This file is indexed.

/usr/share/pyshared/jabberbot/xmppbot.py is in python-moinmoin 1.9.3-1ubuntu2.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
# -*- coding: iso-8859-1 -*-
"""
    MoinMoin - jabber bot

    @copyright: 2007 by Karol Nowak <grywacz@gmail.com>
    @license: GNU GPL, see COPYING for details.
"""

import logging, time, Queue
from threading import Thread
from datetime import timedelta

from pyxmpp.cache import Cache
from pyxmpp.cache import CacheItem
from pyxmpp.client import Client
from pyxmpp.jid import JID
from pyxmpp.streamtls import TLSSettings
from pyxmpp.message import Message
from pyxmpp.presence import Presence
from pyxmpp.iq import Iq
import pyxmpp.jabber.dataforms as forms
import libxml2

import jabberbot.commands as cmd
import jabberbot.i18n as i18n
import jabberbot.oob as oob
import jabberbot.capat as capat


class Contact:
    """Abstraction of a roster item / contact

    This class handles some logic related to keeping track of
    contact availability, status, etc."""

    # Default Time To Live of a contact. If there are no registered
    # resources for that period of time, the contact should be removed
    default_ttl = 3600 * 24 # default of one day

    def __init__(self, jid, resource, priority, show, language=None):
        self.jid = jid
        self.resources = {resource: {'show': show, 'priority': priority, 'supports': []}}
        self.language = language

        # The last time when this contact was seen online.
        # This value has meaning for offline contacts only.
        self.last_online = None

        # Queued messages, waiting for contact to change its "show"
        # status to something different than "dnd". The messages should
        # also be sent when contact becomes "unavailable" directly from
        # "dnd", as we can't guarantee, that the bot will be up and running
        # the next time she becomes "available".
        self.messages = []

    def is_valid(self, current_time):
        """Check if this contact entry is still valid and should be kept

        @param time: current time in seconds

        """
        # No resources == offline
        return self.resources or current_time < self.last_online + self.default_ttl

    def add_resource(self, resource, show, priority):
        """Adds information about a connected resource

        @param resource: resource name
        @param show: a show presence property, as defined in XMPP
        @param priority: priority of the given resource

        """
        self.resources[resource] = {'show': show, 'priority': priority, 'supports': []}
        self.last_online = None

    def set_supports(self, resource, extension):
        """Flag a given resource as supporting a particular extension"""
        self.resources[resource]['supports'].append(extension)

    def supports(self, resource, extension):
        """Check if a given resource supports a particular extension

        If no resource is specified, check the resource with the highest
        priority among currently connected.

        """
        if resource and resource in self.resources:
            return extension in self.resources[resource]['supports']
        else:
            resource = self.max_prio_resource()
            return resource and extension in resource['supports']

    def max_prio_resource(self):
        """Returns the resource (dict) with the highest priority

        @return: highest priority resource or None if contacts is offline
        @rtype: dict or None

        """
        if not self.resources:
            return None

        # Priority can't be lower than -128
        max_prio = -129
        selected = None

        for resource in self.resources.itervalues():
            # TODO: check RFC for behaviour of 2 resources with the same priority
            if resource['priority'] > max_prio:
                max_prio = resource['priority']
                selected = resource

        return selected

    def remove_resource(self, resource):
        """Removes information about a connected resource

        @param resource: resource name

        """
        if self.resources.has_key(resource):
            del self.resources[resource]
        else:
            raise ValueError("No such resource!")

        if not self.resources:
            self.last_online = time.time()

    def is_dnd(self):
        """Checks if contact is DoNotDisturb

        The contact is DND if its resource with the highest priority is DND

        """
        max_prio_res = self.max_prio_resource()

        # If there are no resources the contact is offline, not dnd
        if max_prio_res:
            return max_prio_res['show'] == u"dnd"
        else:
            return False

    def set_show(self, resource, show):
        """Sets show property for a given resource

        @param resource: resource to alter
        @param show: new value of the show property
        @raise ValueError: no resource with given name has been found

        """
        if self.resources.has_key(resource):
            self.resources[resource]['show'] = show
        else:
            raise ValueError("There's no such resource")

    def uses_resource(self, resource):
        """Checks if contact uses a given resource"""
        return self.resources.has_key(resource)

    def __str__(self):
        retval = "%s (%s) has %d queued messages"
        res = ", ".join([name + " is " + res['show'] for name, res in self.resources.items()])
        return retval % (self.jid.as_unicode(), res, len(self.messages))


class XMPPBot(Client, Thread):
    """A simple XMPP bot"""

    def __init__(self, config, from_commands, to_commands):
        """A constructor

        @param from_commands: a Queue object used to send commands to other (xmlrpc) threads
        @param to_commands: a Queue object used to receive commands from other threads

        """
        Thread.__init__(self)

        self.from_commands = from_commands
        self.to_commands = to_commands

        self.config = config
        self.log = logging.getLogger(__name__)
        self.jid = JID(node_or_jid=config.xmpp_node, domain=config.xmpp_server)
        self.tlsconfig = TLSSettings(require = True, verify_peer=False)

        # A dictionary of contact objects, ordered by bare JID
        self.contacts = {}

        # The last time when contacts were checked for expiration, in seconds
        self.last_expiration = time.time()

        # How often should the contacts be checked for expiration, in seconds
        self.contact_check = 600
        self.stopping = False

        self.known_xmlrpc_cmds = [cmd.GetPage, cmd.GetPageHTML, cmd.GetPageList, cmd.GetPageInfo, cmd.Search, cmd.RevertPage]
        self.internal_commands = ["ping", "help", "searchform"]

        self.xmlrpc_commands = {}
        for command, name in [(command, command.__name__) for command in self.known_xmlrpc_cmds]:
            self.xmlrpc_commands[name.lower()] = command

        Client.__init__(self, self.jid, config.xmpp_password, config.xmpp_server, tls_settings=self.tlsconfig)

        # Setup message handlers

        self._msg_handlers = {cmd.NotificationCommand: self._handle_notification,
                              cmd.NotificationCommandI18n: self._handle_notification,
                              cmd.AddJIDToRosterCommand: self._handle_add_contact,
                              cmd.RemoveJIDFromRosterCommand: self._handle_remove_contact,
                              cmd.GetPage: self._handle_get_page,
                              cmd.GetPageHTML: self._handle_get_page,
                              cmd.GetPageList: self._handle_get_page_list,
                              cmd.GetPageInfo: self._handle_get_page_info,
                              cmd.GetUserLanguage: self._handle_get_language,
                              cmd.Search: self._handle_search}

        # cache for service discovery results ( (ver, algo) : Capabilities = libxml2.xmlNode)
        self.disco_cache = Cache(max_items=config.disco_cache_size, default_purge_period=0)

        # dictionary of jids waiting for service discovery results
        # ( (ver, algo) : (timeout=datetime.timedelta, [list_of_jids=pyxmpp.jid]) )
        self.disco_wait = {}

