJSONError, CompatJSONDecodeError):
    """Couldn't decode the text into json"""

    def __init__(self, *args, **kwargs):
        """
        Construct the JSONDecodeError instance first with all
        args. Then use it's args to construct the IOError so that
        the json specific args aren't used as IOError specific args
        and the error message from JSONDecodeError is preserved.
        """
        CompatJSONDecodeError.__init__(self, *args)
        InvalidJSONError.__init__(self, *self.args, **kwargs)

    def __reduce__(self):
        """
        The __reduce__ method called when pickling the object must
        be the one from the JSONDecodeError (be it json/simplejson)
        as it expects all the arguments for instantiation, not just
        one like the IOError, and the MRO would by default call the
        __reduce__ method from the IOError due to the inheritance order.
        """
        return CompatJSONDecodeError.__reduce__(self)


class HTTPError(RequestException):
    """An HTTP error occurred."""


class ConnectionError(RequestException):
    """A Connection error occurred."""


class ProxyError(ConnectionError):
    """A proxy error occurred."""


class SSLError(ConnectionError):
    """An SSL error occurred."""


class Timeout(RequestException):
    """The request timed out.

    Catching this error will catch both
    :exc:`~requests.exceptions.ConnectTimeout` and
    :exc:`~requests.exceptions.ReadTimeout` errors.
    """


class ConnectTimeout(ConnectionError, Timeout):
    """The request timed out while trying to connect to the remote server.

    Requests that produced this error are safe to retry.
    """


class ReadTimeout(Timeout):
    """The server did not send any data in the allotted amount of time."""


class URLRequired(RequestException):
    """A valid URL is required to make a request."""


class TooManyRedirects(RequestException):
    """Too many redirects."""


class MissingSchema(RequestException, ValueError):
    """The URL scheme (e.g. http or https) is missing."""


class InvalidSchema(RequestException, ValueError):
    """The URL scheme provided is either invalid or unsupported."""


class InvalidURL(RequestException, ValueError):
    """The URL provided was somehow invalid."""


class InvalidHeader(RequestException, ValueError):
    """The header value provided was somehow invalid."""


class InvalidProxyURL(InvalidURL):
    """The proxy URL provided is invalid."""


class ChunkedEncodingError(RequestException):
    """The server declared chunked encoding but sent an invalid chunk."""


class ContentDecodingError(RequestException, BaseHTTPError):
    """Failed to decode response content."""


class StreamConsumedError(RequestException, TypeError):
    """The content for this response was already consumed."""


class RetryError(RequestException):
    """Custom retries logic failed"""


class UnrewindableBodyError(RequestException):
    """Requests encountered an error when trying to rewind a body."""


# Warnings


class RequestsWarning(Warning):
    """Base warning for Requests."""


class FileModeWarning(RequestsWarning, DeprecationWarning):
    """A file was opened in text mode, but Requests determined its binary length."""


class RequestsDependencyWarning(RequestsWarning):
    """An imported dependency doesn't match the expected version range."""

from __future__ import annotations

import contextlib
import re
from dataclasses import dataclass
from typing import Iterator, NoReturn

from .specifiers import Specifier


@dataclass
class Token:
    name: str
    text: str
    position: int


class ParserSyntaxError(Exception):
    """The provided source text could not be parsed correctly."""

    def __init__(
        self,
        message: str,
        *,
        source: str,
        span: tuple[int, int],
    ) -> None:
        self.span = span
        self.message = message
        self.source = source

        super().__init__()

    def __str__(self) -> str:
        marker = " " * self.span[0] + "~" * (self.span[1] - self.span[0]) + "^"
        return "\n    ".join([self.message, self.source, marker])


DEFAULT_RULES: dict[str, str | re.Pattern[str]] = {
    "LEFT_PARENTHESIS": r"\(",
    "RIGHT_PARENTHESIS": r"\)",
    "LEFT_BRACKET": r"\[",
    "RIGHT_BRACKET": r"\]",
    "SEMICOLON": r";",
    "COMMA": r",",
    "QUOTED_STRING": re.compile(
        r"""
            (
                ('[^']*')
                |
                ("[^"]*")
            )
        """,
        re.VERBOSE,
    ),
    "OP": r"(===|==|~=|!=|<=|>=|<|>)",
    "BOOLOP": r"\b(or|and)\b",
    "IN": r"\bin\b",
    "NOT": r"\bnot\b",
    "VARIABLE": re.compile(
        r"""
            \b(
                python_version
                |python_full_version
                |os[._]name
                |sys[._]platform
                |platform_(release|system)
                |platform[._](version|machine|python_implementation)
                |python_implementation
                |implementation_(name|version)
                |extra
            )\b
        """,
        re.VERBOSE,
    ),
    "SPECIFIER": re.compile(
        Specifier._operator_regex_str + Specifier._version_regex_str,
        re.VERBOSE | re.IGNORECASE,
    ),
    "AT": r"\@",
    "URL": r"[^ \t]+",
    "IDENTIFIER": r"\b[a-zA-Z0-9][a-zA-Z0-9._-]*\b",
    "VERSION_PREFIX_TRAIL": r"\.\*",
    "VERSION_LOCAL_LABEL_TRAIL": r"\+[a-z0-9]+(?:[-_\.][a-z0-9]+)*",
    "WS": r"[ \t]+",
    "END": r"$",
}


class Tokenizer:
    """Context-sensitive token parsing.

    Provides methods to examine the input stream to check whether the next token
    matches.
    """

    def __init__(
        self,
        source: str,
        *,
        rules: dict[str, str | re.Pattern[str]],
    ) -> None:
        self.source = source
        self.rules: dict[str, re.Pattern[str]] = {
            name: re.compile(pattern) for name, pattern in rules.items()
        }
        self.next_token: Token | None = None
        self.position = 0

    def consume(self, name: str) -> None:
        """Move beyond provided token name, if at current position."""
        if self.check(name):
            self.read()

    def check(self, name: str, *, peek: bool = False) -> bool:
        """Check whether the next token has the provided name.

        By default, if the check succeeds, the token *must* be read before
        another check. If `peek` is set to `True`, the token is not loaded and
        would need to be checked again.
        """
        assert (
            self.next_token is None
        ), f"Cannot check for {name!r}, already have {self.next_token!r}"
        assert name in self.rules, f"Unknown token name: {name!r}"

        expression = self.rules[name]

        match = expression.match(self.source, self.position)
        if match is None:
            return False
        if not peek:
            self.next_token = Token(name, match[0], self.position)
        return True

    def expect(self, name: str, *, expected: str) -> Token:
        """Expect a certain token name next, failing with a syntax error otherwise.

        The token is *not* read.
        """
        if not self.check(name):
            raise self.raise_syntax_error(f"Expected {expected}")
        return self.read()

    def read(self) -> Token:
        """Consume the next token and return it."""
        token = self.next_token
        assert token is not None

        self.position += len(token.text)
        self.next_token = None

        return token

    def raise_syntax_error(
        self,
        message: str,
        *,
        span_start: int | None = None,
        span_end: int | None = None,
    ) -> NoReturn:
        """Raise ParserSyntaxError at the given position."""
        span = (
            self.position if span_start is None else span_start,
            self.position if span_end is None else span_end,
        )
        raise ParserSyntaxError(
            message,
            source=self.source,
            span=span,
        )

    @contextlib.contextmanager
    def enclosing_tokens(
        self, open_token: str, close_token: str, *, around: str
    ) -> Iterator[None]:
        if self.check(open_token):
            open_position = self.position
            self.read()
        else:
            open_position = None

        yield

        if open_position is None:
            return

        if not self.check(close_token):
            self.raise_syntax_error(
                f"Expected matching {close_token} for {open_token}, after {around}",
                span_start=open_position,
            )

        self.read()

# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.
"""
.. testsetup::

    from pip._vendor.packaging.version import parse, Version
"""

from __future__ import annotations

import itertools
import re
from typing import Any, Callable, NamedTuple, SupportsInt, Tuple, Union

from ._structures import Infinity, InfinityType, NegativeInfinity, NegativeInfinityType

__all__ = ["VERSION_PATTERN", "parse", "Version", "InvalidVersion"]

LocalType = Tuple[Union[int, str], ...]

