from __future__ import absolute_import

import logging
import os
import re
import shutil
import sys
import tempfile
import warnings
import zipfile

from distutils.util import change_root
from distutils import sysconfig
from email.parser import FeedParser

from pip._vendor import pkg_resources, six
from pip._vendor.distlib.markers import interpret as markers_interpret
from pip._vendor.six.moves import configparser
from pip._vendor.six.moves.urllib import parse as urllib_parse

import pip.wheel

from pip.compat import native_str, WINDOWS
from pip.download import is_url, url_to_path, path_to_url, is_archive_file
from pip.exceptions import (
    InstallationError, UninstallationError, UnsupportedWheel,
)
from pip.locations import (
    bin_py, running_under_virtualenv, PIP_DELETE_MARKER_FILENAME, bin_user,
)
from pip.utils import (
    display_path, rmtree, ask_path_exists, backup_dir, is_installable_dir,
    dist_in_usersite, dist_in_site_packages, egg_link_path, make_path_relative,
    call_subprocess, read_text_file, FakeFile, _make_build_dir,
)
from pip.utils.deprecation import RemovedInPip8Warning
from pip.utils.logging import indent_log
from pip.req.req_uninstall import UninstallPathSet
from pip.vcs import vcs
from pip.wheel import move_wheel_files, Wheel, wheel_ext
from pip._vendor.packaging.version import Version

logger = logging.getLogger(__name__)

class InstallRequirement(object):

    def __init__(self, req, comes_from, source_dir=None, editable=False,
                 url=None, as_egg=False, update=True, editable_options=None,
                 pycompile=True, markers=None, isolated=False):
        self.extras = ()
        if isinstance(req, six.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.markers = markers
        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
        # 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.pycompile = pycompile

        self.isolated = isolated

    @classmethod
    def from_editable(cls, editable_req, comes_from=None, default_vcs=None,
                      isolated=False):
        name, url, extras_override, editable_options = 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=editable_options,
                  isolated=isolated)

        if extras_override is not None:
            res.extras = extras_override

        return res

    @classmethod
    def from_line(cls, name, comes_from=None, isolated=False):
        """Creates an InstallRequirement from a name, which might be a
        requirement, directory containing 'setup.py', filename, or URL.
        """
        from pip.index import Link

        url = None
        if is_url(name):
            marker_sep = '; '
        else:
            marker_sep = ';'
        if marker_sep in name:
            name, markers = name.split(marker_sep, 1)
            markers = markers.strip()
            if not markers:
                markers = None
        else:
            markers = 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.warning(
                    'Requirement %r looks like a filename, but the file does '
                    'not exist',
                    name
                )
            link = Link(path_to_url(name))

        # it's a local file, dir, or url
        if link:

            url = link.url
            # 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)))

            # wheel file
            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
                    )
                req = "%s==%s" % (wheel.name, wheel.version)
            else:
                # set the req to the egg fragment.  when it's not there, this
                # will become an 'unnamed' requirement
                req = link.egg_fragment

        # a requirement specifier
        else:
            req = name

        return cls(req, comes_from, url=url, markers=markers,
                   isolated=isolated)

    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, 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

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

    def from_path(self):
        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):
        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 native_str(self.req.project_name)

    @property
    def url_name(self):
        if self.req is None:
            return None
        return urllib_parse.quote(self.req.project_name.lower())

    @property
    def setup_py(self):
        try:
            import setuptools  # noqa
        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):
        assert self.source_dir
        if self.name:
            logger.debug(
                'Running setup.py (path:%s) egg_info for package %s',
                self.setup_py, self.name,
            )
        else:
            logger.debug(
                'Running setup.py (path:%s) egg_info for package from %s',
                self.setup_py, self.url,
            )

        with indent_log():
            # 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))
            base_cmd = [sys.executable, '-c', script]
            if self.isolated:
                base_cmd += ["--no-user-cfg"]
            egg_info_cmd = base_cmd + ['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:
                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']
            cwd = self.source_dir
            if self.editable_options and \
                    'subdirectory' in self.editable_options:
                cwd = os.path.join(cwd, self.editable_options['subdirectory'])
            call_subprocess(
                egg_info_cmd + egg_base_option,
                cwd=cwd,
                filter_stdout=self._filter_install,
                show_stdout=False,
                command_level=logging.DEBUG,
                command_desc='python setup.py egg_info')

