#############################################################################
#
# Copyright (c) 2005 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Python easy_install API

This module provides a high-level Python API for installing packages.
It doesn't install scripts.  It uses setuptools and requires it to be
installed.
"""

import distutils.errors
import errno
import glob
import logging
import os
import pkg_resources
import py_compile
import re
import setuptools.archive_util
import setuptools.command.easy_install
import setuptools.command.setopt
import setuptools.package_index
import shutil
import subprocess
import sys
import tempfile
import zc.buildout

_oprp = getattr(os.path, 'realpath', lambda path: path)
def realpath(path):
    return os.path.normcase(os.path.abspath(_oprp(path)))

default_index_url = os.environ.get(
    'buildout-testing-index-url',
    'http://pypi.python.org/simple',
    )

logger = logging.getLogger('zc.buildout.easy_install')

url_match = re.compile('[a-z0-9+.-]+://').match
is_source_encoding_line = re.compile('coding[:=]\s*([-\w.]+)').search
# Source encoding regex from http://www.python.org/dev/peps/pep-0263/

is_win32 = sys.platform == 'win32'
is_jython = sys.platform.startswith('java')

if is_jython:
    import java.lang.System
    jython_os_name = (java.lang.System.getProperties()['os.name']).lower()

# Make sure we're not being run with an older bootstrap.py that gives us
# setuptools instead of setuptools
has_distribute = pkg_resources.working_set.find(
        pkg_resources.Requirement.parse('distribute')) is not None
has_setuptools = pkg_resources.working_set.find(
        pkg_resources.Requirement.parse('setuptools')) is not None
if has_distribute and not has_setuptools:
    sys.exit("zc.buildout 2 needs setuptools, not distribute."
             "  Are you using an outdated bootstrap.py?  Make sure"
             " you have the latest version downloaded from"
             " http://downloads.buildout.org/2/bootstrap.py")

setuptools_loc = pkg_resources.working_set.find(
    pkg_resources.Requirement.parse('setuptools')
    ).location

# Include buildout and setuptools eggs in paths
buildout_and_setuptools_path = [
    setuptools_loc,
    pkg_resources.working_set.find(
        pkg_resources.Requirement.parse('zc.buildout')).location,
    ]

FILE_SCHEME = re.compile('file://', re.I).match

class _Monkey(object):
    def __init__(self, module, **kw):
        mdict = self._mdict = module.__dict__
        self._before = mdict.copy()
        self._overrides = kw

    def __enter__(self):
        self._mdict.update(self._overrides)
        return self

    def __exit__(self, exc_type, exc_value, traceback):
        self._mdict.clear()
        self._mdict.update(self._before)

class _NoWarn(object):
    def warn(self, *args, **kw):
        pass

_no_warn = _NoWarn()

class AllowHostsPackageIndex(setuptools.package_index.PackageIndex):
    """Will allow urls that are local to the system.

    No matter what is allow_hosts.
    """
    def url_ok(self, url, fatal=False):
        if FILE_SCHEME(url):
            return True
        # distutils has its own logging, which can't be hooked / suppressed,
        # so we monkey-patch the 'log' submodule to suppress the stupid
        # "Link to <URL> ***BLOCKED*** by --allow-hosts" message.
        with _Monkey(setuptools.package_index, log=_no_warn):
            return setuptools.package_index.PackageIndex.url_ok(
                                                self, url, False)


_indexes = {}
def _get_index(index_url, find_links, allow_hosts=('*',)):
    key = index_url, tuple(find_links)
    index = _indexes.get(key)
    if index is not None:
        return index

    if index_url is None:
        index_url = default_index_url
    if index_url.startswith('file://'):
        index_url = index_url[7:]
    index = AllowHostsPackageIndex(index_url, hosts=allow_hosts)

    if find_links:
        index.add_find_links(find_links)

    _indexes[key] = index
    return index

clear_index_cache = _indexes.clear

if is_win32:
    # work around spawn lamosity on windows
    # XXX need safe quoting (see the subproces.list2cmdline) and test
    def _safe_arg(arg):
        return '"%s"' % arg
else:
    _safe_arg = str

def call_subprocess(args, **kw):
    if subprocess.call(args, **kw) != 0:
        raise Exception(
            "Failed to run command:\n%s"
            % repr(args)[1:-1])


def _execute_permission():
    current_umask = os.umask(0o022)
    # os.umask only returns the current umask if you also give it one, so we
    # have to give it a dummy one and immediately set it back to the real
    # value...  Distribute does the same.
    os.umask(current_umask)
    return 0o777 - current_umask


_easy_install_cmd = 'from setuptools.command.easy_install import main; main()'

class Installer:

    _versions = {}
    _required_by = {}
    _picked_versions = {}
    _download_cache = None
    _install_from_cache = False
    _prefer_final = True
    _use_dependency_links = True
    _allow_picked_versions = True
    _store_required_by = False

    def __init__(self,
                 dest=None,
                 links=(),
                 index=None,
                 executable=sys.executable,
                 always_unzip=None, # Backward compat :/
                 path=None,
                 newest=True,
                 versions=None,
                 use_dependency_links=None,
                 allow_hosts=('*',)
                 ):
        assert executable == sys.executable, (executable, sys.executable)
        self._dest = dest
        self._allow_hosts = allow_hosts

        if self._install_from_cache:
            if not self._download_cache:
                raise ValueError("install_from_cache set to true with no"
                                 " download cache")
            links = ()
            index = 'file://' + self._download_cache

