from email.parser import FeedParser
import os
import imp
import locale
import re
import sys
import shutil
import tempfile
import textwrap
import zipfile

from distutils.util import change_root
from pip.locations import (bin_py, running_under_virtualenv,PIP_DELETE_MARKER_FILENAME,
                           write_delete_marker_file, bin_user)
from pip.exceptions import (InstallationError, UninstallationError, UnsupportedWheel,
                            BestVersionAlreadyInstalled, InvalidWheelFilename,
                            DistributionNotFound, PreviousBuildDirError)
from pip.vcs import vcs
from pip.log import logger
from pip.util import (display_path, rmtree, ask, ask_path_exists, backup_dir,
                      is_installable_dir, is_local, dist_is_local,
                      dist_in_usersite, dist_in_site_packages, renames,
                      normalize_path, egg_link_path, make_path_relative,
                      call_subprocess, is_prerelease, normalize_name)
from pip.backwardcompat import (urlparse, urllib, uses_pycache,
                                ConfigParser, string_types, HTTPError,
                                get_python_version, b)
from pip.index import Link
from pip.locations import build_prefix
from pip.download import (PipSession, get_file_content, is_url, url_to_path,
                          path_to_url, is_archive_file,
                          unpack_vcs_link, is_vcs_url, is_file_url,
                          unpack_file_url, unpack_http_url)
import pip.wheel
from pip.wheel import move_wheel_files, Wheel, wheel_ext
from pip._vendor import pkg_resources, six


def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data


class InstallRequirement(object):

    def __init__(self, req, comes_from, source_dir=None, editable=False,
                 url=None, as_egg=False, update=True, prereleases=None,
                 editable_options=None, from_bundle=False, pycompile=True):
        self.extras = ()
        if isinstance(req, string_types):
            req = pkg_resources.Requirement.parse(req)
            self.extras = req.extras
        self.req = req
        self.comes_from = comes_from
        self.source_dir = source_dir
        self.editable = editable

        if editable_options is None:
            editable_options = {}

        self.editable_options = editable_options
        self.url = url
        self.as_egg = as_egg
        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
        self._temp_build_dir = None
        self._is_bundle = 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 = None
        self.use_user_site = False
        self.target_dir = None
        self.from_bundle = from_bundle

        self.pycompile = pycompile

        # True if pre-releases are acceptable
        if prereleases:
            self.prereleases = True
        elif self.req is not None:
            self.prereleases = any([is_prerelease(x[1]) and x[0] != "!=" for x in self.req.specs])
        else:
            self.prereleases = False

    @classmethod
    def from_editable(cls, editable_req, comes_from=None, default_vcs=None):
        name, url, extras_override = parse_editable(editable_req, default_vcs)
        if url.startswith('file:'):
            source_dir = url_to_path(url)
        else:
            source_dir = None

        res = cls(name, comes_from, source_dir=source_dir,
                  editable=True,
                  url=url,
                  editable_options=extras_override,
                  prereleases=True)

        if extras_override is not None:
            res.extras = extras_override

        return res

    @classmethod
    def from_line(cls, name, comes_from=None, prereleases=None):
        """Creates an InstallRequirement from a name, which might be a
        requirement, directory containing 'setup.py', filename, or URL.
        """
        url = None
        name = name.strip()
        req = None
        path = os.path.normpath(os.path.abspath(name))
        link = None

        if is_url(name):
            link = Link(name)
        elif os.path.isdir(path) and (os.path.sep in name or name.startswith('.')):
            if not is_installable_dir(path):
                raise InstallationError("Directory %r is not installable. File 'setup.py' not found." % name)
            link = Link(path_to_url(name))
        elif is_archive_file(path):
            if not os.path.isfile(path):
                logger.warn('Requirement %r looks like a filename, but the file does not exist', name)
            link = Link(path_to_url(name))

        # If the line has an egg= definition, but isn't editable, pull the requirement out.
        # Otherwise, assume the name is the req for the non URL/path/archive case.
        if link and req is None:
            url = link.url_without_fragment
            req = link.egg_fragment  #when fragment is None, this will become an 'unnamed' requirement

            # Handle relative file URLs
            if link.scheme == 'file' and re.search(r'\.\./', url):
                url = path_to_url(os.path.normpath(os.path.abspath(link.path)))

            # fail early for invalid or unsupported wheels
            if link.ext == wheel_ext:
                wheel = Wheel(link.filename) # can raise InvalidWheelFilename
                if not wheel.supported():
                    raise UnsupportedWheel("%s is not a supported wheel on this platform." % wheel.filename)

        else:
            req = name

        return cls(req, comes_from, url=url, prereleases=prereleases)

    def __str__(self):
        if self.req:
            s = str(self.req)
            if self.url:
                s += ' from %s' % self.url
        else:
            s = self.url
        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, 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 from_path(self):
        if self.req is None:
            return None
        s = str(self.req)
        if self.comes_from:
            if isinstance(self.comes_from, 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, unpack=True):
        if self._temp_build_dir is not None:
            return self._temp_build_dir
        if self.req is None:
            self._temp_build_dir = tempfile.mkdtemp('-build', 'pip-')
            self._ideal_build_dir = build_dir
            return self._temp_build_dir
        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):
            _make_build_dir(build_dir)
        return os.path.join(build_dir, name)

    def correct_build_location(self):
        """If the build location was a temporary directory, this will move it
        to a new more permanent location"""
        if self.source_dir is not None:
            return
        assert self.req is not None
        assert self._temp_build_dir
        old_location = self._temp_build_dir
        new_build_dir = self._ideal_build_dir
        del self._ideal_build_dir
        if self.editable:
            name = self.name.lower()
        else:
            name = self.name
        new_location = os.path.join(new_build_dir, name)
        if not os.path.exists(new_build_dir):
            logger.debug('Creating directory %s' % new_build_dir)
            _make_build_dir(new_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 = new_location
        self.source_dir = new_location
        self._egg_info_path = None

    @property
    def name(self):
        if self.req is None:
            return None
        return self.req.project_name

    @property
    def url_name(self):
        if self.req is None:
            return None
        return urllib.quote(self.req.unsafe_name)

    @property
    def setup_py(self):
        try:
            import setuptools
        except ImportError:
            # Setuptools is not available
            raise InstallationError(
                "setuptools must be installed to install from a source "
                "distribution"
            )

        setup_file = 'setup.py'

        if self.editable_options and 'subdirectory' in self.editable_options:
            setup_py = os.path.join(self.source_dir,
                                    self.editable_options['subdirectory'],
                                    setup_file)

        else:
            setup_py = os.path.join(self.source_dir, setup_file)

        # Python2 __file__ should not be unicode
        if six.PY2 and isinstance(setup_py, six.text_type):
            setup_py = setup_py.encode(sys.getfilesystemencoding())

        return setup_py

    def run_egg_info(self, force_root_egg_info=False):
        assert self.source_dir
        if self.name:
            logger.notify('Running setup.py (path:%s) egg_info for package %s' % (self.setup_py, self.name))
        else:
            logger.notify('Running setup.py (path:%s) egg_info for package from %s' % (self.setup_py, self.url))
        logger.indent += 2
        try:

            # if it's distribute>=0.7, it won't contain an importable
            # setuptools, and having an egg-info dir blocks the ability of
            # setup.py to find setuptools plugins, so delete the egg-info dir if
            # no setuptools. it will get recreated by the run of egg_info
            # NOTE: this self.name check only works when installing from a specifier
            #       (not archive path/urls)
            # TODO: take this out later
            if self.name == 'distribute' and not os.path.isdir(os.path.join(self.source_dir, 'setuptools')):
                rmtree(os.path.join(self.source_dir, 'distribute.egg-info'))

            script = self._run_setup_py
            script = script.replace('__SETUP_PY__', repr(self.setup_py))
            script = script.replace('__PKG_NAME__', repr(self.name))
            egg_info_cmd = [sys.executable, '-c', script, 'egg_info']
            # We can't put the .egg-info files at the root, because then the source code will be mistaken
            # for an installed egg, causing problems
            if self.editable or force_root_egg_info:
                egg_base_option = []
            else:
                egg_info_dir = os.path.join(self.source_dir, 'pip-egg-info')
                if not os.path.exists(egg_info_dir):
                    os.makedirs(egg_info_dir)
                egg_base_option = ['--egg-base', 'pip-egg-info']
            call_subprocess(
                egg_info_cmd + egg_base_option,
                cwd=self.source_dir, filter_stdout=self._filter_install, show_stdout=False,
                command_level=logger.VERBOSE_DEBUG,
                command_desc='python setup.py egg_info')
        finally:
            logger.indent -= 2
        if not self.req:
            self.req = pkg_resources.Requirement.parse(
                "%(Name)s==%(Version)s" % self.pkg_info())
            self.correct_build_location()