        if not self.req:
            if isinstance(
                    pkg_resources.parse_version(self.pkg_info()["Version"]),
                    Version):
                op = "=="
            else:
                op = "==="
            self.req = pkg_resources.Requirement.parse(
                "".join([
                    self.pkg_info()["Name"],
                    op,
                    self.pkg_info()["Version"],
                ]))
            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
                        elif 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 pkg_info(self):
        p = FeedParser()
        data = self.egg_info_data('PKG-INFO')
        if not data:
            logger.warning(
                'No PKG-INFO file found in %s',
                display_path(self.egg_info_path('PKG-INFO')),
            )
        p.feed(data or '')
        return p.close()

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

    @property
    def installed_version(self):
        # Create a requirement that we'll look for inside of setuptools.
        req = pkg_resources.Requirement.parse(self.name)

        # We want to avoid having this cached, so we need to construct a new
        # working set each time.
        working_set = pkg_resources.WorkingSet()

        # Get the installed distribution from our working set
        dist = working_set.find(req)

        # Check to see if we got an installed distribution or not, if we did
        # we want to return it's version.
        if dist:
            return dist.version

    def assert_source_matches_version(self):
        assert self.source_dir
        version = self.pkg_info()['version']
        if version not in self.req:
            logger.warning(
                '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.debug(
                "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)
        develop_egg_link = egg_link_path(dist)
        egg_info_exists = dist.egg_info and os.path.exists(dist.egg_info)
        # Special case for distutils installed package
        distutils_egg_info = getattr(dist._provider, 'path', None)
        if develop_egg_link:
            # develop egg
            with open(develop_egg_link, 'r') as fh:
                link_pointer = os.path.normcase(fh.readline().strip())
            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 egg_info_exists and dist.egg_info.endswith('.egg-info'):
            paths_to_remove.add(dist.egg_info)
            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(dist.egg_info, 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 distutils_egg_info:
            warnings.warn(
                "Uninstalling a distutils installed project ({0}) has been "
                "deprecated and will be removed in a future version. This is "
                "due to the fact that uninstalling a distutils project will "
                "only partially uninstall the project.".format(self.name),
                RemovedInPip8Warning,
            )
            paths_to_remove.add(distutils_egg_info)

        elif dist.location.endswith('.egg'):
            # package installed by easy_install
            # We cannot match on dist.egg_name because it can slightly vary
            # i.e. setuptools-0.6c11-py2.6.egg vs setuptools-0.6rc11-py2.6.egg
            paths_to_remove.add(dist.location)
            easy_install_egg = os.path.split(dist.location)[1]
            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 egg_info_exists and dist.egg_info.endswith('.dist-info'):
            for path in pip.wheel.uninstallation_paths(dist):
                paths_to_remove.add(path)
        else:
            logger.debug(
                'Not sure how to uninstall: %s - Check: %s',
                dist, dist.location)

        # 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 WINDOWS:
                    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 WINDOWS:
                        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.pkg_info()["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.warning('Deleting %s', display_path(archive_path))
                os.remove(archive_path)
            elif response == 'b':
                dest_file = backup_dir(archive_path)
                logger.warning(
                    '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,
                allowZip64=True
            )
            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.info('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 match_markers(self):
        if self.markers is not None:
            return markers_interpret(self.markers)
        else:
            return True

    def install(self, install_options, global_options=(), root=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)
            self.install_succeeded = True
            return

        if self.isolated:
            global_options = list(global_options) + ["--no-user-cfg"]

        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
                py_ver_str = 'python' + sysconfig.get_python_version()
                install_args += ['--install-headers',
                                 os.path.join(sys.prefix, 'include', 'site',
                                              py_ver_str)]
            logger.info('Running setup.py install for %s', self.name)
            with indent_log():
                call_subprocess(
                    install_args + install_options,
                    cwd=self.source_dir,
                    filter_stdout=self._filter_install,
                    show_stdout=False,
                )

            if not os.path.exists(record_filename):
                logger.debug('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)

