summaryrefslogtreecommitdiff
path: root/src/SemanticScuttle/Service/User.php
blob: 18d5a290a1e8ce00c1d9f19dd2d7dcab83f1240d (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
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
<?php
/**
 * SemanticScuttle - your social bookmark manager.
 *
 * PHP version 5.
 *
 * @category Bookmarking
 * @package  SemanticScuttle
 * @author   Benjamin Huynh-Kim-Bang <mensonge@users.sourceforge.net>
 * @author   Christian Weiske <cweiske@cweiske.de>
 * @author   Eric Dane <ericdane@users.sourceforge.net>
 * @license  GPL http://www.gnu.org/licenses/gpl.html
 * @link     http://sourceforge.net/projects/semanticscuttle
 */

require_once 'SemanticScuttle/Model/User.php';

/**
 * SemanticScuttle user management service.
 *
 * @category Bookmarking
 * @package  SemanticScuttle
 * @author   Benjamin Huynh-Kim-Bang <mensonge@users.sourceforge.net>
 * @author   Christian Weiske <cweiske@cweiske.de>
 * @author   Eric Dane <ericdane@users.sourceforge.net>
 * @license  GPL http://www.gnu.org/licenses/gpl.html
 * @link     http://sourceforge.net/projects/semanticscuttle
 */
class SemanticScuttle_Service_User extends SemanticScuttle_DbService
{
    /**
     * The ID of the currently logged on user.
     * NULL when not logged in.
     *
     * @var integer
     */
    protected $currentuserId = null;

    /**
     * Currently logged on user from database
     *
     * @var array
     *
     * @see getCurrentUserId()
     * @see getCurrentUser()
     * @see setCurrentUserId()
     */
    protected $currentuser = null;

    protected $fields = array(
        'primary'    => 'uId',
        'username'   => 'username',
        'password'   => 'password',
        'privatekey' => 'privatekey'
    );

    protected $profileurl;
    protected $sessionkey;
    protected $cookiekey;
    protected $cookietime = 1209600; // 2 weeks

    /**
     * Returns the single service instance
     *
     * @param sql_db $db Database object
     *
     * @return SemanticScuttle_Service_User
     */
    public static function getInstance($db)
    {
        static $instance;
        if (!isset($instance)) {
            $instance = new self($db);
        }
        return $instance;
    }

    protected function __construct($db)
    {
        $this->db = $db;
        $this->tablename  = $GLOBALS['tableprefix'] .'users';
        $this->sessionkey = INSTALLATION_ID.'-currentuserid';
        $this->cookiekey  = INSTALLATION_ID.'-login';
        $this->profileurl = createURL('profile', '%2$s');
        $this->updateSessionStability();
    }

    /**
     * Fetches the desired user row from database, specified by column and value
     *
     * @param string $fieldname Name of database column to identify user
     * @param string $value     Value of $fieldname
     *
     * @return array Database row or boolean false
     */
    protected function _getuser($fieldname, $value)
    {
        $query = 'SELECT * FROM '. $this->getTableName()
            . ' WHERE ' . $fieldname . ' = "' . $this->db->sql_escape($value) . '"';

        if (!($dbresult = $this->db->sql_query($query)) ) {
            message_die(
                GENERAL_ERROR, 'Could not get user',
                '', __LINE__, __FILE__, $query, $this->db
            );
            return false;
        }

        $row = $this->db->sql_fetchrow($dbresult);
        $this->db->sql_freeresult($dbresult);
        if ($row) {
            return $row;
        } else {
            return false;
        }
    }

    function & getUsers($nb=0) {
        $query = 'SELECT * FROM '. $this->getTableName() .' ORDER BY `uId` DESC';
        if($nb>0) {
            $query .= ' LIMIT 0, '.$nb;
        }
        if (! ($dbresult =& $this->db->sql_query($query)) ) {
            message_die(GENERAL_ERROR, 'Could not get user', '', __LINE__, __FILE__, $query, $this->db);
            return false;
        }

        while ($row = & $this->db->sql_fetchrow($dbresult)) {
            $users[] = $row;
        }
        $this->db->sql_freeresult($dbresult);
        return $users;
    }

