_distutils_system_mod.py

"""
Apply Debian-specific patches to distutils commands and sysconfig.

Extracts the customized behavior from patches as reported
in pypa/distutils#2 and applies those customizations (except
for scheme definitions) to those commands.

Place this module somewhere in sys.path to take effect.
"""

import os
import sys

import distutils.sysconfig
import distutils.command.install as orig_install
import distutils.command.install_egg_info as orig_install_egg_info
from distutils.command.install_egg_info import (
    to_filename,
    safe_name,
    safe_version,
    )
from distutils.errors import DistutilsOptionError


class install(orig_install.install):
    user_options = list(orig_install.install.user_options) + [
        ('install-layout=', None,
         "installation layout to choose (known values: deb, unix)"),
    ]

    def initialize_options(self):
        super().initialize_options()
        self.prefix_option = None
        self.install_layout = None

    def finalize_unix(self):
        self.prefix_option = self.prefix
        super().finalize_unix()
        if self.install_layout:
            if self.install_layout.lower() in ['deb']:
                self.select_scheme("deb_system")
            elif self.install_layout.lower() in ['unix']:
                self.select_scheme("posix_prefix")
            else:
                raise DistutilsOptionError(
                    "unknown value for --install-layout")
        elif ((self.prefix_option and
               os.path.normpath(self.prefix) != '/usr/local')
              or sys.base_prefix != sys.prefix
              or 'PYTHONUSERBASE' in os.environ
              or 'VIRTUAL_ENV' in os.environ
              or 'real_prefix' in sys.__dict__):
            self.select_scheme("posix_prefix")
        else:
            if os.path.normpath(self.prefix) == '/usr/local':
                self.prefix = self.exec_prefix = '/usr'
                self.install_base = self.install_platbase = '/usr'
            self.select_scheme("posix_local")


class install_egg_info(orig_install_egg_info.install_egg_info):
    user_options = list(orig_install_egg_info.install_egg_info.user_options) + [
        ('install-layout', None, "custom installation layout"),
    ]

    def initialize_options(self):
        super().initialize_options()
        self.prefix_option = None
        self.install_layout = None

    def finalize_options(self):
        self.set_undefined_options('install',('install_layout','install_layout'))
        self.set_undefined_options('install',('prefix_option','prefix_option'))
        super().finalize_options()

    @property
    def basename(self):
        if self.install_layout:
            if not self.install_layout.lower() in ['deb', 'unix']:
                raise DistutilsOptionError(
                    "unknown value for --install-layout")
            no_pyver = (self.install_layout.lower() == 'deb')
        elif self.prefix_option:
            no_pyver = False
        else:
            no_pyver = True
        if no_pyver:
            basename = "%s-%s.egg-info" % (
                to_filename(safe_name(self.distribution.get_name())),
                to_filename(safe_version(self.distribution.get_version()))
                )
        else:
            basename = "%s-%s-py%d.%d.egg-info" % (
                to_filename(safe_name(self.distribution.get_name())),
                to_filename(safe_version(self.distribution.get_version())),
                *sys.version_info[:2]
            )
        return basename


def _posix_lib(standard_lib, libpython, early_prefix, prefix):
    is_default_prefix = not early_prefix or os.path.normpath(early_prefix) in ('/usr', '/usr/local')
    if standard_lib:
        return libpython
    elif (is_default_prefix and
              'PYTHONUSERBASE' not in os.environ and
              'VIRTUAL_ENV' not in os.environ and
              'real_prefix' not in sys.__dict__ and
              sys.prefix == sys.base_prefix):
            return os.path.join(prefix, "lib", "python3", "dist-packages")
    else:
        return os.path.join(libpython, "site-packages")


def apply_customizations():
    orig_install.install = install
    orig_install_egg_info.install_egg_info = install_egg_info
    distutils.sysconfig._posix_lib = _posix_lib


apply_customizations()