    ## FIXME: This is a lame hack, entirely for PasteScript which has
    ## a self-provided entry point that causes this awkwardness
    _run_setup_py = """
__file__ = __SETUP_PY__
from setuptools.command import egg_info
import pkg_resources
import os
import tokenize
def replacement_run(self):
    self.mkpath(self.egg_info)
    installer = self.distribution.fetch_build_egg
    for ep in pkg_resources.iter_entry_points('egg_info.writers'):
        # require=False is the change we're making:
        writer = ep.load(require=False)
        if writer:
            writer(self, ep.name, os.path.join(self.egg_info,ep.name))
    self.find_sources()
egg_info.egg_info.run = replacement_run
exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\\r\\n', '\\n'), __file__, 'exec'))
"""

    def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

    def egg_info_path(self, filename):
        if self._egg_info_path is None:
            if self.editable:
                base = self.source_dir
            else:
                base = os.path.join(self.source_dir, 'pip-egg-info')
            filenames = os.listdir(base)
            if self.editable:
                filenames = []
                for root, dirs, files in os.walk(base):
                    for dir in vcs.dirnames:
                        if dir in dirs:
                            dirs.remove(dir)
                    # Iterate over a copy of ``dirs``, since mutating
                    # a list while iterating over it can cause trouble.
                    # (See https://github.com/pypa/pip/pull/462.)
                    for dir in list(dirs):
                        # Don't search in anything that looks like a virtualenv environment
                        if (os.path.exists(os.path.join(root, dir, 'bin', 'python'))
                            or os.path.exists(os.path.join(root, dir, 'Scripts', 'Python.exe'))):
                            dirs.remove(dir)
                        # Also don't search through tests
                        if dir == 'test' or dir == 'tests':
                            dirs.remove(dir)
                    filenames.extend([os.path.join(root, dir)
                                     for dir in dirs])
                filenames = [f for f in filenames if f.endswith('.egg-info')]

            if not filenames:
                raise InstallationError('No files/directories in %s (from %s)' % (base, filename))
            assert filenames, "No files/directories in %s (from %s)" % (base, filename)

            # if we have more than one match, we pick the toplevel one.  This can
            # easily be the case if there is a dist folder which contains an
            # extracted tarball for testing purposes.
            if len(filenames) > 1:
                filenames.sort(key=lambda x: x.count(os.path.sep) +
                                             (os.path.altsep and
                                              x.count(os.path.altsep) or 0))
            self._egg_info_path = os.path.join(base, filenames[0])
        return os.path.join(self._egg_info_path, filename)

    def egg_info_lines(self, filename):
        data = self.egg_info_data(filename)
        if not data:
            return []
        result = []
        for line in data.splitlines():
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            result.append(line)
        return result

    def pkg_info(self):
        p = FeedParser()
        data = self.egg_info_data('PKG-INFO')
        if not data:
            logger.warn('No PKG-INFO file found in %s' % display_path(self.egg_info_path('PKG-INFO')))
        p.feed(data or '')
        return p.close()

    @property
    def dependency_links(self):
        return self.egg_info_lines('dependency_links.txt')

    _requirements_section_re = re.compile(r'\[(.*?)\]')

    def requirements(self, extras=()):
        in_extra = None
        for line in self.egg_info_lines('requires.txt'):
            match = self._requirements_section_re.match(line.lower())
            if match:
                in_extra = match.group(1)
                continue
            if in_extra and in_extra not in extras:
                logger.debug('skipping extra %s' % in_extra)
                # Skip requirement for an extra we aren't requiring
                continue
            yield line

    @property
    def absolute_versions(self):
        for qualifier, version in self.req.specs:
            if qualifier == '==':
                yield version

    @property
    def installed_version(self):
        return self.pkg_info()['version']

    def assert_source_matches_version(self):
        assert self.source_dir
        version = self.installed_version
        if version not in self.req:
            logger.warn('Requested %s, but installing version %s' % (self, self.installed_version))
        else:
            logger.debug('Source in %s has version %s, which satisfies requirement %s'
                         % (display_path(self.source_dir), version, self))

    def update_editable(self, obtain=True):
        if not self.url:
            logger.info("Cannot update repository at %s; repository location is unknown" % self.source_dir)
            return
        assert self.editable
        assert self.source_dir
        if self.url.startswith('file:'):
            # Static paths don't get updated
            return
        assert '+' in self.url, "bad url: %r" % self.url
        if not self.update:
            return
        vc_type, url = self.url.split('+', 1)
        backend = vcs.get_backend(vc_type)
        if backend:
            vcs_backend = backend(self.url)
            if obtain:
                vcs_backend.obtain(self.source_dir)
            else:
                vcs_backend.export(self.source_dir)
        else:
            assert 0, (
                'Unexpected version control type (in %s): %s'
                % (self.url, vc_type))

    def uninstall(self, auto_confirm=False):
        """
        Uninstall the distribution currently satisfying this requirement.

        Prompts before removing or modifying files unless
        ``auto_confirm`` is True.

        Refuses to delete or modify files outside of ``sys.prefix`` -
        thus uninstallation within a virtual environment can only
        modify that virtual environment, even if the virtualenv is
        linked to global site-packages.

        """
        if not self.check_if_exists():
            raise UninstallationError("Cannot uninstall requirement %s, not installed" % (self.name,))
        dist = self.satisfied_by or self.conflicts_with

        paths_to_remove = UninstallPathSet(dist)

        pip_egg_info_path = os.path.join(dist.location,
                                         dist.egg_name()) + '.egg-info'
        dist_info_path = os.path.join(dist.location,
                                      '-'.join(dist.egg_name().split('-')[:2])
                                      ) + '.dist-info'
        # workaround for http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=618367
        debian_egg_info_path = pip_egg_info_path.replace(
            '-py%s' % pkg_resources.PY_MAJOR, '')
        easy_install_egg = dist.egg_name() + '.egg'
        develop_egg_link = egg_link_path(dist)

        pip_egg_info_exists = os.path.exists(pip_egg_info_path)
        debian_egg_info_exists = os.path.exists(debian_egg_info_path)
        dist_info_exists = os.path.exists(dist_info_path)
        if pip_egg_info_exists or debian_egg_info_exists:
            # package installed by pip
            if pip_egg_info_exists:
                egg_info_path = pip_egg_info_path
            else:
                egg_info_path = debian_egg_info_path
            paths_to_remove.add(egg_info_path)
            if dist.has_metadata('installed-files.txt'):
                for installed_file in dist.get_metadata('installed-files.txt').splitlines():
                    path = os.path.normpath(os.path.join(egg_info_path, installed_file))
                    paths_to_remove.add(path)
            #FIXME: need a test for this elif block
            #occurs with --single-version-externally-managed/--record outside of pip
            elif dist.has_metadata('top_level.txt'):
                if dist.has_metadata('namespace_packages.txt'):
                    namespaces = dist.get_metadata('namespace_packages.txt')
                else:
                    namespaces = []
                for top_level_pkg in [p for p
                                      in dist.get_metadata('top_level.txt').splitlines()
                                      if p and p not in namespaces]:
                    path = os.path.join(dist.location, top_level_pkg)
                    paths_to_remove.add(path)
                    paths_to_remove.add(path + '.py')
                    paths_to_remove.add(path + '.pyc')

        elif dist.location.endswith(easy_install_egg):
            # package installed by easy_install
            paths_to_remove.add(dist.location)
            easy_install_pth = os.path.join(os.path.dirname(dist.location),
                                            'easy-install.pth')
            paths_to_remove.add_pth(easy_install_pth, './' + easy_install_egg)

        elif develop_egg_link:
            # develop egg
            fh = open(develop_egg_link, 'r')
            link_pointer = os.path.normcase(fh.readline().strip())
            fh.close()
            assert (link_pointer == dist.location), 'Egg-link %s does not match installed location of %s (at %s)' % (link_pointer, self.name, dist.location)
            paths_to_remove.add(develop_egg_link)
            easy_install_pth = os.path.join(os.path.dirname(develop_egg_link),
                                            'easy-install.pth')
            paths_to_remove.add_pth(easy_install_pth, dist.location)
        elif dist_info_exists:
            for path in pip.wheel.uninstallation_paths(dist):
                paths_to_remove.add(path)

