aboutsummaryrefslogtreecommitdiffstats
path: root/src/net/java/sip/communicator/impl/protocol/gibberish/OperationSetPersistentPresenceGibberishImpl.java
blob: 5f086e3cfb602517e8ca547a5bad0f0616a28930 (plain)
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
/*
 * Jitsi, the OpenSource Java VoIP and Instant Messaging client.
 *
 * Distributable under LGPL license.
 * See terms of license at gnu.org.
 */
package net.java.sip.communicator.impl.protocol.gibberish;

import java.util.*;

import net.java.sip.communicator.service.protocol.*;
import net.java.sip.communicator.service.protocol.event.*;
import net.java.sip.communicator.util.*;

import org.osgi.framework.*;

/**
 * A Gibberish implementation of a persistent presence operation set. In order
 * to simulate server persistence, this operation set would simply accept all
 * unresolved contacts and resolve them immediately. A real world protocol
 * implementation would save it on a server using methods provided by the
 * protocol stack.
 *
 * @author Emil Ivov
 */
public class OperationSetPersistentPresenceGibberishImpl
    extends AbstractOperationSetPersistentPresence<ProtocolProviderServiceGibberishImpl>
{
    private static final Logger logger =
        Logger.getLogger(OperationSetPersistentPresenceGibberishImpl.class);

    /**
     * The root of the gibberish contact list.
     */
    private ContactGroupGibberishImpl contactListRoot = null;

    /**
     * The currently active status message.
     */
    private String statusMessage = "Default Status Message";

    /**
     * Our presence status.
     */
    private PresenceStatus presenceStatus = GibberishStatusEnum.OFFLINE;

    /**
     * The <tt>AuthorizationHandler</tt> instance that we'd have to transmit
     * authorization requests to for approval.
     */
    private AuthorizationHandler authorizationHandler = null;

    /**
     * Creates an instance of this operation set keeping a reference to the
     * specified parent <tt>provider</tt>.
     * @param provider the ProtocolProviderServiceGibberishImpl instance that
     * created us.
     */
    public OperationSetPersistentPresenceGibberishImpl(
            ProtocolProviderServiceGibberishImpl        provider)
    {
        super(provider);

        contactListRoot = new ContactGroupGibberishImpl("RootGroup", provider);

        //add our unregistration listener
        parentProvider.addRegistrationStateChangeListener(
            new UnregistrationListener());
    }

    /**
     * Creates a group with the specified name and parent in the server
     * stored contact list.
     *
     * @param parent the group where the new group should be created
     * @param groupName the name of the new group to create.
     */
    public void createServerStoredContactGroup(ContactGroup parent,
                                               String groupName)
    {
        ContactGroupGibberishImpl newGroup
            = new ContactGroupGibberishImpl(groupName, parentProvider);

        ((ContactGroupGibberishImpl)parent).addSubgroup(newGroup);

        this.fireServerStoredGroupEvent(
            newGroup, ServerStoredGroupEvent.GROUP_CREATED_EVENT);
    }

    /**
     * A Gibberish Provider method to use for fast filling of a contact list.
     *
     * @param contactGroup the group to add
     */
    public void addGibberishGroup(ContactGroupGibberishImpl contactGroup)
    {
        contactListRoot.addSubgroup(contactGroup);
    }

    /**
     * A Gibberish Provider method to use for fast filling of a contact list.
     * This method would add both the group and fire an event.
     *
     * @param parent the group where <tt>contactGroup</tt> should be added.
     * @param contactGroup the group to add
     */
    public void addGibberishGroupAndFireEvent(
                                  ContactGroupGibberishImpl parent
                                , ContactGroupGibberishImpl contactGroup)
    {
        parent.addSubgroup(contactGroup);

        this.fireServerStoredGroupEvent(
            contactGroup, ServerStoredGroupEvent.GROUP_CREATED_EVENT);
    }