        # temporary dictionary ( pyxmpp.jid:  (ver, algo) )
        self.disco_temp = {}

    def run(self):
        """Start the bot - enter the event loop"""

        self.log.info("Starting the jabber bot.")
        self.connect()
        self.loop()

    def stop(self):
        """Stop the thread"""
        self.stopping = True

    def loop(self, timeout=1):
        """Main event loop - stream and command handling"""

        while True:
            if self.stopping:
                break

            stream = self.get_stream()
            if not stream:
                break

            act = stream.loop_iter(timeout)
            if not act:
                # Process all available commands
                while self.poll_commands(): pass
                self.idle()

    def idle(self):
        """Do some maintenance"""

        Client.idle(self)

        current_time = time.time()
        if self.last_expiration + self.contact_check < current_time:
            self.expire_contacts(current_time)
            self.last_expiration = current_time

        self.disco_cache.tick()
        self.check_disco_delays()

    def session_started(self):
        """Handle session started event.
        Requests the user's roster and sends the initial presence with
        a <c> child as described in XEP-0115 (Entity Capabilities)

        """
        self.request_roster()
        pres = capat.create_presence(self.jid)
        self.stream.set_iq_get_handler("query", "http://jabber.org/protocol/disco#info", self.handle_disco_query)
        self.stream.send(pres)

    def expire_contacts(self, current_time):
        """Check which contats have been offline for too long and should be removed

        @param current_time: current time in seconds

        """
        for jid, contact in self.contacts.items():
            if not contact.is_valid(current_time):
                del self.contacts[jid]

    def get_text(self, jid):
        """Returns a gettext function (_) for the given JID

        @param jid: bare Jabber ID of the user we're going to communicate with
        @type jid: str or pyxmpp.jid.JID

        """
        language = "en"
        if isinstance(jid, str) or isinstance(jid, unicode):
            jid = JID(jid).bare().as_unicode()
        else:
            jid = jid.bare().as_unicode()

        if jid in self.contacts:
            language = self.contacts[jid].language

        return lambda text: i18n.get_text(text, lang=language)

    def poll_commands(self):
        """Checks for new commands in the input queue and executes them

        @return: True if any command has been executed, False otherwise.

        """
        try:
            command = self.to_commands.get_nowait()
            self.handle_command(command)
            return True
        except Queue.Empty:
            return False

    def handle_command(self, command, ignore_dnd=False):
        """Excecutes commands from other components

        @param command: a command to execute
        @type command: any class defined in commands.py (FIXME?)
        @param ignore_dnd: if command results in user interaction, should DnD be ignored?

        """

        cmd_cls = command.__class__

        try:
            handler = self._msg_handlers[cmd_cls]
        except KeyError:
            self.log.debug("No such command: " + cmd_cls.__name__)
            return

        # NOTE: handler is a method, so it takes self as a hidden arg
        handler(command, ignore_dnd)

    def handle_changed_action(self, cmd_data, jid, contact):
        """Handles a notification command with 'page_changed' action

        @param cmd_data: notification command data
        @param jid: jid to send the notification to
        @param contact: a roster contact
        @type cmd_data: dict
        @type jid: pyxmpp.jid.JID
        @type contact: Contact

        """
        if contact and contact.supports(jid.resource, u"jabber:x:data"):
            self.send_change_form(jid.as_unicode(), cmd_data)
            return
        else:
            self.send_change_text(jid.as_unicode(), cmd_data)

    def handle_deleted_action(self, cmd_data, jid, contact):
        """Handles a notification cmd_data with 'page_deleted' action

        @param cmd_data: notification cmd_data
        @param jid: jid to send the notification to
        @param contact: a roster contact
        @type cmd_data: dict
        @type jid: pyxmpp.jid.JID
        @type contact: Contact

        """
        if contact and contact.supports(jid.resource, u"jabber:x:data"):
            self.send_deleted_form(jid.as_unicode(), cmd_data)
            return
        else:
            self.send_deleted_text(jid.as_unicode(), cmd_data)

    def handle_attached_action(self, cmd_data, jid, contact):
        """Handles a notification cmd_data with 'file_attached' action

        @param cmd_data: notification cmd_data
        @param jid: jid to send the notification to
        @param contact: a roster contact
        @type cmd_data: dict
        @type jid: pyxmpp.jid.JID
        @type contact: Contact

        """
        if contact and contact.supports(jid.resource, u"jabber:x:data"):
            self.send_attached_form(jid.as_unicode(), cmd_data)
            return
        else:
            self.send_attached_text(jid.as_unicode(), cmd_data)

    def handle_renamed_action(self, cmd_data, jid, contact):
        """Handles a notification cmd_data with 'page_renamed' action

        @param cmd_data: notification cmd_data
        @param jid: jid to send the notification to
        @param contact: a roster contact
        @type cmd_data: dict
        @type jid: pyxmpp.jid.JID
        @type contact: Contact

        """
        if contact and contact.supports(jid.resource, u"jabber:x:data"):
            self.send_renamed_form(jid.as_unicode(), cmd_data)
            return
        else:
            self.send_renamed_text(jid.as_unicode(), cmd_data)

    def handle_user_created_action(self, cmd_data, jid, contact):
        """Handles a notification cmd_data with 'user_created' action

        @param cmd_data: notification cmd_data
        @param jid: jid to send the notification to
        @param contact: a roster contact
        @type cmd_data: dict
        @type jid: pyxmpp.jid.JID
        @type contact: Contact

        """
        # TODO: send as form if user-client supports it
        self.send_user_created_text(jid.as_unicode(), cmd_data)

    def ask_for_subscription(self, jid):
        """Sends a <presence/> stanza with type="subscribe"

        Bot tries to subscribe to every contact's presence, so that
        it can honor special cases, like DoNotDisturb setting.

        @param jid: Jabber ID of entity we're subscribing to
        @type jid: pyxmpp.jid.JID

        """
        stanza = Presence(to_jid=jid, stanza_type="subscribe")
        self.get_stream().send(stanza)

    def remove_subscription(self, jid):
        """Sends a <presence/> stanza with type="unsubscribed

        @param jid: Jabber ID of entity whose subscription we cancel
        @type jid: JID

        """
        stanza = Presence(to_jid=jid, stanza_type="unsubscribed")
        self.get_stream().send(stanza)

    def send_message(self, jid_text, data, msg_type=u"chat"):
        """Sends a message

        @param jid_text: JID to send the message to
        @param data: dictionary containing notification data
        @param msg_type: message type, as defined in RFC
        @type jid_text: unicode

        """
        use_oob = False
        subject = data.get('subject', '')
        jid = JID(jid_text)

        if data.has_key('url_list') and data['url_list']:
            jid_bare = jid.bare().as_unicode()
            contact = self.contacts.get(jid_bare, None)
            if contact and contact.supports(jid.resource, u'jabber:x:oob'):
                use_oob = True
            else:
                url_strings = ['%s - %s' % (entry['url'], entry['description']) for entry in data['url_list']]

                # Insert a newline, so that the list of URLs doesn't start in the same
                # line as the rest of message text
                url_strings.insert(0, '\n')
                data['text'] = data['text'] + '\n'.join(url_strings)

        message = Message(to_jid=jid, body=data['text'], stanza_type=msg_type, subject=subject)

        if use_oob:
            oob.add_urls(message, data['url_list'])

        self.get_stream().send(message)

    def send_form(self, jid, form, subject, url_list=[]):
        """Send a data form

        @param jid: jid to send the form to (full)
        @param form: the form to send
        @param subject: subject of the message
        @param url_list: list of urls to use with OOB
        @type jid: unicode
        @type form: pyxmpp.jabber.dataforms.Form
        @type subject: unicode
        @type url_list: list

        """
        if not isinstance(form, forms.Form):
            raise ValueError("The 'form' argument must be of type pyxmpp.jabber.dataforms.Form!")