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

    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
        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.info('Running setup.py develop for %s', self.name)

        if self.isolated:
            global_options = list(global_options) + ["--no-user-cfg"]

        with indent_log():
            # FIXME: should we do --install-headers here too?
            cwd = self.source_dir
            if self.editable_options and \
                    'subdirectory' in self.editable_options:
                cwd = os.path.join(cwd, self.editable_options['subdirectory'])
            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=cwd, filter_stdout=self._filter_install,
                show_stdout=False)

        self.install_succeeded = True

    def _filter_install(self, line):
        level = logging.INFO
        for regex in [
                r'^running .*',
                r'^writing .*',
                '^creating .*',
                '^[Cc]opying .*',
                r'^reading .*',
                r"^removing .*\.egg-info' \(and everything under it\)$",
                r'^byte-compiling ',
                r'^SyntaxError:',
                r'^SyntaxWarning:',
                r'^\s*Skipping implicit fixer: ',
                r'^\s*(warning: )?no previously-included (files|directories) ',
                r'^\s*warning: no files found matching \'.*\'',
                # Not sure what this warning is, but it seems harmless:
                r"^warning: manifest_maker: standard file '-c' not found$"]:
            if not line or re.search(regex, line.strip()):
                level = logging.DEBUG
                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

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

    def get_dist(self):
        """Return a pkg_resources.Distribution built from self.egg_info_path"""
        egg_info = self.egg_info_path('')
        base_dir = os.path.dirname(egg_info)
        metadata = pkg_resources.PathMetadata(base_dir, egg_info)
        dist_name = os.path.splitext(os.path.basename(egg_info))[0]
        return pkg_resources.Distribution(
            os.path.dirname(egg_info),
            project_name=dist_name,
            metadata=metadata)

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 an editable requirement into:
        - a requirement name
        - an URL
        - extras
        - editable options
    Accepted requirements:
        svn+http://blahblah@rev#egg=Foobar[baz]&subdirectory=version_subdir
        .[some_extra]
    """

    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 as exc:
        raise InstallationError(
            '--editable=%s error in editable options:%s' % (editable_req, exc)
        )
    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, None, options


"""A simple configuration system.

Authors
-------
* Brian Granger
* Fernando Perez
* Min RK
"""

#-----------------------------------------------------------------------------
#  Copyright (C) 2008-2011  The IPython Development Team
#
#  Distributed under the terms of the BSD License.  The full license is in
#  the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------

import __builtin__ as builtin_mod
import os
import re
import sys

from IPython.external import argparse
from IPython.utils.path import filefind, get_ipython_dir
from IPython.utils import py3compat, text, warn
from IPython.utils.encoding import DEFAULT_ENCODING

#-----------------------------------------------------------------------------
# Exceptions
#-----------------------------------------------------------------------------

class ConfigError(Exception):
    pass

class ConfigLoaderError(ConfigError):
    pass

class ConfigFileNotFound(ConfigError):
    pass

class ArgumentError(ConfigLoaderError):
    pass

#-----------------------------------------------------------------------------
# Argparse fix
#-----------------------------------------------------------------------------

# Unfortunately argparse by default prints help messages to stderr instead of
# stdout.  This makes it annoying to capture long help screens at the command
# line, since one must know how to pipe stderr, which many users don't know how
# to do.  So we override the print_help method with one that defaults to
# stdout and use our class instead.

class ArgumentParser(argparse.ArgumentParser):
    """Simple argparse subclass that prints help to stdout by default."""

    def print_help(self, file=None):
        if file is None:
            file = sys.stdout
        return super(ArgumentParser, self).print_help(file)

    print_help.__doc__ = argparse.ArgumentParser.print_help.__doc__

#-----------------------------------------------------------------------------
# Config class for holding config information
#-----------------------------------------------------------------------------

class Config(dict):
    """An attribute based dict that can do smart merges."""