    /**
     * Returns an array of user objects.
     * Array is in order of uids
     *
     * @param integer $nb Number of users to fetch.
     *
     * @return array Array of SemanticScuttle_Model_User objects
     */
    public function getObjectUsers($nb = 0)
    {
        $query = 'SELECT * FROM ' . $this->getTableName()
            . ' ORDER BY uId DESC';

        if ($nb > 0) {
            $query .= ' LIMIT 0, ' . intval($nb);
        }

        if (! ($dbresult =& $this->db->sql_query($query)) ) {
            message_die(
                GENERAL_ERROR, 'Could not get user',
                '', __LINE__, __FILE__, $query, $this->db
            );
            return false;
        }

        $users = array();
        while ($row = & $this->db->sql_fetchrow($dbresult)) {
            $users[] = new SemanticScuttle_Model_User(
                $row[$this->getFieldName('primary')],
                $row[$this->getFieldName('username')]
            );
        }
        $this->db->sql_freeresult($dbresult);
        return $users;
    }

    function _randompassword() {
        $seed = (integer) md5(microtime());
        mt_srand($seed);
        $password = mt_rand(1, 99999999);
        $password = substr(md5($password), mt_rand(0, 19), mt_rand(6, 12));
        return $password;
    }

    /**
     * Updates a single field in the user's database row
     *
     * @param integer $uId       ID of the user
     * @param string  $fieldname Name of table column to change
     * @param string  $value     New value
     *
     * @return boolean True if all was well, false if not
     */
    public function _updateuser($uId, $fieldname, $value)
    {
        $updates = array ($fieldname => $value);
        $sql = 'UPDATE '. $this->getTableName()
            . ' SET '. $this->db->sql_build_array('UPDATE', $updates)
            . ' WHERE '. $this->getFieldName('primary') . '=' . intval($uId);

        // Execute the statement.
        $this->db->sql_transaction('begin');
        if (!($dbresult = $this->db->sql_query($sql))) {
            $this->db->sql_transaction('rollback');
            message_die(
                GENERAL_ERROR, 'Could not update user', '',
                __LINE__, __FILE__, $sql, $this->db
            );
            return false;
        }
        $this->db->sql_transaction('commit');

        // Everything worked out, so return true.
        return true;
    }

    function getProfileUrl($id, $username) {
        return sprintf($this->profileurl, urlencode($id), urlencode($username));
    }

    function getUserByUsername($username) {
        return $this->_getuser($this->getFieldName('username'), $username);
    }

    /**
     * Returns user row from database.
     *
     * @param string $privatekey Private Key
     *
     * @return array User array from database, false if no user was found
     */
    public function getUserByPrivateKey($privatekey)
    {
        return $this->_getuser($this->getFieldName('privatekey'), $privatekey);
    }

    function getObjectUserByUsername($username) {
        $user = $this->_getuser($this->getFieldName('username'), $username);
        if($user != false) {
            return new SemanticScuttle_Model_User(
                $user[$this->getFieldName('primary')], $username
            );
        } else {
            return NULL;
        }
    }

    /**
     * Obtains the ID of the given user name.
     * If a user ID is passed, it is returned.
     * In case the user does not exist, NULL is returned.
     *
     * @param string|integer $user User name or user ID
     *
     * @return integer NULL if not found or the user ID
     */
    public function getIdFromUser($user)
    {
        if (is_int($user)) {
            return intval($user);
        } else {
            $objectUser = $this->getObjectUserByUsername($user);
            if ($objectUser != null) {
                return $objectUser->getId();
            }
        }
        return null;
    }