CmpPrePostDevType = Union[InfinityType, NegativeInfinityType, Tuple[str, int]]
CmpLocalType = Union[
    NegativeInfinityType,
    Tuple[Union[Tuple[int, str], Tuple[NegativeInfinityType, Union[int, str]]], ...],
]
CmpKey = Tuple[
    int,
    Tuple[int, ...],
    CmpPrePostDevType,
    CmpPrePostDevType,
    CmpPrePostDevType,
    CmpLocalType,
]
VersionComparisonMethod = Callable[[CmpKey, CmpKey], bool]


class _Version(NamedTuple):
    epoch: int
    release: tuple[int, ...]
    dev: tuple[str, int] | None
    pre: tuple[str, int] | None
    post: tuple[str, int] | None
    local: LocalType | None


def parse(version: str) -> Version:
    """Parse the given version string.

    >>> parse('1.0.dev1')
    <Version('1.0.dev1')>

    :param version: The version string to parse.
    :raises InvalidVersion: When the version string is not a valid version.
    """
    return Version(version)


class InvalidVersion(ValueError):
    """Raised when a version string is not a valid version.

    >>> Version("invalid")
    Traceback (most recent call last):
        ...
    packaging.version.InvalidVersion: Invalid version: 'invalid'
    """


class _BaseVersion:
    _key: tuple[Any, ...]

    def __hash__(self) -> int:
        return hash(self._key)

    # Please keep the duplicated `isinstance` check
    # in the six comparisons hereunder
    # unless you find a way to avoid adding overhead function calls.
    def __lt__(self, other: _BaseVersion) -> bool:
        if not isinstance(other, _BaseVersion):
            return NotImplemented

        return self._key < other._key

    def __le__(self, other: _BaseVersion) -> bool:
        if not isinstance(other, _BaseVersion):
            return NotImplemented

        return self._key <= other._key

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, _BaseVersion):
            return NotImplemented

        return self._key == other._key

    def __ge__(self, other: _BaseVersion) -> bool:
        if not isinstance(other, _BaseVersion):
            return NotImplemented

        return self._key >= other._key

    def __gt__(self, other: _BaseVersion) -> bool:
        if not isinstance(other, _BaseVersion):
            return NotImplemented

        return self._key > other._key

    def __ne__(self, other: object) -> bool:
        if not isinstance(other, _BaseVersion):
            return NotImplemented

        return self._key != other._key


# Deliberately not anchored to the start and end of the string, to make it
# easier for 3rd party code to reuse
_VERSION_PATTERN = r"""
    v?
    (?:
        (?:(?P<epoch>[0-9]+)!)?                           # epoch
        (?P<release>[0-9]+(?:\.[0-9]+)*)                  # release segment
        (?P<pre>                                          # pre-release
            [-_\.]?
            (?P<pre_l>alpha|a|beta|b|preview|pre|c|rc)
            [-_\.]?
            (?P<pre_n>[0-9]+)?
        )?
        (?P<post>                                         # post release
            (?:-(?P<post_n1>[0-9]+))
            |
            (?:
                [-_\.]?
                (?P<post_l>post|rev|r)
                [-_\.]?
                (?P<post_n2>[0-9]+)?
            )
        )?
        (?P<dev>                                          # dev release
            [-_\.]?
            (?P<dev_l>dev)
            [-_\.]?
            (?P<dev_n>[0-9]+)?
        )?
    )
    (?:\+(?P<local>[a-z0-9]+(?:[-_\.][a-z0-9]+)*))?       # local version
"""

VERSION_PATTERN = _VERSION_PATTERN
"""
A string containing the regular expression used to match a valid version.

The pattern is not anchored at either end, and is intended for embedding in larger
expressions (for example, matching a version number as part of a file name). The
regular expression should be compiled with the ``re.VERBOSE`` and ``re.IGNORECASE``
flags set.

:meta hide-value:
"""


class Version(_BaseVersion):
    """This class abstracts handling of a project's versions.

    A :class:`Version` instance is comparison aware and can be compared and
    sorted using the standard Python interfaces.

    >>> v1 = Version("1.0a5")
    >>> v2 = Version("1.0")
    >>> v1
    <Version('1.0a5')>
    >>> v2
    <Version('1.0')>
    >>> v1 < v2
    True
    >>> v1 == v2
    False
    >>> v1 > v2
    False
    >>> v1 >= v2
    False
    >>> v1 <= v2
    True
    """

    _regex = re.compile(r"^\s*" + VERSION_PATTERN + r"\s*$", re.VERBOSE | re.IGNORECASE)
    _key: CmpKey

    def __init__(self, version: str) -> None:
        """Initialize a Version object.

        :param version:
            The string representation of a version which will be parsed and normalized
            before use.
        :raises InvalidVersion:
            If the ``version`` does not conform to PEP 440 in any way then this
            exception will be raised.
        """

        # Validate the version and parse it into pieces
        match = self._regex.search(version)
        if not match:
            raise InvalidVersion(f"Invalid version: '{version}'")

        # Store the parsed out pieces of the version
        self._version = _Version(
            epoch=int(match.group("epoch")) if match.group("epoch") else 0,
            release=tuple(int(i) for i in match.group("release").split(".")),
            pre=_parse_letter_version(match.group("pre_l"), match.group("pre_n")),
            post=_parse_letter_version(
                match.group("post_l"), match.group("post_n1") or match.group("post_n2")
            ),
            dev=_parse_letter_version(match.group("dev_l"), match.group("dev_n")),
            local=_parse_local_version(match.group("local")),
        )

        # Generate a key which will be used for sorting
        self._key = _cmpkey(
            self._version.epoch,
            self._version.release,
            self._version.pre,
            self._version.post,
            self._version.dev,
            self._version.local,
        )

    def __repr__(self) -> str:
        """A representation of the Version that shows all internal state.

        >>> Version('1.0.0')
        <Version('1.0.0')>
        """
        return f"<Version('{self}')>"

    def __str__(self) -> str:
        """A string representation of the version that can be rounded-tripped.

        >>> str(Version("1.0a5"))
        '1.0a5'
        """
        parts = []

        # Epoch
        if self.epoch != 0:
            parts.append(f"{self.epoch}!")

        # Release segment
        parts.append(".".join(str(x) for x in self.release))

        # Pre-release
        if self.pre is not None:
            parts.append("".join(str(x) for x in self.pre))

        # Post-release
        if self.post is not None:
            parts.append(f".post{self.post}")

        # Development release
        if self.dev is not None:
            parts.append(f".dev{self.dev}")

        # Local version segment
        if self.local is not None:
            parts.append(f"+{self.local}")

        return "".join(parts)

    @property
    def epoch(self) -> int:
        """The epoch of the version.

        >>> Version("2.0.0").epoch
        0
        >>> Version("1!2.0.0").epoch
        1
        """
        return self._version.epoch

    @property
    def release(self) -> tuple[int, ...]:
        """The components of the "release" segment of the version.