    def __init__(self, *args, **kwds):
        dict.__init__(self, *args, **kwds)
        # This sets self.__dict__ = self, but it has to be done this way
        # because we are also overriding __setattr__.
        dict.__setattr__(self, '__dict__', self)

    def _merge(self, other):
        to_update = {}
        for k, v in other.iteritems():
            if not self.has_key(k):
                to_update[k] = v
            else: # I have this key
                if isinstance(v, Config):
                    # Recursively merge common sub Configs
                    self[k]._merge(v)
                else:
                    # Plain updates for non-Configs
                    to_update[k] = v

        self.update(to_update)

    def _is_section_key(self, key):
        if key[0].upper()==key[0] and not key.startswith('_'):
            return True
        else:
            return False

    def __contains__(self, key):
        if self._is_section_key(key):
            return True
        else:
            return super(Config, self).__contains__(key)
    # .has_key is deprecated for dictionaries.
    has_key = __contains__

    def _has_section(self, key):
        if self._is_section_key(key):
            if super(Config, self).__contains__(key):
                return True
        return False

    def copy(self):
        return type(self)(dict.copy(self))

    def __copy__(self):
        return self.copy()

    def __deepcopy__(self, memo):
        import copy
        return type(self)(copy.deepcopy(self.items()))

    def __getitem__(self, key):
        # We cannot use directly self._is_section_key, because it triggers
        # infinite recursion on top of PyPy. Instead, we manually fish the
        # bound method.
        is_section_key = self.__class__._is_section_key.__get__(self)

        # Because we use this for an exec namespace, we need to delegate
        # the lookup of names in __builtin__ to itself.  This means
        # that you can't have section or attribute names that are
        # builtins.
        try:
            return getattr(builtin_mod, key)
        except AttributeError:
            pass
        if is_section_key(key):
            try:
                return dict.__getitem__(self, key)
            except KeyError:
                c = Config()
                dict.__setitem__(self, key, c)
                return c
        else:
            return dict.__getitem__(self, key)

    def __setitem__(self, key, value):
        # Don't allow names in __builtin__ to be modified.
        if hasattr(builtin_mod, key):
            raise ConfigError('Config variable names cannot have the same name '
                              'as a Python builtin: %s' % key)
        if self._is_section_key(key):
            if not isinstance(value, Config):
                raise ValueError('values whose keys begin with an uppercase '
                                 'char must be Config instances: %r, %r' % (key, value))
        else:
            dict.__setitem__(self, key, value)

    def __getattr__(self, key):
        try:
            return self.__getitem__(key)
        except KeyError, e:
            raise AttributeError(e)

    def __setattr__(self, key, value):
        try:
            self.__setitem__(key, value)
        except KeyError, e:
            raise AttributeError(e)

    def __delattr__(self, key):
        try:
            dict.__delitem__(self, key)
        except KeyError, e:
            raise AttributeError(e)

#-----------------------------------------------------------------------------
# Config loading classes
#-----------------------------------------------------------------------------

class ConfigLoader(object):
    """A object for loading configurations from just about anywhere.

    The resulting configuration is packaged as a :class:`Struct`.

    Notes
    -----
    A :class:`ConfigLoader` does one thing: load a config from a source
    (file, command line arguments) and returns the data as a :class:`Struct`.
    There are lots of things that :class:`ConfigLoader` does not do.  It does
    not implement complex logic for finding config files.  It does not handle
    default values or merge multiple configs.  These things need to be
    handled elsewhere.
    """

    def __init__(self):
        """A base class for config loaders.

        Examples
        --------

        >>> cl = ConfigLoader()
        >>> config = cl.load_config()
        >>> config
        {}
        """
        self.clear()

    def clear(self):
        self.config = Config()

    def load_config(self):
        """Load a config from somewhere, return a :class:`Config` instance.

        Usually, this will cause self.config to be set and then returned.
        However, in most cases, :meth:`ConfigLoader.clear` should be called
        to erase any previous state.
        """
        self.clear()
        return self.config

class FileConfigLoader(ConfigLoader):
    """A base class for file based configurations.

    As we add more file based config loaders, the common logic should go
    here.
    """
    pass

class PyFileConfigLoader(FileConfigLoader):
    """A config loader for pure python files.