        # find distutils scripts= scripts
        if dist.has_metadata('scripts') and dist.metadata_isdir('scripts'):
            for script in dist.metadata_listdir('scripts'):
                if dist_in_usersite(dist):
                    bin_dir = bin_user
                else:
                    bin_dir = bin_py
                paths_to_remove.add(os.path.join(bin_dir, script))
                if sys.platform == 'win32':
                    paths_to_remove.add(os.path.join(bin_dir, script) + '.bat')

        # find console_scripts
        if dist.has_metadata('entry_points.txt'):
            config = ConfigParser.SafeConfigParser()
            config.readfp(FakeFile(dist.get_metadata_lines('entry_points.txt')))
            if config.has_section('console_scripts'):
                for name, value in config.items('console_scripts'):
                    if dist_in_usersite(dist):
                        bin_dir = bin_user
                    else:
                        bin_dir = bin_py
                    paths_to_remove.add(os.path.join(bin_dir, name))
                    if sys.platform == 'win32':
                        paths_to_remove.add(os.path.join(bin_dir, name) + '.exe')
                        paths_to_remove.add(os.path.join(bin_dir, name) + '.exe.manifest')
                        paths_to_remove.add(os.path.join(bin_dir, name) + '-script.py')

        paths_to_remove.remove(auto_confirm)
        self.uninstalled = paths_to_remove

    def rollback_uninstall(self):
        if self.uninstalled:
            self.uninstalled.rollback()
        else:
            logger.error("Can't rollback %s, nothing uninstalled."
                         % (self.project_name,))

    def commit_uninstall(self):
        if self.uninstalled:
            self.uninstalled.commit()
        else:
            logger.error("Can't commit %s, nothing uninstalled."
                         % (self.project_name,))

    def archive(self, build_dir):
        assert self.source_dir
        create_archive = True
        archive_name = '%s-%s.zip' % (self.name, self.installed_version)
        archive_path = os.path.join(build_dir, archive_name)
        if os.path.exists(archive_path):
            response = ask_path_exists(
                'The file %s exists. (i)gnore, (w)ipe, (b)ackup ' %
                display_path(archive_path), ('i', 'w', 'b'))
            if response == 'i':
                create_archive = False
            elif response == 'w':
                logger.warn('Deleting %s' % display_path(archive_path))
                os.remove(archive_path)
            elif response == 'b':
                dest_file = backup_dir(archive_path)
                logger.warn('Backing up %s to %s'
                            % (display_path(archive_path), display_path(dest_file)))
                shutil.move(archive_path, dest_file)
        if create_archive:
            zip = zipfile.ZipFile(archive_path, 'w', zipfile.ZIP_DEFLATED)
            dir = os.path.normcase(os.path.abspath(self.source_dir))
            for dirpath, dirnames, filenames in os.walk(dir):
                if 'pip-egg-info' in dirnames:
                    dirnames.remove('pip-egg-info')
                for dirname in dirnames:
                    dirname = os.path.join(dirpath, dirname)
                    name = self._clean_zip_name(dirname, dir)
                    zipdir = zipfile.ZipInfo(self.name + '/' + name + '/')
                    zipdir.external_attr = 0x1ED << 16 # 0o755
                    zip.writestr(zipdir, '')
                for filename in filenames:
                    if filename == PIP_DELETE_MARKER_FILENAME:
                        continue
                    filename = os.path.join(dirpath, filename)
                    name = self._clean_zip_name(filename, dir)
                    zip.write(filename, self.name + '/' + name)
            zip.close()
            logger.indent -= 2
            logger.notify('Saved %s' % display_path(archive_path))

    def _clean_zip_name(self, name, prefix):
        assert name.startswith(prefix+os.path.sep), (
            "name %r doesn't start with prefix %r" % (name, prefix))
        name = name[len(prefix)+1:]
        name = name.replace(os.path.sep, '/')
        return name

    def install(self, install_options, global_options=(), root=None, strip_file_prefix=None):
        if self.editable:
            self.install_editable(install_options, global_options)
            return
        if self.is_wheel:
            version = pip.wheel.wheel_version(self.source_dir)
            pip.wheel.check_compatibility(version, self.name)

            self.move_wheel_files(
                self.source_dir,
                root=root,
                strip_file_prefix=strip_file_prefix
            )
            self.install_succeeded = True
            return

        temp_location = tempfile.mkdtemp('-record', 'pip-')
        record_filename = os.path.join(temp_location, 'install-record.txt')
        try:
            install_args = [sys.executable]
            install_args.append('-c')
            install_args.append(
            "import setuptools, tokenize;__file__=%r;"\
            "exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\\r\\n', '\\n'), __file__, 'exec'))" % self.setup_py)
            install_args += list(global_options) + ['install','--record', record_filename]

            if not self.as_egg:
                install_args += ['--single-version-externally-managed']

            if root is not None:
                install_args += ['--root', root]

            if self.pycompile:
                install_args += ["--compile"]
            else:
                install_args += ["--no-compile"]

            if running_under_virtualenv():
                ## FIXME: I'm not sure if this is a reasonable location; probably not
                ## but we can't put it in the default location, as that is a virtualenv symlink that isn't writable
                install_args += ['--install-headers',
                                 os.path.join(sys.prefix, 'include', 'site',
                                              'python' + get_python_version())]
            logger.notify('Running setup.py install for %s' % self.name)
            logger.indent += 2
            try:
                call_subprocess(install_args + install_options,
                    cwd=self.source_dir, filter_stdout=self._filter_install, show_stdout=False)
            finally:
                logger.indent -= 2
            if not os.path.exists(record_filename):
                logger.notify('Record file %s not found' % record_filename)
                return
            self.install_succeeded = True
            if self.as_egg:
                # there's no --always-unzip option we can pass to install command
                # so we unable to save the installed-files.txt
                return

            def prepend_root(path):
                if root is None or not os.path.isabs(path):
                    return path
                else:
                    return change_root(root, path)

            f = open(record_filename)
            for line in f:
                line = line.strip()
                if line.endswith('.egg-info'):
                    egg_info_dir = prepend_root(line)
                    break
            else:
                logger.warn('Could not find .egg-info directory in install record for %s' % self)
                ## FIXME: put the record somewhere
                ## FIXME: should this be an error?
                return
            f.close()
            new_lines = []
            f = open(record_filename)
            for line in f:
                filename = line.strip()
                if os.path.isdir(filename):
                    filename += os.path.sep
                new_lines.append(make_path_relative(prepend_root(filename), egg_info_dir))
            f.close()
            f = open(os.path.join(egg_info_dir, 'installed-files.txt'), 'w')
            f.write('\n'.join(new_lines)+'\n')
            f.close()
        finally:
            if os.path.exists(record_filename):
                os.remove(record_filename)
            os.rmdir(temp_location)

