#!/usr/bin/python
# Authors: Jr Aquino <jr.aquino@citrix.com>
#
# Copyright (C) 2011  Red Hat
# 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/>.
#

import ldap
import re
import sys
try:
    from optparse import OptionParser
    from ipapython import ipautil, config
    from ipaserver.install import installutils
    from ipaserver import ipaldap
    from ipaserver.plugins.ldap2 import ldap2
    from ipalib import api, errors
    from ipalib.dn import *
    from ipapython.ipa_log_manager import *

except ImportError:
    print >> sys.stderr, """\
There was a problem importing one of the required Python modules. The
error was:

    %s
""" % sys.exc_value
    sys.exit(1)

CACERT = "/etc/ipa/ca.crt"

def parse_options():
    usage = "%prog [options] <status|enable|disable>\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("-e", "--entry", dest="managed_entry",
                      default=None, type="string",
                      help="DN for the Managed Entry Definition")
    parser.add_option("-l", "--list", dest="list_managed_entries",
                      action="store_true",
                      help="DN for the Managed Entry Definition")
    parser.add_option("-p", "--password", dest="dirman_password",
                      help="Directory Manager password")

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

    config.init_config(options)

    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=True)

    return password

def main():
    retval = 0
    def_dn = None
    options, args = parse_options()

    if options.list_managed_entries:
        pass
    elif len(args) != 1:
        sys.exit("You must specify an action, either status, enable or disable")
    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)

    host = installutils.get_fqdn()
    api.bootstrap(context='cli', debug=options.debug)
    api.finalize()

    managed_entry_definitions_dn = DN(
        ('cn', 'Definitions'),
        ('cn', 'Managed Entries'),
        ('cn', 'etc'),
        DN(api.env.basedn)
    )
    managed_entry_definitions_dn = str(managed_entry_definitions_dn)

    conn = None
    try:
        filter = '(objectClass=extensibleObject)'
        conn = ipaldap.IPAdmin(host, 636, cacert=CACERT)

        if options.dirman_password:
            conn.do_simple_bind(bindpw=options.dirman_password)
        else:
            conn.do_sasl_gssapi_bind()
    except ldap.LOCAL_ERROR:
        dirman_password = get_dirman_password()
        if dirman_password is None:
            sys.exit("\nDirectory Manager password required")
        try:
            conn.do_simple_bind(bindpw=dirman_password)
        except ldap.INVALID_CREDENTIALS:
            sys.exit("Invalid credentials")
    except ldap.INVALID_CREDENTIALS:
        sys.exit("Invalid credentials")
    except errors.ExecutionError, lde:
        sys.exit("An error occurred while connecting to the server.\n%s\n" %
            str(lde))
    except errors.ACIError, e:
        sys.exit("Authentication failed: %s" % e.info)

    if options.list_managed_entries:
        # List available Managed Entry Plugins
        managed_entries = None
        try:
            entries = conn.search_s(
                managed_entry_definitions_dn, ldap.SCOPE_SUBTREE, filter
                )
        except Exception, e:
            root_logger.debug("Search for managed entries failed: %s" % str(e))
            sys.exit("Unable to find managed entries at %s" % managed_entry_definitions_dn)
        managed_entries = [entry.cn for entry in entries]
        if managed_entries:
            print "Available Managed Entry Definitions:"
            for managed_entry in managed_entries:
                print managed_entry
        retval = 0
        sys.exit()

    if not options.managed_entry:
        sys.exit("\nYou must specify a managed entry definition")
    else:
        rdn = DN(
            ('cn', options.managed_entry),
            DN(managed_entry_definitions_dn)
        )
        def_dn = str(rdn)

        disabled = True
        try:
            entries = conn.search_s(def_dn,
                ldap.SCOPE_BASE,
                filter,
                ['originfilter'],
            )
            disable_attr = '(objectclass=disable)'
            try:
                org_filter = entries[0].originfilter
                disabled = re.search(r'%s' % disable_attr, org_filter)
            except KeyError:
                sys.exit("%s is not a valid Managed Entry" % def_dn)
        except ldap.NO_SUCH_OBJECT:
            sys.exit("%s is not a valid Managed Entry" % def_dn)
        except errors.NotFound:
            sys.exit("%s is not a valid Managed Entry" % def_dn)
        except errors.ExecutionError, lde:
            print "An error occurred while talking to the server."
            print lde

        if args[0] == "status":
            if not disabled:
                print "Plugin Enabled"
            else:
                print "Plugin Disabled"
            return 0

        if args[0] == "enable":
            try:
                if not disabled:
                    print "Plugin already Enabled"
                    retval = 2
                else:
                    # Remove disable_attr from filter
                    enable_attr = org_filter.replace(disable_attr, '')
                    #enable_attr = {'originfilter': enable_attr}
                    conn.modify_s(
                        def_dn,
                        [(ldap.MOD_REPLACE,
                        'originfilter',
                        enable_attr)]
                    )
                    print "Enabling Plugin"
                    retval = 0
            except errors.NotFound:
                print "Enabling Plugin"
            except errors.ExecutionError, lde:
                print "An error occurred while talking to the server."
                print lde
                retval = 1

        elif args[0] == "disable":
            # Set originFilter to objectclass=disabled
            # In future we should we should dedicate an attribute for enabling/
            # disabling.
            try:
                if disabled:
                    print "Plugin already disabled"
                    retval = 2
                else:
                    if org_filter[:2] == '(&' and org_filter[-1] == ')':
                        disable_attr = org_filter[:2] + disable_attr + org_filter[2:]
                    else:
                        disable_attr = '(&%s(%s))' % (disable_attr, org_filter)
                    conn.modify_s(
                        def_dn,
                        [(ldap.MOD_REPLACE,
                        'originfilter',
                        disable_attr)]
                    )
                    print "Disabling Plugin"
            except errors.NotFound:
                print "Plugin is already disabled"
                retval = 2
            except errors.DatabaseError, dbe:
                print "An error occurred while talking to the server."
                print dbe
                retval = 1
            except errors.ExecutionError, lde:
                print "An error occurred while talking to the server."
                print lde
                retval = 1

        else:
            retval = 1

    return retval

try:
    if __name__ == "__main__":
        sys.exit(main())
except RuntimeError, e:
    print "%s" % e
    sys.exit(1)
except SystemExit, e:
    sys.exit(e)
except KeyboardInterrupt, e:
    sys.exit(1)
except config.IPAConfigError, e:
    print "An IPA server to update cannot be found. Has one been configured yet?"
    print "The error was: %s" % e
    sys.exit(1)
except errors.LDAPError, e:
    print "An error occurred while performing operations: %s" % e
    sys.exit(1)