    This calls execfile on a plain python file and looks for attributes
    that are all caps.  These attribute are added to the config Struct.
    """

    def __init__(self, filename, path=None):
        """Build a config loader for a filename and path.

        Parameters
        ----------
        filename : str
            The file name of the config file.
        path : str, list, tuple
            The path to search for the config file on, or a sequence of
            paths to try in order.
        """
        super(PyFileConfigLoader, self).__init__()
        self.filename = filename
        self.path = path
        self.full_filename = ''
        self.data = None

    def load_config(self):
        """Load the config from a file and return it as a Struct."""
        self.clear()
        try:
            self._find_file()
        except IOError as e:
            raise ConfigFileNotFound(str(e))
        self._read_file_as_dict()
        self._convert_to_config()
        return self.config

    def _find_file(self):
        """Try to find the file by searching the paths."""
        self.full_filename = filefind(self.filename, self.path)

    def _read_file_as_dict(self):
        """Load the config file into self.config, with recursive loading."""
        # This closure is made available in the namespace that is used
        # to exec the config file.  It allows users to call
        # load_subconfig('myconfig.py') to load config files recursively.
        # It needs to be a closure because it has references to self.path
        # and self.config.  The sub-config is loaded with the same path
        # as the parent, but it uses an empty config which is then merged
        # with the parents.

        # If a profile is specified, the config file will be loaded
        # from that profile

        def load_subconfig(fname, profile=None):
            # import here to prevent circular imports
            from IPython.core.profiledir import ProfileDir, ProfileDirError
            if profile is not None:
                try:
                    profile_dir = ProfileDir.find_profile_dir_by_name(
                            get_ipython_dir(),
                            profile,
                    )
                except ProfileDirError:
                    return
                path = profile_dir.location
            else:
                path = self.path
            loader = PyFileConfigLoader(fname, path)
            try:
                sub_config = loader.load_config()
            except ConfigFileNotFound:
                # Pass silently if the sub config is not there. This happens
                # when a user s using a profile, but not the default config.
                pass
            else:
                self.config._merge(sub_config)

        # Again, this needs to be a closure and should be used in config
        # files to get the config being loaded.
        def get_config():
            return self.config

        namespace = dict(load_subconfig=load_subconfig, get_config=get_config)
        fs_encoding = sys.getfilesystemencoding() or 'ascii'
        conf_filename = self.full_filename.encode(fs_encoding)
        py3compat.execfile(conf_filename, namespace)

    def _convert_to_config(self):
        if self.data is None:
            ConfigLoaderError('self.data does not exist')

class CommandLineConfigLoader(ConfigLoader):
    """A config loader for command line arguments.

    As we add more command line based loaders, the common logic should go
    here.
    """

    def _exec_config_str(self, lhs, rhs):
        """execute self.config.<lhs> = <rhs>

        * expands ~ with expanduser
        * tries to assign with raw eval, otherwise assigns with just the string,
          allowing `--C.a=foobar` and `--C.a="foobar"` to be equivalent.  *Not*
          equivalent are `--C.a=4` and `--C.a='4'`.
        """
        rhs = os.path.expanduser(rhs)
        try:
            # Try to see if regular Python syntax will work. This
            # won't handle strings as the quote marks are removed
            # by the system shell.
            value = eval(rhs)
        except (NameError, SyntaxError):
            # This case happens if the rhs is a string.
            value = rhs

        exec u'self.config.%s = value' % lhs

    def _load_flag(self, cfg):
        """update self.config from a flag, which can be a dict or Config"""
        if isinstance(cfg, (dict, Config)):
            # don't clobber whole config sections, update
            # each section from config:
            for sec,c in cfg.iteritems():
                self.config[sec].update(c)
        else:
            raise TypeError("Invalid flag: %r" % cfg)

# raw --identifier=value pattern
# but *also* accept '-' as wordsep, for aliases
# accepts:  --foo=a
#           --Class.trait=value
#           --alias-name=value
# rejects:  -foo=value
#           --foo
#           --Class.trait
kv_pattern = re.compile(r'\-\-[A-Za-z][\w\-]*(\.[\w\-]+)*\=.*')

# just flags, no assignments, with two *or one* leading '-'
# accepts:  --foo
#           -foo-bar-again
# rejects:  --anything=anything
#           --two.word

flag_pattern = re.compile(r'\-\-?\w+[\-\w]*$')

class KeyValueConfigLoader(CommandLineConfigLoader):
    """A config loader that loads key value pairs from the command line.