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

    def install_editable(self, install_options, global_options=()):
        logger.notify('Running setup.py develop for %s' % self.name)
        logger.indent += 2
        try:
            ## FIXME: should we do --install-headers here too?
            call_subprocess(
                [sys.executable, '-c',
                 "import setuptools, tokenize; __file__=%r; exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\\r\\n', '\\n'), __file__, 'exec'))" % self.setup_py]
                + list(global_options) + ['develop', '--no-deps'] + list(install_options),

                cwd=self.source_dir, filter_stdout=self._filter_install,
                show_stdout=False)
        finally:
            logger.indent -= 2
        self.install_succeeded = True

    def _filter_install(self, line):
        level = logger.NOTIFY
        for regex in [r'^running .*', r'^writing .*', '^creating .*', '^[Cc]opying .*',
                      r'^reading .*', r"^removing .*\.egg-info' \(and everything under it\)$",
                      r'^byte-compiling ',
                      # Not sure what this warning is, but it seems harmless:
                      r"^warning: manifest_maker: standard file '-c' not found$"]:
            if re.search(regex, line.strip()):
                level = logger.INFO
                break
        return (level, line)

    def check_if_exists(self):
        """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:
            # DISTRIBUTE TO SETUPTOOLS UPGRADE HACK (1 of 3 parts)
            # if we've already set distribute as a conflict to setuptools
            # then this check has already run before.  we don't want it to
            # run again, and return False, since it would block the uninstall
            # TODO: remove this later
            if (self.req.project_name == 'setuptools'
                and self.conflicts_with
                and self.conflicts_with.project_name == 'distribute'):
                return True
            else:
                self.satisfied_by = pkg_resources.get_distribution(self.req)
        except pkg_resources.DistributionNotFound:
            return False
        except pkg_resources.VersionConflict:
            existing_dist = pkg_resources.get_distribution(self.req.project_name)
            if self.use_user_site:
                if dist_in_usersite(existing_dist):
                    self.conflicts_with = existing_dist
                elif running_under_virtualenv() and dist_in_site_packages(existing_dist):
                    raise InstallationError("Will not install to the user site because it will lack sys.path precedence to %s in %s"
                                            %(existing_dist.project_name, existing_dist.location))
            else:
                self.conflicts_with = existing_dist
        return True

    @property
    def is_wheel(self):
        return self.url and '.whl' in self.url

    @property
    def is_bundle(self):
        if self._is_bundle is not None:
            return self._is_bundle
        base = self._temp_build_dir
        if not base:
            ## FIXME: this doesn't seem right:
            return False
        self._is_bundle = (os.path.exists(os.path.join(base, 'pip-manifest.txt'))
                           or os.path.exists(os.path.join(base, 'pyinstall-manifest.txt')))
        return self._is_bundle

    def bundle_requirements(self):
        for dest_dir in self._bundle_editable_dirs:
            package = os.path.basename(dest_dir)
            ## FIXME: svnism:
            for vcs_backend in vcs.backends:
                url = rev = None
                vcs_bundle_file = os.path.join(
                    dest_dir, vcs_backend.bundle_file)
                if os.path.exists(vcs_bundle_file):
                    vc_type = vcs_backend.name
                    fp = open(vcs_bundle_file)
                    content = fp.read()
                    fp.close()
                    url, rev = vcs_backend().parse_vcs_bundle_file(content)
                    break
            if url:
                url = '%s+%s@%s' % (vc_type, url, rev)
            else:
                url = None
            yield InstallRequirement(
                package, self, editable=True, url=url,
                update=False, source_dir=dest_dir, from_bundle=True)
        for dest_dir in self._bundle_build_dirs:
            package = os.path.basename(dest_dir)
            yield InstallRequirement(package, self,source_dir=dest_dir, from_bundle=True)

    def move_bundle_files(self, dest_build_dir, dest_src_dir):
        base = self._temp_build_dir
        assert base
        src_dir = os.path.join(base, 'src')
        build_dir = os.path.join(base, 'build')
        bundle_build_dirs = []
        bundle_editable_dirs = []
        for source_dir, dest_dir, dir_collection in [
            (src_dir, dest_src_dir, bundle_editable_dirs),
            (build_dir, dest_build_dir, bundle_build_dirs)]:
            if os.path.exists(source_dir):
                for dirname in os.listdir(source_dir):
                    dest = os.path.join(dest_dir, dirname)
                    dir_collection.append(dest)
                    if os.path.exists(dest):
                        logger.warn('The directory %s (containing package %s) already exists; cannot move source from bundle %s'
                                    % (dest, dirname, self))
                        continue
                    if not os.path.exists(dest_dir):
                        logger.info('Creating directory %s' % dest_dir)
                        os.makedirs(dest_dir)
                    shutil.move(os.path.join(source_dir, dirname), dest)
                if not os.listdir(source_dir):
                    os.rmdir(source_dir)
        self._temp_build_dir = None
        self._bundle_build_dirs = bundle_build_dirs
        self._bundle_editable_dirs = bundle_editable_dirs

    def move_wheel_files(self, wheeldir, root=None, strip_file_prefix=None):
        move_wheel_files(
            self.name, self.req, wheeldir,
            user=self.use_user_site,
            home=self.target_dir,
            root=root,
            pycompile=self.pycompile,
            strip_file_prefix=strip_file_prefix,
        )

    @property
    def delete_marker_filename(self):
        assert self.source_dir
        return os.path.join(self.source_dir, PIP_DELETE_MARKER_FILENAME)


class Requirements(object):

    def __init__(self):
        self._keys = []
        self._dict = {}

    def keys(self):
        return self._keys

    def values(self):
        return [self._dict[key] for key in self._keys]

    def __contains__(self, item):
        return item in self._keys

    def __setitem__(self, key, value):
        if key not in self._keys:
            self._keys.append(key)
        self._dict[key] = value

    def __getitem__(self, key):
        return self._dict[key]

    def __repr__(self):
        values = ['%s: %s' % (repr(k), repr(self[k])) for k in self.keys()]
        return 'Requirements({%s})' % ', '.join(values)


class RequirementSet(object):

    def __init__(self, build_dir, src_dir, download_dir, download_cache=None,
                 upgrade=False, ignore_installed=False, as_egg=False,
                 target_dir=None, ignore_dependencies=False,
                 force_reinstall=False, use_user_site=False, session=None,
                 pycompile=True, wheel_download_dir=None):
        self.build_dir = build_dir
        self.src_dir = src_dir
        self.download_dir = download_dir
        if download_cache:
            download_cache = os.path.expanduser(download_cache)
        self.download_cache = download_cache
        self.upgrade = upgrade
        self.ignore_installed = ignore_installed
        self.force_reinstall = force_reinstall
        self.requirements = Requirements()
        # Mapping of alias: real_name
        self.requirement_aliases = {}
        self.unnamed_requirements = []
        self.ignore_dependencies = ignore_dependencies
        self.successfully_downloaded = []
        self.successfully_installed = []
        self.reqs_to_cleanup = []
        self.as_egg = as_egg
        self.use_user_site = use_user_site
        self.target_dir = target_dir #set from --target option
        self.session = session or PipSession()
        self.pycompile = pycompile
        self.wheel_download_dir = wheel_download_dir

    def __str__(self):
        reqs = [req for req in self.requirements.values()
                if not req.comes_from]
        reqs.sort(key=lambda req: req.name.lower())
        return ' '.join([str(req.req) for req in reqs])

    def add_requirement(self, install_req):
        name = install_req.name
        install_req.as_egg = self.as_egg
        install_req.use_user_site = self.use_user_site
        install_req.target_dir = self.target_dir
        install_req.pycompile = self.pycompile
        if not name:
            #url or path requirement w/o an egg fragment
            self.unnamed_requirements.append(install_req)
        else:
            if self.has_requirement(name):
                raise InstallationError(
                    'Double requirement given: %s (already in %s, name=%r)'
                    % (install_req, self.get_requirement(name), name))
            self.requirements[name] = install_req
            ## FIXME: what about other normalizations?  E.g., _ vs. -?
            if name.lower() != name:
                self.requirement_aliases[name.lower()] = name

    def has_requirement(self, project_name):
        for name in project_name, project_name.lower():
            if name in self.requirements or name in self.requirement_aliases:
                return True
        return False

    @property
    def has_requirements(self):
        return list(self.requirements.values()) or self.unnamed_requirements