        >>> Version("1.2.3").release
        (1, 2, 3)
        >>> Version("2.0.0").release
        (2, 0, 0)
        >>> Version("1!2.0.0.post0").release
        (2, 0, 0)

        Includes trailing zeroes but not the epoch or any pre-release / development /
        post-release suffixes.
        """
        return self._version.release

    @property
    def pre(self) -> tuple[str, int] | None:
        """The pre-release segment of the version.

        >>> print(Version("1.2.3").pre)
        None
        >>> Version("1.2.3a1").pre
        ('a', 1)
        >>> Version("1.2.3b1").pre
        ('b', 1)
        >>> Version("1.2.3rc1").pre
        ('rc', 1)
        """
        return self._version.pre

    @property
    def post(self) -> int | None:
        """The post-release number of the version.

        >>> print(Version("1.2.3").post)
        None
        >>> Version("1.2.3.post1").post
        1
        """
        return self._version.post[1] if self._version.post else None

    @property
    def dev(self) -> int | None:
        """The development number of the version.

        >>> print(Version("1.2.3").dev)
        None
        >>> Version("1.2.3.dev1").dev
        1
        """
        return self._version.dev[1] if self._version.dev else None

    @property
    def local(self) -> str | None:
        """The local version segment of the version.

        >>> print(Version("1.2.3").local)
        None
        >>> Version("1.2.3+abc").local
        'abc'
        """
        if self._version.local:
            return ".".join(str(x) for x in self._version.local)
        else:
            return None

    @property
    def public(self) -> str:
        """The public portion of the version.

        >>> Version("1.2.3").public
        '1.2.3'
        >>> Version("1.2.3+abc").public
        '1.2.3'
        >>> Version("1.2.3+abc.dev1").public
        '1.2.3'
        """
        return str(self).split("+", 1)[0]

    @property
    def base_version(self) -> str:
        """The "base version" of the version.

        >>> Version("1.2.3").base_version
        '1.2.3'
        >>> Version("1.2.3+abc").base_version
        '1.2.3'
        >>> Version("1!1.2.3+abc.dev1").base_version
        '1!1.2.3'

        The "base version" is the public version of the project without any pre or post
        release markers.
        """
        parts = []

        # Epoch
        if self.epoch != 0:
            parts.append(f"{self.epoch}!")

        # Release segment
        parts.append(".".join(str(x) for x in self.release))

        return "".join(parts)

    @property
    def is_prerelease(self) -> bool:
        """Whether this version is a pre-release.

        >>> Version("1.2.3").is_prerelease
        False
        >>> Version("1.2.3a1").is_prerelease
        True
        >>> Version("1.2.3b1").is_prerelease
        True
        >>> Version("1.2.3rc1").is_prerelease
        True
        >>> Version("1.2.3dev1").is_prerelease
        True
        """
        return self.dev is not None or self.pre is not None

    @property
    def is_postrelease(self) -> bool:
        """Whether this version is a post-release.

        >>> Version("1.2.3").is_postrelease
        False
        >>> Version("1.2.3.post1").is_postrelease
        True
        """
        return self.post is not None

    @property
    def is_devrelease(self) -> bool:
        """Whether this version is a development release.

        >>> Version("1.2.3").is_devrelease
        False
        >>> Version("1.2.3.dev1").is_devrelease
        True
        """
        return self.dev is not None

    @property
    def major(self) -> int:
        """The first item of :attr:`release` or ``0`` if unavailable.

        >>> Version("1.2.3").major
        1
        """
        return self.release[0] if len(self.release) >= 1 else 0

    @property
    def minor(self) -> int:
        """The second item of :attr:`release` or ``0`` if unavailable.

        >>> Version("1.2.3").minor
        2
        >>> Version("1").minor
        0
        """
        return self.release[1] if len(self.release) >= 2 else 0

    @property
    def micro(self) -> int:
        """The third item of :attr:`release` or ``0`` if unavailable.

        >>> Version("1.2.3").micro
        3
        >>> Version("1").micro
        0
        """
        return self.release[2] if len(self.release) >= 3 else 0


def _parse_letter_version(
    letter: str | None, number: str | bytes | SupportsInt | None
) -> tuple[str, int] | None:
    if letter:
        # We consider there to be an implicit 0 in a pre-release if there is
        # not a numeral associated with it.
        if number is None:
            number = 0

        # We normalize any letters to their lower case form
        letter = letter.lower()

        # We consider some words to be alternate spellings of other words and
        # in those cases we want to normalize the spellings to our preferred
        # spelling.
        if letter == "alpha":
            letter = "a"
        elif letter == "beta":
            letter = "b"
        elif letter in ["c", "pre", "preview"]:
            letter = "rc"
        elif letter in ["rev", "r"]:
            letter = "post"

        return letter, int(number)
    if not letter and number:
        # We assume if we are given a number, but we are not given a letter
        # then this is using the implicit post release syntax (e.g. 1.0-1)
        letter = "post"

        return letter, int(number)

    return None


_local_version_separators = re.compile(r"[\._-]")


def _parse_local_version(local: str | None) -> LocalType | None:
    """
    Takes a string like abc.1.twelve and turns it into ("abc", 1, "twelve").
    """
    if local is not None:
        return tuple(
            part.lower() if not part.isdigit() else int(part)
            for part in _local_version_separators.split(local)
        )
    return None


def _cmpkey(
    epoch: int,
    release: tuple[int, ...],
    pre: tuple[str, int] | None,
    post: tuple[str, int] | None,
    dev: tuple[str, int] | None,
    local: LocalType | None,
) -> CmpKey:
    # When we compare a release version, we want to compare it with all of the
    # trailing zeros removed. So we'll use a reverse the list, drop all the now
    # leading zeros until we come to something non zero, then take the rest
    # re-reverse it back into the correct order and make it a tuple and use
    # that for our sorting key.
    _release = tuple(
        reversed(list(itertools.dropwhile(lambda x: x == 0, reversed(release))))
    )

    # We need to "trick" the sorting algorithm to put 1.0.dev0 before 1.0a0.
    # We'll do this by abusing the pre segment, but we _only_ want to do this
    # if there is not a pre or a post segment. If we have one of those then
    # the normal sorting rules will handle this case correctly.
    if pre is None and post is None and dev is not None:
        _pre: CmpPrePostDevType = NegativeInfinity
    # Versions without a pre-release (except as noted above) should sort after
    # those with one.
    elif pre is None:
        _pre = Infinity
    else:
        _pre = pre

    # Versions without a post segment should sort before those with one.
    if post is None:
        _post: CmpPrePostDevType = NegativeInfinity

    else:
        _post = post

    # Versions without a development segment should sort after those with one.
    if dev is None:
        _dev: CmpPrePostDevType = Infinity

    else:
        _dev = dev

    if local is None:
        # Versions without a local segment should sort before those with one.
        _local: CmpLocalType = NegativeInfinity
    else:
        # Versions with a local segment need that segment parsed to implement
        # the sorting rules in PEP440.
        # - Alpha numeric segments sort before numeric segments
        # - Alpha numeric segments sort lexicographically
        # - Numeric segments sort numerically
        # - Shorter versions sort before longer versions when the prefixes
        #   match exactly
        _local = tuple(
            (i, "") if isinstance(i, int) else (NegativeInfinity, i) for i in local
        )

    return epoch, _release, _pre, _post, _dev, _local

"""Legacy editable installation process, i.e. `setup.py develop`.
"""

import logging
from typing import Optional, Sequence

from pip._internal.build_env import BuildEnvironment
from pip._internal.utils.logging import indent_log
from pip._internal.utils.setuptools_build import make_setuptools_develop_args
from pip._internal.utils.subprocess import call_subprocess

logger = logging.getLogger(__name__)


def install_editable(
    *,
    global_options: Sequence[str],
    prefix: Optional[str],
    home: Optional[str],
    use_user_site: bool,
    name: str,
    setup_py_path: str,
    isolated: bool,
    build_env: BuildEnvironment,
    unpacked_source_directory: str,
) -> None:
    """Install a package in editable mode. Most arguments are pass-through
    to setuptools.
    """
    logger.info("Running setup.py develop for %s", name)

    args = make_setuptools_develop_args(
        setup_py_path,
        global_options=global_options,
        no_user_config=isolated,
        prefix=prefix,
        home=home,
        use_user_site=use_user_site,
    )

    with indent_log():
        with build_env:
            call_subprocess(
                args,
                command_desc="python setup.py develop",
                cwd=unpacked_source_directory,
            )

