#!/usr/bin/python3
# Authors: Rob Crittenden <rcritten@redhat.com>
# Authors: Simo Sorce <ssorce@redhat.com>
#
# Copyright (C) 2008-2016  Red Hat, Inc.
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

from __future__ import print_function

import sys
from ipaplatform.paths import paths
try:
    from optparse import OptionParser  # pylint: disable=deprecated-module
    from ipapython import ipautil, config
    from ipaserver.install import installutils
    from ipaserver.install.ldapupdate import LDAPUpdate
    from ipalib import api, errors
    from ipapython.ipa_log_manager import standard_logging_setup
    from ipapython.dn import DN
except ImportError as e:
    print("""\
There was a problem importing one of the required Python modules. The
error was:

    %s
""" % e, file=sys.stderr)
    sys.exit(1)

compat_dn = DN(('cn', 'Schema Compatibility'), ('cn', 'plugins'), ('cn', 'config'))
nis_config_dn = DN(('cn', 'NIS Server'), ('cn', 'plugins'), ('cn', 'config'))

def parse_options():
    usage = "%prog [options] <enable|disable|status>\n"
    usage += "%prog [options]\n"
    parser = OptionParser(usage=usage, formatter=config.IPAFormatter())

    parser.add_option("-d", "--debug", action="store_true", dest="debug",
                      help="Display debugging information about the update(s)")
    parser.add_option("-y", dest="password",
                      help="File containing the Directory Manager password")

    config.add_standard_options(parser)
    options, args = parser.parse_args()

    return options, args

def get_dirman_password():
    """Prompt the user for the Directory Manager password and verify its
       correctness.
    """
    password = installutils.read_password("Directory Manager", confirm=False, validate=False)

    return password

def get_entry(dn):
    """
    Return the entry for the given DN. If the entry is not found return
    None.
    """
    entry = None
    try:
        entry = api.Backend.ldap2.get_entry(dn)
    except errors.NotFound:
        pass
    return entry

def main():
    retval = 0
    files = [paths.SCHEMA_COMPAT_ULDIF]

    options, args = parse_options()

    if len(args) != 1:
        sys.exit("You must specify one action: enable | disable | status")
    elif args[0] != "enable" and args[0] != "disable" and args[0] != "status":
        sys.exit("Unrecognized action [" + args[0] + "]")

    standard_logging_setup(None, debug=options.debug)

    dirman_password = ""
    if options.password:
        pw = ipautil.template_file(options.password, [])
        dirman_password = pw.strip()
    else:
        dirman_password = get_dirman_password()
        if dirman_password is None:
            sys.exit("Directory Manager password required")

    api.bootstrap(context='cli',
                  in_server=True,
                  debug=options.debug,
                  confdir=paths.ETC_IPA)
    api.finalize()
    api.Backend.ldap2.connect(bind_pw=dirman_password)

    if args[0] == "status":
        entry = None
        try:
            entry = get_entry(compat_dn)
            if entry is not None and entry.get('nsslapd-pluginenabled', [''])[0].lower() == 'on':
                print("Plugin Enabled")
            else:
                print("Plugin Disabled")
        except errors.LDAPError as lde:
            print("An error occurred while talking to the server.")
            print(lde)

    if args[0] == "enable":
        entry = None
        try:
            entry = get_entry(compat_dn)
            if entry is not None and entry.get('nsslapd-pluginenabled', [''])[0].lower() == 'on':
                print("Plugin already Enabled")
                retval = 2
            else:
                print("Enabling plugin")

                if entry is None:
                    ld = LDAPUpdate(dm_password=dirman_password, sub_dict={})
                    if not ld.update(files):
                        print("Updating Directory Server failed.")
                        retval = 1
                else:
                    entry['nsslapd-pluginenabled'] = ['on']
                    api.Backend.ldap2.update_entry(entry)
        except errors.ExecutionError as lde:
            print("An error occurred while talking to the server.")
            print(lde)
            retval = 1

    elif args[0] == "disable":
        entry = None
        try:
            entry = get_entry(nis_config_dn)
            # We can't disable schema compat if the NIS plugin is enabled
            if entry is not None and entry.get('nsslapd-pluginenabled', [''])[0].lower() == 'on':
                print("The NIS plugin is configured, cannot disable compatibility.", file=sys.stderr)
                print("Run 'ipa-nis-manage disable' first.", file=sys.stderr)
                retval = 2
        except errors.ExecutionError as lde:
            print("An error occurred while talking to the server.")
            print(lde)
            retval = 1

        if retval == 0:
            entry = None
            try:
                entry = get_entry(compat_dn)
                if entry is None or entry.get('nsslapd-pluginenabled', [''])[0].lower() == 'off':
                    print("Plugin is already disabled")
                    retval = 2
                else:
                    print("Disabling plugin")

                    entry['nsslapd-pluginenabled'] = ['off']
                    api.Backend.ldap2.update_entry(entry)
            except errors.DatabaseError as dbe:
                print("An error occurred while talking to the server.")
                print(dbe)
                retval = 1
            except errors.ExecutionError as lde:
                print("An error occurred while talking to the server.")
                print(lde)
                retval = 1

    else:
        retval = 1

    if retval == 0:
        print("This setting will not take effect until you restart Directory Server.")

    api.Backend.ldap2.disconnect()

    return retval

if __name__ == '__main__':
    installutils.run_script(main, operation_name='ipa-compat-manage')