        _ = self.get_text(JID(jid).bare().as_unicode())

        message = Message(to_jid=jid, subject=subject)
        message.add_content(form)

        if url_list:
            oob.add_urls(message, url_list)

        self.get_stream().send(message)

    def send_search_form(self, jid):
        _ = self.get_text(jid)

        # These encode()s may look weird, but due to some pyxmpp oddness we have
        # to provide an utf-8 string instead of unicode. Bug reported, patches submitted...
        form_title = _("Wiki search").encode("utf-8")
        help_form = _("Submit this form to perform a wiki search").encode("utf-8")
        search_type1 = _("Title search")
        search_type2 = _("Full-text search")
        search_label = _("Search type")
        search_label2 = _("Search text")
        case_label = _("Case-sensitive search")
        regexp_label = _("Treat terms as regular expressions")
        forms_warn = _("If you see this, your client probably doesn't support Data Forms.")

        title_search = forms.Option("t", search_type1)
        full_search = forms.Option("f", search_type2)

        form = forms.Form(xmlnode_or_type="form", title=form_title, instructions=help_form)
        form.add_field(name="action", field_type="hidden", value="search")
        form.add_field(name="case", field_type="boolean", label=case_label)
        form.add_field(name="regexp", field_type="boolean", label=regexp_label)
        form.add_field(name="search_type", options=[title_search, full_search], field_type="list-single", label=search_label)
        form.add_field(name="search", field_type="text-single", label=search_label2)

        self.send_form(jid, form, _("Wiki search"))

    def send_change_form(self, jid, msg_data):
        """Sends a page change notification using Data Forms

        @param jid: a Jabber ID to send the notification to
        @type jid: unicode
        @param msg_data: dictionary with notification data
        @type msg_data: dict

        """
        _ = self.get_text(jid)

        form_title = _("Page changed notification").encode("utf-8")
        instructions = _("Submit this form with a specified action to continue.").encode("utf-8")
        action_label = _("What to do next")

        action1 = _("Do nothing")
        action2 = _("Revert change")
        action3 = _("View page info")
        action4 = _("Perform a search")

        do_nothing = forms.Option("n", action1)
        revert = forms.Option("r", action2)
        view_info = forms.Option("v", action3)
        search = forms.Option("s", action4)

        form = forms.Form(xmlnode_or_type="form", title=form_title, instructions=instructions)
        form.add_field(name='revision', field_type='hidden', value=msg_data['revision'])
        form.add_field(name='page_name', field_type='hidden', value=msg_data['page_name'])
        form.add_field(name='editor', field_type='text-single', value=msg_data['editor'], label=_("Editor"))
        form.add_field(name='comment', field_type='text-single', value=msg_data.get('comment', ''), label=_("Comment"))

        # Add lines of text as separate values, as recommended in XEP
        diff_lines = msg_data['diff'].split('\n')
        form.add_field(name="diff", field_type="text-multi", values=diff_lines, label=("Diff"))

        full_jid = JID(jid)
        bare_jid = full_jid.bare().as_unicode()
        resource = full_jid.resource

        # Add URLs as OOB data if it's supported and as separate fields otherwise
        if bare_jid in self.contacts and self.contacts[bare_jid].supports(resource, u'jabber:x:oob'):
            url_list = msg_data['url_list']
        else:
            url_list = []

            for number, url in enumerate(msg_data['url_list']):
                field_name = "url%d" % (number, )
                form.add_field(name=field_name, field_type="text-single", value=url["url"], label=url["description"])

        # Selection of a following action
        form.add_field(name="options", field_type="list-single", options=[do_nothing, revert, view_info, search], label=action_label)

        self.send_form(jid, form, _("Page change notification"), url_list)

    def send_change_text(self, jid, msg_data):
        """Sends a simple, text page change notification

        @param jid: a Jabber ID to send the notification to
        @type jid: unicode
        @param msg_data: dictionary with notification data
        @type msg_data: dict

        """
        _ = self.get_text(jid)
        separator = '-' * 78
        urls_text = '\n'.join(["%s - %s" % (url["description"], url["url"]) for url in msg_data['url_list']])
        message = _("%(preamble)s\nComment: %(comment)s\n%(separator)s\n%(diff)s\n%(separator)s\n%(links)s") % {
                    'preamble': msg_data['text'],
                    'separator': separator,
                    'diff': msg_data['diff'],
                    'comment': msg_data.get('comment', _('no comment')),
                    'links': urls_text,
                  }

        data = {'text': message, 'subject': msg_data.get('subject', '')}
        self.send_message(jid, data, u"normal")

    def send_deleted_form(self, jid, msg_data):
        """Sends a page deleted notification using Data Forms

        @param jid: a Jabber ID to send the notification to
        @type jid: unicode
        @param msg_data: dictionary with notification data
        @type msg_data: dict

        """
        _ = self.get_text(jid)

        form_title = _("Page deletion notification").encode("utf-8")
        instructions = _("Submit this form with a specified action to continue.").encode("utf-8")
        action_label = _("What to do next")

        action1 = _("Do nothing")
        action2 = _("Perform a search")

        do_nothing = forms.Option("n", action1)
        search = forms.Option("s", action2)

        form = forms.Form(xmlnode_or_type="form", title=form_title, instructions=instructions)
        form.add_field(name='editor', field_type='text-single', value=msg_data['editor'], label=_("Editor"))
        form.add_field(name='comment', field_type='text-single', value=msg_data.get('comment', ''), label=_("Comment"))

        full_jid = JID(jid)
        bare_jid = full_jid.bare().as_unicode()
        resource = full_jid.resource

        # Add URLs as OOB data if it's supported and as separate fields otherwise
        if bare_jid in self.contacts and self.contacts[bare_jid].supports(resource, u'jabber:x:oob'):
            url_list = msg_data['url_list']
        else:
            url_list = []

            for number, url in enumerate(msg_data['url_list']):
                field_name = "url%d" % (number, )
                form.add_field(name=field_name, field_type="text-single", value=url["url"], label=url["description"])

