"""distutils.command.install_egg_info

Implements the Distutils 'install_egg_info' command, for installing
a package's PKG-INFO metadata."""


from distutils.cmd import Command
from distutils import log, dir_util
import os, sys, re

class install_egg_info(Command):
    """Install an .egg-info file for the package"""

    description = "Install package's PKG-INFO metadata as an .egg-info file"
    user_options = [
        ('install-dir=', 'd', "directory to install to"),
        ('install-layout', None, "custom installation layout"),
    ]

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

    def finalize_options(self):
        self.set_undefined_options('install_lib',('install_dir','install_dir'))
        self.set_undefined_options('install',('install_layout','install_layout'))
        self.set_undefined_options('install',('prefix_option','prefix_option'))
        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%s.egg-info" % (
                to_filename(safe_name(self.distribution.get_name())),
                to_filename(safe_version(self.distribution.get_version())),
                sys.version[:3]
                )
        self.target = os.path.join(self.install_dir, basename)
        self.outputs = [self.target]

    def run(self):
        target = self.target
        if os.path.isdir(target) and not os.path.islink(target):
            dir_util.remove_tree(target, dry_run=self.dry_run)
        elif os.path.exists(target):
            self.execute(os.unlink,(self.target,),"Removing "+target)
        elif not os.path.isdir(self.install_dir):
            self.execute(os.makedirs, (self.install_dir,),
                         "Creating "+self.install_dir)
        log.info("Writing %s", target)
        if not self.dry_run:
            with open(target, 'w', encoding='UTF-8') as f:
                self.distribution.metadata.write_pkg_file(f)

    def get_outputs(self):
        return self.outputs


# The following routines are taken from setuptools' pkg_resources module and
# can be replaced by importing them from pkg_resources once it is included
# in the stdlib.

def safe_name(name):
    """Convert an arbitrary string to a standard distribution name

    Any runs of non-alphanumeric/. characters are replaced with a single '-'.
    """
    return re.sub('[^A-Za-z0-9.]+', '-', name)


def safe_version(version):
    """Convert an arbitrary string to a standard version string

    Spaces become dots, and all other non-alphanumeric characters become
    dashes, with runs of multiple dashes condensed to a single dash.
    """
    version = version.replace(' ','.')
    return re.sub('[^A-Za-z0-9.]+', '-', version)


def to_filename(name):
    """Convert a project or version name to its filename-escaped form

    Any '-' characters are currently replaced with '_'.
    """
    return name.replace('-','_')