        if use_dependency_links is not None:
            self._use_dependency_links = use_dependency_links
        self._links = links = list(_fix_file_links(links))
        if self._download_cache and (self._download_cache not in links):
            links.insert(0, self._download_cache)

        self._index_url = index
        path = (path and path[:] or []) + buildout_and_setuptools_path
        if dest is not None and dest not in path:
            path.insert(0, dest)
        self._path = path
        if self._dest is None:
            newest = False
        self._newest = newest
        self._env = pkg_resources.Environment(path)
        self._index = _get_index(index, links, self._allow_hosts)

        if versions is not None:
            self._versions = normalize_versions(versions)

    def _satisfied(self, req, source=None):
        dists = [dist for dist in self._env[req.project_name] if dist in req]
        if not dists:
            logger.debug('We have no distributions for %s that satisfies %r.',
                         req.project_name, str(req))

            return None, self._obtain(req, source)

        # Note that dists are sorted from best to worst, as promised by
        # env.__getitem__

        for dist in dists:
            if (dist.precedence == pkg_resources.DEVELOP_DIST):
                logger.debug('We have a develop egg: %s', dist)
                return dist, None

        # Special common case, we have a specification for a single version:
        specs = req.specs
        if len(specs) == 1 and specs[0][0] == '==':
            logger.debug('We have the distribution that satisfies %r.',
                         str(req))
            return dists[0], None

        if self._prefer_final:
            fdists = [dist for dist in dists
                      if _final_version(dist.parsed_version)
                      ]
            if fdists:
                # There are final dists, so only use those
                dists = fdists

        if not self._newest:
            # We don't need the newest, so we'll use the newest one we
            # find, which is the first returned by
            # Environment.__getitem__.
            return dists[0], None

        best_we_have = dists[0] # Because dists are sorted from best to worst

        # We have some installed distros.  There might, theoretically, be
        # newer ones.  Let's find out which ones are available and see if
        # any are newer.  We only do this if we're willing to install
        # something, which is only true if dest is not None:

        best_available = self._obtain(req, source)

        if best_available is None:
            # That's a bit odd.  There aren't any distros available.
            # We should use the best one we have that meets the requirement.
            logger.debug(
                'There are no distros available that meet %r.\n'
                'Using our best, %s.',
                str(req), best_available)
            return best_we_have, None

        if self._prefer_final:
            if _final_version(best_available.parsed_version):
                if _final_version(best_we_have.parsed_version):
                    if (best_we_have.parsed_version
                        <
                        best_available.parsed_version
                        ):
                        return None, best_available
                else:
                    return None, best_available
            else:
                if (not _final_version(best_we_have.parsed_version)
                    and
                    (best_we_have.parsed_version
                     <
                     best_available.parsed_version
                     )
                    ):
                    return None, best_available
        else:
            if (best_we_have.parsed_version
                <
                best_available.parsed_version
                ):
                return None, best_available

        logger.debug(
            'We have the best distribution that satisfies %r.',
            str(req))
        return best_we_have, None

    def _load_dist(self, dist):
        dists = pkg_resources.Environment(dist.location)[dist.project_name]
        assert len(dists) == 1
        return dists[0]

    def _call_easy_install(self, spec, ws, dest, dist):

        tmp = tempfile.mkdtemp(dir=dest)
        try:
            path = setuptools_loc

            args = [sys.executable, '-c', _easy_install_cmd, '-mZUNxd', tmp]
            level = logger.getEffectiveLevel()
            if level > 0:
                args.append('-q')
            elif level < 0:
                args.append('-v')

            args.append(spec)

            if level <= logging.DEBUG:
                logger.debug('Running easy_install:\n"%s"\npath=%s\n',
                             '" "'.join(args), path)

            sys.stdout.flush() # We want any pending output first

            exit_code = subprocess.call(
                list(args),
                env=dict(os.environ, PYTHONPATH=path))

            dists = []
            env = pkg_resources.Environment([tmp])
            for project in env:
                dists.extend(env[project])

            if exit_code:
                logger.error(
                    "An error occurred when trying to install %s. "
                    "Look above this message for any errors that "
                    "were output by easy_install.",
                    dist)

            if not dists:
                raise zc.buildout.UserError("Couldn't install: %s" % dist)

            if len(dists) > 1:
                logger.warn("Installing %s\n"
                            "caused multiple distributions to be installed:\n"
                            "%s\n",
                            dist, '\n'.join(map(str, dists)))
            else:
                d = dists[0]
                if d.project_name != dist.project_name:
                    logger.warn("Installing %s\n"
                                "Caused installation of a distribution:\n"
                                "%s\n"
                                "with a different project name.",
                                dist, d)
                if d.version != dist.version:
                    logger.warn("Installing %s\n"
                                "Caused installation of a distribution:\n"
                                "%s\n"
                                "with a different version.",
                                dist, d)

            result = []
            for d in dists:
                newloc = os.path.join(dest, os.path.basename(d.location))
                if os.path.exists(newloc):
                    if os.path.isdir(newloc):
                        shutil.rmtree(newloc)
                    else:
                        os.remove(newloc)
                os.rename(d.location, newloc)

                [d] = pkg_resources.Environment([newloc])[d.project_name]

                result.append(d)

            return result

        finally:
            shutil.rmtree(tmp)

    def _obtain(self, requirement, source=None):
        # initialize out index for this project:
        index = self._index

        if index.obtain(requirement) is None:
            # Nothing is available.
            return None