        # Selection of a following action
        form.add_field(name="options", field_type="list-single", options=[do_nothing, search], label=action_label)

        self.send_form(jid, form, _("Page deletion notification"), url_list)

    def send_deleted_text(self, jid, msg_data):
        """Sends a simple, text page deletion notification

        @param jid: a Jabber ID to send the notification to
        @type jid: unicode
        @param msg_data: dictionary with notification data
        @type msg_data: dict

        """
        _ = self.get_text(jid)
        separator = '-' * 78
        urls_text = '\n'.join(["%s - %s" % (url["description"], url["url"]) for url in msg_data['url_list']])
        message = _("%(preamble)s\nComment: %(comment)s\n%(separator)s\n%(links)s") % {
                    'preamble': msg_data['text'],
                    'separator': separator,
                    'comment': msg_data.get('comment', _('no comment')),
                    'links': urls_text,
                  }

        data = {'text': message, 'subject': msg_data.get('subject', '')}
        self.send_message(jid, data, u"normal")

    def send_attached_form(self, jid, msg_data):
        """Sends a new attachment notification using Data Forms

        @param jid: a Jabber ID to send the notification to
        @type jid: unicode
        @param msg_data: dictionary with notification data
        @type msg_data: dict

        """
        _ = self.get_text(jid)

        form_title = _("File attached notification").encode("utf-8")
        instructions = _("Submit this form with a specified action to continue.").encode("utf-8")
        action_label = _("What to do next")

        action1 = _("Do nothing")
        action2 = _("View page info")
        action3 = _("Perform a search")

        do_nothing = forms.Option("n", action1)
        view_info = forms.Option("v", action2)
        search = forms.Option("s", action3)

        form = forms.Form(xmlnode_or_type="form", title=form_title, instructions=instructions)
        form.add_field(name='page_name', field_type='hidden', value=msg_data['page_name'])
        form.add_field(name='editor', field_type='text-single', value=msg_data['editor'], label=_("Editor"))
        form.add_field(name='page', field_type='text-single', value=msg_data['page_name'], label=_("Page name"))
        form.add_field(name='name', field_type='text-single', value=msg_data['attach_name'], label=_("File name"))
        form.add_field(name='size', field_type='text-single', value=msg_data['attach_size'], label=_("File size"))

        full_jid = JID(jid)
        bare_jid = full_jid.bare().as_unicode()
        resource = full_jid.resource

        # Add URLs as OOB data if it's supported and as separate fields otherwise
        if bare_jid in self.contacts and self.contacts[bare_jid].supports(resource, u'jabber:x:oob'):
            url_list = msg_data['url_list']
        else:
            url_list = []

            for number, url in enumerate(msg_data['url_list']):
                field_name = "url%d" % (number, )
                form.add_field(name=field_name, field_type="text-single", value=url["url"], label=url["description"])

        # Selection of a following action
        form.add_field(name="options", field_type="list-single", options=[do_nothing, view_info, search], label=action_label)

        self.send_form(jid, form, _("File attached notification"), url_list)

    def send_attached_text(self, jid, msg_data):
        """Sends a simple, text page deletion notification

        @param jid: a Jabber ID to send the notification to
        @type jid: unicode
        @param msg_data: dictionary with notification data
        @type msg_data: dict

        """
        _ = self.get_text(jid)
        separator = '-' * 78
        urls_text = '\n'.join(["%s - %s" % (url["description"], url["url"]) for url in msg_data['url_list']])
        message = _("%(preamble)s\n%(separator)s\n%(links)s") % {
                    'preamble': msg_data['text'],
                    'separator': separator,
                    'links': urls_text,
                  }

        data = {'text': message, 'subject': msg_data['subject']}
        self.send_message(jid, data, u"normal")

    def send_renamed_form(self, jid, msg_data):
        """Sends a page rename notification using Data Forms

        @param jid: a Jabber ID to send the notification to
        @type jid: unicode
        @param msg_data: dictionary with notification data
        @type msg_data: dict

        """
        _ = self.get_text(jid)

        form_title = _("Page rename notification").encode("utf-8")
        instructions = _("Submit this form with a specified action to continue.").encode("utf-8")
        action_label = _("What to do next")

        action1 = _("Do nothing")
        action2 = _("Revert change")
        action3 = _("View page info")
        action4 = _("Perform a search")

        do_nothing = forms.Option("n", action1)
        revert = forms.Option("r", action2)
        view_info = forms.Option("v", action3)
        search = forms.Option("s", action4)

        form = forms.Form(xmlnode_or_type="form", title=form_title, instructions=instructions)
        form.add_field(name='revision', field_type='hidden', value=msg_data['revision'])
        form.add_field(name='page_name', field_type='hidden', value=msg_data['page_name'])
        form.add_field(name='editor', field_type='text-single', value=msg_data['editor'], label=_("Editor"))
        form.add_field(name='comment', field_type='text-single', value=msg_data.get('comment', ''), label=_("Comment"))
        form.add_field(name='old', field_type='text-single', value=msg_data['old_name'], label=_("Old name"))
        form.add_field(name='new', field_type='text-single', value=msg_data['page_name'], label=_("New name"))

        full_jid = JID(jid)
        bare_jid = full_jid.bare().as_unicode()
        resource = full_jid.resource

        # Add URLs as OOB data if it's supported and as separate fields otherwise
        if bare_jid in self.contacts and self.contacts[bare_jid].supports(resource, u'jabber:x:oob'):
            url_list = msg_data['url_list']
        else:
            url_list = []

            for number, url in enumerate(msg_data['url_list']):
                field_name = "url%d" % (number, )
                form.add_field(name=field_name, field_type="text-single", value=url["url"], label=url["description"])

        # Selection of a following action
        form.add_field(name="options", field_type="list-single", options=[do_nothing, revert, view_info, search], label=action_label)

        self.send_form(jid, form, _("Page rename notification"), url_list)

    def send_renamed_text(self, jid, msg_data):
        """Sends a simple, text page rename notification

        @param jid: a Jabber ID to send the notification to
        @type jid: unicode
        @param msg_data: dictionary with notification data
        @type msg_data: dict

        """
        _ = self.get_text(jid)
        separator = '-' * 78
        urls_text = '\n'.join(["%s - %s" % (url["description"], url["url"]) for url in msg_data['url_list']])
        message = _("%(preamble)s\nComment: %(comment)s\n%(separator)s\n%(links)s") % {
                    'preamble': msg_data['text'],
                    'separator': separator,
                    'comment': msg_data.get('comment', _('no comment')),
                    'links': urls_text,
                  }

        data = {'text': message, 'subject': msg_data['subject']}
        self.send_message(jid, data, u"normal")

    def send_user_created_text(self, jid, msg_data):
        """Sends a simple, text page user-created-notification

        @param jid: a Jabber ID to send the notification to
        @type jid: unicode
        @param msg_data: dictionary with notification data
        @type msg_data: dict