    @property
    def has_editables(self):
        if any(req.editable for req in self.requirements.values()):
            return True
        if any(req.editable for req in self.unnamed_requirements):
            return True
        return False

    @property
    def is_download(self):
        if self.download_dir:
            self.download_dir = os.path.expanduser(self.download_dir)
            if os.path.exists(self.download_dir):
                return True
            else:
                logger.fatal('Could not find download directory')
                raise InstallationError(
                    "Could not find or access download directory '%s'"
                    % display_path(self.download_dir))
        return False

    def get_requirement(self, project_name):
        for name in project_name, project_name.lower():
            if name in self.requirements:
                return self.requirements[name]
            if name in self.requirement_aliases:
                return self.requirements[self.requirement_aliases[name]]
        raise KeyError("No project with the name %r" % project_name)

    def uninstall(self, auto_confirm=False):
        for req in self.requirements.values():
            req.uninstall(auto_confirm=auto_confirm)
            req.commit_uninstall()

    def locate_files(self):
        ## FIXME: duplicates code from prepare_files; relevant code should
        ##        probably be factored out into a separate method
        unnamed = list(self.unnamed_requirements)
        reqs = list(self.requirements.values())
        while reqs or unnamed:
            if unnamed:
                req_to_install = unnamed.pop(0)
            else:
                req_to_install = reqs.pop(0)
            install_needed = True
            if not self.ignore_installed and not req_to_install.editable:
                req_to_install.check_if_exists()
                if req_to_install.satisfied_by:
                    if self.upgrade:
                        #don't uninstall conflict if user install and and conflict is not user install
                        if not (self.use_user_site and not dist_in_usersite(req_to_install.satisfied_by)):
                            req_to_install.conflicts_with = req_to_install.satisfied_by
                        req_to_install.satisfied_by = None
                    else:
                        install_needed = False
                if req_to_install.satisfied_by:
                    logger.notify('Requirement already satisfied '
                                  '(use --upgrade to upgrade): %s'
                                  % req_to_install)

            if req_to_install.editable:
                if req_to_install.source_dir is None:
                    req_to_install.source_dir = req_to_install.build_location(self.src_dir)
            elif install_needed:
                req_to_install.source_dir = req_to_install.build_location(self.build_dir, not self.is_download)

            if req_to_install.source_dir is not None and not os.path.isdir(req_to_install.source_dir):
                raise InstallationError('Could not install requirement %s '
                                       'because source folder %s does not exist '
                                       '(perhaps --no-download was used without first running '
                                       'an equivalent install with --no-install?)'
                                       % (req_to_install, req_to_install.source_dir))

    def prepare_files(self, finder, force_root_egg_info=False, bundle=False):
        """Prepare process. Create temp directories, download and/or unpack files."""
        unnamed = list(self.unnamed_requirements)
        reqs = list(self.requirements.values())
        while reqs or unnamed:
            if unnamed:
                req_to_install = unnamed.pop(0)
            else:
                req_to_install = reqs.pop(0)
            install = True
            best_installed = False
            not_found = None
            if not self.ignore_installed and not req_to_install.editable:
                req_to_install.check_if_exists()
                if req_to_install.satisfied_by:
                    if self.upgrade:
                        if not self.force_reinstall and not req_to_install.url:
                            try:
                                url = finder.find_requirement(
                                    req_to_install, self.upgrade)
                            except BestVersionAlreadyInstalled:
                                best_installed = True
                                install = False
                            except DistributionNotFound:
                                not_found = sys.exc_info()[1]
                            else:
                                # Avoid the need to call find_requirement again
                                req_to_install.url = url.url

                        if not best_installed:
                            #don't uninstall conflict if user install and conflict is not user install
                            if not (self.use_user_site and not dist_in_usersite(req_to_install.satisfied_by)):
                                req_to_install.conflicts_with = req_to_install.satisfied_by
                            req_to_install.satisfied_by = None
                    else:
                        install = False
                if req_to_install.satisfied_by:
                    if best_installed:
                        logger.notify('Requirement already up-to-date: %s'
                                      % req_to_install)
                    else:
                        logger.notify('Requirement already satisfied '
                                      '(use --upgrade to upgrade): %s'
                                      % req_to_install)
            if req_to_install.editable:
                logger.notify('Obtaining %s' % req_to_install)
            elif install:
                if req_to_install.url and req_to_install.url.lower().startswith('file:'):
                    logger.notify('Unpacking %s' % display_path(url_to_path(req_to_install.url)))
                else:
                    logger.notify('Downloading/unpacking %s' % req_to_install)
            logger.indent += 2
            try:
                is_bundle = False
                is_wheel = False
                if req_to_install.editable:
                    if req_to_install.source_dir is None:
                        location = req_to_install.build_location(self.src_dir)
                        req_to_install.source_dir = location
                    else:
                        location = req_to_install.source_dir
                    if not os.path.exists(self.build_dir):
                        _make_build_dir(self.build_dir)
                    req_to_install.update_editable(not self.is_download)
                    if self.is_download:
                        req_to_install.run_egg_info()
                        req_to_install.archive(self.download_dir)
                    else:
                        req_to_install.run_egg_info()
                elif install:
                    ##@@ if filesystem packages are not marked
                    ##editable in a req, a non deterministic error
                    ##occurs when the script attempts to unpack the
                    ##build directory

                    # NB: This call can result in the creation of a temporary build directory
                    location = req_to_install.build_location(self.build_dir, not self.is_download)
                    unpack = True
                    url = None

                    # In the case where the req comes from a bundle, we should
                    # assume a build dir exists and move on
                    if req_to_install.from_bundle:
                        pass
                    # If a checkout exists, it's unwise to keep going.  version
                    # inconsistencies are logged later, but do not fail the
                    # installation.
                    elif os.path.exists(os.path.join(location, 'setup.py')):
                        raise PreviousBuildDirError(textwrap.dedent("""
                          pip can't proceed with requirement '%s' due to a pre-existing build directory.
                           location: %s
                          This is likely due to a previous installation that failed.
                          pip is being responsible and not assuming it can delete this.
                          Please delete it and try again.
                        """ % (req_to_install, location)))
                    else:
                        ## FIXME: this won't upgrade when there's an existing package unpacked in `location`
                        if req_to_install.url is None:
                            if not_found:
                                raise not_found
                            url = finder.find_requirement(req_to_install, upgrade=self.upgrade)
                        else:
                            ## FIXME: should req_to_install.url already be a link?
                            url = Link(req_to_install.url)
                            assert url
                        if url:
                            try:

                                if (
                                    url.filename.endswith(wheel_ext)
                                    and self.wheel_download_dir
                                ):
                                    # when doing 'pip wheel`
                                    download_dir = self.wheel_download_dir
                                    do_download = True
                                else:
                                    download_dir = self.download_dir
                                    do_download = self.is_download
                                self.unpack_url(
                                    url, location, download_dir,
                                    do_download,
                                    )
                            except HTTPError as exc:
                                logger.fatal(
                                    'Could not install requirement %s because '
                                    'of error %s' % (req_to_install, exc)
                                )
                                raise InstallationError(
                                    'Could not install requirement %s because of HTTP error %s for URL %s'
                                    % (req_to_install, e, url))
                        else:
                            unpack = False
                    if unpack:
                        is_bundle = req_to_install.is_bundle
                        is_wheel = url and url.filename.endswith(wheel_ext)
                        if is_bundle:
                            req_to_install.move_bundle_files(self.build_dir, self.src_dir)
                            for subreq in req_to_install.bundle_requirements():
                                reqs.append(subreq)
                                self.add_requirement(subreq)
                        elif self.is_download:
                            req_to_install.source_dir = location
                            if not is_wheel:
                                # FIXME: see https://github.com/pypa/pip/issues/1112
                                req_to_install.run_egg_info()
                            if url and url.scheme in vcs.all_schemes:
                                req_to_install.archive(self.download_dir)
                        elif is_wheel:
                            req_to_install.source_dir = location
                            req_to_install.url = url.url
                        else:
                            req_to_install.source_dir = location
                            req_to_install.run_egg_info()
                            if force_root_egg_info:
                                # We need to run this to make sure that the .egg-info/
                                # directory is created for packing in the bundle
                                req_to_install.run_egg_info(force_root_egg_info=True)
                            req_to_install.assert_source_matches_version()
                            #@@ sketchy way of identifying packages not grabbed from an index
                            if bundle and req_to_install.url:
                                self.copy_to_build_dir(req_to_install)
                                install = False
                        # req_to_install.req is only avail after unpack for URL pkgs
                        # repeat check_if_exists to uninstall-on-upgrade (#14)
                        if not self.ignore_installed:
                            req_to_install.check_if_exists()
                        if req_to_install.satisfied_by:
                            if self.upgrade or self.ignore_installed:
                                #don't uninstall conflict if user install and and conflict is not user install
                                if not (self.use_user_site and not dist_in_usersite(req_to_install.satisfied_by)):
                                    req_to_install.conflicts_with = req_to_install.satisfied_by
                                req_to_install.satisfied_by = None
                            else:
                                logger.notify(
                                    'Requirement already satisfied (use '
                                    '--upgrade to upgrade): %s' %
                                    req_to_install
                                )
                                install = False
                if is_wheel:
                    dist = list(
                        pkg_resources.find_distributions(location)
                    )[0]
                    if not req_to_install.req:
                        req_to_install.req = dist.as_requirement()
                        self.add_requirement(req_to_install)
                    if not self.ignore_dependencies:
                        for subreq in dist.requires(
                                req_to_install.extras):
                            if self.has_requirement(
                                    subreq.project_name):
                                continue
                            subreq = InstallRequirement(str(subreq),
                                                        req_to_install)
                            reqs.append(subreq)
                            self.add_requirement(subreq)

                # sdists
                elif not is_bundle:
                    ## FIXME: shouldn't be globally added:
                    finder.add_dependency_links(req_to_install.dependency_links)
                    if (req_to_install.extras):
                        logger.notify("Installing extra requirements: %r" % ','.join(req_to_install.extras))
                    if not self.ignore_dependencies:
                        for req in req_to_install.requirements(req_to_install.extras):
                            try:
                                name = pkg_resources.Requirement.parse(req).project_name
                            except ValueError:
                                e = sys.exc_info()[1]
                                ## FIXME: proper warning
                                logger.error('Invalid requirement: %r (%s) in requirement %s' % (req, e, req_to_install))
                                continue
                            if self.has_requirement(name):
                                ## FIXME: check for conflict
                                continue
                            subreq = InstallRequirement(req, req_to_install)
                            reqs.append(subreq)
                            self.add_requirement(subreq)
                    if not self.has_requirement(req_to_install.name):
                        #'unnamed' requirements will get added here
                        self.add_requirement(req_to_install)

                # cleanup tmp src
                if not is_bundle:
                    if (
                        self.is_download or
                        req_to_install._temp_build_dir is not None
                    ):
                        self.reqs_to_cleanup.append(req_to_install)

                if install:
                    self.successfully_downloaded.append(req_to_install)
                    if bundle and (req_to_install.url and req_to_install.url.startswith('file:///')):
                        self.copy_to_build_dir(req_to_install)
            finally:
                logger.indent -= 2

    def cleanup_files(self, bundle=False):
        """Clean up files, remove builds."""
        logger.notify('Cleaning up...')
        logger.indent += 2
        for req in self.reqs_to_cleanup:
            req.remove_temporary_source()

        remove_dir = []
        if self._pip_has_created_build_dir():
            remove_dir.append(self.build_dir)

        # The source dir of a bundle can always be removed.
        # FIXME: not if it pre-existed the bundle!
        if bundle:
            remove_dir.append(self.src_dir)

        for dir in remove_dir:
            if os.path.exists(dir):
                logger.info('Removing temporary dir %s...' % dir)
                rmtree(dir)

        logger.indent -= 2

    def _pip_has_created_build_dir(self):
        return (self.build_dir == build_prefix and
                os.path.exists(os.path.join(self.build_dir, PIP_DELETE_MARKER_FILENAME)))

    def copy_to_build_dir(self, req_to_install):
        target_dir = req_to_install.editable and self.src_dir or self.build_dir
        logger.info("Copying %s to %s" % (req_to_install.name, target_dir))
        dest = os.path.join(target_dir, req_to_install.name)
        shutil.copytree(req_to_install.source_dir, dest)
        call_subprocess(["python", "%s/setup.py" % dest, "clean"], cwd=dest,
                        command_desc='python setup.py clean')

    def unpack_url(self, link, location, download_dir=None,
                   only_download=False):
        if download_dir is None:
            download_dir = self.download_dir

        # non-editable vcs urls
        if is_vcs_url(link):
            if only_download:
                loc = download_dir
            else:
                loc = location
            unpack_vcs_link(link, loc, only_download)

        # file urls
        elif is_file_url(link):
            unpack_file_url(link, location, download_dir)
            if only_download:
                write_delete_marker_file(location)

        # http urls
        else:
            unpack_http_url(
                link,
                location,
                self.download_cache,
                download_dir,
                self.session,
            )
            if only_download:
                write_delete_marker_file(location)

    def install(self, install_options, global_options=(), *args, **kwargs):
        """Install everything in this set (after having downloaded and unpacked the packages)"""
        to_install = [r for r in self.requirements.values()
                      if not r.satisfied_by]

        # DISTRIBUTE TO SETUPTOOLS UPGRADE HACK (1 of 3 parts)
        # move the distribute-0.7.X wrapper to the end because it does not
        # install a setuptools package. by moving it to the end, we ensure it's
        # setuptools dependency is handled first, which will provide the
        # setuptools package
        # TODO: take this out later
        distribute_req = pkg_resources.Requirement.parse("distribute>=0.7")
        for req in to_install:
            if req.name == 'distribute' and req.installed_version in distribute_req:
                to_install.remove(req)
                to_install.append(req)

        if to_install:
            logger.notify('Installing collected packages: %s' % ', '.join([req.name for req in to_install]))
        logger.indent += 2
        try:
            for requirement in to_install:

                # DISTRIBUTE TO SETUPTOOLS UPGRADE HACK (1 of 3 parts)
                # when upgrading from distribute-0.6.X to the new merged
                # setuptools in py2, we need to force setuptools to uninstall
                # distribute. In py3, which is always using distribute, this
                # conversion is already happening in distribute's pkg_resources.
                # It's ok *not* to check if setuptools>=0.7 because if someone
                # were actually trying to ugrade from distribute to setuptools
                # 0.6.X, then all this could do is actually help, although that
                # upgade path was certainly never "supported"
                # TODO: remove this later
                if requirement.name == 'setuptools':
                    try:
                        # only uninstall distribute<0.7. For >=0.7, setuptools
                        # will also be present, and that's what we need to
                        # uninstall
                        distribute_requirement = pkg_resources.Requirement.parse("distribute<0.7")
                        existing_distribute = pkg_resources.get_distribution("distribute")
                        if existing_distribute in distribute_requirement:
                            requirement.conflicts_with = existing_distribute
                    except pkg_resources.DistributionNotFound:
                        # distribute wasn't installed, so nothing to do
                        pass

                if requirement.conflicts_with:
                    logger.notify('Found existing installation: %s'
                                  % requirement.conflicts_with)
                    logger.indent += 2
                    try:
                        requirement.uninstall(auto_confirm=True)
                    finally:
                        logger.indent -= 2
                try:
                    requirement.install(install_options, global_options, *args, **kwargs)
                except:
                    # if install did not succeed, rollback previous uninstall
                    if requirement.conflicts_with and not requirement.install_succeeded:
                        requirement.rollback_uninstall()
                    raise
                else:
                    if requirement.conflicts_with and requirement.install_succeeded:
                        requirement.commit_uninstall()
                requirement.remove_temporary_source()
        finally:
            logger.indent -= 2
        self.successfully_installed = to_install

    def create_bundle(self, bundle_filename):
        ## FIXME: can't decide which is better; zip is easier to read
        ## random files from, but tar.bz2 is smaller and not as lame a
        ## format.