    /**
     * Returns a reference to the contact with the specified ID in case we
     * have a subscription for it and null otherwise/
     *
     * @param contactID a String identifier of the contact which we're
     *   seeking a reference of.
     * @return a reference to the Contact with the specified
     *   <tt>contactID</tt> or null if we don't have a subscription for the
     *   that identifier.
     */
    public Contact findContactByID(String contactID)
    {
        return contactListRoot.findContactByID(contactID);
    }

    /**
     * Sets the specified status message.
     * @param statusMessage a String containing the new status message.
     */
    public void setStatusMessage(String statusMessage)
    {
        this.statusMessage = statusMessage;
    }

    /**
     * Returns the status message that was last set through
     * setCurrentStatusMessage.
     *
     * @return the last status message that we have requested and the aim
     *   server has confirmed.
     */
    public String getCurrentStatusMessage()
    {
        return statusMessage;
    }

    /**
     * Returns the protocol specific contact instance representing the local
     * user.
     *
     * @return the Contact (address, phone number, or uin) that the Provider
     *   implementation is communicating on behalf of.
     */
    public Contact getLocalContact()
    {
        return null;
    }

    /**
     * Returns a PresenceStatus instance representing the state this provider
     * is currently in.
     *
     * @return the PresenceStatus last published by this provider.
     */
    public PresenceStatus getPresenceStatus()
    {
        return presenceStatus;
    }

    /**
     * Returns the root group of the server stored contact list.
     *
     * @return the root ContactGroup for the ContactList stored by this
     *   service.
     */
    public ContactGroup getServerStoredContactListRoot()
    {
        return contactListRoot;
    }

    /**
     * Returns the set of PresenceStatus objects that a user of this service
     * may request the provider to enter.
     *
     * @return Iterator a PresenceStatus array containing "enterable" status
     *   instances.
     */
    public Iterator<PresenceStatus> getSupportedStatusSet()
    {
        return GibberishStatusEnum.supportedStatusSet();
    }

    /**
     * Removes the specified contact from its current parent and places it
     * under <tt>newParent</tt>.
     *
     * @param contactToMove the <tt>Contact</tt> to move
     * @param newParent the <tt>ContactGroup</tt> where <tt>Contact</tt>
     *   would be placed.
     */
    public void moveContactToGroup(Contact contactToMove,
                                   ContactGroup newParent)
    {
        ContactGibberishImpl gibberishContact
            = (ContactGibberishImpl)contactToMove;

        ContactGroupGibberishImpl parentGibberishGroup
            = findContactParent(gibberishContact);

        parentGibberishGroup.removeContact(gibberishContact);

        //if this is a volatile contact then we haven't really subscribed to
        //them so we'd need to do so here
        if(!gibberishContact.isPersistent())
        {
            //first tell everyone that the volatile contact was removed
            fireSubscriptionEvent(gibberishContact
                                  , parentGibberishGroup
                                  , SubscriptionEvent.SUBSCRIPTION_REMOVED);

            try
            {
                //now subscribe
                this.subscribe(newParent, contactToMove.getAddress());

                //now tell everyone that we've added the contact
                fireSubscriptionEvent(gibberishContact
                                      , newParent
                                      , SubscriptionEvent.SUBSCRIPTION_CREATED);
            }
            catch (Exception ex)
            {
                logger.error("Failed to move contact "
                             + gibberishContact.getAddress()
                             , ex);
            }
        }
        else
        {
            ( (ContactGroupGibberishImpl) newParent)
                    .addContact(gibberishContact);

            fireSubscriptionMovedEvent(contactToMove
                                      , parentGibberishGroup
                                       , newParent);
        }
    }

    /**
     * Requests the provider to enter into a status corresponding to the
     * specified paramters.
     *
     * @param status the PresenceStatus as returned by
     *   getRequestableStatusSet
     * @param statusMessage the message that should be set as the reason to
     *   enter that status
     * @throws IllegalArgumentException if the status requested is not a
     *   valid PresenceStatus supported by this provider.
     * @throws IllegalStateException if the provider is not currently
     *   registered.
     * @throws OperationFailedException with code NETWORK_FAILURE if
     *   publishing the status fails due to a network error.
     */
    public void publishPresenceStatus(PresenceStatus status,
                                      String statusMessage) throws
        IllegalArgumentException, IllegalStateException,
        OperationFailedException
    {
        PresenceStatus oldPresenceStatus = this.presenceStatus;
        this.presenceStatus = status;
        this.statusMessage = statusMessage;

        this.fireProviderStatusChangeEvent(oldPresenceStatus);