__version__ = '3.7'

from typing import Iterable, Tuple, TypeVar

T = TypeVar("T")


def loop_first(values: Iterable[T]) -> Iterable[Tuple[bool, T]]:
    """Iterate and generate a tuple with a flag for first value."""
    iter_values = iter(values)
    try:
        value = next(iter_values)
    except StopIteration:
        return
    yield True, value
    for value in iter_values:
        yield False, value


def loop_last(values: Iterable[T]) -> Iterable[Tuple[bool, T]]:
    """Iterate and generate a tuple with a flag for last value."""
    iter_values = iter(values)
    try:
        previous_value = next(iter_values)
    except StopIteration:
        return
    for value in iter_values:
        yield False, previous_value
        previous_value = value
    yield True, previous_value


def loop_first_last(values: Iterable[T]) -> Iterable[Tuple[bool, bool, T]]:
    """Iterate and generate a tuple with a flag for first and last value."""
    iter_values = iter(values)
    try:
        previous_value = next(iter_values)
    except StopIteration:
        return
    first = True
    for value in iter_values:
        yield first, False, previous_value
        first = False
        previous_value = value
    yield first, True, previous_value

"""
    pygments.token
    ~~~~~~~~~~~~~~

    Basic token types and the standard tokens.

    :copyright: Copyright 2006-2024 by the Pygments team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""


class _TokenType(tuple):
    parent = None

    def split(self):
        buf = []
        node = self
        while node is not None:
            buf.append(node)
            node = node.parent
        buf.reverse()
        return buf

    def __init__(self, *args):
        # no need to call super.__init__
        self.subtypes = set()

    def __contains__(self, val):
        return self is val or (
            type(val) is self.__class__ and
            val[:len(self)] == self
        )

    def __getattr__(self, val):
        if not val or not val[0].isupper():
            return tuple.__getattribute__(self, val)
        new = _TokenType(self + (val,))
        setattr(self, val, new)
        self.subtypes.add(new)
        new.parent = self
        return new

    def __repr__(self):
        return 'Token' + (self and '.' or '') + '.'.join(self)

    def __copy__(self):
        # These instances are supposed to be singletons
        return self

    def __deepcopy__(self, memo):
        # These instances are supposed to be singletons
        return self


Token = _TokenType()

# Special token types
Text = Token.Text
Whitespace = Text.Whitespace
Escape = Token.Escape
Error = Token.Error
# Text that doesn't belong to this lexer (e.g. HTML in PHP)
Other = Token.Other

# Common token types for source code
Keyword = Token.Keyword
Name = Token.Name
Literal = Token.Literal
String = Literal.String
Number = Literal.Number
Punctuation = Token.Punctuation
Operator = Token.Operator
Comment = Token.Comment

# Generic types for non-source code
Generic = Token.Generic

# String and some others are not direct children of Token.
# alias them:
Token.Token = Token
Token.String = String
Token.Number = Number


def is_token_subtype(ttype, other):
    """
    Return True if ``ttype`` is a subtype of ``other``.

    exists for backwards compatibility. use ``ttype in other`` now.
    """
    return ttype in other


def string_to_tokentype(s):
    """
    Convert a string into a token type::

        >>> string_to_token('String.Double')
        Token.Literal.String.Double
        >>> string_to_token('Token.Literal.Number')
        Token.Literal.Number
        >>> string_to_token('')
        Token

    Tokens that are already tokens are returned unchanged:

        >>> string_to_token(String)
        Token.Literal.String
    """
    if isinstance(s, _TokenType):
        return s
    if not s:
        return Token
    node = Token
    for item in s.split('.'):
        node = getattr(node, item)
    return node


# Map standard token types to short names, used in CSS class naming.
# If you add a new item, please be sure to run this file to perform
# a consistency check for duplicate values.
STANDARD_TYPES = {
    Token:                         '',

    Text:                          '',
    Whitespace:                    'w',
    Escape:                        'esc',
    Error:                         'err',
    Other:                         'x',

    Keyword:                       'k',
    Keyword.Constant:              'kc',
    Keyword.Declaration:           'kd',
    Keyword.Namespace:             'kn',
    Keyword.Pseudo:                'kp',
    Keyword.Reserved:              'kr',
    Keyword.Type:                  'kt',

    Name:                          'n',
    Name.Attribute:                'na',
    Name.Builtin:                  'nb',
    Name.Builtin.Pseudo:           'bp',
    Name.Class:                    'nc',
    Name.Constant:                 'no',
    Name.Decorator:                'nd',
    Name.Entity:                   'ni',
    Name.Exception:                'ne',
    Name.Function:                 'nf',
    Name.Function.Magic:           'fm',
    Name.Property:                 'py',
    Name.Label:                    'nl',
    Name.Namespace:                'nn',
    Name.Other:                    'nx',
    Name.Tag:                      'nt',
    Name.Variable:                 'nv',
    Name.Variable.Class:           'vc',
    Name.Variable.Global:          'vg',
    Name.Variable.Instance:        'vi',
    Name.Variable.Magic:           'vm',

    Literal:                       'l',
    Literal.Date:                  'ld',

    String:                        's',
    String.Affix:                  'sa',
    String.Backtick:               'sb',
    String.Char:                   'sc',
    String.Delimiter:              'dl',
    String.Doc:                    'sd',
    String.Double:                 's2',
    String.Escape:                 'se',
    String.Heredoc:                'sh',
    String.Interpol:               'si',
    String.Other:                  'sx',
    String.Regex:                  'sr',
    String.Single:                 's1',
    String.Symbol:                 'ss',

    Number:                        'm',
    Number.Bin:                    'mb',
    Number.Float:                  'mf',
    Number.Hex:                    'mh',
    Number.Integer:                'mi',
    Number.Integer.Long:           'il',
    Number.Oct:                    'mo',

    Operator:                      'o',
    Operator.Word:                 'ow',

    Punctuation:                   'p',
    Punctuation.Marker:            'pm',

    Comment:                       'c',
    Comment.Hashbang:              'ch',
    Comment.Multiline:             'cm',
    Comment.Preproc:               'cp',
    Comment.PreprocFile:           'cpf',
    Comment.Single:                'c1',
    Comment.Special:               'cs',

    Generic:                       'g',
    Generic.Deleted:               'gd',
    Generic.Emph:                  'ge',
    Generic.Error:                 'gr',
    Generic.Heading:               'gh',
    Generic.Inserted:              'gi',
    Generic.Output:                'go',
    Generic.Prompt:                'gp',
    Generic.Strong:                'gs',
    Generic.Subheading:            'gu',
    Generic.EmphStrong:            'ges',
    Generic.Traceback:             'gt',
}

