#!/usr/bin/python3
# Authors: Rob Crittenden <rcritten@redhat.com>
#
# Based on ipa-replica-manage by Karl MacMillan <kmacmillan@mentalrootkit.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/>.
#

from __future__ import print_function

import logging
import sys
import os

from ipaplatform.paths import paths
from ipaserver.install import (replication, installutils, bindinstance,
    cainstance)
from ipalib import api, errors
from ipalib.constants import FQDN
from ipalib.util import has_managed_topology, print_replication_status
from ipapython import ipautil, ipaldap, version
from ipapython.admintool import ScriptError
from ipapython.dn import DN

logger = logging.getLogger(os.path.basename(__file__))

# dict of command name and tuples of min/max num of args needed
commands = {
    "list": (0, 1, "[master fqdn]", ""),
    "connect": (1, 2, "<master fqdn> [other master fqdn]",
                "must provide the name of the servers to connect"),
    "disconnect": (1, 2, "<master fqdn> [other master fqdn]",
                   "must provide the name of the server to disconnect"),
    "del": (1, 1, "<master fqdn>",
            "must provide hostname of master to delete"),
    "re-initialize": (0, 0, "", ""),
    "force-sync": (0, 0, "", ""),
    "set-renewal-master": (0, 1, "[master fqdn]", "")
}


def parse_options():
    from optparse import OptionParser  # pylint: disable=deprecated-module

    parser = OptionParser(version=version.VERSION)
    parser.add_option("-H", "--host", dest="host", help="starting host")
    parser.add_option("-p", "--password", dest="dirman_passwd", help="Directory Manager password")
    parser.add_option("-v", "--verbose", dest="verbose", action="store_true", default=False,
                      help="provide additional information")
    parser.add_option("-f", "--force", dest="force", action="store_true", default=False,
                      help="ignore some types of errors")
    parser.add_option("--from", dest="fromhost", help="Host to get data from")

    options, args = parser.parse_args()

    valid_syntax = False

    if len(args):
        n = len(args) - 1
        for cmd in commands:
            if cmd == args[0]:
                v = commands[cmd]
                err = None
                if n < v[0]:
                    err = v[3]
                elif n > v[1]:
                    err = "too many arguments"
                else:
                    valid_syntax = True
                if err:
                    parser.error("Invalid syntax: %s\nUsage: %s [options] %s" % (err, cmd, v[2]))

    if not valid_syntax:
        cmdstr = " | ".join(commands.keys())
        parser.error("must provide a command [%s]" % cmdstr)

    return options, args

def list_replicas(realm, host, replica, dirman_passwd, verbose):

    peers = {}

    try:
        # connect to main IPA LDAP server
        ldap_uri = ipaldap.get_ldap_uri(host, 636, cacert=paths.IPA_CA_CRT)
        conn = ipaldap.LDAPClient(ldap_uri, cacert=paths.IPA_CA_CRT)
        conn.simple_bind(bind_dn=ipaldap.DIRMAN_DN,
                         bind_password=dirman_passwd)

        dn = DN(('cn', 'masters'), ('cn', 'ipa'), ('cn', 'etc'), ipautil.realm_to_suffix(realm))
        entries = conn.get_entries(dn, conn.SCOPE_ONELEVEL)

        for ent in entries:
            try:
                cadn = DN(('cn', 'CA'), DN(ent.dn))
                entry = conn.get_entry(cadn)
                peers[ent.single_value['cn']] = ['master', '']
            except errors.NotFound:
                peers[ent.single_value['cn']] = ['CA not configured', '']

    except Exception as e:
        sys.exit(
            "Failed to get data from '%s' while trying to list replicas: %s" %
            (host, e))
    finally:
        conn.unbind()

    if not replica:
        for k, p in peers.items():
            print('%s: %s' % (k, p[0]))
        return

    try:
        repl = replication.get_cs_replication_manager(realm, replica, dirman_passwd)
    except Exception as e:
        sys.exit(str(e))

    entries = repl.find_replication_agreements()

    for entry in entries:
        print('%s' % entry.single_value.get('nsds5replicahost'))
        print_replication_status(entry, verbose)


def del_link(realm, replica1, replica2, dirman_passwd, force=False):

    repl2 = None

    try:
        repl1 = replication.get_cs_replication_manager(realm, replica1, dirman_passwd)

        repl1.hostnames = [replica1, replica2]

        repl_list1 = repl1.find_replication_agreements()

