#! /usr/bin/python -E
# 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/>.
#
import sys
import os

import ldap, krbV
from ipapython.ipa_log_manager import *

from ipapython import ipautil
from ipaserver.install import replication, installutils
from ipaserver import ipaldap
from ipapython import version
from ipapython import dogtag
from ipalib import api, errors, util
from ipapython.dn import DN

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

# 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, "", "")
}

def convert_error(exc):
    """
    LDAP exceptions are a dictionary, make them prettier.
    """
    if isinstance(exc, ldap.LDAPError):
        desc = exc.args[0]['desc'].strip()
        info = exc.args[0].get('info', '').strip()
        return '%s %s' % (desc, info)
    else:
        return str(exc)


def get_cs_replication_manager(realm, host, dirman_passwd):
    """Get a CSReplicationManager for a remote host

    Detects if the host has a merged database, connects to appropriate port.
    """

    # Try merged database port first. If it has the ipaca tree, return
    # corresponding replication manager
    # If we can't connect to it at all, we're not dealing with an IPA master
    # anyway; let the exception propagate up
    # Fall back to the old PKI-only DS port. Check that it has the ipaca tree
    # (IPA with merged DB theoretically leaves port 7389 free for anyone).
    # If it doesn't, raise exception.
    ports = [
        dogtag.Dogtag10Constants.DS_PORT,
        dogtag.Dogtag9Constants.DS_PORT,
    ]
    for port in ports:
        root_logger.debug('Looking for PKI DS on %s:%s' % (host, port))
        replication_manager = CSReplicationManager(
            realm, host, dirman_passwd, port)
        if replication_manager.has_ipaca():
            root_logger.debug('PKI DS found on %s:%s' % (host, port))
            return replication_manager
        else:
            root_logger.debug('PKI tree not found on %s:%s' % (host, port))
    sys.exit('Cannot reach PKI DS at %s on ports %s' % (host, ports))


class CSReplicationManager(replication.ReplicationManager):
    """ReplicationManager specific to CA agreements

    Note that in most cases we don't know if we're connecting to an old-style
    separate PKI DS, or to a host with a merged DB.
    Use the get_cs_replication_manager function to determine this and return
    an appropriate CSReplicationManager.
    """

    def __init__(self, realm, hostname, dirman_passwd, port):
        super(CSReplicationManager, self).__init__(
            realm, hostname, dirman_passwd, port, starttls=True)
        self.suffix = DN(('o', 'ipaca'))
        self.hostnames = [] # set before calling or agreement_dn() will fail

    def agreement_dn(self, hostname, master=None):
        """
        Construct a dogtag replication agreement name. This needs to be much
        more agressive than the IPA replication agreements because the name
        is different on each side.

        hostname is the local hostname, not the remote one, for both sides

        NOTE: The agreement number is hardcoded in dogtag as well

        TODO: configurable instance name
        """
        dn = None
        cn = None
        instance_name = dogtag.configured_constants(api).PKI_INSTANCE_NAME

        # if master is not None we know what dn to return:
        if master is not None:
            if master is True:
                name = "master"
            else:
                name = "clone"
            cn="%sAgreement1-%s-%s" % (name, hostname, instance_name)
            dn = DN(('cn', cn), self.replica_dn())
            return (cn, dn)

        for host in self.hostnames:
            for master in ["master", "clone"]:
                try:
                    cn="%sAgreement1-%s-%s" % (master, host, instance_name)
                    dn = DN(('cn', cn), self.replica_dn())
                    self.conn.getEntry(dn, ldap.SCOPE_BASE)
                    return (cn, dn)
                except errors.NotFound:
                    dn = None
                    cn = None

        raise errors.NotFound(reason='No agreement found for %s' % hostname)

    def delete_referral(self, hostname, port):
        dn = DN(('cn', self.suffix), ('cn', 'mapping tree'), ('cn', 'config'))
        # TODO: should we detect proto somehow ?
        mod = [(ldap.MOD_DELETE, 'nsslapd-referral',
                'ldap://%s/%s' % (ipautil.format_netloc(hostname, port), self.suffix))]

        try:
            self.conn.modify_s(dn, mod)
        except Exception, e:
            root_logger.debug("Failed to remove referral value: %s" % convert_error(e))

    def has_ipaca(self):
        try:
            entry = self.conn.getEntry(self.suffix, ldap.SCOPE_BASE)
        except errors.NotFound:
            return False
        else:
            return True


def parse_options():
    from optparse import OptionParser

    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
        k = commands.keys()
        for cmd in k:
            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
        conn = ipaldap.IPAdmin(host, 636, cacert=CACERT)
        conn.do_simple_bind(bindpw=dirman_passwd)

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

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

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

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

    repl = get_cs_replication_manager(realm, replica, dirman_passwd)
    entries = repl.find_replication_agreements()

    for entry in entries:
        print '%s' % entry.single_value('nsds5replicahost', None)

        if verbose:
            print "  last init status: %s" % entry.single_value(
                'nsds5replicalastinitstatus', None)
            print "  last init ended: %s" % str(
                ipautil.parse_generalized_time(
                    entry.single_value('nsds5replicalastinitend')))
            print "  last update status: %s" % entry.single_value(
                'nsds5replicalastupdatestatus', None)
            print "  last update ended: %s" % str(
                ipautil.parse_generalized_time(
                    entry.single_value('nsds5replicalastupdateend')))