        """
        _ = self.get_text(jid)
        message = _("%(text)s") % {'text': msg_data['text']}

        data = {'text': message, 'subject': msg_data['subject']}
        self.send_message(jid, data, u"normal")

    def handle_page_info(self, command):
        """Handles GetPageInfo commands

        @param command: a command instance
        @type command: jabberbot.commands.GetPageInfo

        """
        # Process command data first so it can be directly usable
        if command.data['author'].startswith("Self:"):
            command.data['author'] = command.data['author'][5:]

        datestr = str(command.data['lastModified'])
        command.data['lastModified'] = u"%(year)s-%(month)s-%(day)s at %(time)s" % {
                    'year': datestr[:4],
                    'month': datestr[4:6],
                    'day': datestr[6:8],
                    'time': datestr[9:17],
        }

        if command.presentation == u"text":
            self.send_pageinfo_text(command)
        elif command.presentation == u"dataforms":
            self.send_pageinfo_form(command)

        else:
            raise ValueError("presentation value '%s' is not supported!" % (command.presentation, ))

    def send_pageinfo_text(self, command):
        """Sends detailed page info with plain text

        @param command: command with detailed data
        @type command: jabberbot.command.GetPageInfo

        """
        _ = self.get_text(command.jid)

        intro = _("""Following detailed information on page "%(pagename)s" \
is available:""")

        msg = _("""Last author: %(author)s
Last modification: %(modification)s
Current version: %(version)s""") % {
         'author': command.data['author'],
         'modification': command.data['lastModified'],
         'version': command.data['version'],
        }

        self.send_message(command.jid, {'text': intro % {'pagename': command.pagename}})
        self.send_message(command.jid, {'text': msg})

    def send_pageinfo_form(self, command):
        """Sends page info using Data Forms


        """
        _ = self.get_text(command.jid)
        data = command.data

        form_title = _("Detailed page information").encode("utf-8")
        instructions = _("Submit this form with a specified action to continue.").encode("utf-8")
        action_label = _("What to do next")

        action1 = _("Do nothing")
        action2 = _("Get page contents")
        action3 = _("Get page contents (HTML)")
        action4 = _("Perform a search")

        do_nothing = forms.Option("n", action1)
        get_content = forms.Option("c", action2)
        get_content_html = forms.Option("h", action3)
        search = forms.Option("s", action4)

        form = forms.Form(xmlnode_or_type="form", title=form_title, instructions=instructions)
        form.add_field(name='pagename', field_type='text-single', value=command.pagename, label=_("Page name"))
        form.add_field(name="changed", field_type='text-single', value=data['lastModified'], label=_("Last changed"))
        form.add_field(name='editor', field_type='text-single', value=data['author'], label=_("Last editor"))
        form.add_field(name='version', field_type='text-single', value=data['version'], label=_("Current version"))

#        full_jid = JID(jid)
#        bare_jid = full_jid.bare().as_unicode()
#        resource = full_jid.resource

        # Add URLs as OOB data if it's supported and as separate fields otherwise
#        if bare_jid in self.contacts and self.contacts[bare_jid].supports(resource, u'jabber:x:oob'):
#            url_list = msg_data['url_list']
#        else:
#            url_list = []
#
#            for number, url in enumerate(msg_data['url_list']):
#                field_name = "url%d" % (number, )
#                form.add_field(name=field_name, field_type="text-single", value=url["url"], label=url["description"])

        # Selection of a following action
        form.add_field(name="options", field_type="list-single", options=[do_nothing, get_content, get_content_html, search], label=action_label)

        self.send_form(command.jid, form, _("Detailed page information"))

    def is_internal(self, command):
        """Check if a given command is internal

        @type command: unicode

        """
        for internal_cmd in self.internal_commands:
            if internal_cmd.lower() == command:
                return True

        return False

    def is_xmlrpc(self, command):
        """Checks if a given commands requires interaction via XMLRPC

        @type command: unicode

        """
        for xmlrpc_cmd in self.xmlrpc_commands:
            if xmlrpc_cmd.lower() == command:
                return True

        return False

    def contains_form(self, message):
        """Checks if passed message stanza contains a submitted form and parses it

        @param message: message stanza
        @type message: pyxmpp.message.Message
        @return: xml node with form data if found, or None

        """
        if not isinstance(message, Message):
            raise ValueError("The 'message' parameter must be of type pyxmpp.message.Message!")

        payload = message.get_node()
        form = message.xpath_eval('/ns:message/data:x', {'data': 'jabber:x:data'})

        if form:
            return form[0]
        else:
            return None

    def handle_form(self, jid, form_node):
        """Handles a submitted data form

        @param jid: jid that submitted the form (full jid)
        @type jid: pyxmpp.jid.JID
        @param form_node: a xml node with data form
        @type form_node: libxml2.xmlNode

        """
        if not isinstance(form_node, libxml2.xmlNode):
            raise ValueError("The 'form' parameter must be of type libxml2.xmlNode!")

        if not isinstance(jid, JID):
            raise ValueError("The 'jid' parameter must be of type jid!")

        _ = self.get_text(jid.bare().as_unicode())

        form = forms.Form(form_node)

        if form.type != u"submit":
            return

        if "action" in form:
            action = form["action"].value
            if action == u"search":
                self.handle_search_form(jid, form)
            else:
                data = {'text': _('The form you submitted was invalid!'), 'subject': _('Invalid data')}
                self.send_message(jid.as_unicode(), data, u"normal")
        elif "options" in form:
            option = form["options"].value

            # View page info
            if option == "v":
                command = cmd.GetPageInfo(jid.as_unicode(), form["page_name"].value, presentation="dataforms")
                self.from_commands.put_nowait(command)

            # Perform an another search
            elif option == "s":
                self.handle_internal_command(jid, ["searchform"])

            # Revert a change
            elif option == "r":
                revision = int(form["revision"].value)

                # We can't really revert creation of a page, right?
                if revision == 1:
                    return

                self.handle_xmlrpc_command(jid, ["revertpage", form["page_name"].value, "%d" % (revision - 1, )])

    def handle_search_form(self, jid, form):
        """Handles a search form

        @param jid: jid that submitted the form
        @type jid: pyxmpp.jid.JID
        @param form: a form object
        @type form_node: pyxmpp.jabber.dataforms.Form

        """
        required_fields = ["case", "regexp", "search_type", "search"]
        jid_text = jid.bare().as_unicode()
        _ = self.get_text(jid_text)

        for field in required_fields:
            if field not in form:
                data = {'text': _('The form you submitted was invalid!'), 'subject': _('Invalid data')}
                self.send_message(jid.as_unicode(), data, u"normal")

        case_sensitive = form['case'].value
        regexp_terms = form['regexp'].value
        if form['search_type'].value == 't':
            search_type = 'title'
        else:
            search_type = 'text'

        command = cmd.Search(jid.as_unicode(), search_type, form["search"].value, case=form['case'].value,
                             regexp=form['regexp'].value, presentation='dataforms')
        self.from_commands.put_nowait(command)

    def handle_message(self, message):
        """Handles incoming messages

        @param message: a message stanza to parse
        @type message: pyxmpp.message.Message

