from setuptools import Command
from setuptools.archive_util import unpack_archive
from distutils import log, dir_util
import os, shutil, pkg_resources

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

    description = "Install an .egg-info directory for the package"

    user_options = [
        ('install-dir=', 'd', "directory to install to"),
    ]

    def initialize_options(self):
        self.install_dir = None

    def finalize_options(self):
        self.set_undefined_options('install_lib',('install_dir','install_dir'))
        ei_cmd = self.get_finalized_command("egg_info")
        basename = pkg_resources.Distribution(
            None, None, ei_cmd.egg_name, ei_cmd.egg_version
        ).egg_name()+'.egg-info'
        self.source = ei_cmd.egg_info
        self.target = os.path.join(self.install_dir, basename)
        self.outputs = []

    def run(self):
        self.run_command('egg_info')
        target = self.target
        if os.path.isdir(self.target) and not os.path.islink(self.target):
            dir_util.remove_tree(self.target, dry_run=self.dry_run)
        elif os.path.exists(self.target):
            self.execute(os.unlink,(self.target,),"Removing "+self.target)
        if not self.dry_run:
            pkg_resources.ensure_directory(self.target)
        self.execute(self.copytree, (),
            "Copying %s to %s" % (self.source, self.target)
        )
        self.install_namespaces()

    def get_outputs(self):
        return self.outputs

    def copytree(self):
        # Copy the .egg-info tree to site-packages
        def skimmer(src,dst):
            # filter out source-control directories; note that 'src' is always
            # a '/'-separated path, regardless of platform.  'dst' is a
            # platform-specific path.
            for skip in '.svn/','CVS/':
                if src.startswith(skip) or '/'+skip in src:
                    return None
            self.outputs.append(dst)
            log.debug("Copying %s to %s", src, dst)
            return dst
        unpack_archive(self.source, self.target, skimmer)

























    def install_namespaces(self):
        nsp = self._get_all_ns_packages()
        if not nsp: return
        filename,ext = os.path.splitext(self.target)
        filename += '-nspkg.pth'; self.outputs.append(filename)
        log.info("Installing %s",filename)
        if not self.dry_run:
            f = open(filename,'wt')
            for pkg in nsp:
                # ensure pkg is not a unicode string under Python 2.7
                pkg = str(pkg)
                pth = tuple(pkg.split('.'))
                trailer = '\n'
                if '.' in pkg:
                    trailer = (
                        "; m and setattr(sys.modules[%r], %r, m)\n"
                        % ('.'.join(pth[:-1]), pth[-1])
                    )
                f.write(
                    "import sys,types,os; "
                    "p = os.path.join(sys._getframe(1).f_locals['sitedir'], "
                        "*%(pth)r); "
                    "ie = os.path.exists(os.path.join(p,'__init__.py')); "
                    "m = not ie and "
                        "sys.modules.setdefault(%(pkg)r,types.ModuleType(%(pkg)r)); "
                    "mp = (m or []) and m.__dict__.setdefault('__path__',[]); "
                    "(p not in mp) and mp.append(p)%(trailer)s"
                    % locals()
                )
            f.close()

    def _get_all_ns_packages(self):
        nsp = {}
        for pkg in self.distribution.namespace_packages or []:
            pkg = pkg.split('.')
            while pkg:
                nsp['.'.join(pkg)] = 1
                pkg.pop()
        nsp=list(nsp)
        nsp.sort()  # set up shorter names first
        return nsp


