from __future__ import print_function, division, absolute_import

#
# Copyright (c) 2010 - 2012 Red Hat, Inc.
#
# This software is licensed to you under the GNU General Public License,
# version 2 (GPLv2). There is NO WARRANTY for this software, express or
# implied, including the implied warranties of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. You should have received a copy of GPLv2
# along with this software; if not, see
# http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
#
# Red Hat trademarks are not licensed under GPLv2. No permission is
# granted to use or replicate Red Hat trademarks that are incorporated
# in this software or its documentation.
#
import base64
import os

from rhsm import certificate, _certificate
from rhsm.certificate2 import EntitlementCertificate

from rct.commands import RCTCliCommand
from rct.printing import printc, type_to_string

from subscription_manager.cli import InvalidCLIOptionError

from subscription_manager.i18n import ugettext as _


class RCTCertCommand(RCTCliCommand):

    def __init__(self, name="cli", aliases=None, shortdesc=None, primary=False):
        RCTCliCommand.__init__(self, name=name, aliases=aliases,
                shortdesc=shortdesc, primary=primary)

    def _get_usage(self):
        return _("%(prog)s {name} [OPTIONS] CERT_FILE").format(name=self.name)

    def _create_cert(self):
        cert_file = self._get_file_from_args()
        try:
            return certificate.create_from_file(cert_file)
        except certificate.CertificateException as ce:
            raise InvalidCLIOptionError(
                    _("Unable to read certificate file '%s': %s") % (cert_file,
                        ce))

    def _validate_options(self):
        cert_file = self._get_file_from_args()
        if not cert_file:
            raise InvalidCLIOptionError(_("You must specify a certificate file."))

        if not os.path.isfile(cert_file):
            raise InvalidCLIOptionError(_("The specified certificate file does not exist."))


class CatCertCommand(RCTCertCommand):

    def __init__(self):
        RCTCliCommand.__init__(self, name="cat-cert", aliases=['cc'],
                               shortdesc=_("Print certificate information"),
                               primary=True)

        self.parser.add_argument("--no-products", dest="no_products", action="store_true",
                               help=_("do not show the cert's product information"))
        self.parser.add_argument("--no-content", dest="no_content", action="store_true",
                               help=_("do not show the cert's content info"))

    def _do_command(self):
        """
        Does the work that this command intends.
        """
        cert = self._create_cert()
        printc(cert, skip_content=self.options.no_content,
               skip_products=self.options.no_products)


class StatCertCommand(RCTCertCommand):

    def __init__(self):
        RCTCliCommand.__init__(self, name="stat-cert", aliases=['sc'],
                               shortdesc=_("Print certificate statistics and sizes"),
                               primary=True)

    def _do_command(self):
        cert = self._create_cert()
        pem = self._get_pem(self._get_file_from_args())
        print(_("Type: %s") % type_to_string(cert))
        print(_("Version: %s") % cert.version)
        print(_("DER size: %db") % self._get_der_size(pem))

        subject_key_id = self._get_subject_key_id(pem)
        if subject_key_id is not None:
            print(_("Subject Key ID size: %db") % len(subject_key_id))

        if isinstance(cert, EntitlementCertificate):
            content_len = 0
            if cert.content:
                content_len = len(cert.content)
            print(_("Content sets: %s") % content_len)

    def _get_pem(self, filename):
        return open(filename, 'r',).read()

    def _get_der_size(self, pem):
        parts = pem.split("-----BEGIN CERTIFICATE-----\n")
        cert = parts[1].split("-----END CERTIFICATE-----")[0]
        return len(base64.b64decode(cert))

    def _get_subject_key_id(self, pem):
        cert = _certificate.load(pem=pem)
        subject_key_id = cert.get_extension(oid="2.5.29.14")
        return subject_key_id