        """
        if self.config.verbose:
            msg = "Message from %s." % (message.get_from_jid().as_unicode(), )
            self.log.debug(msg)

        form = self.contains_form(message)
        if form:
            self.handle_form(message.get_from_jid(), form)
            return

        text = message.get_body()
        sender = message.get_from_jid()
        if text:
            command = text.split()
            command[0] = command[0].lower()
        else:
            return

        if self.is_internal(command[0]):
            response = self.handle_internal_command(sender, command)
        elif self.is_xmlrpc(command[0]):
            response = self.handle_xmlrpc_command(sender, command)
        else:
            response = self.reply_help(sender)

        if response:
            self.send_message(sender, {'text': response})

    def handle_internal_command(self, sender, command):
        """Handles internal commands, that can be completed by the XMPP bot itself

        @param command: list representing a command
        @param sender: JID of sender
        @type sender: pyxmpp.jid.JID

        """
        _ = self.get_text(sender)

        if command[0] == "ping":
            return "pong"
        elif command[0] == "help":
            if len(command) == 1:
                return self.reply_help(sender)
            else:
                return self.help_on(sender, command[1])
        elif command[0] == "searchform":
            jid = sender.bare().as_unicode()
            resource = sender.resource

            # Assume that outsiders know what they are doing. Clients that don't support
            # data forms should display a warning passed in message <body>.
            if jid not in self.contacts or self.contacts[jid].supports(resource, u"jabber:x:data"):
                self.send_search_form(sender)
            else:
                msg = {'text': _("This command requires a client supporting Data Forms.")}
                self.send_message(sender, msg, u"")
        else:
            # For unknown command return a generic help message
            return self.reply_help(sender)

    def do_search(self, jid, search_type, presentation, *args):
        """Performs a Wiki search of term

        @param jid: Jabber ID of user performing a search
        @type jid: pyxmpp.jid.JID
        @param term: term to search for
        @type term: unicode
        @param search_type: type of search; either "text" or "title"
        @type search_type: unicode
        @param presentation: how to present the results; "text" or "dataforms"
        @type presentation: unicode

        """
        search = cmd.Search(jid, search_type, presentation=presentation, *args)
        self.from_commands.put_nowait(search)

    def help_on(self, jid, command):
        """Returns a help message on a given topic

        @param command: a command to describe in a help message
        @type command: str or unicode
        @return: a help message

        """
        _ = self.get_text(jid)

        if command == "help":
            return _("""The "help" command prints a short, helpful message \
about a given topic or function.\n\nUsage: help [topic_or_function]""")

        elif command == "ping":
            return _("""The "ping" command returns a "pong" message as soon \
as it's received.""")

        elif command == "searchform":
            return _("""searchform - perform a wiki search using a form""")

        # Here we have to deal with help messages of external (xmlrpc) commands
        else:
            if command in self.xmlrpc_commands:
                classobj = self.xmlrpc_commands[command]
                help_str = _(u"%(command)s - %(description)s\n\nUsage: %(command)s %(params)s")
                return help_str % {'command': command,
                                   'description': classobj.description,
                                   'params': classobj.parameter_list,
                                  }
            else:
                return _("""Unknown command "%s" """) % (command, )

    def handle_xmlrpc_command(self, sender, command):
        """Creates a command object, and puts it the command queue

        @param command: a valid name of available xmlrpc command
        @type command: list representing a command, name and parameters

        """
        _ = self.get_text(sender)
        command_class = self.xmlrpc_commands[command[0]]

        # Add sender's JID to the argument list
        command.insert(1, sender.as_unicode())

        try:
            instance = command_class.__new__(command_class)
            instance.__init__(*command[1:])
            self.from_commands.put_nowait(instance)

        # This happens when user specifies wrong parameters
        except TypeError:
            msg = _("You've specified a wrong parameter list. \
The call should look like:\n\n%(command)s %(params)s")

            return msg % {'command': command[0], 'params': command_class.parameter_list}

    def handle_unsubscribed_presence(self, stanza):
        """Handles unsubscribed presence stanzas"""

        # FiXME: what policy should we adopt in this case?
        pass

    def handle_subscribe_presence(self, stanza):
        """Handles subscribe presence stanzas (requests)"""

        # FIXME: Let's just accept all subscribtion requests for now
        response = stanza.make_accept_response()
        self.get_stream().send(response)

    def handle_unavailable_presence(self, stanza):
        """Handles unavailable presence stanzas

        @type stanza: pyxmpp.presence.Presence

        """
        self.log.debug("Handling unavailable presence.")

        jid = stanza.get_from_jid()
        bare_jid = jid.bare().as_unicode()

        # If we get presence, this contact should already be known
        if bare_jid in self.contacts:
            contact = self.contacts[bare_jid]

            if self.config.verbose:
                self.log.debug("%s, going OFFLINE." % contact)

            # check if we are waiting for disco#info from this jid
            self.check_if_waiting(jid)
            del self.disco_temp[jid]

            try:
                # Send queued messages now, as we can't guarantee to be
                # alive the next time this contact becomes available.
                if len(contact.resources) == 1:
                    self.send_queued_messages(contact, ignore_dnd=True)
                    contact.remove_resource(jid.resource)
                else:
                    contact.remove_resource(jid.resource)

                    # The highest-priority resource, which used to be DnD might
                    # have gone offline. If so, try to deliver messages now.
                    if not contact.is_dnd():
                        self.send_queued_messages(contact)

            except ValueError:
                self.log.error("Unknown contact (resource) going offline...")

        else:
            self.log.error("Unavailable presence from unknown contact.")

        # Confirm that we've handled this stanza
        return True

    def handle_available_presence(self, presence):
        """Handles available presence stanzas

        @type presence: pyxmpp.presence.Presence

        """
        self.log.debug("Handling available presence.")

        show = presence.get_show()
        if show is None:
            show = u'available'

        priority = presence.get_priority()
        jid = presence.get_from_jid()
        bare_jid = jid.bare().as_unicode()

        if bare_jid in self.contacts:
            contact = self.contacts[bare_jid]

            # The resource is already known, so update it
            if contact.uses_resource(jid.resource):
                contact.set_show(jid.resource, show)

            # Unknown resource, add it to the list
            else:
                contact.add_resource(jid.resource, show, priority)

                # Discover capabilities of the newly connected client
                self.service_discovery(jid, presence)

            if self.config.verbose:
                self.log.debug(contact)

            # Either way check, if we can deliver queued messages now
            if not contact.is_dnd():
                self.send_queued_messages(contact)

        else:
            self.contacts[bare_jid] = Contact(jid, jid.resource, priority, show)
            self.service_discovery(jid, presence)
            self.get_user_language(bare_jid)
            self.log.debug(self.contacts[bare_jid])

        # Confirm that we've handled this stanza
        return True

    def get_user_language(self, jid):
        """Request user's language setting from the wiki