        //since we are not a real protocol, we set the contact presence status
        //ourselves and make them have the same status as ours.
        changePresenceStatusForAllContacts( getServerStoredContactListRoot()
                                            , getPresenceStatus());

        //now check whether we are in someone else's contact list and modify
        //our status there
        List<Contact> contacts = findContactsPointingToUs();

        Iterator<Contact> contactsIter = contacts.iterator();
        while (contactsIter.hasNext())
        {
            ContactGibberishImpl contact = (ContactGibberishImpl)contactsIter.next();

            PresenceStatus oldStatus = contact.getPresenceStatus();
            contact.setPresenceStatus(status);
            contact.getParentPresenceOperationSet()
                .fireContactPresenceStatusChangeEvent(
                    contact
                    , contact.getParentContactGroup()
                    , oldStatus);

        }
    }



    /**
     * Get the PresenceStatus for a particular contact.
     *
     * @param contactIdentifier the identifier of the contact whose status
     *   we're interested in.
     * @return PresenceStatus the <tt>PresenceStatus</tt> of the specified
     *   <tt>contact</tt>
     * @throws IllegalArgumentException if <tt>contact</tt> is not a contact
     *   known to the underlying protocol provider
     * @throws IllegalStateException if the underlying protocol provider is
     *   not registered/signed on a public service.
     * @throws OperationFailedException with code NETWORK_FAILURE if
     *   retrieving the status fails due to errors experienced during
     *   network communication
     */
    public PresenceStatus queryContactStatus(String contactIdentifier) throws
        IllegalArgumentException, IllegalStateException,
        OperationFailedException
    {
        return findContactByID(contactIdentifier).getPresenceStatus();
    }

    /**
     * Sets the presence status of <tt>contact</tt> to <tt>newStatus</tt>.
     *
     * @param contact the <tt>ContactGibberishImpl</tt> whose status we'd like
     * to set.
     * @param newStatus the new status we'd like to set to <tt>contact</tt>.
     */
    private void changePresenceStatusForContact(
                                            ContactGibberishImpl contact
                                         ,  PresenceStatus       newStatus)
    {
        PresenceStatus oldStatus = contact.getPresenceStatus();
        contact.setPresenceStatus(newStatus);

        fireContactPresenceStatusChangeEvent(
                contact, findContactParent(contact), oldStatus);
    }

    /**
     * Sets the presence status of all <tt>contact</tt>s in our contact list
     * (except those that  correspond to another provider registered with SC)
     * to <tt>newStatus</tt>.
     *
     * @param newStatus the new status we'd like to set to <tt>contact</tt>.
     * @param parent the group in which we'd have to update the status of all
     * direct and indirect child contacts.
     */
    private void changePresenceStatusForAllContacts(ContactGroup   parent,
                                                    PresenceStatus newStatus)
    {
        //first set the status for contacts in this group
        Iterator<Contact> childContacts = parent.contacts();

        while(childContacts.hasNext())
        {
            ContactGibberishImpl contact
                = (ContactGibberishImpl)childContacts.next();

            if(findProviderForGibberishUserID(contact.getAddress()) != null)
            {
                //this is a contact corresponding to another SIP Communicator
                //provider so we won't change it's status here.
                continue;
            }
            PresenceStatus oldStatus = contact.getPresenceStatus();
            contact.setPresenceStatus(newStatus);

            fireContactPresenceStatusChangeEvent(
                contact, parent, oldStatus);
        }

        //now call this method recursively for all subgroups
        Iterator<ContactGroup> subgroups = parent.subgroups();

        while(subgroups.hasNext())
        {
            ContactGroup subgroup = subgroups.next();
            changePresenceStatusForAllContacts(subgroup, newStatus);
        }
    }