    /**
     * Returns user row from database.
     *
     * @param integer $id User ID
     *
     * @return array User array from database
     */
    public function getUser($id)
    {
        return $this->_getuser($this->getFieldName('primary'), $id);
    }

    /**
     * Returns user object for given user id
     *
     * @param integer $id User ID
     *
     * @return SemanticScuttle_Model_User User object
     */
    public function getObjectUser($id)
    {
        $user = $this->_getuser($this->getFieldName('primary'), $id);
        return new SemanticScuttle_Model_User(
            $id, $user[$this->getFieldName('username')]
        );
    }

    function isLoggedOn() {
        return ($this->getCurrentUserId() !== false);
    }

    /**
     * Tells you if the private key is enabled and valid
     *
     * @param string $privateKey Private Key
     *
     * @return boolean True if enabled and valid
     */
    public function isPrivateKeyValid($privateKey)
    {
        // check length of private key
        if (strlen($privateKey) == 32) {
            return true;
        }
        return false;
    }

    /**
     * Returns the current user object
     *
     * @param boolean $refresh Reload the user from database
     *                         based on current user id
     * @param mixed   $newval  New user value (used internally
     *                         as setter method)
     *
     * @return array User from database
     */
    public function getCurrentUser($refresh = false, $newval = null)
    {
        if (!is_null($newval)) {
            //internal use only: reset currentuser
            $this->currentuser = $newval;
        } else if ($refresh || !isset($this->currentuser)) {
            if ($id = $this->getCurrentUserId()) {
                $this->currentuser = $this->getUser($id);
            } else {
                $this->currentuser = null;
            }
        }
        return $this->currentuser;
    }

    /**
     * Return current user as object
     *
     * @param boolean $refresh Reload the user from database
     *                         based on current user id
     * @param mixed   $newval  New user value (used internally
     *                         as setter method)
     *
     * @return SemanticScuttle_Model_User User object
     */
    function getCurrentObjectUser($refresh = false, $newval = null)
    {
        static $currentObjectUser;
        if (!is_null($newval)) {
            //internal use only: reset currentuser
            $currentObjectUser = $newval;
        } else if ($refresh || !isset($currentObjectUser)) {
            if ($id = $this->getCurrentUserId()) {
                $currentObjectUser = $this->getObjectUser($id);
            } else {
                $currentObjectUser = null;
            }
        }
        return $currentObjectUser;
    }

    function existsUserWithUsername($username) {
        if($this->getUserByUsername($username) != '') {
            return true;
        } else {
            return false;
        }
    }

    function existsUser($id) {
        if($this->getUser($id) != '') {
            return true;
        } else {
            return false;
        }
    }

    /**
     * Checks if the given user is an administrator.
     * Uses global admin_users property containing admin
     * user names.
     *
     * Passing the user id makes this function load the user
     * from database. For efficiency reasons, try to pass
     * the user name or database row.
     *
     * @param integer|array|string $user User ID or user row from DB
     *                                   or user name
     *
     * @return boolean True if the user is admin
     */
    function isAdmin($user)
    {
        if (is_numeric($user)) {
            $user = $this->getUser($user);
            $user = $user['username'];
        } else if (is_array($user)) {
            $user = $user['username'];
        }

        if (isset($GLOBALS['admin_users'])
            && in_array($user, $GLOBALS['admin_users'])
        ) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * Return current user id based on session or cookie
     *
     * @return mixed Integer user id or boolean false when user
     *               could not be found or is not logged on.
     */
    public function getCurrentUserId()
    {
        if ($this->currentuserId !== null) {
            return $this->currentuserId;
        }

        if (isset($_SESSION[$this->getSessionKey()])) {
            $this->currentuserId = (int)$_SESSION[$this->getSessionKey()];
            return $this->currentuserId;