        @param jid: bare Jabber ID of the user to query for
        @type jid: unicode
        """
        request = cmd.GetUserLanguage(jid)
        self.from_commands.put_nowait(request)

    def handle_disco_query(self, stanza):
        """Handler for <Iq /> service discovery query

        @param stanza: received query stanza (pyxmpp.iq.Iq)
        """
        response = capat.create_response(stanza)
        self.get_stream().send(response)

    def service_discovery(self, jid, presence):
        """General handler for XEP-0115 (Entity Capabilities)

        @param jid: whose capabilities to discover (pyxmpp.jid.JID)
        @param presence: received presence stanza (pyxmpp.presence.Presence)
        """
        ver_algo = self.check_presence(presence)
        self.disco_temp[jid] = ver_algo

        if ver_algo is None:
            # legacy client - send disco#info query
            self.send_disco_query(jid)
        else:
            # check if we have this (ver,algo) already cached
            cache_item = self.disco_cache.get_item(ver_algo, state='stale')

            if cache_item is None:
                # add to disco_wait
                self.add_to_disco_wait(ver_algo, jid)
            else:
                # use cached capabilities
                self.log.debug(u"%s: using cached capabilities." % jid.as_unicode())
                payload = cache_item.value
                self.set_support(jid, payload)

    def check_presence(self, presence):
        """Search received presence for a <c> child with 'ver' and 'algo' attributes
        return (ver, algo) or None if no 'ver' found.
        (no 'algo' attribute defaults to 'sha-1', as described in XEP-0115)

        @param presence: received presence stanza (pyxmpp.presence.Presence)
        @return type: tuple of (str, str) or None
        """
        # TODO: <c> could be found directly using more appropriate xpath
        tags = presence.xpath_eval('child::*')
        for tag in tags:
            if tag.name == 'c':
                ver = tag.xpathEval('@ver')
                algo = tag.xpathEval('@algo')
                if ver:
                    if algo:
                        ver_algo = (ver[0].children.content, algo[0].children.content)
                    else:
                        # no algo attribute defaults to 'sha-1'
                        ver_algo = (ver[0].children.content, 'sha-1')

                    return ver_algo
                else:
                    #self.log.debug(u"%s: presence with <c> but without 'ver' attribute." % jid.as_unicode())
                    return None
                break
        else:
            #self.log.debug(u"%s: presence without a <c> tag." % jid.as_unicode())
            return None

    def send_disco_query(self, jid):
        """Sends disco#info query to a given jid

        @type jid: pyxmpp.jid.JID
        """
        query = Iq(to_jid=jid, stanza_type="get")
        query.new_query("http://jabber.org/protocol/disco#info")
        self.get_stream().set_response_handlers(query, self.handle_disco_result, None)
        self.get_stream().send(query)

    def add_to_disco_wait(self, ver_algo, jid):
        """Adds given jid to the list of contacts waiting for service
        discovery results.

        @param ver_algo: 'ver' and 'algo' attributes of the given jid
        @type ver_algo: tuple of (str, str)
        @type jid: pyxmpp.jid.JID
        """
        if ver_algo in self.disco_wait:
            # query already sent, add to the end of waiting list
            self.disco_wait[ver_algo][1].append(jid)
        else:
            # send a query and create a new entry
            self.send_disco_query(jid)
            timeout = time.time() + self.config.disco_answering_timeout
            self.disco_wait[ver_algo] = (timeout, [jid])

    def handle_disco_result(self, stanza):
        """Handler for <iq> service discovery results
        check if contact is still available and if 'ver' matches the capabilities' hash

        @param stanza: a received result stanza (pyxmpp.iq.Iq)
        """
        jid = stanza.get_from_jid()
        bare_jid = jid.bare().as_unicode()
        payload = stanza.get_query()

        if bare_jid in self.contacts:
            ver_algo = self.disco_temp[jid]

            if ver_algo is not None:
                ver, algo = ver_algo
                payload_hash = capat.hash_iq(stanza, algo)

                if payload_hash == ver:
                    # we can trust this 'ver' string
                    self.disco_result_right(ver_algo, payload)
                else:
                    self.log.debug(u"%s: 'ver' and hash do not match! (legacy client?)" % jid.as_unicode())
                    self.disco_result_wrong(ver_algo)

            self.set_support(jid, payload)

        else:
            self.log.debug(u"%s is unavailable but sends service discovery response." % jid.as_unicode())
            # such situation is handled by check_if_waiting

    def disco_result_right(self, ver_algo, payload):
        """We received a correct service discovery response so we can safely cache it
        for future use and apply to every waiting contact from the list (first one is already done)

        @param ver_algo: 'ver' and 'algo' attributes matching received capabilities
        @param payload: received capabilities
        @type ver_algo: tuple of (str, str)
        @type payload: libxml2.xmlNode
        """
        delta = timedelta(0)
        cache_item = CacheItem(ver_algo, payload, delta, delta, delta)
        self.disco_cache.add_item(cache_item)

        timeout, jid_list = self.disco_wait[ver_algo]
        for jid in jid_list[1:]:
            if jid.bare().as_unicode() in self.contacts:
                self.set_support(jid, payload)
        del self.disco_wait[ver_algo]

    def disco_result_wrong(self, ver_algo):
        """First jid from the list returned wrong response
        if it is possible try to ask the second one

        @param ver_algo: 'ver' and 'algo' attributes for which we received an inappropriate response
        @type ver_algo: tuple of (str, str)
        """
        timeout, jid_list = self.disco_wait[ver_algo]
        jid_list = jid_list[1:]
        if jid_list:
            self.send_disco_query(jid_list[0])
            timeout = time.time() + self.config.disco_answering_timeout
            self.disco_wait[ver_algo] = (timeout, jid_list)
        else:
            del self.disco_wait[ver_algo]

    def check_disco_delays(self):
        """Called when idle to check if some contacts haven't answered in allowed time"""
        for item in self.disco_wait:
            timeout, jid_list = self.disco_wait[item]
            if timeout < time.time():
                self.disco_result_wrong(item)

    def check_if_waiting(self, jid):
        """Check if we were waiting for disco#info reply from client that
        has just become unavailable. If so, ask next candidate.

        @param jid: jid that has just gone unavailable
        @type jid: pyxmpp.jid.JID
        """
        ver_algo = self.disco_temp[jid]
        if ver_algo in self.disco_wait:
            timeout, jid_list = self.disco_wait[ver_algo]
            if jid_list:
                if jid == jid_list[0]:
                    self.disco_result_wrong(ver_algo)
            else:
                # this should never happen
                self.log.debug(u"disco_wait: keeping empty entry at (%s, %s) !" % ver_algo)

    def set_support(self, jid, payload):
        """Searches service discovery results for support for
        Out Of Band Data (XEP-066) and Data Forms (XEP-004)
        and applies it to newly created Contact.