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

    repl2 = None

    try:
        repl1 = 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('nsDS5ReplicaHost', None) == 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 ldap.SERVER_DOWN, e:
        sys.exit("Unable to connect to %s: %s" % (replica1, convert_error(e)))
    except Exception, e:
        sys.exit("Failed to get data from '%s': %s" % (replica1, convert_error(e)))

    try:
        repl2 = 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 e in repl_list:
            if e.single_value('nsDS5ReplicaHost', None) == replica1:
                replica2_dn = e.dn
                break

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

    except ldap.NO_SUCH_OBJECT:
        print "'%s' has no replication agreement for '%s'" % (replica2, replica1)
        if not force:
            sys.exit(1)
    except errors.NotFound:
        print "'%s' has no replication agreement for '%s'" % (replica2, replica1)
        if not force:
            return
    except Exception, e:
        print "Failed to get data from '%s': %s" % (replica2, convert_error(e))
        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, e:
            print "Unable to remove agreement on %s: %s" % (replica2, convert_error(e))
            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):

    force_del = False

    delrepl = None

    # 1. Connect to the local dogtag DS server
    try:
        thisrepl = get_cs_replication_manager(realm, options.host,
                                              options.dirman_passwd)
    except Exception, e:
        sys.exit("Failed to connect to server %s: %s" % (options.host, convert_error(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 = get_cs_replication_manager(realm, hostname,
                                             options.dirman_passwd)
    except Exception, e:
        if not options.force:
            print "Unable to delete replica %s: %s" % (hostname, convert_error(e))
            sys.exit(1)
        else:
            print "Unable to connect to replica %s, forcing removal" % hostname
            force_del = True

    # 4. Get list of agreements.
    if delrepl is None:
        # server not up, just remove it from this server
        replica_names = [options.host]
    else:
        replica_names = delrepl.find_ipa_replication_agreements()

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

def add_link(realm, replica1, replica2, dirman_passwd, options):
    repl2 = get_cs_replication_manager(realm, replica2, dirman_passwd)
    try:
        conn = ipaldap.IPAdmin(replica2, 636, cacert=CACERT)
        conn.do_simple_bind(bindpw=dirman_passwd)

        dn = DN(('cn', 'CA'), ('cn', replica2), ('cn', 'masters'), ('cn', 'ipa'), ('cn', 'etc'),
                ipautil.realm_to_suffix(realm))
        conn.search_s(dn, ldap.SCOPE_ONELEVEL)
        conn.unbind_s()
    except ldap.NO_SUCH_OBJECT:
        sys.exit('%s does not have a CA configured.' % replica2)
    except ldap.SERVER_DOWN, e:
        sys.exit("Unable to connect to %s: %s" % (ipautil.format_netloc(replica2, 636), convert_error(e)))
    except Exception, e:
        sys.exit("Failed to get data while trying to bind to '%s': %s" % (replica1, convert_error(e)))

    try:
        repl1 = get_cs_replication_manager(realm, replica1, dirman_passwd)
        entries = repl1.find_replication_agreements()
        for e in entries:
            if e.single_value('nsDS5ReplicaHost', None) == replica2:
                sys.exit('This replication agreement already exists.')
        repl1.hostnames = [replica1, replica2]

    except ldap.NO_SUCH_OBJECT:
        sys.exit("Cannot find replica '%s'" % replica1)
    except ldap.SERVER_DOWN, e:
        sys.exit("Unable to connect to %s: %s" % (replica1, convert_error(e)))
    except Exception, e:
        sys.exit("Failed to get data from '%s' while trying to get current agreements: %s" % (replica1, convert_error(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>")

    repl = get_cs_replication_manager(realm, options.fromhost,
                                      options.dirman_passwd)

    thishost = installutils.get_fqdn()

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

    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):

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

def main():
    options, args = parse_options()

    # Just initialize the environment. This is so the installer can have
    # access to the plugin environment
    api_env = {'in_server' : True,
               'verbose'   : options.verbose,
              }

    if os.getegid() != 0:
        api_env['log'] = None # turn off logging for non-root

    api.bootstrap(**api_env)
    api.finalize()

    dirman_passwd = None
    realm = krbV.default_context().default_realm

    if options.host:
        host = options.host
    else:
        host = installutils.get_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("\nDirectory Manager password required")

    options.dirman_passwd = 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":
        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 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 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)

try:
    main()
except KeyboardInterrupt:
    sys.exit(1)
except SystemExit, e:
    sys.exit(e)
except ldap.INVALID_CREDENTIALS:
    sys.exit("Invalid password")
except ldap.INSUFFICIENT_ACCESS:
    sys.exit("Insufficient access")
except ldap.LOCAL_ERROR, e:
    sys.exit(convert_error(e))
except ldap.SERVER_DOWN, e:
    sys.exit("%s" % convert_error(e))
except Exception, e:
    sys.exit("unexpected error: %s" % convert_error(e))