        }

        if (isset($_COOKIE[$this->getCookieKey()])) {
            $cook = explode(':', $_COOKIE[$this->getCookieKey()]);
            //cookie looks like this: 'id:md5(username+password)'
            $query = 'SELECT * FROM '. $this->getTableName() .
                     ' WHERE MD5(CONCAT('.$this->getFieldName('username') .
                                     ', '.$this->getFieldName('password') .
                     ')) = \''.$this->db->sql_escape($cook[1]).'\' AND '.
            $this->getFieldName('primary'). ' = '. $this->db->sql_escape($cook[0]);

            if (! ($dbresult =& $this->db->sql_query($query)) ) {
                message_die(
                    GENERAL_ERROR, 'Could not get user',
                    '', __LINE__, __FILE__, $query, $this->db
                );
                return false;
            }

            if ($row = $this->db->sql_fetchrow($dbresult)) {
                $this->setCurrentUserId(
                    (int)$row[$this->getFieldName('primary')], true
                );
                $this->db->sql_freeresult($dbresult);
                return $this->currentuserId;
            }
        }

        $ssls = SemanticScuttle_Service_Factory::get('User_SslClientCert');
        if ($ssls->hasValidCert()) {
            $id = $ssls->getUserIdFromCert();
            if ($id !== false) {
                $this->setCurrentUserId($id, true);
                return $this->currentuserId;
            }
        }
        return false;
    }



    /**
     * Set the current user ID (i.e. when logging on)
     *
     * @internal
     * No ID verification is being done.
     *
     * @param integer $user           User ID or null to unset the user
     * @param boolean $storeInSession Store the user ID in the session
     *
     * @return void
     */
    public function setCurrentUserId($user, $storeInSession = false)
    {
        if ($user === null) {
            $this->currentuserId = null;
            if ($storeInSession) {
                unset($_SESSION[$this->getSessionKey()]);
            }
        } else {
            $this->currentuserId = (int)$user;
            if ($storeInSession) {
                $_SESSION[$this->getSessionKey()] = $this->currentuserId;
            }
        }
        //reload user object
        $this->getCurrentUser(true);
        $this->getCurrentObjectUser(true);
    }



    /**
     * Try to authenticate and login a user with
     * username and password.
     *
     * @param string  $username Name of user
     * @param string  $password Password
     * @param boolean $remember If a long-time cookie shall be set
     *
     * @return boolean True if the user could be authenticated,
     *                 false if not.
     */
    public function login($username, $password, $remember = false)
    {
        $password = $this->sanitisePassword($password);
        $query = 'SELECT '. $this->getFieldName('primary') .' FROM '. $this->getTableName() .' WHERE '. $this->getFieldName('username') .' = "'. $this->db->sql_escape($username) .'" AND '. $this->getFieldName('password') .' = "'. $this->db->sql_escape($password) .'"';

        if (!($dbresult = $this->db->sql_query($query))) {
            message_die(
                GENERAL_ERROR,
                'Could not get user',
                '', __LINE__, __FILE__, $query, $this->db
            );
            return false;
        }

        $row = $this->db->sql_fetchrow($dbresult);
        $this->db->sql_freeresult($dbresult);

        if ($row) {
            $this->setCurrentUserId($row[$this->getFieldName('primary')], true);
            if ($remember) {
                $cookie = $this->currentuserId . ':' . md5($username.$password);
                setcookie(
                    $this->cookiekey, $cookie,
                    time() + $this->cookietime, '/'
                );
            }
            return true;
        } else {
            return false;
        }
    }

    /**
     * Try to authenticate via the privatekey
     *
     * @param string $privatekey Private Key
     *
     * @return boolean true if the user could be authenticated,
     *                 false if not.
     */
    public function loginPrivateKey($privatekey)
    {
        /* Check if private key valid and enabled */
        if (!$this->isPrivateKeyValid($privatekey)) {
            return false;
        }

