message/lib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Library functions for messaging
  19  *
  20  * @package   core_message
  21  * @copyright 2008 Luis Rodrigues
  22  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 require_once($CFG->libdir.'/eventslib.php');
  26
  27 define ('MESSAGE_SHORTLENGTH', 300);
  28
  29 define ('MESSAGE_DISCUSSION_WIDTH',600);
  30 define ('MESSAGE_DISCUSSION_HEIGHT',500);
  31
  32 define ('MESSAGE_SHORTVIEW_LIMIT', 8);//the maximum number of messages to show on the short message history
  33
  34 define('MESSAGE_HISTORY_SHORT',0);
  35 define('MESSAGE_HISTORY_ALL',1);
  36
  37 define('MESSAGE_VIEW_UNREAD_MESSAGES','unread');
  38 define('MESSAGE_VIEW_RECENT_CONVERSATIONS','recentconversations');
  39 define('MESSAGE_VIEW_RECENT_NOTIFICATIONS','recentnotifications');
  40 define('MESSAGE_VIEW_CONTACTS','contacts');
  41 define('MESSAGE_VIEW_BLOCKED','blockedusers');
  42 define('MESSAGE_VIEW_COURSE','course_');
  43 define('MESSAGE_VIEW_SEARCH','search');
  44
  45 define('MESSAGE_SEARCH_MAX_RESULTS', 200);
  46
  47 define('MESSAGE_CONTACTS_PER_PAGE',10);
  48 define('MESSAGE_MAX_COURSE_NAME_LENGTH', 30);
  49
  50 /**
  51  * Define contants for messaging default settings population. For unambiguity of
  52  * plugin developer intentions we use 4-bit value (LSB numbering):
  53  * bit 0 - whether to send message when user is loggedin (MESSAGE_DEFAULT_LOGGEDIN)
  54  * bit 1 - whether to send message when user is loggedoff (MESSAGE_DEFAULT_LOGGEDOFF)
  55  * bit 2..3 - messaging permission (MESSAGE_DISALLOWED|MESSAGE_PERMITTED|MESSAGE_FORCED)
  56  *
  57  * MESSAGE_PERMITTED_MASK contains the mask we use to distinguish permission setting
  58  */
  59
  60 define('MESSAGE_DEFAULT_LOGGEDIN', 0x01); // 0001
  61 define('MESSAGE_DEFAULT_LOGGEDOFF', 0x02); // 0010
  62
  63 define('MESSAGE_DISALLOWED', 0x04); // 0100
  64 define('MESSAGE_PERMITTED', 0x08); // 1000
  65 define('MESSAGE_FORCED', 0x0c); // 1100
  66
  67 define('MESSAGE_PERMITTED_MASK', 0x0c); // 1100
  68
  69 /**
  70  * Set default value for default outputs permitted setting
  71  */
  72 define('MESSAGE_DEFAULT_PERMITTED', 'permitted');
  73
  74 /**
  75  * Print the selector that allows the user to view their contacts, course participants, their recent
  76  * conversations etc
  77  *
  78  * @param int $countunreadtotal how many unread messages does the user have?
  79  * @param int $viewing What is the user viewing? ie MESSAGE_VIEW_UNREAD_MESSAGES, MESSAGE_VIEW_SEARCH etc
  80  * @param object $user1 the user whose messages are being viewed
  81  * @param object $user2 the user $user1 is talking to
  82  * @param array $blockedusers an array of users blocked by $user1
  83  * @param array $onlinecontacts an array of $user1's online contacts
  84  * @param array $offlinecontacts an array of $user1's offline contacts
  85  * @param array $strangers an array of users who have messaged $user1 who aren't contacts
  86  * @param bool $showactionlinks show action links (add/remove contact etc)
  87  * @param int $page if there are so many users listed that they have to be split into pages what page are we viewing
  88  * @return void
  89  */
  90 function message_print_contact_selector($countunreadtotal, $viewing, $user1, $user2, $blockedusers, $onlinecontacts, $offlinecontacts, $strangers, $showactionlinks, $page=0) {
  91     global $PAGE;
  92
  93     echo html_writer::start_tag('div', array('class' => 'contactselector mdl-align'));
  94
  95     //if 0 unread messages and they've requested unread messages then show contacts
  96     if ($countunreadtotal == 0 && $viewing == MESSAGE_VIEW_UNREAD_MESSAGES) {
  97         $viewing = MESSAGE_VIEW_CONTACTS;
  98     }
  99
 100     //if they have no blocked users and they've requested blocked users switch them over to contacts
 101     if (count($blockedusers) == 0 && $viewing == MESSAGE_VIEW_BLOCKED) {
 102         $viewing = MESSAGE_VIEW_CONTACTS;
 103     }
 104
 105     $onlyactivecourses = true;
 106     $courses = enrol_get_users_courses($user1->id, $onlyactivecourses);
 107     $coursecontexts = message_get_course_contexts($courses);//we need one of these again so holding on to them
 108
 109     $strunreadmessages = null;
 110     if ($countunreadtotal>0) { //if there are unread messages
 111         $strunreadmessages = get_string('unreadmessages','message', $countunreadtotal);
 112     }
 113
 114     message_print_usergroup_selector($viewing, $courses, $coursecontexts, $countunreadtotal, count($blockedusers), $strunreadmessages, $user1);
 115
 116     if ($viewing == MESSAGE_VIEW_UNREAD_MESSAGES) {
 117         message_print_contacts($onlinecontacts, $offlinecontacts, $strangers, $PAGE->url, 1, $showactionlinks,$strunreadmessages, $user2);
 118     } else if ($viewing == MESSAGE_VIEW_CONTACTS || $viewing == MESSAGE_VIEW_SEARCH || $viewing == MESSAGE_VIEW_RECENT_CONVERSATIONS || $viewing == MESSAGE_VIEW_RECENT_NOTIFICATIONS) {
 119         message_print_contacts($onlinecontacts, $offlinecontacts, $strangers, $PAGE->url, 0, $showactionlinks, $strunreadmessages, $user2);
 120     } else if ($viewing == MESSAGE_VIEW_BLOCKED) {
 121         message_print_blocked_users($blockedusers, $PAGE->url, $showactionlinks, null, $user2);
 122     } else if (substr($viewing, 0, 7) == MESSAGE_VIEW_COURSE) {
 123         $courseidtoshow = intval(substr($viewing, 7));
 124
 125         if (!empty($courseidtoshow)
 126             && array_key_exists($courseidtoshow, $coursecontexts)
 127             && has_capability('moodle/course:viewparticipants', $coursecontexts[$courseidtoshow])) {
 128
 129             message_print_participants($coursecontexts[$courseidtoshow], $courseidtoshow, $PAGE->url, $showactionlinks, null, $page, $user2);
 130         }
 131     }
 132
 133     // Only show the search button if we're viewing our own contacts.