        # Filter the available dists for the requirement and source flag
        dists = [dist for dist in index[requirement.project_name]
                 if ((dist in requirement)
                     and
                     ((not source) or
                      (dist.precedence == pkg_resources.SOURCE_DIST)
                      )
                     )
                 ]

        # If we prefer final dists, filter for final and use the
        # result if it is non empty.
        if self._prefer_final:
            fdists = [dist for dist in dists
                      if _final_version(dist.parsed_version)
                      ]
            if fdists:
                # There are final dists, so only use those
                dists = fdists

        # Now find the best one:
        best = []
        bestv = ()
        for dist in dists:
            distv = dist.parsed_version
            if distv > bestv:
                best = [dist]
                bestv = distv
            elif distv == bestv:
                best.append(dist)

        if not best:
            return None

        if len(best) == 1:
            return best[0]

        if self._download_cache:
            for dist in best:
                if (realpath(os.path.dirname(dist.location))
                    ==
                    self._download_cache
                    ):
                    return dist

        best.sort()
        return best[-1]

    def _fetch(self, dist, tmp, download_cache):
        if (download_cache
            and (realpath(os.path.dirname(dist.location)) == download_cache)
            ):
            return dist

        new_location = self._index.download(dist.location, tmp)
        if (download_cache
            and (realpath(new_location) == realpath(dist.location))
            and os.path.isfile(new_location)
            ):
            # setuptools avoids making extra copies, but we want to copy
            # to the download cache
            shutil.copy2(new_location, tmp)
            new_location = os.path.join(tmp, os.path.basename(new_location))

        return dist.clone(location=new_location)

    def _get_dist(self, requirement, ws, for_buildout_run=False):
        __doing__ = 'Getting distribution for %r.', str(requirement)

        # Maybe an existing dist is already the best dist that satisfies the
        # requirement
        dist, avail = self._satisfied(requirement)

        if dist is None:
            if self._dest is None:
                raise zc.buildout.UserError(
                    "We don't have a distribution for %s\n"
                    "and can't install one in offline (no-install) mode.\n"
                    % requirement)

            logger.info(*__doing__)

            # Retrieve the dist:
            if avail is None:
                self._index.obtain(requirement)
                raise MissingDistribution(requirement, ws)

            # We may overwrite distributions, so clear importer
            # cache.
            sys.path_importer_cache.clear()

            tmp = self._download_cache
            if tmp is None:
                tmp = tempfile.mkdtemp('get_dist')

            try:
                dist = self._fetch(avail, tmp, self._download_cache)

                if dist is None:
                    raise zc.buildout.UserError(
                        "Couln't download distribution %s." % avail)

                if dist.precedence == pkg_resources.EGG_DIST:
                    # It's already an egg, just fetch it into the dest

                    newloc = os.path.join(
                        self._dest, os.path.basename(dist.location))

                    if os.path.isdir(dist.location):
                        # we got a directory. It must have been
                        # obtained locally.  Just copy it.
                        shutil.copytree(dist.location, newloc)
                    else:
                        setuptools.archive_util.unpack_archive(
                            dist.location, newloc)

                    redo_pyc(newloc)

                    # Getting the dist from the environment causes the
                    # distribution meta data to be read.  Cloning isn't
                    # good enough.
                    dists = pkg_resources.Environment([newloc])[
                        dist.project_name]
                else:
                    # It's some other kind of dist.  We'll let easy_install
                    # deal with it:
                    dists = self._call_easy_install(
                        dist.location, ws, self._dest, dist)
                    for dist in dists:
                        redo_pyc(dist.location)
                        if for_buildout_run:
                            # ws is the global working set and we're
                            # installing buildout, setuptools, extensions or
                            # recipes. Make sure that whatever correct version
                            # we've just installed is the active version,
                            # hence the ``replace=True``.
                            ws.add(dist, replace=True)

            finally:
                if tmp != self._download_cache:
                    shutil.rmtree(tmp)

            self._env.scan([self._dest])
            dist = self._env.best_match(requirement, ws)
            logger.info("Got %s.", dist)

        else:
            dists = [dist]

        for dist in dists:
            if (dist.has_metadata('dependency_links.txt')
                and not self._install_from_cache
                and self._use_dependency_links
                ):
                for link in dist.get_metadata_lines('dependency_links.txt'):
                    link = link.strip()
                    if link not in self._links:
                        logger.debug('Adding find link %r from %s', link, dist)
                        self._links.append(link)
                        self._index = _get_index(self._index_url, self._links,
                                                 self._allow_hosts)

        for dist in dists:
            # Check whether we picked a version and, if we did, report it:
            if not (
                dist.precedence == pkg_resources.DEVELOP_DIST
                or
                (len(requirement.specs) == 1
                 and
                 requirement.specs[0][0] == '==')
                ):
                logger.debug('Picked: %s = %s',
                             dist.project_name, dist.version)
                self._picked_versions[dist.project_name] = dist.version

                if not self._allow_picked_versions:
                    raise zc.buildout.UserError(
                        'Picked: %s = %s' % (dist.project_name, dist.version)
                        )

        return dists

    def _maybe_add_setuptools(self, ws, dist):
        if dist.has_metadata('namespace_packages.txt'):
            for r in dist.requires():
                if r.project_name in ('setuptools', 'setuptools'):
                    break
            else:
                # We have a namespace package but no requirement for setuptools
                if dist.precedence == pkg_resources.DEVELOP_DIST:
                    logger.warn(
                        "Develop distribution: %s\n"
                        "uses namespace packages but the distribution "
                        "does not require setuptools.",
                        dist)
                requirement = self._constrain(
                    pkg_resources.Requirement.parse('setuptools')
                    )
                if ws.find(requirement) is None:
                    for dist in self._get_dist(requirement, ws):
                        ws.add(dist)