"""
requests.api
~~~~~~~~~~~~

This module implements the Requests API.

:copyright: (c) 2012 by Kenneth Reitz.
:license: Apache2, see LICENSE for more details.
"""

from . import sessions


def request(method, url, **kwargs):
    """Constructs and sends a :class:`Request <Request>`.

    :param method: method for the new :class:`Request` object: ``GET``, ``OPTIONS``, ``HEAD``, ``POST``, ``PUT``, ``PATCH``, or ``DELETE``.
    :param url: URL for the new :class:`Request` object.
    :param params: (optional) Dictionary, list of tuples or bytes to send
        in the query string for the :class:`Request`.
    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
        object to send in the body of the :class:`Request`.
    :param json: (optional) A JSON serializable Python object to send in the body of the :class:`Request`.
    :param headers: (optional) Dictionary of HTTP Headers to send with the :class:`Request`.
    :param cookies: (optional) Dict or CookieJar object to send with the :class:`Request`.
    :param files: (optional) Dictionary of ``'name': file-like-objects`` (or ``{'name': file-tuple}``) for multipart encoding upload.
        ``file-tuple`` can be a 2-tuple ``('filename', fileobj)``, 3-tuple ``('filename', fileobj, 'content_type')``
        or a 4-tuple ``('filename', fileobj, 'content_type', custom_headers)``, where ``'content_type'`` is a string
        defining the content type of the given file and ``custom_headers`` a dict-like object containing additional headers
        to add for the file.
    :param auth: (optional) Auth tuple to enable Basic/Digest/Custom HTTP Auth.
    :param timeout: (optional) How many seconds to wait for the server to send data
        before giving up, as a float, or a :ref:`(connect timeout, read
        timeout) <timeouts>` tuple.
    :type timeout: float or tuple
    :param allow_redirects: (optional) Boolean. Enable/disable GET/OPTIONS/POST/PUT/PATCH/DELETE/HEAD redirection. Defaults to ``True``.
    :type allow_redirects: bool
    :param proxies: (optional) Dictionary mapping protocol to the URL of the proxy.
    :param verify: (optional) Either a boolean, in which case it controls whether we verify
            the server's TLS certificate, or a string, in which case it must be a path
            to a CA bundle to use. Defaults to ``True``.
    :param stream: (optional) if ``False``, the response content will be immediately downloaded.
    :param cert: (optional) if String, path to ssl client cert file (.pem). If Tuple, ('cert', 'key') pair.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response

    Usage::

      >>> import requests
      >>> req = requests.request('GET', 'https://httpbin.org/get')
      >>> req
      <Response [200]>
    """

    # By using the 'with' statement we are sure the session is closed, thus we
    # avoid leaving sockets open which can trigger a ResourceWarning in some
    # cases, and look like a memory leak in others.
    with sessions.Session() as session:
        return session.request(method=method, url=url, **kwargs)


def get(url, params=None, **kwargs):
    r"""Sends a GET request.

    :param url: URL for the new :class:`Request` object.
    :param params: (optional) Dictionary, list of tuples or bytes to send
        in the query string for the :class:`Request`.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    return request("get", url, params=params, **kwargs)


def options(url, **kwargs):
    r"""Sends an OPTIONS request.

    :param url: URL for the new :class:`Request` object.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    return request("options", url, **kwargs)


def head(url, **kwargs):
    r"""Sends a HEAD request.

    :param url: URL for the new :class:`Request` object.
    :param \*\*kwargs: Optional arguments that ``request`` takes. If
        `allow_redirects` is not provided, it will be set to `False` (as
        opposed to the default :meth:`request` behavior).
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    kwargs.setdefault("allow_redirects", False)
    return request("head", url, **kwargs)


def post(url, data=None, json=None, **kwargs):
    r"""Sends a POST request.

    :param url: URL for the new :class:`Request` object.
    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
        object to send in the body of the :class:`Request`.
    :param json: (optional) A JSON serializable Python object to send in the body of the :class:`Request`.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    return request("post", url, data=data, json=json, **kwargs)


def put(url, data=None, **kwargs):
    r"""Sends a PUT request.

    :param url: URL for the new :class:`Request` object.
    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
        object to send in the body of the :class:`Request`.
    :param json: (optional) A JSON serializable Python object to send in the body of the :class:`Request`.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    return request("put", url, data=data, **kwargs)


def patch(url, data=None, **kwargs):
    r"""Sends a PATCH request.

    :param url: URL for the new :class:`Request` object.
    :param data: (optional) Dictionary, list of tuples, bytes, or file-like
        object to send in the body of the :class:`Request`.
    :param json: (optional) A JSON serializable Python object to send in the body of the :class:`Request`.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    return request("patch", url, data=data, **kwargs)


def delete(url, **kwargs):
    r"""Sends a DELETE request.

    :param url: URL for the new :class:`Request` object.
    :param \*\*kwargs: Optional arguments that ``request`` takes.
    :return: :class:`Response <Response>` object
    :rtype: requests.Response
    """

    return request("delete", url, **kwargs)

CONSOLE_HTML_FORMAT = """\
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<style>
{stylesheet}
body {{
    color: {foreground};
    background-color: {background};
}}
</style>
</head>
<body>
    <pre style="font-family:Menlo,'DejaVu Sans Mono',consolas,'Courier New',monospace"><code style="font-family:inherit">{code}</code></pre>
</body>
</html>
"""

CONSOLE_SVG_FORMAT = """\
<svg class="rich-terminal" viewBox="0 0 {width} {height}" xmlns="http://www.w3.org/2000/svg">
    <!-- Generated with Rich https://www.textualize.io -->
    <style>

    @font-face {{
        font-family: "Fira Code";
        src: local("FiraCode-Regular"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff2/FiraCode-Regular.woff2") format("woff2"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff/FiraCode-Regular.woff") format("woff");
        font-style: normal;
        font-weight: 400;
    }}
    @font-face {{
        font-family: "Fira Code";
        src: local("FiraCode-Bold"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff2/FiraCode-Bold.woff2") format("woff2"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff/FiraCode-Bold.woff") format("woff");
        font-style: bold;
        font-weight: 700;
    }}

    .{unique_id}-matrix {{
        font-family: Fira Code, monospace;
        font-size: {char_height}px;
        line-height: {line_height}px;
        font-variant-east-asian: full-width;
    }}

    .{unique_id}-title {{
        font-size: 18px;
        font-weight: bold;
        font-family: arial;
    }}

    {styles}
    </style>

    <defs>
    <clipPath id="{unique_id}-clip-terminal">
      <rect x="0" y="0" width="{terminal_width}" height="{terminal_height}" />
    </clipPath>
    {lines}
    </defs>

    {chrome}
    <g transform="translate({terminal_x}, {terminal_y})" clip-path="url(#{unique_id}-clip-terminal)">
    {backgrounds}
    <g class="{unique_id}-matrix">
    {matrix}
    </g>
    </g>
</svg>
"""

_SVG_FONT_FAMILY = "Rich Fira Code"
_SVG_CLASSES_PREFIX = "rich-svg"

"""Prepares a distribution for installation
"""

# The following comment should be removed at some point in the future.
# mypy: strict-optional=False

import mimetypes
import os
import shutil
from dataclasses import dataclass
from pathlib import Path
from typing import Dict, Iterable, List, Optional

from pip._vendor.packaging.utils import canonicalize_name

from pip._internal.distributions import make_distribution_for_install_requirement
from pip._internal.distributions.installed import InstalledDistribution
from pip._internal.exceptions import (
    DirectoryUrlHashUnsupported,
    HashMismatch,
    HashUnpinned,
    InstallationError,
    MetadataInconsistent,
    NetworkConnectionError,
    VcsHashUnsupported,
)
from pip._internal.index.package_finder import PackageFinder
from pip._internal.metadata import BaseDistribution, get_metadata_distribution
from pip._internal.models.direct_url import ArchiveInfo
from pip._internal.models.link import Link
from pip._internal.models.wheel import Wheel
from pip._internal.network.download import BatchDownloader, Downloader
from pip._internal.network.lazy_wheel import (
    HTTPRangeRequestUnsupported,
    dist_from_wheel_url,
)
from pip._internal.network.session import PipSession
from pip._internal.operations.build.build_tracker import BuildTracker