        $query = 'SELECT '. $this->getFieldName('primary') .' FROM '
            . $this->getTableName() .' WHERE '
            . $this->getFieldName('privatekey') .' = "'
            . $this->db->sql_escape($privatekey) .'"';

        if (!($dbresult = $this->db->sql_query($query))) {
            message_die(
                GENERAL_ERROR,
                'Could not get user',
                '', __LINE__, __FILE__, $query, $this->db
            );
            return false;
        }

        $row = $this->db->sql_fetchrow($dbresult);
        $this->db->sql_freeresult($dbresult);

        if ($row) {
            $id = $_SESSION[$this->getSessionKey()]
                = $row[$this->getFieldName('primary')];
            return true;
        } else {
            return false;
        }
    }

    /**
     * Logs the user off
     *
     * @return void
     */
    public function logout()
    {
        @setcookie($this->getCookiekey(), '', time() - 1, '/');
        unset($_COOKIE[$this->getCookiekey()]);
        session_unset();
        $this->currentuserId = null;
        $this->currentuser = null;
    }

    function getWatchlist($uId) {
        // Gets the list of user IDs being watched by the given user.
        $query = 'SELECT watched FROM '. $GLOBALS['tableprefix'] .'watched WHERE uId = '. intval($uId);

        if (! ($dbresult =& $this->db->sql_query($query)) ) {
            message_die(GENERAL_ERROR, 'Could not get watchlist', '', __LINE__, __FILE__, $query, $this->db);
            return false;
        }

        $arrWatch = array();
        if ($this->db->sql_numrows($dbresult) == 0) {
            $this->db->sql_freeresult($dbresult);
            return $arrWatch;
        }
        while ($row =& $this->db->sql_fetchrow($dbresult)) {
            $arrWatch[] = $row['watched'];
        }
        $this->db->sql_freeresult($dbresult);
        return $arrWatch;
    }


    /**
     * Gets the list of user names being watched by the given user.
     *
     * @param integer $uId       User ID
     * @param boolean $watchedby if false: get the list of users that $uId watches
     *                           if true: get the list of users that watch $uId
     *
     * @return array Array of user names
     */
    public function getWatchNames($uId, $watchedby = false)
    {
        if ($watchedby) {
            $table1 = 'b';
            $table2 = 'a';
        } else {
            $table1 = 'a';
            $table2 = 'b';
        }
        $primary   = $this->getFieldName('primary');
        $userfield = $this->getFieldName('username');
        $query = 'SELECT '. $table1 .'.'. $userfield
            . ' FROM '. $GLOBALS['tableprefix'] . 'watched AS W,'
            . ' ' . $this->getTableName() .' AS a,'
            . ' ' . $this->getTableName() .' AS b'
            . ' WHERE W.watched = a.' . $primary
            . ' AND W.uId = b.' . $primary
            . ' AND ' . $table2 . '.' . $primary . ' = '. intval($uId)
            . ' ORDER BY '. $table1 . '.' . $userfield;

        if (!($dbresult = $this->db->sql_query($query))) {
            message_die(
                GENERAL_ERROR, 'Could not get watchlist',
                '', __LINE__, __FILE__, $query, $this->db
            );
            return false;
        }

        $arrWatch = array();
        if ($this->db->sql_numrows($dbresult) == 0) {
            $this->db->sql_freeresult($dbresult);
            return $arrWatch;
        }
        while ($row = $this->db->sql_fetchrow($dbresult)) {
            $arrWatch[] = $row[$this->getFieldName('username')];
        }
        $this->db->sql_freeresult($dbresult);
        return $arrWatch;
    }


    function getWatchStatus($watcheduser, $currentuser) {
        // Returns true if the current user is watching the given user, and false otherwise.
        $query = 'SELECT watched FROM '. $GLOBALS['tableprefix'] .'watched AS W INNER JOIN '. $this->getTableName() .' AS U ON U.'. $this->getFieldName('primary') .' = W.watched WHERE U.'. $this->getFieldName('primary') .' = '. intval($watcheduser) .' AND W.uId = '. intval($currentuser);

        if (! ($dbresult =& $this->db->sql_query($query)) ) {
            message_die(GENERAL_ERROR, 'Could not get watchstatus', '', __LINE__, __FILE__, $query, $this->db);
            return false;
        }