    def _constrain(self, requirement):
        constraint = self._versions.get(requirement.project_name.lower())
        if constraint:
            requirement = _constrained_requirement(constraint, requirement)
        return requirement

    def install(self, specs, working_set=None):

        logger.debug('Installing %s.', repr(specs)[1:-1])

        for_buildout_run = bool(working_set)
        path = self._path
        dest = self._dest
        if dest is not None and dest not in path:
            path.insert(0, dest)

        requirements = [self._constrain(pkg_resources.Requirement.parse(spec))
                        for spec in specs]

        if working_set is None:
            ws = pkg_resources.WorkingSet([])
        else:
            ws = working_set

        for requirement in requirements:
            for dist in self._get_dist(requirement, ws,
                                       for_buildout_run=for_buildout_run):
                ws.add(dist)
                self._maybe_add_setuptools(ws, dist)

        # OK, we have the requested distributions and they're in the working
        # set, but they may have unmet requirements.  We'll resolve these
        # requirements. This is code modified from
        # pkg_resources.WorkingSet.resolve.  We can't reuse that code directly
        # because we have to constrain our requirements (see
        # versions_section_ignored_for_dependency_in_favor_of_site_packages in
        # zc.buildout.tests).
        requirements.reverse() # Set up the stack.
        processed = {}  # This is a set of processed requirements.
        best = {}  # This is a mapping of package name -> dist.
        # Note that we don't use the existing environment, because we want
        # to look for new eggs unless what we have is the best that
        # matches the requirement.
        env = pkg_resources.Environment(ws.entries)

        while requirements:
            # Process dependencies breadth-first.
            current_requirement = requirements.pop(0)
            req = self._constrain(current_requirement)
            if req in processed:
                # Ignore cyclic or redundant dependencies.
                continue
            dist = best.get(req.key)
            if dist is None:
                try:
                    dist = env.best_match(req, ws)
                except pkg_resources.VersionConflict as err:
                    logger.debug(
                        "Version conflict while processing requirement %s "
                        "(constrained to %s)",
                        current_requirement, req)
                    # Installing buildout itself and its extensions and
                    # recipes requires the global
                    # ``pkg_resources.working_set`` to be active, which also
                    # includes all system packages. So there might be
                    # conflicts, which are fine to ignore. We'll grab the
                    # correct version a few lines down.
                    if not for_buildout_run:
                        raise VersionConflict(err, ws)
            if dist is None:
                if dest:
                    logger.debug('Getting required %r', str(req))
                else:
                    logger.debug('Adding required %r', str(req))
                _log_requirement(ws, req)
                for dist in self._get_dist(req, ws,
                                           for_buildout_run=for_buildout_run):
                    ws.add(dist)
                    self._maybe_add_setuptools(ws, dist)
            if dist not in req:
                # Oops, the "best" so far conflicts with a dependency.
                raise VersionConflict(
                    pkg_resources.VersionConflict(dist, req), ws)

            best[req.key] = dist
            requirements.extend(dist.requires(req.extras)[::-1])
            processed[req] = True
        return ws

    def build(self, spec, build_ext):

        requirement = self._constrain(pkg_resources.Requirement.parse(spec))

        dist, avail = self._satisfied(requirement, 1)
        if dist is not None:
            return [dist.location]

        # Retrieve the dist:
        if avail is None:
            raise zc.buildout.UserError(
                "Couldn't find a source distribution for %r."
                % str(requirement))

        if self._dest is None:
            raise zc.buildout.UserError(
                "We don't have a distribution for %s\n"
                "and can't build one in offline (no-install) mode.\n"
                % requirement
                )

        logger.debug('Building %r', spec)

        tmp = self._download_cache
        if tmp is None:
            tmp = tempfile.mkdtemp('get_dist')

        try:
            dist = self._fetch(avail, tmp, self._download_cache)

            build_tmp = tempfile.mkdtemp('build')
            try:
                setuptools.archive_util.unpack_archive(dist.location,
                                                       build_tmp)
                if os.path.exists(os.path.join(build_tmp, 'setup.py')):
                    base = build_tmp
                else:
                    setups = glob.glob(
                        os.path.join(build_tmp, '*', 'setup.py'))
                    if not setups:
                        raise distutils.errors.DistutilsError(
                            "Couldn't find a setup script in %s"
                            % os.path.basename(dist.location)
                            )
                    if len(setups) > 1:
                        raise distutils.errors.DistutilsError(
                            "Multiple setup scripts in %s"
                            % os.path.basename(dist.location)
                            )
                    base = os.path.dirname(setups[0])

                setup_cfg = os.path.join(base, 'setup.cfg')
                if not os.path.exists(setup_cfg):
                    f = open(setup_cfg, 'w')
                    f.close()
                setuptools.command.setopt.edit_config(
                    setup_cfg, dict(build_ext=build_ext))

                dists = self._call_easy_install(
                    base, pkg_resources.WorkingSet(),
                    self._dest, dist)

                for dist in dists:
                    redo_pyc(dist.location)

                return [dist.location for dist in dists]
            finally:
                shutil.rmtree(build_tmp)

        finally:
            if tmp != self._download_cache:
                shutil.rmtree(tmp)


def normalize_versions(versions):
    """Return version dict with keys normalized to lowercase.