    /**
     * Returns the group that is parent of the specified gibberishGroup  or null
     * if no parent was found.
     * @param gibberishGroup the group whose parent we're looking for.
     * @return the ContactGroupGibberishImpl instance that gibberishGroup
     * belongs to or null if no parent was found.
     */
    public ContactGroupGibberishImpl findGroupParent(
                                    ContactGroupGibberishImpl gibberishGroup)
    {
        return contactListRoot.findGroupParent(gibberishGroup);
    }

    /**
     * Returns the group that is parent of the specified gibberishContact  or
     * null if no parent was found.
     * @param gibberishContact the contact whose parent we're looking for.
     * @return the ContactGroupGibberishImpl instance that gibberishContact
     * belongs to or null if no parent was found.
     */
    public ContactGroupGibberishImpl findContactParent(
                                        ContactGibberishImpl gibberishContact)
    {
        return (ContactGroupGibberishImpl)gibberishContact
                                                .getParentContactGroup();
    }


    /**
     * Removes the specified group from the server stored contact list.
     *
     * @param group the group to remove.
     *
     * @throws IllegalArgumentException if <tt>group</tt> was not found in this
     * protocol's contact list.
     */
    public void removeServerStoredContactGroup(ContactGroup group)
        throws IllegalArgumentException
    {
        ContactGroupGibberishImpl gibberishGroup
                                        = (ContactGroupGibberishImpl)group;

        ContactGroupGibberishImpl parent = findGroupParent(gibberishGroup);

        if(parent == null){
            throw new IllegalArgumentException(
                "group " + group
                + " does not seem to belong to this protocol's contact list.");
        }

        parent.removeSubGroup(gibberishGroup);

        this.fireServerStoredGroupEvent(
            gibberishGroup, ServerStoredGroupEvent.GROUP_REMOVED_EVENT);
    }

    /**
     * Renames the specified group from the server stored contact list.
     *
     * @param group the group to rename.
     * @param newName the new name of the group.
     */
    public void renameServerStoredContactGroup(ContactGroup group,
                                               String newName)
    {
        ((ContactGroupGibberishImpl)group).setGroupName(newName);

        this.fireServerStoredGroupEvent(
                group,
                ServerStoredGroupEvent.GROUP_RENAMED_EVENT);
    }

    /**
     * Handler for incoming authorization requests.
     *
     * @param handler an instance of an AuthorizationHandler for
     *   authorization requests coming from other users requesting
     *   permission add us to their contact list.
     */
    public void setAuthorizationHandler(AuthorizationHandler handler)
    {
        this.authorizationHandler = handler;
    }

    /**
     * Persistently adds a subscription for the presence status of the
     * contact corresponding to the specified contactIdentifier and indicates
     * that it should be added to the specified group of the server stored
     * contact list.
     *
     * @param parent the parent group of the server stored contact list
     *   where the contact should be added. <p>
     * @param contactIdentifier the contact whose status updates we are
     *   subscribing for.
     * @throws IllegalArgumentException if <tt>contact</tt> or
     *   <tt>parent</tt> are not a contact known to the underlying protocol
     *   provider.
     * @throws IllegalStateException if the underlying protocol provider is
     *   not registered/signed on a public service.
     * @throws OperationFailedException with code NETWORK_FAILURE if
     *   subscribing fails due to errors experienced during network
     *   communication
     */
    public void subscribe(ContactGroup parent, String contactIdentifier) throws
        IllegalArgumentException, IllegalStateException,
        OperationFailedException
    {
        ContactGibberishImpl contact = new ContactGibberishImpl(
            contactIdentifier
            , parentProvider);

        if(authorizationHandler != null)
        {
            //we require authorizations in gibberish
            AuthorizationRequest request
                = authorizationHandler.createAuthorizationRequest(contact);


            //and finally pretend that the remote contact has granted us
            //authorization
            AuthorizationResponse response
                = deliverAuthorizationRequest(request, contact);

            authorizationHandler.processAuthorizationResponse(
                response, contact);

