from __future__ import absolute_import

import logging
import os
import shutil
import sys
import sysconfig
import zipfile
from distutils.util import change_root

from pip._vendor import pkg_resources, six
from pip._vendor.packaging.requirements import Requirement
from pip._vendor.packaging.utils import canonicalize_name
from pip._vendor.packaging.version import Version
from pip._vendor.packaging.version import parse as parse_version
from pip._vendor.pep517.wrappers import Pep517HookCaller

from pip._internal import wheel
from pip._internal.build_env import NoOpBuildEnvironment
from pip._internal.exceptions import InstallationError
from pip._internal.locations import (
    PIP_DELETE_MARKER_FILENAME, running_under_virtualenv,
)
from pip._internal.models.link import Link
from pip._internal.pyproject import load_pyproject_toml
from pip._internal.req.req_uninstall import UninstallPathSet
from pip._internal.utils.compat import native_str
from pip._internal.utils.hashes import Hashes
from pip._internal.utils.logging import indent_log
from pip._internal.utils.misc import (
    _make_build_dir, ask_path_exists, backup_dir, call_subprocess,
    display_path, dist_in_site_packages, dist_in_usersite, ensure_dir,
    get_installed_version, rmtree,
)
from pip._internal.utils.packaging import get_metadata
from pip._internal.utils.setuptools_build import SETUPTOOLS_SHIM
from pip._internal.utils.temp_dir import TempDirectory
from pip._internal.utils.ui import open_spinner
from pip._internal.vcs import vcs
from pip._internal.wheel import move_wheel_files

logger = logging.getLogger(__name__)


class InstallRequirement(object):
    """
    Represents something that may be installed later on, may have information
    about where to fetch the relavant requirement and also contains logic for
    installing the said requirement.
    """

    def __init__(self, req, comes_from, source_dir=None, editable=False,
                 link=None, update=True, markers=None,
                 isolated=False, options=None, wheel_cache=None,
                 constraint=False, extras=()):
        assert req is None or isinstance(req, Requirement), req
        self.req = req
        self.comes_from = comes_from
        self.constraint = constraint
        if source_dir is not None:
            self.source_dir = os.path.normpath(os.path.abspath(source_dir))
        else:
            self.source_dir = None
        self.editable = editable

        self._wheel_cache = wheel_cache
        if link is not None:
            self.link = self.original_link = link
        else:
            self.link = self.original_link = req and req.url and Link(req.url)

        if extras:
            self.extras = extras
        elif req:
            self.extras = {
                pkg_resources.safe_extra(extra) for extra in req.extras
            }
        else:
            self.extras = set()
        if markers is not None:
            self.markers = markers
        else:
            self.markers = req and req.marker
        self._egg_info_path = None
        # This holds the pkg_resources.Distribution object if this requirement
        # is already available:
        self.satisfied_by = None
        # This hold the pkg_resources.Distribution object if this requirement
        # conflicts with another installed distribution:
        self.conflicts_with = None
        # Temporary build location
        self._temp_build_dir = TempDirectory(kind="req-build")
        # Used to store the global directory where the _temp_build_dir should
        # have been created. Cf _correct_build_location method.
        self._ideal_build_dir = None
        # True if the editable should be updated:
        self.update = update
        # Set to True after successful installation
        self.install_succeeded = None
        # UninstallPathSet of uninstalled distribution (for possible rollback)
        self.uninstalled_pathset = None
        self.options = options if options else {}
        # Set to True after successful preparation of this requirement
        self.prepared = False
        self.is_direct = False

        self.isolated = isolated
        self.build_env = NoOpBuildEnvironment()

        # The static build requirements (from pyproject.toml)
        self.pyproject_requires = None

        # Build requirements that we will check are available
        # TODO: We don't do this for --no-build-isolation. Should we?
        self.requirements_to_check = []

        # The PEP 517 backend we should use to build the project
        self.pep517_backend = None

        # Are we using PEP 517 for this requirement?
        # After pyproject.toml has been loaded, the only valid values are True
        # and False. Before loading, None is valid (meaning "use the default").
        # Setting an explicit value before loading pyproject.toml is supported,
        # but after loading this flag should be treated as read only.
        self.use_pep517 = None

    def __str__(self):
        if self.req:
            s = str(self.req)
            if self.link:
                s += ' from %s' % self.link.url
        elif self.link:
            s = self.link.url
        else:
            s = '<InstallRequirement>'
        if self.satisfied_by is not None:
            s += ' in %s' % display_path(self.satisfied_by.location)
        if self.comes_from:
            if isinstance(self.comes_from, six.string_types):
                comes_from = self.comes_from
            else:
                comes_from = self.comes_from.from_path()
            if comes_from:
                s += ' (from %s)' % comes_from
        return s

    def __repr__(self):
        return '<%s object: %s editable=%r>' % (
            self.__class__.__name__, str(self), self.editable)

    def populate_link(self, finder, upgrade, require_hashes):
        """Ensure that if a link can be found for this, that it is found.

        Note that self.link may still be None - if Upgrade is False and the
        requirement is already installed.

        If require_hashes is True, don't use the wheel cache, because cached
        wheels, always built locally, have different hashes than the files
        downloaded from the index server and thus throw false hash mismatches.
        Furthermore, cached wheels at present have undeterministic contents due
        to file modification times.
        """
        if self.link is None:
            self.link = finder.find_requirement(self, upgrade)
        if self._wheel_cache is not None and not require_hashes:
            old_link = self.link
            self.link = self._wheel_cache.get(self.link, self.name)
            if old_link != self.link:
                logger.debug('Using cached wheel link: %s', self.link)

    # Things that are valid for all kinds of requirements?
    @property
    def name(self):
        if self.req is None:
            return None
        return native_str(pkg_resources.safe_name(self.req.name))

    @property
    def specifier(self):
        return self.req.specifier

    @property
    def is_pinned(self):
        """Return whether I am pinned to an exact version.