        @param jid: client's jabber ID (pyxmpp.jid.JID)
        @param payload: client's capabilities (libxml2.xmlNode)
        """
        supports = payload.xpathEval('//*[@var="jabber:x:oob"]')
        if supports:
            self.contacts[jid.bare().as_unicode()].set_supports(jid.resource, u"jabber:x:oob")

        supports = payload.xpathEval('//*[@var="jabber:x:data"]')
        if supports:
            self.contacts[jid.bare().as_unicode()].set_supports(jid.resource, u"jabber:x:data")

    def send_queued_messages(self, contact, ignore_dnd=False):
        """Sends messages queued for the contact

        @param contact: a contact whose queued messages are to be sent
        @type contact: jabberbot.xmppbot.Contact
        @param ignore_dnd: should contact's DnD status be ignored?

        """
        for command in contact.messages:
            self.handle_command(command, ignore_dnd)

    def reply_help(self, jid):
        """Constructs a generic help message

        It's sent in response to an uknown message or the "help" command.

        """
        _ = self.get_text(jid)

        msg = _("Hello there! I'm a MoinMoin Notification Bot. Available commands:\
\n\n%(internal)s\n%(xmlrpc)s")
        internal = ", ".join(self.internal_commands)
        xmlrpc = ", ".join(self.xmlrpc_commands.keys())

        return msg % {'internal': internal, 'xmlrpc': xmlrpc}

    def authenticated(self):
        """Called when authentication succeedes"""
        self.log.info("Authenticated.")

    def authorized(self):
        """Called when authorization succeedes"""

        self.log.info("Authorized.")

        stream = self.get_stream()
        stream.set_message_handler("normal", self.handle_message)
        stream.set_presence_handler("available", self.handle_available_presence)
        stream.set_presence_handler("unavailable", self.handle_unavailable_presence)
        stream.set_presence_handler("unsubscribed", self.handle_unsubscribed_presence)
        stream.set_presence_handler("subscribe", self.handle_subscribe_presence)

        self.request_session()

    def connected(self):
        """Called when connections has been established"""
        self.log.info("Connected.")

    def disconnected(self):
        """Called when disconnection occurs"""
        self.log.info("Disconnected.")

    def roster_updated(self, item=None):
        """Called when roster gets updated"""
        self.log.debug("Updating roster.")

    def stream_closed(self, stream):
        """Called when stream closes"""
        self.log.debug("Stream closed.")

    def stream_created(self, stream):
        """Called when stream gets created"""
        self.log.debug("Stream created.")

    def stream_error(self, error):
        """Called when stream error gets received"""
        self.log.error("Received a stream error.")

    # Message handlers

    def _handle_notification(self, command, ignore_dnd):
        cmd_data = command.notification
        original_text = cmd_data.get('text', '')
        original_subject = cmd_data.get('subject', '')

        for recipient in command.jids:
            jid = JID(recipient)
            jid_text = jid.bare().as_unicode()

            if isinstance(command, cmd.NotificationCommandI18n):
                # Translate&interpolate the message with data
                gettext_func = self.get_text(jid_text)
                text, subject = command.translate(gettext_func)
                cmd_data['text'] = text
                cmd_data['subject'] = subject
            else:
                cmd_data['text'] = original_text
                cmd_data['subject'] = original_subject

            # Check if contact is DoNotDisturb.
            # If so, queue the message for delayed delivery.
            contact = self.contacts.get(jid_text, '')
            if contact:
                if command.async and contact.is_dnd() and not ignore_dnd:
                    contact.messages.append(command)
                    return

            action = cmd_data.get('action', '')
            if action == u'page_changed':
                self.handle_changed_action(cmd_data, jid, contact)
            elif action == u'page_deleted':
                self.handle_deleted_action(cmd_data, jid, contact)
            elif action == u'file_attached':
                self.handle_attached_action(cmd_data, jid, contact)
            elif action == u'page_renamed':
                self.handle_renamed_action(cmd_data, jid, contact)
            elif action == u'user_created':
                self.handle_user_created_action(cmd_data, jid, contact)
            else:
                self.send_message(jid, cmd_data, command.msg_type)

    def _handle_search(self, command, ignore_dnd):
        warnings = []
        _ = self.get_text(command.jid)

        if not command.data:
            warnings.append(_("There are no pages matching your search criteria!"))

        # This hardcoded limitation relies on (mostly correct) assumption that Jabber
        # servers have rather tight traffic limits. Sending more than 25 results is likely
        # to take a second or two - users should not have to wait longer (+search time!).
        elif len(command.data) > 25:
            warnings.append(_("There are too many results (%(number)s). Limiting to first 25 entries.") % {'number': str(len(command.data))})
            command.data = command.data[:25]

        results = [{'description': result[0], 'url': result[2]} for result in command.data]

        if command.presentation == u"text":
            for warning in warnings:
                self.send_message(command.jid, {'text': warning})

            if not results:
                return

            data = {'text': _('Following pages match your search criteria:'), 'url_list': results}
            self.send_message(command.jid, data, u"chat")
        else:
            form_title = _("Search results").encode("utf-8")
            help_form = _("Submit this form to perform a wiki search").encode("utf-8")
            form = forms.Form(xmlnode_or_type="result", title=form_title, instructions=help_form)

            action_label = _("What to do next")
            do_nothing = forms.Option("n", _("Do nothing"))
            search_again = forms.Option("s", _("Search again"))

            for no, warning in enumerate(warnings):
                form.add_field(name="warning", field_type="fixed", value=warning)

            for no, result in enumerate(results):
                field_name = "url%d" % (no, )
                form.add_field(name=field_name, value=unicode(result["url"]), label=result["description"].encode("utf-8"), field_type="text-single")

            # Selection of a following action
            form.add_field(name="options", field_type="list-single", options=[do_nothing, search_again], label=action_label)

            self.send_form(command.jid, form, _("Search results"))

    def _handle_add_contact(self, command, ignore_dnd):
        jid = JID(node_or_jid = command.jid)
        self.ask_for_subscription(jid)

    def _handle_remove_contact(self, command, ignore_dnd):
        jid = JID(node_or_jid = command.jid)
        self.remove_subscription(jid)

    def _handle_get_page(self, command, ignore_dnd):
        _ = self.get_text(command.jid)
        msg = _(u"""Here's the page "%(pagename)s" that you've requested:\n\n%(data)s""")

        cmd_data = {'text': msg % {'pagename': command.pagename, 'data': command.data}}
        self.send_message(command.jid, cmd_data)

    def _handle_get_page_list(self, command, ignore_dnd):
        _ = self.get_text(command.jid)
        msg = _("That's the list of pages accesible to you:\n\n%s")
        pagelist = u"\n".join(command.data)

        self.send_message(command.jid, {'text': msg % (pagelist, )})

    def _handle_get_page_info(self, command, ignore_dnd):
        self.handle_page_info(command)

    def _handle_get_language(self, command, ignore_dnd):
        if command.jid in self.contacts:
            self.contacts[command.jid].language = command.language