import collections
import logging
from dataclasses import dataclass
from typing import Generator, List, Optional, Sequence, Tuple

from pip._internal.utils.logging import indent_log

from .req_file import parse_requirements
from .req_install import InstallRequirement
from .req_set import RequirementSet

__all__ = [
    "RequirementSet",
    "InstallRequirement",
    "parse_requirements",
    "install_given_reqs",
]

logger = logging.getLogger(__name__)


@dataclass(frozen=True)
class InstallationResult:
    name: str


def _validate_requirements(
    requirements: List[InstallRequirement],
) -> Generator[Tuple[str, InstallRequirement], None, None]:
    for req in requirements:
        assert req.name, f"invalid to-be-installed requirement: {req}"
        yield req.name, req


def install_given_reqs(
    requirements: List[InstallRequirement],
    global_options: Sequence[str],
    root: Optional[str],
    home: Optional[str],
    prefix: Optional[str],
    warn_script_location: bool,
    use_user_site: bool,
    pycompile: bool,
) -> List[InstallationResult]:
    """
    Install everything in the given list.

    (to be called after having downloaded and unpacked the packages)
    """
    to_install = collections.OrderedDict(_validate_requirements(requirements))

    if to_install:
        logger.info(
            "Installing collected packages: %s",
            ", ".join(to_install.keys()),
        )

    installed = []

    with indent_log():
        for req_name, requirement in to_install.items():
            if requirement.should_reinstall:
                logger.info("Attempting uninstall: %s", req_name)
                with indent_log():
                    uninstalled_pathset = requirement.uninstall(auto_confirm=True)
            else:
                uninstalled_pathset = None

            try:
                requirement.install(
                    global_options,
                    root=root,
                    home=home,
                    prefix=prefix,
                    warn_script_location=warn_script_location,
                    use_user_site=use_user_site,
                    pycompile=pycompile,
                )
            except Exception:
                # if install did not succeed, rollback previous uninstall
                if uninstalled_pathset and not requirement.install_succeeded:
                    uninstalled_pathset.rollback()
                raise
            else:
                if uninstalled_pathset and requirement.install_succeeded:
                    uninstalled_pathset.commit()

            installed.append(InstallationResult(req_name))

    return installed

# 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.

__title__ = "packaging"
__summary__ = "Core utilities for Python packages"
__uri__ = "https://github.com/pypa/packaging"

__version__ = "24.1"

__author__ = "Donald Stufft and individual contributors"
__email__ = "donald@stufft.io"

__license__ = "BSD-2-Clause or Apache-2.0"
__copyright__ = "2014 %s" % __author__

import functools
import os
import site
import sys
import sysconfig
import typing

from pip._internal.exceptions import InstallationError
from pip._internal.utils import appdirs
from pip._internal.utils.virtualenv import running_under_virtualenv

# Application Directories
USER_CACHE_DIR = appdirs.user_cache_dir("pip")

# FIXME doesn't account for venv linked to global site-packages
site_packages: str = sysconfig.get_path("purelib")


def get_major_minor_version() -> str:
    """
    Return the major-minor version of the current Python as a string, e.g.
    "3.7" or "3.10".
    """
    return "{}.{}".format(*sys.version_info)


def change_root(new_root: str, pathname: str) -> str:
    """Return 'pathname' with 'new_root' prepended.

    If 'pathname' is relative, this is equivalent to os.path.join(new_root, pathname).
    Otherwise, it requires making 'pathname' relative and then joining the
    two, which is tricky on DOS/Windows and Mac OS.

    This is borrowed from Python's standard library's distutils module.
    """
    if os.name == "posix":
        if not os.path.isabs(pathname):
            return os.path.join(new_root, pathname)
        else:
            return os.path.join(new_root, pathname[1:])

    elif os.name == "nt":
        (drive, path) = os.path.splitdrive(pathname)
        if path[0] == "\\":
            path = path[1:]
        return os.path.join(new_root, path)

    else:
        raise InstallationError(
            f"Unknown platform: {os.name}\n"
            "Can not change root path prefix on unknown platform."
        )


def get_src_prefix() -> str:
    if running_under_virtualenv():
        src_prefix = os.path.join(sys.prefix, "src")
    else:
        # FIXME: keep src in cwd for now (it is not a temporary folder)
        try:
            src_prefix = os.path.join(os.getcwd(), "src")
        except OSError:
            # In case the current working directory has been renamed or deleted
            sys.exit("The folder you are executing pip from can no longer be found.")

    # under macOS + virtualenv sys.prefix is not properly resolved
    # it is something like /path/to/python/bin/..
    return os.path.abspath(src_prefix)


try:
    # Use getusersitepackages if this is present, as it ensures that the
    # value is initialised properly.
    user_site: typing.Optional[str] = site.getusersitepackages()
except AttributeError:
    user_site = site.USER_SITE


@functools.lru_cache(maxsize=None)
def is_osx_framework() -> bool:
    return bool(sysconfig.get_config_var("PYTHONFRAMEWORK"))