        $retval = true;
        if ($this->db->sql_numrows($dbresult) == 0)
        $retval = false;

        $this->db->sql_freeresult($dbresult);
        return $retval;
    }

    function setWatchStatus($subjectUserID) {
        if (!is_numeric($subjectUserID))
        return false;

        $currentUserID = $this->getCurrentUserId();
        $watched = $this->getWatchStatus($subjectUserID, $currentUserID);

        if ($watched) {
            $sql = 'DELETE FROM '. $GLOBALS['tableprefix'] .'watched WHERE uId = '. intval($currentUserID) .' AND watched = '. intval($subjectUserID);
            if (!($dbresult =& $this->db->sql_query($sql))) {
                $this->db->sql_transaction('rollback');
                message_die(GENERAL_ERROR, 'Could not add user to watch list', '', __LINE__, __FILE__, $sql, $this->db);
                return false;
            }
        } else {
            $values = array(
                'uId' => intval($currentUserID),
                'watched' => intval($subjectUserID)
            );
            $sql = 'INSERT INTO '. $GLOBALS['tableprefix'] .'watched '. $this->db->sql_build_array('INSERT', $values);
            if (!($dbresult =& $this->db->sql_query($sql))) {
                $this->db->sql_transaction('rollback');
                message_die(GENERAL_ERROR, 'Could not add user to watch list', '', __LINE__, __FILE__, $sql, $this->db);
                return false;
            }
        }

        $this->db->sql_transaction('commit');
        return true;
    }

    /**
     * Create a new user in database.
     * No checks are done in here - you ought to have checked
     * everything before calling this method!
     *
     * @param string $username   Username to use
     * @param string $password   Password to use
     * @param string $email      Email to use
     * @param string $privateKey Key for RSS auth
     *
     * @return mixed Integer user ID if all is well,
     *               boolean false if an error occured
     */
    public function addUser($username, $password, $email, $privateKey = null)
    {
        // Set up the SQL UPDATE statement.
        $datetime = gmdate('Y-m-d H:i:s', time());
        $password = $this->sanitisePassword($password);
        $values   = array(
            'username'   => $username,
            'password'   => $password,
            'email'      => $email,
            'uDatetime'  => $datetime,
            'uModified'  => $datetime,
            'privateKey' => $privateKey
        );
        $sql = 'INSERT INTO '. $this->getTableName()
            . ' '. $this->db->sql_build_array('INSERT', $values);

        // Execute the statement.
        $this->db->sql_transaction('begin');
        if (!($dbresult = & $this->db->sql_query($sql))) {
            $this->db->sql_transaction('rollback');
            message_die(
                GENERAL_ERROR, 'Could not insert user',
                '', __LINE__, __FILE__, $sql, $this->db
            );
            return false;
        }
        $uId = $this->db->sql_nextid($dbresult);
        $this->db->sql_transaction('commit');

        return $uId;
    }

    /**
     * Updates the given user
     *
     * @param integer $uId              ID of user to change
     * @param string  $password         Password to use
     * @param string  $name             Realname to use
     * @param string  $email            Email to use
     * @param string  $homepage         User's homepage
     * @param string  $uContent         User note
     * @param string  $privateKey       RSS Private Key
     * @param boolean $enablePrivateKey RSS Private Key Flag
     *
     * @return boolean True when all is well, false if not
     */
    public function updateUser(
        $uId, $password, $name, $email, $homepage, $uContent,
        $privateKey = null, $enablePrivateKey = false
    ) {
        if (!is_numeric($uId)) {
            return false;
        }