        # Find the DN of the replication agreement to remove
        replica1_dn = None
        for e in repl_list1:
            if e.single_value.get('nsDS5ReplicaHost') == replica2:
                replica1_dn = e.dn
                break

        if replica1_dn is None:
            sys.exit("'%s' has no replication agreement for '%s'" % (replica1, replica2))

        repl1.hostnames = [replica1, replica2]

    except errors.NetworkError as e:
        sys.exit("Unable to connect to %s: %s" % (replica1, e))
    except Exception as e:
        sys.exit("Failed to get data from '%s': %s" % (replica1, e))

    try:
        repl2 = replication.get_cs_replication_manager(realm, replica2, dirman_passwd)

        repl2.hostnames = [replica1, replica2]

        repl_list = repl2.find_replication_agreements()

        # Now that we've confirmed that both hostnames are vaild, make sure
        # that we aren't removing the last link from either side.
        if not force and len(repl_list) <= 1:
            print("Cannot remove the last replication link of '%s'" % replica2)
            print("Please use the 'del' command to remove it from the domain")
            sys.exit(1)

        if not force and len(repl_list1) <= 1:
            print("Cannot remove the last replication link of '%s'" % replica1)
            print("Please use the 'del' command to remove it from the domain")
            sys.exit(1)

        # Find the DN of the replication agreement to remove
        replica2_dn = None
        for entry in repl_list:
            if entry.single_value.get('nsDS5ReplicaHost') == replica1:
                replica2_dn = entry.dn
                break

        # This should never happen
        if replica2_dn is None:
            sys.exit("'%s' has no replication agreement for '%s'" % (replica1, replica2))

    except errors.NotFound:
        print("'%s' has no replication agreement for '%s'" % (replica2, replica1))
        if not force:
            return
    except Exception as exc:
        print("Failed to get data from '%s': %s" % (replica2, exc))
        if not force:
            sys.exit(1)

    if repl2:
        failed = False
        try:
            repl2.delete_agreement(replica1, replica2_dn)
            repl2.delete_referral(replica1, repl1.port)
        except Exception as exc:
            print("Unable to remove agreement on %s: %s" % (replica2, exc))
            failed = True

        if failed:
            if force:
                print("Forcing removal on '%s'" % replica1)
            else:
                sys.exit(1)

    if not repl2 and force:
        print("Forcing removal on '%s'" % replica1)

    repl1.delete_agreement(replica2, replica1_dn)
    repl1.delete_referral(replica2, repl2.port)

    print("Deleted replication agreement from '%s' to '%s'" % (replica1, replica2))

def del_master(realm, hostname, options):
    delrepl = None

    # 1. Connect to the local dogtag DS server
    try:
        thisrepl = replication.get_cs_replication_manager(realm, options.host,
                                                          options.dirman_passwd)
    except Exception as e:
        sys.exit("Failed to connect to server %s: %s" % (options.host, e))

    # 2. Ensure we have an agreement with the master
    if thisrepl.get_replication_agreement(hostname) is None:
        sys.exit("'%s' has no replication agreement for '%s'" % (options.host, hostname))

    # 3. Connect to the dogtag DS to be removed.
    try:
        delrepl = replication.get_cs_replication_manager(realm, hostname,
                                                         options.dirman_passwd)
    except Exception as e:
        if not options.force:
            print("Unable to delete replica %s: %s" % (hostname, e))
            sys.exit(1)
        else:
            print("Unable to connect to replica %s, forcing removal" % hostname)

    # 4. Get list of agreements.
    if delrepl is None:
        # server not up, just remove it from this server
        replica_names = [options.host]
    else:
        replica_entries = delrepl.find_ipa_replication_agreements()
        replica_names = [rep.single_value.get('nsds5replicahost')
                         for rep in replica_entries]