            //if the request was not accepted - return the contact.
            if(response.getResponseCode() == AuthorizationResponse.REJECT)
                return;
        }
        ((ContactGroupGibberishImpl)parent).addContact(contact);

        fireSubscriptionEvent(contact,
                              parent,
                              SubscriptionEvent.SUBSCRIPTION_CREATED);
        //if the newly added contact corresponds to another provider - set their
        //status accordingly
        ProtocolProviderServiceGibberishImpl gibProvider
            = findProviderForGibberishUserID(contactIdentifier);
        if(gibProvider != null)
        {
            OperationSetPersistentPresence opSetPresence
                = gibProvider
                    .getOperationSet(OperationSetPersistentPresence.class);

            changePresenceStatusForContact(
                contact,
                opSetPresence.getPresenceStatus());
        }
        else
        {
            //otherwise - since we are not a real protocol, we set the contact
            //presence status ourselves
            changePresenceStatusForContact(contact, getPresenceStatus());
        }

        //notify presence listeners for the status change.
        fireContactPresenceStatusChangeEvent(contact
                                             , parent
                                             , GibberishStatusEnum.OFFLINE);
    }


    /**
     * Depending on whether <tt>contact</tt> corresponds to another protocol
     * provider installed in sip-communicator, this method would either deliver
     * it to that provider or simulate a corresponding request from the
     * destination contact and make return a response after it has received
     * one If the destination contact matches us, then we'll ask the user to
     * act upon the request, and return the response.
     *
     * @param request the authorization request that we'd like to deliver to the
     * desination <tt>contact</tt>.
     * @param contact the <tt>Contact</tt> to notify
     *
     * @return the <tt>AuthorizationResponse</tt> that has been given or
     * generated in response to <tt>request</tt>.
     */
    private AuthorizationResponse deliverAuthorizationRequest(
                AuthorizationRequest request,
                Contact contact)
    {
        String userID = contact.getAddress();

        //if the user id is our own id, then this request is being routed to us
        //from another instance of the gibberish provider.
        if (userID.equals(this.parentProvider.getAccountID().getUserID()))
        {
            //check who is the provider sending the message
            String sourceUserID = contact.getProtocolProvider()
                .getAccountID().getUserID();

            //check whether they are in our contact list
            Contact from = findContactByID(sourceUserID);

            //and if not - add them there as volatile.
            if (from == null)
            {
                from = createVolatileContact(sourceUserID);
            }

            //and now handle the request.
            return authorizationHandler.processAuthorisationRequest(
                request, from);
        }
        else
        {
            //if userID is not our own, try a check whether another provider
            //has that id and if yes - deliver the request to them.
            ProtocolProviderServiceGibberishImpl gibberishProvider
                = this.findProviderForGibberishUserID(userID);
            if (gibberishProvider != null)
            {
                OperationSetPersistentPresenceGibberishImpl opSetPersPresence
                    = (OperationSetPersistentPresenceGibberishImpl)
                    gibberishProvider.getOperationSet(
                        OperationSetPersistentPresence.class);
                return opSetPersPresence
                    .deliverAuthorizationRequest(request, contact);
            }
            else
            {
                //if we got here then "to" is simply someone in our contact
                //list so let's just simulate a reciproce request and generate
                //a response accordingly.

                //pretend that the remote contact is asking for authorization
                authorizationHandler.processAuthorisationRequest(
                    request, contact);

                //and now pretend that the remote contact has granted us
                //authorization
                return new AuthorizationResponse(AuthorizationResponse.ACCEPT
                                                , "You are welcome!");
            }
        }
    }

    /**
     * Adds a subscription for the presence status of the contact
     * corresponding to the specified contactIdentifier.
     *
     * @param contactIdentifier the identifier of the contact whose status
     *   updates we are subscribing for. <p>
     * @throws IllegalArgumentException if <tt>contact</tt> is not a contact
     *   known to the underlying protocol provider
     * @throws IllegalStateException if the underlying protocol provider is
     *   not registered/signed on a public service.
     * @throws OperationFailedException with code NETWORK_FAILURE if
     *   subscribing fails due to errors experienced during network
     *   communication
     */
    public void subscribe(String contactIdentifier) throws
        IllegalArgumentException, IllegalStateException,
        OperationFailedException
    {
        subscribe(contactListRoot, contactIdentifier);