        For example, some-package==1.2 is pinned; some-package>1.2 is not.
        """
        specifiers = self.specifier
        return (len(specifiers) == 1 and
                next(iter(specifiers)).operator in {'==', '==='})

    @property
    def installed_version(self):
        return get_installed_version(self.name)

    def match_markers(self, extras_requested=None):
        if not extras_requested:
            # Provide an extra to safely evaluate the markers
            # without matching any extra
            extras_requested = ('',)
        if self.markers is not None:
            return any(
                self.markers.evaluate({'extra': extra})
                for extra in extras_requested)
        else:
            return True

    @property
    def has_hash_options(self):
        """Return whether any known-good hashes are specified as options.

        These activate --require-hashes mode; hashes specified as part of a
        URL do not.

        """
        return bool(self.options.get('hashes', {}))

    def hashes(self, trust_internet=True):
        """Return a hash-comparer that considers my option- and URL-based
        hashes to be known-good.

        Hashes in URLs--ones embedded in the requirements file, not ones
        downloaded from an index server--are almost peers with ones from
        flags. They satisfy --require-hashes (whether it was implicitly or
        explicitly activated) but do not activate it. md5 and sha224 are not
        allowed in flags, which should nudge people toward good algos. We
        always OR all hashes together, even ones from URLs.

        :param trust_internet: Whether to trust URL-based (#md5=...) hashes
            downloaded from the internet, as by populate_link()

        """
        good_hashes = self.options.get('hashes', {}).copy()
        link = self.link if trust_internet else self.original_link
        if link and link.hash:
            good_hashes.setdefault(link.hash_name, []).append(link.hash)
        return Hashes(good_hashes)

    def from_path(self):
        """Format a nice indicator to show where this "comes from"
        """
        if self.req is None:
            return None
        s = str(self.req)
        if self.comes_from:
            if isinstance(self.comes_from, six.string_types):
                comes_from = self.comes_from
            else:
                comes_from = self.comes_from.from_path()
            if comes_from:
                s += '->' + comes_from
        return s

    def build_location(self, build_dir):
        assert build_dir is not None
        if self._temp_build_dir.path is not None:
            return self._temp_build_dir.path
        if self.req is None:
            # for requirement via a path to a directory: the name of the
            # package is not available yet so we create a temp directory
            # Once run_egg_info will have run, we'll be able
            # to fix it via _correct_build_location
            # Some systems have /tmp as a symlink which confuses custom
            # builds (such as numpy). Thus, we ensure that the real path
            # is returned.
            self._temp_build_dir.create()
            self._ideal_build_dir = build_dir

            return self._temp_build_dir.path
        if self.editable:
            name = self.name.lower()
        else:
            name = self.name
        # FIXME: Is there a better place to create the build_dir? (hg and bzr
        # need this)
        if not os.path.exists(build_dir):
            logger.debug('Creating directory %s', build_dir)
            _make_build_dir(build_dir)
        return os.path.join(build_dir, name)

    def _correct_build_location(self):
        """Move self._temp_build_dir to self._ideal_build_dir/self.req.name

        For some requirements (e.g. a path to a directory), the name of the
        package is not available until we run egg_info, so the build_location
        will return a temporary directory and store the _ideal_build_dir.

        This is only called by self.run_egg_info to fix the temporary build
        directory.
        """
        if self.source_dir is not None:
            return
        assert self.req is not None
        assert self._temp_build_dir.path
        assert self._ideal_build_dir.path
        old_location = self._temp_build_dir.path
        self._temp_build_dir.path = None

        new_location = self.build_location(self._ideal_build_dir)
        if os.path.exists(new_location):
            raise InstallationError(
                'A package already exists in %s; please remove it to continue'
                % display_path(new_location))
        logger.debug(
            'Moving package %s from %s to new location %s',
            self, display_path(old_location), display_path(new_location),
        )
        shutil.move(old_location, new_location)
        self._temp_build_dir.path = new_location
        self._ideal_build_dir = None
        self.source_dir = os.path.normpath(os.path.abspath(new_location))
        self._egg_info_path = None

    def remove_temporary_source(self):
        """Remove the source files from this requirement, if they are marked
        for deletion"""
        if self.source_dir and os.path.exists(
                os.path.join(self.source_dir, PIP_DELETE_MARKER_FILENAME)):
            logger.debug('Removing source in %s', self.source_dir)
            rmtree(self.source_dir)
        self.source_dir = None
        self._temp_build_dir.cleanup()
        self.build_env.cleanup()

    def check_if_exists(self, use_user_site):
        """Find an installed distribution that satisfies or conflicts
        with this requirement, and set self.satisfied_by or
        self.conflicts_with appropriately.
        """
        if self.req is None:
            return False
        try:
            # get_distribution() will resolve the entire list of requirements
            # anyway, and we've already determined that we need the requirement
            # in question, so strip the marker so that we don't try to
            # evaluate it.
            no_marker = Requirement(str(self.req))
            no_marker.marker = None
            self.satisfied_by = pkg_resources.get_distribution(str(no_marker))
            if self.editable and self.satisfied_by:
                self.conflicts_with = self.satisfied_by
                # when installing editables, nothing pre-existing should ever
                # satisfy
                self.satisfied_by = None
                return True