from pip._internal.req.req_install import InstallRequirement
from pip._internal.utils._log import getLogger
from pip._internal.utils.direct_url_helpers import (
    direct_url_for_editable,
    direct_url_from_link,
)
from pip._internal.utils.hashes import Hashes, MissingHashes
from pip._internal.utils.logging import indent_log
from pip._internal.utils.misc import (
    display_path,
    hash_file,
    hide_url,
    redact_auth_from_requirement,
)
from pip._internal.utils.temp_dir import TempDirectory
from pip._internal.utils.unpacking import unpack_file
from pip._internal.vcs import vcs

logger = getLogger(__name__)


def _get_prepared_distribution(
    req: InstallRequirement,
    build_tracker: BuildTracker,
    finder: PackageFinder,
    build_isolation: bool,
    check_build_deps: bool,
) -> BaseDistribution:
    """Prepare a distribution for installation."""
    abstract_dist = make_distribution_for_install_requirement(req)
    tracker_id = abstract_dist.build_tracker_id
    if tracker_id is not None:
        with build_tracker.track(req, tracker_id):
            abstract_dist.prepare_distribution_metadata(
                finder, build_isolation, check_build_deps
            )
    return abstract_dist.get_metadata_distribution()


def unpack_vcs_link(link: Link, location: str, verbosity: int) -> None:
    vcs_backend = vcs.get_backend_for_scheme(link.scheme)
    assert vcs_backend is not None
    vcs_backend.unpack(location, url=hide_url(link.url), verbosity=verbosity)


@dataclass
class File:
    path: str
    content_type: Optional[str] = None

    def __post_init__(self) -> None:
        if self.content_type is None:
            self.content_type = mimetypes.guess_type(self.path)[0]


def get_http_url(
    link: Link,
    download: Downloader,
    download_dir: Optional[str] = None,
    hashes: Optional[Hashes] = None,
) -> File:
    temp_dir = TempDirectory(kind="unpack", globally_managed=True)
    # If a download dir is specified, is the file already downloaded there?
    already_downloaded_path = None
    if download_dir:
        already_downloaded_path = _check_download_dir(link, download_dir, hashes)

    if already_downloaded_path:
        from_path = already_downloaded_path
        content_type = None
    else:
        # let's download to a tmp dir
        from_path, content_type = download(link, temp_dir.path)
        if hashes:
            hashes.check_against_path(from_path)

    return File(from_path, content_type)


def get_file_url(
    link: Link, download_dir: Optional[str] = None, hashes: Optional[Hashes] = None
) -> File:
    """Get file and optionally check its hash."""
    # If a download dir is specified, is the file already there and valid?
    already_downloaded_path = None
    if download_dir:
        already_downloaded_path = _check_download_dir(link, download_dir, hashes)

    if already_downloaded_path:
        from_path = already_downloaded_path
    else:
        from_path = link.file_path

    # If --require-hashes is off, `hashes` is either empty, the
    # link's embedded hash, or MissingHashes; it is required to
    # match. If --require-hashes is on, we are satisfied by any
    # hash in `hashes` matching: a URL-based or an option-based
    # one; no internet-sourced hash will be in `hashes`.
    if hashes:
        hashes.check_against_path(from_path)
    return File(from_path, None)


def unpack_url(
    link: Link,
    location: str,
    download: Downloader,
    verbosity: int,
    download_dir: Optional[str] = None,
    hashes: Optional[Hashes] = None,
) -> Optional[File]:
    """Unpack link into location, downloading if required.

    :param hashes: A Hashes object, one of whose embedded hashes must match,
        or HashMismatch will be raised. If the Hashes is empty, no matches are
        required, and unhashable types of requirements (like VCS ones, which
        would ordinarily raise HashUnsupported) are allowed.
    """
    # non-editable vcs urls
    if link.is_vcs:
        unpack_vcs_link(link, location, verbosity=verbosity)
        return None

    assert not link.is_existing_dir()

    # file urls
    if link.is_file:
        file = get_file_url(link, download_dir, hashes=hashes)

    # http urls
    else:
        file = get_http_url(
            link,
            download,
            download_dir,
            hashes=hashes,
        )

    # unpack the archive to the build dir location. even when only downloading
    # archives, they have to be unpacked to parse dependencies, except wheels
    if not link.is_wheel:
        unpack_file(file.path, location, file.content_type)

    return file


def _check_download_dir(
    link: Link,
    download_dir: str,
    hashes: Optional[Hashes],
    warn_on_hash_mismatch: bool = True,
) -> Optional[str]:
    """Check download_dir for previously downloaded file with correct hash
    If a correct file is found return its path else None
    """
    download_path = os.path.join(download_dir, link.filename)

    if not os.path.exists(download_path):
        return None

    # If already downloaded, does its hash match?
    logger.info("File was already downloaded %s", download_path)
    if hashes:
        try:
            hashes.check_against_path(download_path)
        except HashMismatch:
            if warn_on_hash_mismatch:
                logger.warning(
                    "Previously-downloaded file %s has bad hash. Re-downloading.",
                    download_path,
                )
            os.unlink(download_path)
            return None
    return download_path


class RequirementPreparer:
    """Prepares a Requirement"""

    def __init__(
        self,
        build_dir: str,
        download_dir: Optional[str],
        src_dir: str,
        build_isolation: bool,
        check_build_deps: bool,
        build_tracker: BuildTracker,
        session: PipSession,
        progress_bar: str,
        finder: PackageFinder,
        require_hashes: bool,
        use_user_site: bool,
        lazy_wheel: bool,
        verbosity: int,
        legacy_resolver: bool,
    ) -> None:
        super().__init__()

        self.src_dir = src_dir
        self.build_dir = build_dir
        self.build_tracker = build_tracker
        self._session = session
        self._download = Downloader(session, progress_bar)
        self._batch_download = BatchDownloader(session, progress_bar)
        self.finder = finder

        # Where still-packed archives should be written to. If None, they are
        # not saved, and are deleted immediately after unpacking.
        self.download_dir = download_dir

        # Is build isolation allowed?
        self.build_isolation = build_isolation

        # Should check build dependencies?
        self.check_build_deps = check_build_deps

        # Should hash-checking be required?
        self.require_hashes = require_hashes

        # Should install in user site-packages?
        self.use_user_site = use_user_site

        # Should wheels be downloaded lazily?
        self.use_lazy_wheel = lazy_wheel

        # How verbose should underlying tooling be?
        self.verbosity = verbosity

        # Are we using the legacy resolver?
        self.legacy_resolver = legacy_resolver

        # Memoized downloaded files, as mapping of url: path.
        self._downloaded: Dict[str, str] = {}

        # Previous "header" printed for a link-based InstallRequirement
        self._previous_requirement_header = ("", "")

    def _log_preparing_link(self, req: InstallRequirement) -> None:
        """Provide context for the requirement being prepared."""
        if req.link.is_file and not req.is_wheel_from_cache:
            message = "Processing %s"
            information = str(display_path(req.link.file_path))
        else:
            message = "Collecting %s"
            information = redact_auth_from_requirement(req.req) if req.req else str(req)

        # If we used req.req, inject requirement source if available (this
        # would already be included if we used req directly)
        if req.req and req.comes_from:
            if isinstance(req.comes_from, str):
                comes_from: Optional[str] = req.comes_from
            else:
                comes_from = req.comes_from.from_path()
            if comes_from:
                information += f" (from {comes_from})"

        if (message, information) != self._previous_requirement_header:
            self._previous_requirement_header = (message, information)
            logger.info(message, information)

        if req.is_wheel_from_cache:
            with indent_log():
                logger.info("Using cached %s", req.link.filename)

    def _ensure_link_req_src_dir(
        self, req: InstallRequirement, parallel_builds: bool
    ) -> None:
        """Ensure source_dir of a linked InstallRequirement."""
        # Since source_dir is only set for editable requirements.
        if req.link.is_wheel:
            # We don't need to unpack wheels, so no need for a source
            # directory.
            return
        assert req.source_dir is None
        if req.link.is_existing_dir():