    }

    /**
     * Removes a subscription for the presence status of the specified
     * contact.
     *
     * @param contact the contact whose status updates we are unsubscribing
     *   from.
     * @throws IllegalArgumentException if <tt>contact</tt> is not a contact
     *   known to the underlying protocol provider
     * @throws IllegalStateException if the underlying protocol provider is
     *   not registered/signed on a public service.
     * @throws OperationFailedException with code NETWORK_FAILURE if
     *   unsubscribing fails due to errors experienced during network
     *   communication
     */
    public void unsubscribe(Contact contact) throws IllegalArgumentException,
        IllegalStateException, OperationFailedException
    {
        ContactGroupGibberishImpl parentGroup
            = (ContactGroupGibberishImpl)((ContactGibberishImpl)contact)
            .getParentContactGroup();

        parentGroup.removeContact((ContactGibberishImpl)contact);

        fireSubscriptionEvent(
            contact,
            contact.getParentContactGroup(),
            SubscriptionEvent.SUBSCRIPTION_REMOVED);
    }

    /**
     * Creates and returns a unresolved contact from the specified
     * <tt>address</tt> and <tt>persistentData</tt>. The method will not try
     * to establish a network connection and resolve the newly created Contact
     * against the server. The protocol provider may will later try and resolve
     * the contact. When this happens the corresponding event would notify
     * interested subscription listeners.
     *
     * @param address an identifier of the contact that we'll be creating.
     * @param persistentData a String returned Contact's getPersistentData()
     * method during a previous run and that has been persistently stored
     * locally.
     * @return the unresolved <tt>Contact</tt> created from the specified
     * <tt>address</tt> and <tt>persistentData</tt>
     */
    public Contact createUnresolvedContact(String address,
                                           String persistentData)
    {
        return createUnresolvedContact(address
                                      , persistentData
                                      , getServerStoredContactListRoot());
    }

    /**
     * Creates and returns a unresolved contact from the specified
     * <tt>address</tt> and <tt>persistentData</tt>. The method will not try
     * to establish a network connection and resolve the newly created Contact
     * against the server. The protocol provider may will later try and resolve
     * the contact. When this happens the corresponding event would notify
     * interested subscription listeners.
     *
     * @param address an identifier of the contact that we'll be creating.
     * @param persistentData a String returned Contact's getPersistentData()
     * method during a previous run and that has been persistently stored
     * locally.
     * @param parent the group where the unresolved contact is
     * supposed to belong to.
     *
     * @return the unresolved <tt>Contact</tt> created from the specified
     * <tt>address</tt> and <tt>persistentData</tt>
     */
    public Contact createUnresolvedContact(String address,
                                           String persistentData,
                                           ContactGroup parent)
    {
        ContactGibberishImpl contact = new ContactGibberishImpl(
            address
            , parentProvider);
        contact.setResolved(false);

        ( (ContactGroupGibberishImpl) parent).addContact(contact);

        fireSubscriptionEvent(contact,
                              parent,
                              SubscriptionEvent.SUBSCRIPTION_CREATED);

        //since we don't have any server, we'll simply resolve the contact
        //ourselves as if we've just received an event from the server telling
        //us that it has been resolved.
        fireSubscriptionEvent(
            contact, parent, SubscriptionEvent.SUBSCRIPTION_RESOLVED);

        //since we are not a real protocol, we set the contact presence status
        //ourselves
        changePresenceStatusForContact( contact, getPresenceStatus());

        return contact;
    }

    /**
     * Looks for a gibberish protocol provider registered for a user id matching
     * <tt>gibberishUserID</tt>.
     *
     * @param gibberishUserID the ID of the Gibberish user whose corresponding
     * protocol provider we'd like to find.
     * @return ProtocolProviderServiceGibberishImpl a gibberish protocol
     * provider registered for a user with id <tt>gibberishUserID</tt> or null
     * if there is no such protocol provider.
     */
    public ProtocolProviderServiceGibberishImpl
                        findProviderForGibberishUserID(String gibberishUserID)
    {
        BundleContext bc = GibberishActivator.getBundleContext();