        // prepend '-' to privateKey if disabled
        if ($privateKey != null && strlen($privateKey) == 32
            && $enablePrivateKey == false
        ) {
            $privateKey = '-' . $privateKey;
        }

        // remove '-' from privateKey if enabling
        if ($privateKey != null && strlen($privateKey) == 33
            && $enablePrivateKey == true
        ) {
            $privateKey = substr($privateKey, 1, 32);
        }

        // if new user is enabling Private Key, create new key
        if ($privateKey == null && $enablePrivateKey == true) {
            $privateKey = $this->getNewPrivateKey();
        }

        // Set up the SQL UPDATE statement.
        $moddatetime = gmdate('Y-m-d H:i:s', time());
        if ($password == '') {
            $updates = array(
                'uModified'  => $moddatetime,
                'name'       => $name,
                'email'      => $email,
                'homepage'   => $homepage,
                'uContent'   => $uContent,
                'privateKey' => $privateKey
            );
        } else {
            $updates = array(
                'uModified'  => $moddatetime,
                'password'   => $this->sanitisePassword($password),
                'name'       => $name,
                'email'      => $email,
                'homepage'   => $homepage,
                'uContent'   => $uContent,
                'privateKey' => $privateKey
            );
        }
        $sql = 'UPDATE '. $this->getTableName()
            . ' SET '. $this->db->sql_build_array('UPDATE', $updates)
            . ' WHERE '. $this->getFieldName('primary') . '=' . intval($uId);

        // Execute the statement.
        $this->db->sql_transaction('begin');
        if (!($dbresult = & $this->db->sql_query($sql))) {
            $this->db->sql_transaction('rollback');
            message_die(
                GENERAL_ERROR, 'Could not update user', '',
                __LINE__, __FILE__, $sql, $this->db
            );
            return false;
        }
        $this->db->sql_transaction('commit');

        // Everything worked out, so return true.
        return true;
    }



    function getAllUsers ( ) {
        $query = 'SELECT * FROM '. $this->getTableName();

        if (! ($dbresult =& $this->db->sql_query($query)) ) {
            message_die(GENERAL_ERROR, 'Could not get users', '', __LINE__, __FILE__, $query, $this->db);
            return false;
        }

        $rows = array();

        while ( $row = $this->db->sql_fetchrow($dbresult) ) {
            $rows[] = $row;
        }
        $this->db->sql_freeresult($dbresult);
        return $rows;
    }

    // Returns an array with admin uIds
    function getAdminIds() {
        $admins = array();
        foreach($GLOBALS['admin_users'] as $adminName) {
            if($this->getIdFromUser($adminName) != NULL)
            $admins[] = $this->getIdFromUser($adminName);
        }
        return $admins;
    }

    function deleteUser($uId) {
        $query = 'DELETE FROM '. $this->getTableName() .' WHERE uId = '. intval($uId);

        if (!($dbresult = & $this->db->sql_query($query))) {
            message_die(GENERAL_ERROR, 'Could not delete user', '', __LINE__, __FILE__, $query, $this->db);
            return false;
        }

        return true;
    }

    /**
     * Delete all users and their watch states.
     * Mainly used in unit tests.
     *
     * @return void
     */
    public function deleteAll()
    {
        $query = 'TRUNCATE TABLE `'. $this->getTableName() .'`';
        $this->db->sql_query($query);

        $query = 'TRUNCATE TABLE `' . $GLOBALS['tableprefix'] . 'watched' . '`';
        $this->db->sql_query($query);
    }

    /**
     * Hashes the password for storage in/querying the database.
     *
     * @param string $password Password to hash
     *
     * @return string Hashed password
     */
    public function sanitisePassword($password)
    {
        return sha1(trim($password));
    }

    /**
     * Changes the password for the given user to a new, random one.
     *
     * @param integer $uId User ID
     *
     * @return string New password of false if something went wrong
     */
    public function generatePassword($uId)
    {
        if (!is_numeric($uId)) {
            return false;
        }