    This allows command line options to be gives in the following form::

        ipython --profile="foo" --InteractiveShell.autocall=False
    """

    def __init__(self, argv=None, aliases=None, flags=None):
        """Create a key value pair config loader.

        Parameters
        ----------
        argv : list
            A list that has the form of sys.argv[1:] which has unicode
            elements of the form u"key=value". If this is None (default),
            then sys.argv[1:] will be used.
        aliases : dict
            A dict of aliases for configurable traits.
            Keys are the short aliases, Values are the resolved trait.
            Of the form: `{'alias' : 'Configurable.trait'}`
        flags : dict
            A dict of flags, keyed by str name. Vaues can be Config objects,
            dicts, or "key=value" strings.  If Config or dict, when the flag
            is triggered, The flag is loaded as `self.config.update(m)`.

        Returns
        -------
        config : Config
            The resulting Config object.

        Examples
        --------

            >>> from IPython.config.loader import KeyValueConfigLoader
            >>> cl = KeyValueConfigLoader()
            >>> d = cl.load_config(["--A.name='brian'","--B.number=0"])
            >>> sorted(d.items())
            [('A', {'name': 'brian'}), ('B', {'number': 0})]
        """
        self.clear()
        if argv is None:
            argv = sys.argv[1:]
        self.argv = argv
        self.aliases = aliases or {}
        self.flags = flags or {}

    def clear(self):
        super(KeyValueConfigLoader, self).clear()
        self.extra_args = []

    def _decode_argv(self, argv, enc=None):
        """decode argv if bytes, using stin.encoding, falling back on default enc"""
        uargv = []
        if enc is None:
            enc = DEFAULT_ENCODING
        for arg in argv:
            if not isinstance(arg, unicode):
                # only decode if not already decoded
                arg = arg.decode(enc)
            uargv.append(arg)
        return uargv

    def load_config(self, argv=None, aliases=None, flags=None):
        """Parse the configuration and generate the Config object.

        After loading, any arguments that are not key-value or
        flags will be stored in self.extra_args - a list of
        unparsed command-line arguments.  This is used for
        arguments such as input files or subcommands.

        Parameters
        ----------
        argv : list, optional
            A list that has the form of sys.argv[1:] which has unicode
            elements of the form u"key=value". If this is None (default),
            then self.argv will be used.
        aliases : dict
            A dict of aliases for configurable traits.
            Keys are the short aliases, Values are the resolved trait.
            Of the form: `{'alias' : 'Configurable.trait'}`
        flags : dict
            A dict of flags, keyed by str name. Values can be Config objects
            or dicts.  When the flag is triggered, The config is loaded as
            `self.config.update(cfg)`.
        """
        from IPython.config.configurable import Configurable

        self.clear()
        if argv is None:
            argv = self.argv
        if aliases is None:
            aliases = self.aliases
        if flags is None:
            flags = self.flags

        # ensure argv is a list of unicode strings:
        uargv = self._decode_argv(argv)
        for idx,raw in enumerate(uargv):
            # strip leading '-'
            item = raw.lstrip('-')

            if raw == '--':
                # don't parse arguments after '--'
                # this is useful for relaying arguments to scripts, e.g.
                # ipython -i foo.py --pylab=qt -- args after '--' go-to-foo.py
                self.extra_args.extend(uargv[idx+1:])
                break

            if kv_pattern.match(raw):
                lhs,rhs = item.split('=',1)
                # Substitute longnames for aliases.
                if lhs in aliases:
                    lhs = aliases[lhs]
                if '.' not in lhs:
                    # probably a mistyped alias, but not technically illegal
                    warn.warn("Unrecognized alias: '%s', it will probably have no effect."%lhs)
                try:
                    self._exec_config_str(lhs, rhs)
                except Exception:
                    raise ArgumentError("Invalid argument: '%s'" % raw)