        String osgiQuery = "(&"
                + "(" + ProtocolProviderFactory.PROTOCOL
                + "=Gibberish)"
                + "(" + ProtocolProviderFactory.USER_ID
                + "=" + gibberishUserID + ")"
                + ")";

        ServiceReference[] refs = null;
        try
        {
            refs = bc.getServiceReferences(
                ProtocolProviderService.class.getName()
                ,osgiQuery);
        }
        catch (InvalidSyntaxException ex)
        {
            logger.error("Failed to execute the following osgi query: "
                         + osgiQuery
                         , ex);
        }

        if(refs != null && refs.length > 0)
        {
            return (ProtocolProviderServiceGibberishImpl)bc.getService(refs[0]);
        }

        return null;
    }

    /**
     * Looks for gibberish protocol providers that have added us to their
     * contact list and returns list of all contacts representing us in these
     * providers.
     *
     * @return a list of all contacts in other providers' contact lists that
     * point to us.
     */
    public List<Contact> findContactsPointingToUs()
    {
        List<Contact> contacts = new LinkedList<Contact>();
        BundleContext bc = GibberishActivator.getBundleContext();

        String osgiQuery =
                "(" + ProtocolProviderFactory.PROTOCOL
                + "=Gibberish)";

        ServiceReference[] refs = null;
        try
        {
            refs = bc.getServiceReferences(
                ProtocolProviderService.class.getName()
                ,osgiQuery);
        }
        catch (InvalidSyntaxException ex)
        {
            logger.error("Failed to execute the following osgi query: "
                         + osgiQuery
                         , ex);
        }

        for (int i =0; refs != null && i < refs.length; i++)
        {
            ProtocolProviderServiceGibberishImpl gibProvider
               = (ProtocolProviderServiceGibberishImpl)bc.getService(refs[i]);

           OperationSetPersistentPresenceGibberishImpl opSetPersPresence
               = (OperationSetPersistentPresenceGibberishImpl)gibProvider
                    .getOperationSet(OperationSetPersistentPresence.class);

            Contact contact = opSetPersPresence.findContactByID(
                parentProvider.getAccountID().getUserID());

            if (contact != null)
                contacts.add(contact);
        }

        return contacts;
    }


    /**
     * Creates and returns a unresolved contact group from the specified
     * <tt>address</tt> and <tt>persistentData</tt>. The method will not try
     * to establish a network connection and resolve the newly created
     * <tt>ContactGroup</tt> against the server or the contact itself. The
     * protocol provider will later resolve the contact group. When this happens
     * the corresponding event would notify interested subscription listeners.
     *
     * @param groupUID an identifier, returned by ContactGroup's getGroupUID,
     * that the protocol provider may use in order to create the group.
     * @param persistentData a String returned ContactGroups's
     * getPersistentData() method during a previous run and that has been
     * persistently stored locally.
     * @param parentGroup the group under which the new group is to be created
     * or null if this is group directly underneath the root.
     * @return the unresolved <tt>ContactGroup</tt> created from the specified
     * <tt>uid</tt> and <tt>persistentData</tt>
     */
    public ContactGroup createUnresolvedContactGroup(String groupUID,
        String persistentData, ContactGroup parentGroup)
    {
        ContactGroupGibberishImpl newGroup
            = new ContactGroupGibberishImpl(
                ContactGroupGibberishImpl.createNameFromUID(groupUID)
                , parentProvider);
        newGroup.setResolved(false);

        //if parent is null then we're adding under root.
        if(parentGroup == null)
            parentGroup = getServerStoredContactListRoot();