        $password = $this->_randompassword();

        $ok = $this->_updateuser(
            $uId, $this->getFieldName('password'),
            $this->sanitisePassword($password)
        );

        if ($ok) {
            return $password;
        } else {
            return false;
        }
    }

    /**
     * Generates a new private key and confirms it isn't being used.
     * Private key is 32 characters long, consisting of lowercase and
     * numeric characters.
     *
     * @return string the new key value
     */
    public function getNewPrivateKey()
    {
        do {
            $newKey = md5(uniqid('SemanticScuttle', true));
        } while ($this->privateKeyExists($newKey));

        return $newKey;
    }

    /**
     * Checks if a private key already exists
     *
     * @param string $privateKey key that has been generated
     *
     * @return boolean true when the private key exists,
     *                 False if not.
     */
    public function privateKeyExists($privateKey)
    {
        if (!$privateKey) {
            return false;
        }
        $crit = array('privateKey' => $privateKey);

        $sql = 'SELECT COUNT(*) as "0" FROM '
            . $GLOBALS['tableprefix'] . 'users'
            . ' WHERE '. $this->db->sql_build_array('SELECT', $crit);

        if (!($dbresult = $this->db->sql_query($sql))) {
            message_die(
                GENERAL_ERROR, 'Could not get vars', '',
                __LINE__, __FILE__, $sql, $this->db
            );
        }
        if ($this->db->sql_fetchfield(0, 0) > 0) {
            $exists = true;
        } else {
            $exists = false;
        }
        $this->db->sql_freeresult($dbresult);
        return $exists;
    }

    function isReserved($username) {
        if (in_array($username, $GLOBALS['reservedusers'])) {
            return true;
        } else {
            return false;
        }
    }

    function isValidUsername($username) {
        if (strlen($username) < 4) {
            return false;
        }elseif (strlen($username) > 24) {
            // too long usernames are cut by database and may cause bugs when compared
            return false;
        } elseif (preg_match('/(\W)/', $username) > 0) {
            // forbidden non-alphanumeric characters
            return false;
        }
        return true;
    }



    /**
     * Checks if the given email address is valid
     *
     * @param string $email Email address
     *
     * @return boolean True if it is valid, false if not
     */
    public function isValidEmail($email)
    {
        return filter_var($email, FILTER_VALIDATE_EMAIL) !== false;
    }

    /**
     * Sets a session variable.
     * Updates it when it is already set.
     * This is used to detect if cookies work.
     *
     * @return void
     *
     * @see isSessionStable()
     */
    public function updateSessionStability()
    {
        //find out if we have cookies enabled
        if (!isset($_SESSION['sessionStable'])) {
            $_SESSION['sessionStable'] = 0;
        } else {
            $_SESSION['sessionStable'] = 1;
        }
    }

    /**
     * Tells you if the session is fresh or old.
     * If the session is fresh, it's the first page
     * call with that session id. If the session is old,
     * we know that cookies (or session persistance) works
     *
     * @return boolean True if the
     *
     * @see updateSessionStability()
     */
    public function isSessionStable()
    {
        return $_SESSION['sessionStable'] == 1;
    }

    /**
     * Get database column name.
     *
     * @param string $field Field name like 'primary', 'username'
     *                      and 'password'
     *
     * @return string Real field name
     */
    public function getFieldName($field)
    {
        return $this->fields[$field];
    }

    /**
     * Set field name
     *
     * @param string $field Field name like 'primary', 'username'
     *                      and 'password'
     * @param string $value Real database column name
     *
     * @return void
     */
    public function setFieldName($field, $value)
    {
        $this->fields[$field] = $value;
    }

    function getSessionKey()       { return $this->sessionkey; }
    function setSessionKey($value) { $this->sessionkey = $value; }

    function getCookieKey()       { return $this->cookiekey; }
    function setCookieKey($value) { $this->cookiekey = $value; }
}

?>