            elif flag_pattern.match(raw):
                if item in flags:
                    cfg,help = flags[item]
                    self._load_flag(cfg)
                else:
                    raise ArgumentError("Unrecognized flag: '%s'"%raw)
            elif raw.startswith('-'):
                kv = '--'+item
                if kv_pattern.match(kv):
                    raise ArgumentError("Invalid argument: '%s', did you mean '%s'?"%(raw, kv))
                else:
                    raise ArgumentError("Invalid argument: '%s'"%raw)
            else:
                # keep all args that aren't valid in a list,
                # in case our parent knows what to do with them.
                self.extra_args.append(item)
        return self.config

class ArgParseConfigLoader(CommandLineConfigLoader):
    """A loader that uses the argparse module to load from the command line."""

    def __init__(self, argv=None, aliases=None, flags=None, *parser_args, **parser_kw):
        """Create a config loader for use with argparse.

        Parameters
        ----------

        argv : optional, list
          If given, used to read command-line arguments from, otherwise
          sys.argv[1:] is used.

        parser_args : tuple
          A tuple of positional arguments that will be passed to the
          constructor of :class:`argparse.ArgumentParser`.

        parser_kw : dict
          A tuple of keyword arguments that will be passed to the
          constructor of :class:`argparse.ArgumentParser`.

        Returns
        -------
        config : Config
            The resulting Config object.
        """
        super(CommandLineConfigLoader, self).__init__()
        self.clear()
        if argv is None:
            argv = sys.argv[1:]
        self.argv = argv
        self.aliases = aliases or {}
        self.flags = flags or {}

        self.parser_args = parser_args
        self.version = parser_kw.pop("version", None)
        kwargs = dict(argument_default=argparse.SUPPRESS)
        kwargs.update(parser_kw)
        self.parser_kw = kwargs

    def load_config(self, argv=None, aliases=None, flags=None):
        """Parse command line arguments and return as a Config object.

        Parameters
        ----------

        args : optional, list
          If given, a list with the structure of sys.argv[1:] to parse
          arguments from. If not given, the instance's self.argv attribute
          (given at construction time) is used."""
        self.clear()
        if argv is None:
            argv = self.argv
        if aliases is None:
            aliases = self.aliases
        if flags is None:
            flags = self.flags
        self._create_parser(aliases, flags)
        self._parse_args(argv)
        self._convert_to_config()
        return self.config

    def get_extra_args(self):
        if hasattr(self, 'extra_args'):
            return self.extra_args
        else:
            return []

    def _create_parser(self, aliases=None, flags=None):
        self.parser = ArgumentParser(*self.parser_args, **self.parser_kw)
        self._add_arguments(aliases, flags)

    def _add_arguments(self, aliases=None, flags=None):
        raise NotImplementedError("subclasses must implement _add_arguments")

    def _parse_args(self, args):
        """self.parser->self.parsed_data"""
        # decode sys.argv to support unicode command-line options
        enc = DEFAULT_ENCODING
        uargs = [py3compat.cast_unicode(a, enc) for a in args]
        self.parsed_data, self.extra_args = self.parser.parse_known_args(uargs)

    def _convert_to_config(self):
        """self.parsed_data->self.config"""
        for k, v in vars(self.parsed_data).iteritems():
            exec "self.config.%s = v"%k in locals(), globals()

class KVArgParseConfigLoader(ArgParseConfigLoader):
    """A config loader that loads aliases and flags with argparse,
    but will use KVLoader for the rest.  This allows better parsing
    of common args, such as `ipython -c 'print 5'`, but still gets
    arbitrary config with `ipython --InteractiveShell.use_readline=False`"""

    def _add_arguments(self, aliases=None, flags=None):
        self.alias_flags = {}
        # print aliases, flags
        if aliases is None:
            aliases = self.aliases
        if flags is None:
            flags = self.flags
        paa = self.parser.add_argument
        for key,value in aliases.iteritems():
            if key in flags:
                # flags
                nargs = '?'
            else:
                nargs = None
            if len(key) is 1:
                paa('-'+key, '--'+key, type=unicode, dest=value, nargs=nargs)
            else:
                paa('--'+key, type=unicode, dest=value, nargs=nargs)
        for key, (value, help) in flags.iteritems():
            if key in self.aliases:
                #
                self.alias_flags[self.aliases[key]] = value
                continue
            if len(key) is 1:
                paa('-'+key, '--'+key, action='append_const', dest='_flags', const=value)
            else:
                paa('--'+key, action='append_const', dest='_flags', const=value)