        ## FIXME: this file should really include a manifest of the
        ## packages, maybe some other metadata files.  It would make
        ## it easier to detect as well.
        zip = zipfile.ZipFile(bundle_filename, 'w', zipfile.ZIP_DEFLATED)
        vcs_dirs = []
        for dir, basename in (self.build_dir, 'build'), (self.src_dir, 'src'):
            dir = os.path.normcase(os.path.abspath(dir))
            for dirpath, dirnames, filenames in os.walk(dir):
                for backend in vcs.backends:
                    vcs_backend = backend()
                    vcs_url = vcs_rev = None
                    if vcs_backend.dirname in dirnames:
                        for vcs_dir in vcs_dirs:
                            if dirpath.startswith(vcs_dir):
                                # vcs bundle file already in parent directory
                                break
                        else:
                            vcs_url, vcs_rev = vcs_backend.get_info(
                                os.path.join(dir, dirpath))
                            vcs_dirs.append(dirpath)
                        vcs_bundle_file = vcs_backend.bundle_file
                        vcs_guide = vcs_backend.guide % {'url': vcs_url,
                                                         'rev': vcs_rev}
                        dirnames.remove(vcs_backend.dirname)
                        break
                if 'pip-egg-info' in dirnames:
                    dirnames.remove('pip-egg-info')
                for dirname in dirnames:
                    dirname = os.path.join(dirpath, dirname)
                    name = self._clean_zip_name(dirname, dir)
                    zip.writestr(basename + '/' + name + '/', '')
                for filename in filenames:
                    if filename == PIP_DELETE_MARKER_FILENAME:
                        continue
                    filename = os.path.join(dirpath, filename)
                    name = self._clean_zip_name(filename, dir)
                    zip.write(filename, basename + '/' + name)
                if vcs_url:
                    name = os.path.join(dirpath, vcs_bundle_file)
                    name = self._clean_zip_name(name, dir)
                    zip.writestr(basename + '/' + name, vcs_guide)

        zip.writestr('pip-manifest.txt', self.bundle_requirements())
        zip.close()

    BUNDLE_HEADER = '''\
# This is a pip bundle file, that contains many source packages
# that can be installed as a group.  You can install this like:
#     pip this_file.zip
# The rest of the file contains a list of all the packages included:
'''

    def bundle_requirements(self):
        parts = [self.BUNDLE_HEADER]
        for req in [req for req in self.requirements.values()
                    if not req.comes_from]:
            parts.append('%s==%s\n' % (req.name, req.installed_version))
        parts.append('# These packages were installed to satisfy the above requirements:\n')
        for req in [req for req in self.requirements.values()
                    if req.comes_from]:
            parts.append('%s==%s\n' % (req.name, req.installed_version))
        ## FIXME: should we do something with self.unnamed_requirements?
        return ''.join(parts)

    def _clean_zip_name(self, name, prefix):
        assert name.startswith(prefix+os.path.sep), (
            "name %r doesn't start with prefix %r" % (name, prefix))
        name = name[len(prefix)+1:]
        name = name.replace(os.path.sep, '/')
        return name


def _make_build_dir(build_dir):
    os.makedirs(build_dir)
    write_delete_marker_file(build_dir)


_scheme_re = re.compile(r'^(http|https|file):', re.I)


def parse_requirements(filename, finder=None, comes_from=None, options=None,
                       session=None):
    if session is None:
        session = PipSession()

    skip_match = None
    skip_regex = options.skip_requirements_regex if options else None
    if skip_regex:
        skip_match = re.compile(skip_regex)
    reqs_file_dir = os.path.dirname(os.path.abspath(filename))
    filename, content = get_file_content(filename,
        comes_from=comes_from,
        session=session,
    )
    for line_number, line in enumerate(content.splitlines()):
        line_number += 1
        line = line.strip()

        # Remove comments from file
        line = re.sub(r"(^|\s)#.*$", "", line)

        if not line or line.startswith('#'):
            continue
        if skip_match and skip_match.search(line):
            continue
        if line.startswith('-r') or line.startswith('--requirement'):
            if line.startswith('-r'):
                req_url = line[2:].strip()
            else:
                req_url = line[len('--requirement'):].strip().strip('=')
            if _scheme_re.search(filename):
                # Relative to a URL
                req_url = urlparse.urljoin(filename, req_url)
            elif not _scheme_re.search(req_url):
                req_url = os.path.join(os.path.dirname(filename), req_url)
            for item in parse_requirements(req_url, finder, comes_from=filename, options=options, session=session):
                yield item
        elif line.startswith('-Z') or line.startswith('--always-unzip'):
            # No longer used, but previously these were used in
            # requirement files, so we'll ignore.
            pass
        elif line.startswith('-f') or line.startswith('--find-links'):
            if line.startswith('-f'):
                line = line[2:].strip()
            else:
                line = line[len('--find-links'):].strip().lstrip('=')
            ## FIXME: it would be nice to keep track of the source of
            ## the find_links:
            # support a find-links local path relative to a requirements file
            relative_to_reqs_file = os.path.join(reqs_file_dir, line)
            if os.path.exists(relative_to_reqs_file):
                line = relative_to_reqs_file
            if finder:
                finder.find_links.append(line)
        elif line.startswith('-i') or line.startswith('--index-url'):
            if line.startswith('-i'):
                line = line[2:].strip()
            else:
                line = line[len('--index-url'):].strip().lstrip('=')
            if finder:
                finder.index_urls = [line]
        elif line.startswith('--extra-index-url'):
            line = line[len('--extra-index-url'):].strip().lstrip('=')
            if finder:
                finder.index_urls.append(line)
        elif line.startswith('--use-wheel'):
            finder.use_wheel = True
        elif line.startswith('--no-index'):
            finder.index_urls = []
        elif line.startswith("--allow-external"):
            line = line[len("--allow-external"):].strip().lstrip("=")
            finder.allow_external |= set([normalize_name(line).lower()])
        elif line.startswith("--allow-all-external"):
            finder.allow_all_external = True
        # Remove in 1.7
        elif line.startswith("--no-allow-external"):
            pass
        # Remove in 1.7
        elif line.startswith("--no-allow-insecure"):
            pass
        # Remove after 1.7
        elif line.startswith("--allow-insecure"):
            line = line[len("--allow-insecure"):].strip().lstrip("=")
            finder.allow_unverified |= set([normalize_name(line).lower()])
        elif line.startswith("--allow-unverified"):
            line = line[len("--allow-unverified"):].strip().lstrip("=")
            finder.allow_unverified |= set([normalize_name(line).lower()])
        else:
            comes_from = '-r %s (line %s)' % (filename, line_number)
            if line.startswith('-e') or line.startswith('--editable'):
                if line.startswith('-e'):
                    line = line[2:].strip()
                else:
                    line = line[len('--editable'):].strip().lstrip('=')
                req = InstallRequirement.from_editable(
                    line, comes_from=comes_from, default_vcs=options.default_vcs if options else None)
            else:
                req = InstallRequirement.from_line(line, comes_from, prereleases=getattr(options, "pre", None))
            yield req

def _strip_postfix(req):
    """
        Strip req postfix ( -dev, 0.2, etc )
    """
    ## FIXME: use package_to_requirement?
    match = re.search(r'^(.*?)(?:-dev|-\d.*)$', req)
    if match:
        # Strip off -dev, -0.2, etc.
        req = match.group(1)
    return req

def _build_req_from_url(url):

    parts = [p for p in url.split('#', 1)[0].split('/') if p]

    req = None
    if parts[-2] in ('tags', 'branches', 'tag', 'branch'):
        req = parts[-3]
    elif parts[-1] == 'trunk':
        req = parts[-2]
    return req

def _build_editable_options(req):