    PyPI is case-insensitive and not all distributions are consistent in
    their own naming.
    """
    return dict([(k.lower(), v) for (k, v) in versions.items()])


def default_versions(versions=None):
    old = Installer._versions
    if versions is not None:
        Installer._versions = normalize_versions(versions)
    return old

def download_cache(path=-1):
    old = Installer._download_cache
    if path != -1:
        if path:
            path = realpath(path)
        Installer._download_cache = path
    return old

def install_from_cache(setting=None):
    old = Installer._install_from_cache
    if setting is not None:
        Installer._install_from_cache = bool(setting)
    return old

def prefer_final(setting=None):
    old = Installer._prefer_final
    if setting is not None:
        Installer._prefer_final = bool(setting)
    return old

def use_dependency_links(setting=None):
    old = Installer._use_dependency_links
    if setting is not None:
        Installer._use_dependency_links = bool(setting)
    return old

def allow_picked_versions(setting=None):
    old = Installer._allow_picked_versions
    if setting is not None:
        Installer._allow_picked_versions = bool(setting)
    return old

def store_required_by(setting=None):
    old = Installer._store_required_by
    if setting is not None:
        Installer._store_required_by = bool(setting)
    return old

def get_picked_versions():
    picked_versions = sorted(Installer._picked_versions.items())
    required_by = Installer._required_by
    return (picked_versions, required_by)


def install(specs, dest,
            links=(), index=None,
            executable=sys.executable,
            always_unzip=None, # Backward compat :/
            path=None, working_set=None, newest=True, versions=None,
            use_dependency_links=None, allow_hosts=('*',),
            include_site_packages=None,
            allowed_eggs_from_site_packages=None,
            ):
    assert executable == sys.executable, (executable, sys.executable)
    assert include_site_packages is None
    assert allowed_eggs_from_site_packages is None

    installer = Installer(dest, links, index, sys.executable,
                          always_unzip, path,
                          newest, versions, use_dependency_links,
                          allow_hosts=allow_hosts)
    return installer.install(specs, working_set)


def build(spec, dest, build_ext,
          links=(), index=None,
          executable=sys.executable,
          path=None, newest=True, versions=None, allow_hosts=('*',)):
    assert executable == sys.executable, (executable, sys.executable)
    installer = Installer(dest, links, index, executable,
                          True, path, newest,
                          versions, allow_hosts=allow_hosts)
    return installer.build(spec, build_ext)



def _rm(*paths):
    for path in paths:
        if os.path.isdir(path):
            shutil.rmtree(path)
        elif os.path.exists(path):
            os.remove(path)

def _copyeggs(src, dest, suffix, undo):
    result = []
    undo.append(lambda : _rm(*result))
    for name in os.listdir(src):
        if name.endswith(suffix):
            new = os.path.join(dest, name)
            _rm(new)
            os.rename(os.path.join(src, name), new)
            result.append(new)

    assert len(result) == 1, str(result)
    undo.pop()

    return result[0]

def develop(setup, dest,
            build_ext=None,
            executable=sys.executable):
    assert executable == sys.executable, (executable, sys.executable)
    if os.path.isdir(setup):
        directory = setup
        setup = os.path.join(directory, 'setup.py')
    else:
        directory = os.path.dirname(setup)

    undo = []
    try:
        if build_ext:
            setup_cfg = os.path.join(directory, 'setup.cfg')
            if os.path.exists(setup_cfg):
                os.rename(setup_cfg, setup_cfg+'-develop-aside')
                def restore_old_setup():
                    if os.path.exists(setup_cfg):
                        os.remove(setup_cfg)
                    os.rename(setup_cfg+'-develop-aside', setup_cfg)
                undo.append(restore_old_setup)
            else:
                f = open(setup_cfg, 'w')
                f.close()
                undo.append(lambda: os.remove(setup_cfg))
            setuptools.command.setopt.edit_config(
                setup_cfg, dict(build_ext=build_ext))

        fd, tsetup = tempfile.mkstemp()
        undo.append(lambda: os.remove(tsetup))
        undo.append(lambda: os.close(fd))

        os.write(fd, (runsetup_template % dict(
            setuptools=setuptools_loc,
            setupdir=directory,
            setup=setup,
            __file__ = setup,
            )).encode())

        tmp3 = tempfile.mkdtemp('build', dir=dest)
        undo.append(lambda : shutil.rmtree(tmp3))

        args = [executable,  tsetup, '-q', 'develop', '-mxN', '-d', tmp3]

        log_level = logger.getEffectiveLevel()
        if log_level <= 0:
            if log_level == 0:
                del args[2]
            else:
                args[2] == '-v'
        if log_level < logging.DEBUG:
            logger.debug("in: %r\n%s", directory, ' '.join(args))

        call_subprocess(args)

        return _copyeggs(tmp3, dest, '.egg-link', undo)

    finally:
        undo.reverse()
        [f() for f in undo]


def working_set(specs, executable, path=None,
                include_site_packages=None,
                allowed_eggs_from_site_packages=None):
    # Backward compat:
    if path is None:
        path = executable
    else:
        assert executable == sys.executable, (executable, sys.executable)
    assert include_site_packages is None
    assert allowed_eggs_from_site_packages is None

    return install(specs, None, path=path)

def scripts(reqs, working_set, executable, dest=None,
            scripts=None,
            extra_paths=(),
            arguments='',
            interpreter=None,
            initialization='',
            relative_paths=False,
            ):
    assert executable == sys.executable, (executable, sys.executable)

    path = [dist.location for dist in working_set]
    path.extend(extra_paths)
    # order preserving unique
    unique_path = []
    for p in path:
        if p not in unique_path:
            unique_path.append(p)
    path = list(map(realpath, unique_path))

    generated = []

    if isinstance(reqs, str):
        raise TypeError('Expected iterable of requirements or entry points,'
                        ' got string.')