    def _convert_to_config(self):
        """self.parsed_data->self.config, parse unrecognized extra args via KVLoader."""
        # remove subconfigs list from namespace before transforming the Namespace
        if '_flags' in self.parsed_data:
            subcs = self.parsed_data._flags
            del self.parsed_data._flags
        else:
            subcs = []

        for k, v in vars(self.parsed_data).iteritems():
            if v is None:
                # it was a flag that shares the name of an alias
                subcs.append(self.alias_flags[k])
            else:
                # eval the KV assignment
                self._exec_config_str(k, v)

        for subc in subcs:
            self._load_flag(subc)

        if self.extra_args:
            sub_parser = KeyValueConfigLoader()
            sub_parser.load_config(self.extra_args)
            self.config._merge(sub_parser.config)
            self.extra_args = sub_parser.extra_args

def load_pyconfig_files(config_files, path):
    """Load multiple Python config files, merging each of them in turn.

    Parameters
    ==========
    config_files : list of str
        List of config files names to load and merge into the config.
    path : unicode
        The full path to the location of the config files.
    """
    config = Config()
    for cf in config_files:
        loader = PyFileConfigLoader(cf, path=path)
        try:
            next_config = loader.load_config()
        except ConfigFileNotFound:
            pass
        except:
            raise
        else:
            config._merge(next_config)
    return config


"""Utility functions for finding modules

Utility functions for finding modules on sys.path.

`find_mod` finds named module on sys.path.

`get_init` helper function that finds __init__ file in a directory.

`find_module` variant of imp.find_module in std_lib that only returns
path to module and not an open file object as well.

"""
#-----------------------------------------------------------------------------
# Copyright (c) 2011, the IPython Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file COPYING.txt, distributed with this software.
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
from __future__ import print_function

# Stdlib imports
import imp
import os

# Third-party imports

# Our own imports

#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Local utilities
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Classes and functions
#-----------------------------------------------------------------------------
def find_module(name, path=None):
    """imp.find_module variant that only return path of module.

    The `imp.find_module` returns a filehandle that we are not interested in.
    Also we ignore any bytecode files that `imp.find_module` finds.

    Parameters
    ----------
    name : str
        name of module to locate
    path : list of str
        list of paths to search for `name`. If path=None then search sys.path

    Returns
    -------
    filename : str
        Return full path of module or None if module is missing or does not have
        .py or .pyw extension
    """
    if name is None:
        return None
    try:
        file, filename, _ = imp.find_module(name, path)
    except ImportError:
        return None
    if file is None:
        return filename
    else:
        file.close()
    if os.path.splitext(filename)[1] in [".py", "pyc"]:
        return filename
    else:
        return None

def get_init(dirname):
    """Get __init__ file path for module directory

    Parameters
    ----------
    dirname : str
        Find the __init__ file in directory `dirname`

    Returns
    -------
    init_path : str
        Path to __init__ file
    """
    fbase =  os.path.join(dirname, "__init__")
    for ext in [".py", ".pyw"]:
        fname = fbase + ext
        if os.path.isfile(fname):
            return fname

def find_mod(module_name):
    """Find module `module_name` on sys.path

    Return the path to module `module_name`. If `module_name` refers to
    a module directory then return path to __init__ file. Return full
    path of module or None if module is missing or does not have .py or .pyw
    extension. We are not interested in running bytecode.

    Parameters
    ----------
    module_name : str

    Returns
    -------
    modulepath : str
        Path to module `module_name`.
    """
    parts = module_name.split(".")
    basepath = find_module(parts[0])
    for submodname in parts[1:]:
        basepath = find_module(submodname, [basepath])
    if basepath and os.path.isdir(basepath):
        basepath = get_init(basepath)
    return basepath