    """
        This method generates a dictionary of the query string
        parameters contained in a given editable URL.
    """
    regexp = re.compile(r"[\?#&](?P<name>[^&=]+)=(?P<value>[^&=]+)")
    matched = regexp.findall(req)

    if matched:
        ret = dict()
        for option in matched:
            (name, value) = option
            if name in ret:
                raise Exception("%s option already defined" % name)
            ret[name] = value
        return ret
    return None


def parse_editable(editable_req, default_vcs=None):
    """Parses svn+http://blahblah@rev#egg=Foobar into a requirement
    (Foobar) and a URL"""

    url = editable_req
    extras = None

    # If a file path is specified with extras, strip off the extras.
    m = re.match(r'^(.+)(\[[^\]]+\])$', url)
    if m:
        url_no_extras = m.group(1)
        extras = m.group(2)
    else:
        url_no_extras = url

    if os.path.isdir(url_no_extras):
        if not os.path.exists(os.path.join(url_no_extras, 'setup.py')):
            raise InstallationError("Directory %r is not installable. File 'setup.py' not found." % url_no_extras)
        # Treating it as code that has already been checked out
        url_no_extras = path_to_url(url_no_extras)

    if url_no_extras.lower().startswith('file:'):
        if extras:
            return None, url_no_extras, pkg_resources.Requirement.parse('__placeholder__' + extras).extras
        else:
            return None, url_no_extras, None

    for version_control in vcs:
        if url.lower().startswith('%s:' % version_control):
            url = '%s+%s' % (version_control, url)
            break

    if '+' not in url:
        if default_vcs:
            url = default_vcs + '+' + url
        else:
            raise InstallationError(
                '%s should either be a path to a local project or a VCS url beginning with svn+, git+, hg+, or bzr+' % editable_req)

    vc_type = url.split('+', 1)[0].lower()

    if not vcs.get_backend(vc_type):
        error_message = 'For --editable=%s only ' % editable_req + \
            ', '.join([backend.name + '+URL' for backend in vcs.backends]) + \
            ' is currently supported'
        raise InstallationError(error_message)

    try:
        options = _build_editable_options(editable_req)
    except Exception:
        message = sys.exc_info()[1]
        raise InstallationError(
            '--editable=%s error in editable options:%s' % (editable_req, message))

    if not options or 'egg' not in options:
        req = _build_req_from_url(editable_req)
        if not req:
            raise InstallationError('--editable=%s is not the right format; it must have #egg=Package' % editable_req)
    else:
        req = options['egg']

    package = _strip_postfix(req)
    return package, url, options


class UninstallPathSet(object):
    """A set of file paths to be removed in the uninstallation of a
    requirement."""
    def __init__(self, dist):
        self.paths = set()
        self._refuse = set()
        self.pth = {}
        self.dist = dist
        self.save_dir = None
        self._moved_paths = []

    def _permitted(self, path):
        """
        Return True if the given path is one we are permitted to
        remove/modify, False otherwise.

        """
        return is_local(path)

    def _can_uninstall(self):
        if not dist_is_local(self.dist):
            logger.notify("Not uninstalling %s at %s, outside environment %s"
                          % (self.dist.project_name, normalize_path(self.dist.location), sys.prefix))
            return False
        return True

    def add(self, path):
        path = normalize_path(path)
        if not os.path.exists(path):
            return
        if self._permitted(path):
            self.paths.add(path)
        else:
            self._refuse.add(path)

        # __pycache__ files can show up after 'installed-files.txt' is created, due to imports
        if os.path.splitext(path)[1] == '.py' and uses_pycache:
            self.add(imp.cache_from_source(path))


    def add_pth(self, pth_file, entry):
        pth_file = normalize_path(pth_file)
        if self._permitted(pth_file):
            if pth_file not in self.pth:
                self.pth[pth_file] = UninstallPthEntries(pth_file)
            self.pth[pth_file].add(entry)
        else:
            self._refuse.add(pth_file)

    def compact(self, paths):
        """Compact a path set to contain the minimal number of paths
        necessary to contain all paths in the set. If /a/path/ and
        /a/path/to/a/file.txt are both in the set, leave only the
        shorter path."""
        short_paths = set()
        for path in sorted(paths, key=len):
            if not any([(path.startswith(shortpath) and
                         path[len(shortpath.rstrip(os.path.sep))] == os.path.sep)
                        for shortpath in short_paths]):
                short_paths.add(path)
        return short_paths

    def _stash(self, path):
        return os.path.join(
            self.save_dir, os.path.splitdrive(path)[1].lstrip(os.path.sep))

    def remove(self, auto_confirm=False):
        """Remove paths in ``self.paths`` with confirmation (unless
        ``auto_confirm`` is True)."""
        if not self._can_uninstall():
            return
        if not self.paths:
            logger.notify("Can't uninstall '%s'. No files were found to uninstall." % self.dist.project_name)
            return
        logger.notify('Uninstalling %s:' % self.dist.project_name)
        logger.indent += 2
        paths = sorted(self.compact(self.paths))
        try:
            if auto_confirm:
                response = 'y'
            else:
                for path in paths:
                    logger.notify(path)
                response = ask('Proceed (y/n)? ', ('y', 'n'))
            if self._refuse:
                logger.notify('Not removing or modifying (outside of prefix):')
                for path in self.compact(self._refuse):
                    logger.notify(path)
            if response == 'y':
                self.save_dir = tempfile.mkdtemp(suffix='-uninstall',
                                                 prefix='pip-')
                for path in paths:
                    new_path = self._stash(path)
                    logger.info('Removing file or directory %s' % path)
                    self._moved_paths.append(path)
                    renames(path, new_path)
                for pth in self.pth.values():
                    pth.remove()
                logger.notify('Successfully uninstalled %s' % self.dist.project_name)

        finally:
            logger.indent -= 2

    def rollback(self):
        """Rollback the changes previously made by remove()."""
        if self.save_dir is None:
            logger.error("Can't roll back %s; was not uninstalled" % self.dist.project_name)
            return False
        logger.notify('Rolling back uninstall of %s' % self.dist.project_name)
        for path in self._moved_paths:
            tmp_path = self._stash(path)
            logger.info('Replacing %s' % path)
            renames(tmp_path, path)
        for pth in self.pth:
            pth.rollback()

    def commit(self):
        """Remove temporary save dir: rollback will no longer be possible."""
        if self.save_dir is not None:
            rmtree(self.save_dir)
            self.save_dir = None
            self._moved_paths = []


class UninstallPthEntries(object):
    def __init__(self, pth_file):
        if not os.path.isfile(pth_file):
            raise UninstallationError("Cannot remove entries from nonexistent file %s" % pth_file)
        self.file = pth_file
        self.entries = set()
        self._saved_lines = None

    def add(self, entry):
        entry = os.path.normcase(entry)
        # On Windows, os.path.normcase converts the entry to use
        # backslashes.  This is correct for entries that describe absolute
        # paths outside of site-packages, but all the others use forward
        # slashes.
        if sys.platform == 'win32' and not os.path.splitdrive(entry)[0]:
            entry = entry.replace('\\', '/')
        self.entries.add(entry)

    def remove(self):
        logger.info('Removing pth entries from %s:' % self.file)
        fh = open(self.file, 'rb')
        # windows uses '\r\n' with py3k, but uses '\n' with py2.x
        lines = fh.readlines()
        self._saved_lines = lines
        fh.close()
        if any(b('\r\n') in line for line in lines):
            endline = '\r\n'
        else:
            endline = '\n'
        for entry in self.entries:
            try:
                logger.info('Removing entry: %s' % entry)
                lines.remove(b(entry + endline))
            except ValueError:
                pass
        fh = open(self.file, 'wb')
        fh.writelines(lines)
        fh.close()

    def rollback(self):
        if self._saved_lines is None:
            logger.error('Cannot roll back changes to %s, none were made' % self.file)
            return False
        logger.info('Rolling %s back to previous state' % self.file)
        fh = open(self.file, 'wb')
        fh.writelines(self._saved_lines)
        fh.close()
        return True


class FakeFile(object):
    """Wrap a list of lines in an object with readline() to make
    ConfigParser happy."""
    def __init__(self, lines):
        self._gen = (l for l in lines)

    def readline(self):
        try:
            try:
                return next(self._gen)
            except NameError:
                return self._gen.next()
        except StopIteration:
            return ''

    def __iter__(self):
        return self._gen