    if initialization:
        initialization = '\n'+initialization+'\n'

    entry_points = []
    distutils_scripts = []
    for req in reqs:
        if isinstance(req, str):
            req = pkg_resources.Requirement.parse(req)
            dist = working_set.find(req)
            # regular console_scripts entry points
            for name in pkg_resources.get_entry_map(dist, 'console_scripts'):
                entry_point = dist.get_entry_info('console_scripts', name)
                entry_points.append(
                    (name, entry_point.module_name,
                     '.'.join(entry_point.attrs))
                    )
            # The metadata on "old-style" distutils scripts is not retained by
            # distutils/setuptools, except by placing the original scripts in
            # /EGG-INFO/scripts/.
            if dist.metadata_isdir('scripts'):
                for name in dist.metadata_listdir('scripts'):
                    if dist.metadata_isdir('scripts/' + name):
                        # Probably Python 3 __pycache__ directory.
                        continue
                    contents = dist.get_metadata('scripts/' + name)
                    distutils_scripts.append((name, contents))
        else:
            entry_points.append(req)

    for name, module_name, attrs in entry_points:
        if scripts is not None:
            sname = scripts.get(name)
            if sname is None:
                continue
        else:
            sname = name

        sname = os.path.join(dest, sname)
        spath, rpsetup = _relative_path_and_setup(sname, path, relative_paths)

        generated.extend(
            _script(module_name, attrs, spath, sname, arguments,
                    initialization, rpsetup)
            )

    for name, contents in distutils_scripts:
        if scripts is not None:
            sname = scripts.get(name)
            if sname is None:
                continue
        else:
            sname = name

        sname = os.path.join(dest, sname)
        spath, rpsetup = _relative_path_and_setup(sname, path, relative_paths)

        generated.extend(
            _distutils_script(spath, sname, contents, initialization, rpsetup)
            )

    if interpreter:
        sname = os.path.join(dest, interpreter)
        spath, rpsetup = _relative_path_and_setup(sname, path, relative_paths)
        generated.extend(_pyscript(spath, sname, rpsetup, initialization))

    return generated


def _relative_path_and_setup(sname, path, relative_paths):
    if relative_paths:
        relative_paths = os.path.normcase(relative_paths)
        sname = os.path.normcase(os.path.abspath(sname))
        spath = ',\n  '.join(
            [_relativitize(os.path.normcase(path_item), sname, relative_paths)
             for path_item in path]
            )
        rpsetup = relative_paths_setup
        for i in range(_relative_depth(relative_paths, sname)):
            rpsetup += "base = os.path.dirname(base)\n"
    else:
        spath = repr(path)[1:-1].replace(', ', ',\n  ')
        rpsetup = ''
    return spath, rpsetup


def _relative_depth(common, path):
    n = 0
    while 1:
        dirname = os.path.dirname(path)
        if dirname == path:
            raise AssertionError("dirname of %s is the same" % dirname)
        if dirname == common:
            break
        n += 1
        path = dirname
    return n


def _relative_path(common, path):
    r = []
    while 1:
        dirname, basename = os.path.split(path)
        r.append(basename)
        if dirname == common:
            break
        if dirname == path:
            raise AssertionError("dirname of %s is the same" % dirname)
        path = dirname
    r.reverse()
    return os.path.join(*r)


def _relativitize(path, script, relative_paths):
    if path == script:
        raise AssertionError("path == script")
    common = os.path.dirname(os.path.commonprefix([path, script]))
    if (common == relative_paths or
        common.startswith(os.path.join(relative_paths, ''))
        ):
        return "join(base, %r)" % _relative_path(common, path)
    else:
        return repr(path)


relative_paths_setup = """
import os

join = os.path.join
base = os.path.dirname(os.path.abspath(os.path.realpath(__file__)))
"""

def _script(module_name, attrs, path, dest, arguments, initialization, rsetup):
    if is_win32:
        dest += '-script.py'

    python = _safe_arg(sys.executable)

    contents = script_template % dict(
        python = python,
        path = path,
        module_name = module_name,
        attrs = attrs,
        arguments = arguments,
        initialization = initialization,
        relative_paths_setup = rsetup,
        )
    return _create_script(contents, dest)


def _distutils_script(path, dest, script_content, initialization, rsetup):
    if is_win32:
        dest += '-script.py'

    lines = script_content.splitlines(True)
    if not ('#!' in lines[0]) and ('python' in lines[0]):
        # The script doesn't follow distutil's rules.  Ignore it.
        return []
    lines = lines[1:]  # Strip off the first hashbang line.
    line_with_first_import = len(lines)
    for line_number, line in enumerate(lines):
        if not 'import' in line:
            continue
        if not (line.startswith('import') or line.startswith('from')):
            continue
        if '__future__' in line:
            continue
        line_with_first_import = line_number
        break

    before = ''.join(lines[:line_with_first_import])
    after = ''.join(lines[line_with_first_import:])