            # build local directories in-tree
            req.source_dir = req.link.file_path
            return

        # We always delete unpacked sdists after pip runs.
        req.ensure_has_source_dir(
            self.build_dir,
            autodelete=True,
            parallel_builds=parallel_builds,
        )
        req.ensure_pristine_source_checkout()

    def _get_linked_req_hashes(self, req: InstallRequirement) -> Hashes:
        # By the time this is called, the requirement's link should have
        # been checked so we can tell what kind of requirements req is
        # and raise some more informative errors than otherwise.
        # (For example, we can raise VcsHashUnsupported for a VCS URL
        # rather than HashMissing.)
        if not self.require_hashes:
            return req.hashes(trust_internet=True)

        # We could check these first 2 conditions inside unpack_url
        # and save repetition of conditions, but then we would
        # report less-useful error messages for unhashable
        # requirements, complaining that there's no hash provided.
        if req.link.is_vcs:
            raise VcsHashUnsupported()
        if req.link.is_existing_dir():
            raise DirectoryUrlHashUnsupported()

        # Unpinned packages are asking for trouble when a new version
        # is uploaded.  This isn't a security check, but it saves users
        # a surprising hash mismatch in the future.
        # file:/// URLs aren't pinnable, so don't complain about them
        # not being pinned.
        if not req.is_direct and not req.is_pinned:
            raise HashUnpinned()

        # If known-good hashes are missing for this requirement,
        # shim it with a facade object that will provoke hash
        # computation and then raise a HashMissing exception
        # showing the user what the hash should be.
        return req.hashes(trust_internet=False) or MissingHashes()

    def _fetch_metadata_only(
        self,
        req: InstallRequirement,
    ) -> Optional[BaseDistribution]:
        if self.legacy_resolver:
            logger.debug(
                "Metadata-only fetching is not used in the legacy resolver",
            )
            return None
        if self.require_hashes:
            logger.debug(
                "Metadata-only fetching is not used as hash checking is required",
            )
            return None
        # Try PEP 658 metadata first, then fall back to lazy wheel if unavailable.
        return self._fetch_metadata_using_link_data_attr(
            req
        ) or self._fetch_metadata_using_lazy_wheel(req.link)

    def _fetch_metadata_using_link_data_attr(
        self,
        req: InstallRequirement,
    ) -> Optional[BaseDistribution]:
        """Fetch metadata from the data-dist-info-metadata attribute, if possible."""
        # (1) Get the link to the metadata file, if provided by the backend.
        metadata_link = req.link.metadata_link()
        if metadata_link is None:
            return None
        assert req.req is not None
        logger.verbose(
            "Obtaining dependency information for %s from %s",
            req.req,
            metadata_link,
        )
        # (2) Download the contents of the METADATA file, separate from the dist itself.
        metadata_file = get_http_url(
            metadata_link,
            self._download,
            hashes=metadata_link.as_hashes(),
        )
        with open(metadata_file.path, "rb") as f:
            metadata_contents = f.read()
        # (3) Generate a dist just from those file contents.
        metadata_dist = get_metadata_distribution(
            metadata_contents,
            req.link.filename,
            req.req.name,
        )
        # (4) Ensure the Name: field from the METADATA file matches the name from the
        #     install requirement.
        #
        #     NB: raw_name will fall back to the name from the install requirement if
        #     the Name: field is not present, but it's noted in the raw_name docstring
        #     that that should NEVER happen anyway.
        if canonicalize_name(metadata_dist.raw_name) != canonicalize_name(req.req.name):
            raise MetadataInconsistent(
                req, "Name", req.req.name, metadata_dist.raw_name
            )
        return metadata_dist

    def _fetch_metadata_using_lazy_wheel(
        self,
        link: Link,
    ) -> Optional[BaseDistribution]:
        """Fetch metadata using lazy wheel, if possible."""
        # --use-feature=fast-deps must be provided.
        if not self.use_lazy_wheel:
            return None
        if link.is_file or not link.is_wheel:
            logger.debug(
                "Lazy wheel is not used as %r does not point to a remote wheel",
                link,
            )
            return None

        wheel = Wheel(link.filename)
        name = canonicalize_name(wheel.name)
        logger.info(
            "Obtaining dependency information from %s %s",
            name,
            wheel.version,
        )
        url = link.url.split("#", 1)[0]
        try:
            return dist_from_wheel_url(name, url, self._session)
        except HTTPRangeRequestUnsupported:
            logger.debug("%s does not support range requests", url)
            return None

    def _complete_partial_requirements(
        self,
        partially_downloaded_reqs: Iterable[InstallRequirement],
        parallel_builds: bool = False,
    ) -> None:
        """Download any requirements which were only fetched by metadata."""
        # Download to a temporary directory. These will be copied over as
        # needed for downstream 'download', 'wheel', and 'install' commands.
        temp_dir = TempDirectory(kind="unpack", globally_managed=True).path

        # Map each link to the requirement that owns it. This allows us to set
        # `req.local_file_path` on the appropriate requirement after passing
        # all the links at once into BatchDownloader.
        links_to_fully_download: Dict[Link, InstallRequirement] = {}
        for req in partially_downloaded_reqs:
            assert req.link
            links_to_fully_download[req.link] = req

        batch_download = self._batch_download(
            links_to_fully_download.keys(),
            temp_dir,
        )
        for link, (filepath, _) in batch_download:
            logger.debug("Downloading link %s to %s", link, filepath)
            req = links_to_fully_download[link]
            # Record the downloaded file path so wheel reqs can extract a Distribution
            # in .get_dist().
            req.local_file_path = filepath
            # Record that the file is downloaded so we don't do it again in
            # _prepare_linked_requirement().
            self._downloaded[req.link.url] = filepath

            # If this is an sdist, we need to unpack it after downloading, but the
            # .source_dir won't be set up until we are in _prepare_linked_requirement().
            # Add the downloaded archive to the install requirement to unpack after
            # preparing the source dir.
            if not req.is_wheel:
                req.needs_unpacked_archive(Path(filepath))

        # This step is necessary to ensure all lazy wheels are processed
        # successfully by the 'download', 'wheel', and 'install' commands.
        for req in partially_downloaded_reqs:
            self._prepare_linked_requirement(req, parallel_builds)

    def prepare_linked_requirement(
        self, req: InstallRequirement, parallel_builds: bool = False
    ) -> BaseDistribution:
        """Prepare a requirement to be obtained from req.link."""
        assert req.link
        self._log_preparing_link(req)
        with indent_log():
            # Check if the relevant file is already available
            # in the download directory
            file_path = None
            if self.download_dir is not None and req.link.is_wheel:
                hashes = self._get_linked_req_hashes(req)
                file_path = _check_download_dir(
                    req.link,
                    self.download_dir,
                    hashes,
                    # When a locally built wheel has been found in cache, we don't warn
                    # about re-downloading when the already downloaded wheel hash does
                    # not match. This is because the hash must be checked against the
                    # original link, not the cached link. It that case the already
                    # downloaded file will be removed and re-fetched from cache (which
                    # implies a hash check against the cache entry's origin.json).
                    warn_on_hash_mismatch=not req.is_wheel_from_cache,
                )

            if file_path is not None:
                # The file is already available, so mark it as downloaded
                self._downloaded[req.link.url] = file_path
            else:
                # The file is not available, attempt to fetch only metadata
                metadata_dist = self._fetch_metadata_only(req)
                if metadata_dist is not None:
                    req.needs_more_preparation = True
                    return metadata_dist

            # None of the optimizations worked, fully prepare the requirement
            return self._prepare_linked_requirement(req, parallel_builds)

    def prepare_linked_requirements_more(
        self, reqs: Iterable[InstallRequirement], parallel_builds: bool = False
    ) -> None:
        """Prepare linked requirements more, if needed."""
        reqs = [req for req in reqs if req.needs_more_preparation]
        for req in reqs:
            # Determine if any of these requirements were already downloaded.
            if self.download_dir is not None and req.link.is_wheel:
                hashes = self._get_linked_req_hashes(req)
                file_path = _check_download_dir(req.link, self.download_dir, hashes)
                if file_path is not None:
                    self._downloaded[req.link.url] = file_path
                    req.needs_more_preparation = False

        # Prepare requirements we found were already downloaded for some
        # reason. The other downloads will be completed separately.
        partially_downloaded_reqs: List[InstallRequirement] = []
        for req in reqs:
            if req.needs_more_preparation:
                partially_downloaded_reqs.append(req)
            else:
                self._prepare_linked_requirement(req, parallel_builds)

        # TODO: separate this part out from RequirementPreparer when the v1
        # resolver can be removed!
        self._complete_partial_requirements(
            partially_downloaded_reqs,
            parallel_builds=parallel_builds,
        )

    def _prepare_linked_requirement(
        self, req: InstallRequirement, parallel_builds: bool
    ) -> BaseDistribution:
        assert req.link
        link = req.link

        hashes = self._get_linked_req_hashes(req)

        if hashes and req.is_wheel_from_cache:
            assert req.download_info is not None
            assert link.is_wheel
            assert link.is_file
            # We need to verify hashes, and we have found the requirement in the cache
            # of locally built wheels.
            if (
                isinstance(req.download_info.info, ArchiveInfo)
                and req.download_info.info.hashes
                and hashes.has_one_of(req.download_info.info.hashes)
            ):
                # At this point we know the requirement was built from a hashable source
                # artifact, and we verified that the cache entry's hash of the original
                # artifact matches one of the hashes we expect. We don't verify hashes
                # against the cached wheel, because the wheel is not the original.
                hashes = None
            else:
                logger.warning(
                    "The hashes of the source archive found in cache entry "
                    "don't match, ignoring cached built wheel "
                    "and re-downloading source."
                )
                req.link = req.cached_wheel_source_link
                link = req.link

        self._ensure_link_req_src_dir(req, parallel_builds)

        if link.is_existing_dir():
            local_file = None
        elif link.url not in self._downloaded:
            try:
                local_file = unpack_url(
                    link,
                    req.source_dir,
                    self._download,
                    self.verbosity,
                    self.download_dir,
                    hashes,
                )
            except NetworkConnectionError as exc:
                raise InstallationError(
                    f"Could not install requirement {req} because of HTTP "
                    f"error {exc} for URL {link}"
                )
        else:
            file_path = self._downloaded[link.url]
            if hashes:
                hashes.check_against_path(file_path)
            local_file = File(file_path, content_type=None)

        # If download_info is set, we got it from the wheel cache.
        if req.download_info is None:
            # Editables don't go through this function (see
            # prepare_editable_requirement).
            assert not req.editable
            req.download_info = direct_url_from_link(link, req.source_dir)
            # Make sure we have a hash in download_info. If we got it as part of the
            # URL, it will have been verified and we can rely on it. Otherwise we
            # compute it from the downloaded file.
            # FIXME: https://github.com/pypa/pip/issues/11943
            if (
                isinstance(req.download_info.info, ArchiveInfo)
                and not req.download_info.info.hashes
                and local_file
            ):
                hash = hash_file(local_file.path)[0].hexdigest()
                # We populate info.hash for backward compatibility.
                # This will automatically populate info.hashes.
                req.download_info.info.hash = f"sha256={hash}"

        # For use in later processing,
        # preserve the file path on the requirement.
        if local_file:
            req.local_file_path = local_file.path

        dist = _get_prepared_distribution(
            req,
            self.build_tracker,
            self.finder,
            self.build_isolation,
            self.check_build_deps,
        )
        return dist

    def save_linked_requirement(self, req: InstallRequirement) -> None:
        assert self.download_dir is not None
        assert req.link is not None
        link = req.link
        if link.is_vcs or (link.is_existing_dir() and req.editable):
            # Make a .zip of the source_dir we already created.
            req.archive(self.download_dir)
            return

        if link.is_existing_dir():
            logger.debug(
                "Not copying link to destination directory "
                "since it is a directory: %s",
                link,
            )
            return
        if req.local_file_path is None:
            # No distribution was downloaded for this requirement.
            return

        download_location = os.path.join(self.download_dir, link.filename)
        if not os.path.exists(download_location):
            shutil.copy(req.local_file_path, download_location)
            download_path = display_path(download_location)
            logger.info("Saved %s", download_path)

    def prepare_editable_requirement(
        self,
        req: InstallRequirement,
    ) -> BaseDistribution:
        """Prepare an editable requirement."""
        assert req.editable, "cannot prepare a non-editable req as editable"

        logger.info("Obtaining %s", req)

        with indent_log():
            if self.require_hashes:
                raise InstallationError(
                    f"The editable requirement {req} cannot be installed when "
                    "requiring hashes, because there is no single file to "
                    "hash."
                )
            req.ensure_has_source_dir(self.src_dir)
            req.update_editable()
            assert req.source_dir
            req.download_info = direct_url_for_editable(req.unpacked_source_directory)

            dist = _get_prepared_distribution(
                req,
                self.build_tracker,
                self.finder,
                self.build_isolation,
                self.check_build_deps,
            )

            req.check_if_exists(self.use_user_site)

        return dist

    def prepare_installed_requirement(
        self,
        req: InstallRequirement,
        skip_reason: str,
    ) -> BaseDistribution:
        """Prepare an already-installed requirement."""
        assert req.satisfied_by, "req should have been satisfied but isn't"
        assert skip_reason is not None, (
            "did not get skip reason skipped but req.satisfied_by "
            f"is set to {req.satisfied_by}"
        )
        logger.info(
            "Requirement %s: %s (%s)", skip_reason, req, req.satisfied_by.version
        )
        with indent_log():
            if self.require_hashes:
                logger.debug(
                    "Since it is already installed, we are trusting this "
                    "package without checking its hash. To ensure a "
                    "completely repeatable environment, install into an "
                    "empty virtualenv."
                )
            return InstalledDistribution(req).get_metadata_distribution()

# -*- coding: utf-8 -*-
#
# Copyright (C) 2012-2023 Vinay Sajip.
# Licensed to the Python Software Foundation under a contributor agreement.
# See LICENSE.txt and CONTRIBUTORS.txt.
#
import logging

__version__ = '0.3.9'


class DistlibException(Exception):
    pass


try:
    from logging import NullHandler
except ImportError:  # pragma: no cover

    class NullHandler(logging.Handler):

        def handle(self, record):
            pass

        def emit(self, record):
            pass

        def createLock(self):
            self.lock = None


logger = logging.getLogger(__name__)
logger.addHandler(NullHandler())