"""Locations where we look for configs, install stuff, etc"""

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

# If pip's going to use distutils, it should not be using the copy that setuptools
# might have injected into the environment. This is done by removing the injected
# shim, if it's injected.
#
# See https://github.com/pypa/pip/issues/8761 for the original discussion and
# rationale for why this is done within pip.
try:
    __import__("_distutils_hack").remove_shim()
except (ImportError, AttributeError):
    pass

import logging
import os
import sys
from distutils.cmd import Command as DistutilsCommand
from distutils.command.install import SCHEME_KEYS
from distutils.command.install import install as distutils_install_command
from distutils.sysconfig import get_python_lib
from typing import Dict, List, Optional, Union

from pip._internal.models.scheme import Scheme
from pip._internal.utils.compat import WINDOWS
from pip._internal.utils.virtualenv import running_under_virtualenv

from .base import get_major_minor_version

logger = logging.getLogger(__name__)


def distutils_scheme(
    dist_name: str,
    user: bool = False,
    home: Optional[str] = None,
    root: Optional[str] = None,
    isolated: bool = False,
    prefix: Optional[str] = None,
    *,
    ignore_config_files: bool = False,
) -> Dict[str, str]:
    """
    Return a distutils install scheme
    """
    from distutils.dist import Distribution

    dist_args: Dict[str, Union[str, List[str]]] = {"name": dist_name}
    if isolated:
        dist_args["script_args"] = ["--no-user-cfg"]

    d = Distribution(dist_args)
    if not ignore_config_files:
        try:
            d.parse_config_files()
        except UnicodeDecodeError:
            paths = d.find_config_files()
            logger.warning(
                "Ignore distutils configs in %s due to encoding errors.",
                ", ".join(os.path.basename(p) for p in paths),
            )
    obj: Optional[DistutilsCommand] = None
    obj = d.get_command_obj("install", create=True)
    assert obj is not None
    i: distutils_install_command = obj
    # NOTE: setting user or home has the side-effect of creating the home dir
    # or user base for installations during finalize_options()
    # ideally, we'd prefer a scheme class that has no side-effects.
    assert not (user and prefix), f"user={user} prefix={prefix}"
    assert not (home and prefix), f"home={home} prefix={prefix}"
    i.user = user or i.user
    if user or home:
        i.prefix = ""
    i.prefix = prefix or i.prefix
    i.home = home or i.home
    i.root = root or i.root
    i.finalize_options()

    scheme: Dict[str, str] = {}
    for key in SCHEME_KEYS:
        scheme[key] = getattr(i, "install_" + key)

    # install_lib specified in setup.cfg should install *everything*
    # into there (i.e. it takes precedence over both purelib and
    # platlib).  Note, i.install_lib is *always* set after
    # finalize_options(); we only want to override here if the user
    # has explicitly requested it hence going back to the config
    if "install_lib" in d.get_option_dict("install"):
        scheme.update({"purelib": i.install_lib, "platlib": i.install_lib})

    if running_under_virtualenv():
        if home:
            prefix = home
        elif user:
            prefix = i.install_userbase
        else:
            prefix = i.prefix
        scheme["headers"] = os.path.join(
            prefix,
            "include",
            "site",
            f"python{get_major_minor_version()}",
            dist_name,
        )

        if root is not None:
            path_no_drive = os.path.splitdrive(os.path.abspath(scheme["headers"]))[1]
            scheme["headers"] = os.path.join(root, path_no_drive[1:])

    return scheme


def get_scheme(
    dist_name: str,
    user: bool = False,
    home: Optional[str] = None,
    root: Optional[str] = None,
    isolated: bool = False,
    prefix: Optional[str] = None,
) -> Scheme:
    """
    Get the "scheme" corresponding to the input parameters. The distutils
    documentation provides the context for the available schemes:
    https://docs.python.org/3/install/index.html#alternate-installation

    :param dist_name: the name of the package to retrieve the scheme for, used
        in the headers scheme path
    :param user: indicates to use the "user" scheme
    :param home: indicates to use the "home" scheme and provides the base
        directory for the same
    :param root: root under which other directories are re-based
    :param isolated: equivalent to --no-user-cfg, i.e. do not consider
        ~/.pydistutils.cfg (posix) or ~/pydistutils.cfg (non-posix) for
        scheme paths
    :param prefix: indicates to use the "prefix" scheme and provides the
        base directory for the same
    """
    scheme = distutils_scheme(dist_name, user, home, root, isolated, prefix)
    return Scheme(
        platlib=scheme["platlib"],
        purelib=scheme["purelib"],
        headers=scheme["headers"],
        scripts=scheme["scripts"],
        data=scheme["data"],
    )


def get_bin_prefix() -> str:
    # XXX: In old virtualenv versions, sys.prefix can contain '..' components,
    # so we need to call normpath to eliminate them.
    prefix = os.path.normpath(sys.prefix)
    if WINDOWS:
        bin_py = os.path.join(prefix, "Scripts")
        # buildout uses 'bin' on Windows too?
        if not os.path.exists(bin_py):
            bin_py = os.path.join(prefix, "bin")
        return bin_py
    # Forcing to use /usr/local/bin for standard macOS framework installs
    # Also log to ~/Library/Logs/ for use with the Console.app log viewer
    if sys.platform[:6] == "darwin" and prefix[:16] == "/System/Library/":
        return "/usr/local/bin"
    return os.path.join(prefix, "bin")


def get_purelib() -> str:
    return get_python_lib(plat_specific=False)


def get_platlib() -> str:
    return get_python_lib(plat_specific=True)

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()