    # 5. Remove each agreement
    for r in replica_names:
        try:
            del_link(realm, r, hostname, options.dirman_passwd, force=True)
        except Exception as e:
            sys.exit("There were issues removing a connection: %s" % e)

    # 6. Pick CA renewal master
    ca = cainstance.CAInstance(api.env.realm)
    if ca.is_renewal_master(hostname):
        ca.set_renewal_master(options.host)

    # 7. And clean up the removed replica DNS entries if any.
    try:
        if bindinstance.dns_container_exists(api.env.basedn):
            bind = bindinstance.BindInstance()
            bind.update_system_records()
    except Exception as e:
        print("Failed to cleanup %s DNS entries: %s" % (hostname, e))
        print("You may need to manually remove them from the tree")

def add_link(realm, replica1, replica2, dirman_passwd, options):
    try:
        repl2 = replication.get_cs_replication_manager(realm, replica2,
                                                       dirman_passwd)
    except Exception as e:
        sys.exit(str(e))
    try:
        ldap_uri = ipaldap.get_ldap_uri(replica2, 636, cacert=paths.IPA_CA_CRT)
        conn = ipaldap.LDAPClient(ldap_uri, cacert=paths.IPA_CA_CRT)
        conn.simple_bind(bind_dn=ipaldap.DIRMAN_DN,
                         bind_password=dirman_passwd)

        dn = DN(('cn', 'CA'), ('cn', replica2), ('cn', 'masters'), ('cn', 'ipa'), ('cn', 'etc'),
                ipautil.realm_to_suffix(realm))
        conn.get_entries(dn, conn.SCOPE_BASE)
        conn.unbind()
    except errors.NotFound:
        sys.exit('%s does not have a CA configured.' % replica2)
    except errors.NetworkError as e:
        sys.exit("Unable to connect to %s: %s" % (ipautil.format_netloc(replica2, 636), str(e)))
    except Exception as e:
        sys.exit("Failed to get data while trying to bind to '%s': %s" % (replica1, str(e)))

    try:
        repl1 = replication.get_cs_replication_manager(realm, replica1,
                                                       dirman_passwd)
        entries = repl1.find_replication_agreements()
        for e in entries:
            if e.single_value.get('nsDS5ReplicaHost') == replica2:
                sys.exit('This replication agreement already exists.')
        repl1.hostnames = [replica1, replica2]

    except errors.NotFound:
        sys.exit("Cannot find replica '%s'" % replica1)
    except errors.NetworkError as e:
        sys.exit("Unable to connect to %s: %s" % (replica1, e))
    except Exception as e:
        sys.exit(
            "Failed to get data from '%s' while trying to get current "
            "agreements: %s" % (replica1, e))

    repl1.setup_replication(
        replica2, repl2.port, 0, DN(('cn', 'Directory Manager')),
        dirman_passwd, is_cs_replica=True, local_port=repl1.port)
    print("Connected '%s' to '%s'" % (replica1, replica2))

def re_initialize(realm, options):

    if not options.fromhost:
        sys.exit("re-initialize requires the option --from <host name>")

    thishost = FQDN

    try:
        repl = replication.get_cs_replication_manager(realm, options.fromhost,
                                                      options.dirman_passwd)
        thisrepl = replication.get_cs_replication_manager(realm, thishost,
                                                          options.dirman_passwd)
    except Exception as e:
        sys.exit(str(e))

    filter = repl.get_agreement_filter(host=thishost)
    try:
        entry = repl.conn.get_entries(
            DN(('cn', 'config')), repl.conn.SCOPE_SUBTREE, filter)
    except errors.NotFound:
        logger.error("Unable to find %s -> %s replication agreement",
                     options.fromhost, thishost)
        sys.exit(1)
    if len(entry) > 1:
        logger.error("Found multiple agreements for %s. Only initializing the "
                     "first one returned: %s", thishost, entry[0].dn)

    repl.hostnames = thisrepl.hostnames = [thishost, options.fromhost]
    thisrepl.enable_agreement(options.fromhost)
    repl.enable_agreement(thishost)