        ((ContactGroupGibberishImpl)parentGroup).addSubgroup(newGroup);

        this.fireServerStoredGroupEvent(
            newGroup, ServerStoredGroupEvent.GROUP_CREATED_EVENT);

        return newGroup;
    }

    private class UnregistrationListener
        implements RegistrationStateChangeListener
    {
        /**
         * The method is called by a ProtocolProvider implementation whenver
         * a change in the registration state of the corresponding provider had
         * occurred. The method is particularly interested in events stating
         * that the gibberish provider has unregistered so that it would fire
         * status change events for all contacts in our buddy list.
         *
         * @param evt ProviderStatusChangeEvent the event describing the status
         * change.
         */
        public void registrationStateChanged(RegistrationStateChangeEvent evt)
        {
            if (! evt.getNewState().equals(RegistrationState.UNREGISTERED)
                && !evt.getNewState().equals(RegistrationState.AUTHENTICATION_FAILED)
                && !evt.getNewState().equals(RegistrationState.CONNECTION_FAILED))
            {
                return;
            }

            //send event notifications saying that all our buddies are
            //offline. The icq protocol does not implement top level buddies
            //nor subgroups for top level groups so a simple nested loop
            //would be enough.
            Iterator<ContactGroup> groupsIter
                = getServerStoredContactListRoot().subgroups();
            while (groupsIter.hasNext())
            {
                ContactGroup group = groupsIter.next();
                Iterator<Contact> contactsIter = group.contacts();

                while (contactsIter.hasNext())
                {
                    ContactGibberishImpl contact
                        = (ContactGibberishImpl) contactsIter.next();
                    PresenceStatus oldContactStatus
                        = contact.getPresenceStatus();

                    if (!oldContactStatus.isOnline())
                        continue;

                    contact.setPresenceStatus(GibberishStatusEnum.OFFLINE);

                    fireContactPresenceStatusChangeEvent(
                        contact
                        , contact.getParentContactGroup()
                        , oldContactStatus);
                }
            }
        }
    }

    /**
     * Returns the volatile group or null if this group has not yet been
     * created.
     *
     * @return a volatile group existing in our contact list or <tt>null</tt>
     * if such a group has not yet been created.
     */
    private ContactGroupGibberishImpl getNonPersistentGroup()
    {
        for (int i = 0
             ; i < getServerStoredContactListRoot().countSubgroups()
             ; i++)
        {
            ContactGroupGibberishImpl gr =
                (ContactGroupGibberishImpl)getServerStoredContactListRoot()
                    .getGroup(i);

            if(!gr.isPersistent())
                return gr;
        }

        return null;
    }


    /**
     * Creates a non persistent contact for the specified address. This would
     * also create (if necessary) a group for volatile contacts that would not
     * be added to the server stored contact list. This method would have no
     * effect on the server stored contact list.
     *
     * @param contactAddress the address of the volatile contact we'd like to
     * create.
     * @return the newly created volatile contact.
     */
    public ContactGibberishImpl createVolatileContact(String contactAddress)
    {
        //First create the new volatile contact;
        ContactGibberishImpl newVolatileContact
            = new ContactGibberishImpl(contactAddress
                                       , this.parentProvider);
        newVolatileContact.setPersistent(false);


        //Check whether a volatile group already exists and if not create
        //one
        ContactGroupGibberishImpl theVolatileGroup = getNonPersistentGroup();


        //if the parent volatile group is null then we create it
        if (theVolatileGroup == null)
        {
            theVolatileGroup = new ContactGroupGibberishImpl(
                GibberishActivator.getResources().getI18NString(
                    "service.gui.NOT_IN_CONTACT_LIST_GROUP_NAME")
                , parentProvider);
            theVolatileGroup.setResolved(false);
            theVolatileGroup.setPersistent(false);

            this.contactListRoot.addSubgroup(theVolatileGroup);

            fireServerStoredGroupEvent(theVolatileGroup
                           , ServerStoredGroupEvent.GROUP_CREATED_EVENT);
        }

        //now add the volatile contact instide it
        theVolatileGroup.addContact(newVolatileContact);
        fireSubscriptionEvent(newVolatileContact
                         , theVolatileGroup
                         , SubscriptionEvent.SUBSCRIPTION_CREATED);

        return newVolatileContact;
    }

}