    python = _safe_arg(sys.executable)

    contents = distutils_script_template % dict(
        python = python,
        path = path,
        initialization = initialization,
        relative_paths_setup = rsetup,
        before = before,
        after = after
        )
    return _create_script(contents, dest)

def _file_changed(filename, old_contents, mode='r'):
    try:
        with open(filename, mode) as f:
            return f.read() != old_contents
    except EnvironmentError as e:
        if e.errno == errno.ENOENT:
            return True
        else:
            raise

def _create_script(contents, dest):
    generated = []
    script = dest

    changed = _file_changed(dest, contents)

    if is_win32:
        # generate exe file and give the script a magic name:
        win32_exe = os.path.splitext(dest)[0] # remove ".py"
        if win32_exe.endswith('-script'):
            win32_exe = win32_exe[:-7] # remove "-script"
        win32_exe = win32_exe + '.exe' # add ".exe"
        try:
            new_data = setuptools.command.easy_install.get_win_launcher('cli')
        except AttributeError:
            # fall back for compatibility with older Distribute versions
            new_data = pkg_resources.resource_string('setuptools', 'cli.exe')

        if _file_changed(win32_exe, new_data, 'rb'):
            # Only write it if it's different.
            with open(win32_exe, 'wb') as f:
                f.write(new_data)
        generated.append(win32_exe)

    if changed:
        with open(dest, 'w') as f:
            f.write(contents)
        logger.info(
            "Generated script %r.",
            # Normalize for windows
            script.endswith('-script.py') and script[:-10] or script)

        try:
            os.chmod(dest, _execute_permission())
        except (AttributeError, os.error):
            pass

    generated.append(dest)
    return generated


if is_jython and jython_os_name == 'linux':
    script_header = '#!/usr/bin/env %(python)s'
else:
    script_header = '#!%(python)s'


script_template = script_header + '''\

%(relative_paths_setup)s
import sys
sys.path[0:0] = [
  %(path)s,
  ]
%(initialization)s
import %(module_name)s

if __name__ == '__main__':
    sys.exit(%(module_name)s.%(attrs)s(%(arguments)s))
'''

distutils_script_template = script_header + '''
%(before)s
%(relative_paths_setup)s
import sys
sys.path[0:0] = [
  %(path)s,
  ]
%(initialization)s

%(after)s'''


def _pyscript(path, dest, rsetup, initialization=''):
    generated = []
    script = dest
    if is_win32:
        dest += '-script.py'

    python = _safe_arg(sys.executable)
    if path:
        path += ','  # Courtesy comma at the end of the list.

    contents = py_script_template % dict(
        python = python,
        path = path,
        relative_paths_setup = rsetup,
        initialization=initialization,
        )
    changed = _file_changed(dest, contents)

    if is_win32:
        # generate exe file and give the script a magic name:
        exe = script + '.exe'
        with open(exe, 'wb') as f:
            f.write(
                pkg_resources.resource_string('setuptools', 'cli.exe')
            )
        generated.append(exe)

    if changed:
        with open(dest, 'w') as f:
            f.write(contents)
        try:
            os.chmod(dest, _execute_permission())
        except (AttributeError, os.error):
            pass
        logger.info("Generated interpreter %r.", script)

    generated.append(dest)
    return generated

py_script_template = script_header + '''\

%(relative_paths_setup)s
import sys

sys.path[0:0] = [
  %(path)s
  ]
%(initialization)s

_interactive = True
if len(sys.argv) > 1:
    _options, _args = __import__("getopt").getopt(sys.argv[1:], 'ic:m:')
    _interactive = False
    for (_opt, _val) in _options:
        if _opt == '-i':
            _interactive = True
        elif _opt == '-c':
            exec(_val)
        elif _opt == '-m':
            sys.argv[1:] = _args
            _args = []
            __import__("runpy").run_module(
                 _val, {}, "__main__", alter_sys=True)

    if _args:
        sys.argv[:] = _args
        __file__ = _args[0]
        del _options, _args
        with open(__file__, 'U') as __file__f:
            exec(compile(__file__f.read(), __file__, "exec"))

if _interactive:
    del _interactive
    __import__("code").interact(banner="", local=globals())
'''

runsetup_template = """
import sys
sys.path.insert(0, %(setupdir)r)
sys.path.insert(0, %(setuptools)r)

import os, setuptools

__file__ = %(__file__)r

os.chdir(%(setupdir)r)
sys.argv[0] = %(setup)r

with open(%(setup)r, 'U') as f:
    exec(compile(f.read(), %(setup)r, 'exec'))
"""


class VersionConflict(zc.buildout.UserError):

    def __init__(self, err, ws):
        ws = list(ws)
        ws.sort()
        self.err, self.ws = err, ws

    def __str__(self):
        existing_dist, req = self.err.args
        result = ["There is a version conflict.",
                  "We already have: %s" % existing_dist,
                  ]
        for dist in self.ws:
            if req in dist.requires():
                result.append("but %s requires %r." % (dist, str(req)))
        return '\n'.join(result)


class MissingDistribution(zc.buildout.UserError):

    def __init__(self, req, ws):
        ws = list(ws)
        ws.sort()
        self.data = req, ws

    def __str__(self):
        req, ws = self.data
        return "Couldn't find a distribution for %r." % str(req)

def _log_requirement(ws, req):
    if (not logger.isEnabledFor(logging.DEBUG) and
        not Installer._store_required_by):
        # Sorting the working set and iterating over it's requirements
        # is expensive, so short circuit the work if it won't even be
        # logged.  When profiling a simple buildout with 10 parts with
        # identical and large working sets, this resulted in a
        # decrease of run time from 93.411 to 15.068 seconds, about a
        # 6 fold improvement.
        return

    ws = list(ws)
    ws.sort()
    for dist in ws:
        if req in dist.requires():
            logger.debug("  required by %s." % dist)
            req_ = str(req)
            if req_ not in Installer._required_by:
                Installer._required_by[req_] = set()
            Installer._required_by[req_].add(str(dist.as_requirement()))

def _fix_file_links(links):
    for link in links:
        if link.startswith('file://') and link[-1] != '/':
            if os.path.isdir(link[7:]):
                # work around excessive restriction in setuptools:
                link += '/'
        yield link

