import os

import site

import sys

from distutils.sysconfig import get_python_lib

from setuptools import setup

# Allow editable install into user site directory.

# See https://github.com/pypa/pip/issues/7953.

site.ENABLE_USER_SITE = "--user" in sys.argv[1:]

# Warn if we are installing over top of an existing installation. This can

# cause issues where files that were deleted from a more recent Django are

# still present in site-packages. See #18115.

overlay_warning = False

if "install" in sys.argv:

    lib_paths = [get_python_lib()]

    if lib_paths[0].startswith("/usr/lib/"):

        # We have to try also with an explicit prefix of /usr/local in order to

        # catch Debian's custom user site-packages directory.

        lib_paths.append(get_python_lib(prefix="/usr/local"))

    for lib_path in lib_paths:

        existing_path = os.path.abspath(os.path.join(lib_path, "django"))

        if os.path.exists(existing_path):

            # We note the need for the warning here, but present it after the

            # command is run, so it's more likely to be seen.

            overlay_warning = True

            break

setup()

if overlay_warning:

    sys.stderr.write(

        """

========

WARNING!

========

You have just installed Django over top of an existing

installation, without removing it first. Because of this,

your install may now include extraneous files from a

previous version that have since been removed from

Django. This is known to cause a variety of problems. You

should manually remove the

%(existing_path)s

directory and re-install Django.

"""

        % {"existing_path": existing_path}

    )