    repl.initialize_replication(entry[0].dn, repl.conn)
    repl.wait_for_repl_init(repl.conn, entry[0].dn)

def force_sync(realm, thishost, fromhost, dirman_passwd):

    try:
        repl = replication.get_cs_replication_manager(realm, fromhost,
                                                      dirman_passwd)
        repl.force_sync(repl.conn, thishost)
    except Exception as e:
        sys.exit(str(e))

def set_renewal_master(realm, replica):
    if not replica:
        replica = FQDN

    ca = cainstance.CAInstance(realm)
    if ca.is_renewal_master(replica):
        sys.exit("%s is already the renewal master" % replica)

    try:
        ca.set_renewal_master(replica)
    except Exception as e:
        sys.exit("Failed to set renewal master to %s: %s" % (replica, e))

    print("%s is now the renewal master" % replica)


def exit_on_managed_topology(what, hint="topologysegment"):
    if hint == "topologysegment":
        hinttext = ("Please use `ipa topologysegment-*` commands to manage "
                   "the topology.")
    elif hint == "ipa-replica-manage-del":
        hinttext = ("Please use the `ipa-replica-manage del` command.")
    else:
        assert False, "Unexpected value"
    sys.exit("{0} is deprecated with managed IPA replication topology. {1}"
             .format(what, hinttext))


def main():
    installutils.check_server_configuration()
    options, args = parse_options()

    # Just initialize the environment. This is so the installer can have
    # access to the plugin environment
    api_env = {}
    if os.getegid() != 0:
        api_env['log'] = None # turn off logging for non-root

    api.bootstrap(
        context='cli',
        in_server=True,
        verbose=options.verbose,
        confdir=paths.ETC_IPA,
        **api_env
    )
    api.finalize()

    dirman_passwd = None
    realm = api.env.realm

    if options.host:
        host = options.host
    else:
        host = FQDN

    options.host = host

    if options.dirman_passwd:
        dirman_passwd = options.dirman_passwd
    else:
        dirman_passwd = installutils.read_password("Directory Manager", confirm=False,
            validate=False, retry=False)
        if dirman_passwd is None:
            sys.exit("Directory Manager password required")

    options.dirman_passwd = dirman_passwd

    api.Backend.ldap2.connect(bind_pw=options.dirman_passwd)

    if args[0] == "list":
        replica = None
        if len(args) == 2:
            replica = args[1]
        list_replicas(realm, host, replica, dirman_passwd, options.verbose)
    elif args[0] == "del":
        if has_managed_topology(api):
            exit_on_managed_topology(
                "Removal of IPA CS replication agreement and replication data",
                hint="ipa-replica-manage-del")
        del_master(realm, args[1], options)
    elif args[0] == "re-initialize":
        re_initialize(realm, options)
    elif args[0] == "force-sync":
        if not options.fromhost:
            sys.exit("force-sync requires the option --from <host name>")
        force_sync(realm, host, options.fromhost, options.dirman_passwd)
    elif args[0] == "connect":
        if has_managed_topology(api):
            exit_on_managed_topology("Creation of IPA CS replication agreement")
        if len(args) == 3:
            replica1 = args[1]
            replica2 = args[2]
        elif len(args) == 2:
            replica1 = host
            replica2 = args[1]
        add_link(realm, replica1, replica2, dirman_passwd, options)
    elif args[0] == "disconnect":
        if has_managed_topology(api):
            exit_on_managed_topology("Removal of IPA CS replication agreement")
        if len(args) == 3:
            replica1 = args[1]
            replica2 = args[2]
        elif len(args) == 2:
            replica1 = host
            replica2 = args[1]
        del_link(realm, replica1, replica2, dirman_passwd, options.force)
    elif args[0] == 'set-renewal-master':
        replica = None
        if len(args) > 1:
            replica = args[1]
        set_renewal_master(realm, replica)

    api.Backend.ldap2.disconnect()

try:
    main()
except KeyboardInterrupt:
    sys.exit(1)
except (SystemExit, ScriptError) as e:
    sys.exit(e)
except Exception as e:
    sys.exit("unexpected error: %s" % e)