_final_parts = '*final-', '*final'
def _final_version(parsed_version):
    for part in parsed_version:
        if (part[:1] == '*') and (part not in _final_parts):
            return False
    return True

def redo_pyc(egg):
    if not os.path.isdir(egg):
        return
    for dirpath, dirnames, filenames in os.walk(egg):
        for filename in filenames:
            if not filename.endswith('.py'):
                continue
            filepath = os.path.join(dirpath, filename)
            if not (os.path.exists(filepath+'c')
                    or os.path.exists(filepath+'o')):
                # If it wasn't compiled, it may not be compilable
                continue

            # OK, it looks like we should try to compile.

            # Remove old files.
            for suffix in 'co':
                if os.path.exists(filepath+suffix):
                    os.remove(filepath+suffix)

            # Compile under current optimization
            try:
                py_compile.compile(filepath)
            except py_compile.PyCompileError:
                logger.warning("Couldn't compile %s", filepath)
            else:
                # Recompile under other optimization. :)
                args = [sys.executable]
                if __debug__:
                    args.append('-O')
                args.extend(['-m', 'py_compile', filepath])

                call_subprocess(args)

def _constrained_requirement(constraint, requirement):
    return pkg_resources.Requirement.parse(
        "%s[%s]%s" % (
            requirement.project_name,
            ','.join(requirement.extras),
            _constrained_requirement_constraint(constraint, requirement)
            )
        )

class IncompatibleConstraintError(zc.buildout.UserError):
    """A specified version is incompatible with a given requirement.
    """

IncompatibleVersionError = IncompatibleConstraintError # Backward compatibility

def bad_constraint(constraint, requirement):
    logger.error("The constraint, %s, is not consistent with the "
                 "requirement, %r.", constraint, str(requirement))
    raise IncompatibleConstraintError("Bad constraint", constraint, requirement)

_parse_constraint = re.compile(r'([<>]=?)\s*(\S+)').match
_comparef = {
    '>' : lambda x, y: x >  y,
    '>=': lambda x, y: x >= y,
    '<' : lambda x, y: x <  y,
    '<=': lambda x, y: x <= y,
    }
_opop = {'<': '>', '>': '<'}
_opeqop = {'<': '>=', '>': '<='}
def _constrained_requirement_constraint(constraint, requirement):

    # Simple cases:

    # No specs to merge with:
    if not requirement.specs:
        if not constraint[0] in '<=>':
            constraint = '==' + constraint
        return constraint

    # Simple single-version constraint:
    if constraint[0] not in '<>':
        if constraint.startswith('='):
            assert constraint.startswith('==')
            constraint = constraint[2:]
        if constraint in requirement:
            return '=='+constraint
        bad_constraint(constraint, requirement)


    # OK, we have a complex constraint (<. <=, >=, or >) and specs.
    # In many cases, the spec needs to filter constraints.
    # In other cases, the constraints need to limit the constraint.

    specs = requirement.specs
    cop, cv = _parse_constraint(constraint).group(1, 2)
    pcv = pkg_resources.parse_version(cv)

    # Special case, all of the specs are == specs:
    if not [op for (op, v) in specs if op != '==']:
        # There aren't any non-== specs.

        # See if any of the specs satisfy the constraint:
        specs = [op+v for (op, v) in specs
                 if _comparef[cop](pkg_resources.parse_version(v), pcv)]
        if specs:
            return ','.join(specs)

        bad_constraint(constraint, requirement)

    cop0 = cop[0]

    # Normalize specs by splitting >= and <= specs. We need to do this
    # because these have really weird semantics. Also cache parsed
    # versions, which we'll need for comparisons:
    specs = []
    for op, v in requirement.specs:
        pv = pkg_resources.parse_version(v)
        if op == _opeqop[cop0]:
            specs.append((op[0], v, pv))
            specs.append(('==', v, pv))
        else:
            specs.append((op, v, pv))

    # Error if there are opposite specs that conflict with the constraint
    # and there are no equal specs that satisfy the constraint:
    if [v for (op, v, pv) in specs
        if op == _opop[cop0] and _comparef[_opop[cop0]](pv, pcv)
        ]:
        eqspecs = [op+v for (op, v, pv) in specs
                   if _comparef[cop](pv, pcv)]
        if eqspecs:
            # OK, we do, use these:
            return ','.join(eqspecs)

        bad_constraint(constraint, requirement)

    # We have a combination of range constraints and eq specs that
    # satisfy the requirement.

    # Return the constraint + the filtered specs
    return ','.join(
        op+v
        for (op, v) in (
            [(cop, cv)] +
            [(op, v) for (op, v, pv) in specs if _comparef[cop](pv, pcv)]
            )
        )