 134     if ($viewing == MESSAGE_VIEW_CONTACTS && $user2 == null) {
 135         echo html_writer::start_tag('form', array('action' => 'index.php','method' => 'GET'));
 136         echo html_writer::start_tag('fieldset');
 137         $managebuttonclass = 'visible';
 138         $strmanagecontacts = get_string('search','message');
 139         echo html_writer::empty_tag('input', array('type' => 'hidden','name' => 'viewing','value' => MESSAGE_VIEW_SEARCH));
 140         echo html_writer::empty_tag('input', array('type' => 'submit','value' => $strmanagecontacts,'class' => $managebuttonclass));
 141         echo html_writer::end_tag('fieldset');
 142         echo html_writer::end_tag('form');
 143     }
 144
 145     echo html_writer::end_tag('div');
 146 }
 147
 148 /**
 149  * Print course participants. Called by message_print_contact_selector()
 150  *
 151  * @param object $context the course context
 152  * @param int $courseid the course ID
 153  * @param string $contactselecturl the url to send the user to when a contact's name is clicked
 154  * @param bool $showactionlinks show action links (add/remove contact etc) next to the users
 155  * @param string $titletodisplay Optionally specify a title to display above the participants
 156  * @param int $page if there are so many users listed that they have to be split into pages what page are we viewing
 157  * @param object $user2 the user $user1 is talking to. They will be highlighted if they appear in the list of participants
 158  * @return void
 159  */
 160 function message_print_participants($context, $courseid, $contactselecturl=null, $showactionlinks=true, $titletodisplay=null, $page=0, $user2=null) {
 161     global $DB, $USER, $PAGE, $OUTPUT;
 162
 163     if (empty($titletodisplay)) {
 164         $titletodisplay = get_string('participants');
 165     }
 166
 167     $countparticipants = count_enrolled_users($context);
 168
 169     list($esql, $params) = get_enrolled_sql($context);
 170     $params['mcuserid'] = $USER->id;
 171     $ufields = user_picture::fields('u');
 172
 173     $sql = "SELECT $ufields, mc.id as contactlistid, mc.blocked
 174               FROM {user} u
 175               JOIN ($esql) je ON je.id = u.id
 176               LEFT JOIN {message_contacts} mc ON mc.contactid = u.id AND mc.userid = :mcuserid
 177              WHERE u.deleted = 0";
 178
 179     $participants = $DB->get_records_sql($sql, $params, $page * MESSAGE_CONTACTS_PER_PAGE, MESSAGE_CONTACTS_PER_PAGE);
 180
 181     $pagingbar = new paging_bar($countparticipants, $page, MESSAGE_CONTACTS_PER_PAGE, $PAGE->url, 'page');
 182     $pagingbar->maxdisplay = 4;
 183     echo $OUTPUT->render($pagingbar);
 184
 185     echo html_writer::start_tag('div', array('id' => 'message_participants', 'class' => 'boxaligncenter'));
 186
 187     echo html_writer::tag('div' , $titletodisplay, array('class' => 'heading'));
 188
 189     $users = '';
 190     foreach ($participants as $participant) {
 191         if ($participant->id != $USER->id) {
 192
 193             $iscontact = false;
 194             $isblocked = false;
 195             if ( $participant->contactlistid )  {
 196                 if ($participant->blocked == 0) {
 197                     // Is contact. Is not blocked.
 198                     $iscontact = true;
 199                     $isblocked = false;
 200                 } else {
 201                     // Is blocked.
 202                     $iscontact = false;
 203                     $isblocked = true;
 204                 }
 205             }
 206
 207             $participant->messagecount = 0;//todo it would be nice if the course participant could report new messages
 208             $content = message_print_contactlist_user($participant, $iscontact, $isblocked,
 209                 $contactselecturl, $showactionlinks, $user2);
 210             $users .= html_writer::tag('li', $content);
 211         }
 212     }
 213     if (strlen($users) > 0) {
 214         echo html_writer::tag('ul', $users, array('id' => 'message-courseparticipants', 'class' => 'message-contacts'));
 215     }
 216
 217     echo html_writer::end_tag('div');
 218 }
 219
 220 /**
 221  * Retrieve users blocked by $user1
 222  *
 223  * @param object $user1 the user whose messages are being viewed
 224  * @param object $user2 the user $user1 is talking to. If they are being blocked
 225  *                      they will have a variable called 'isblocked' added to their user object
 226  * @return array the users blocked by $user1
 227  */
 228 function message_get_blocked_users($user1=null, $user2=null) {
 229     global $DB, $USER;
 230
 231     if (empty($user1)) {
 232         $user1 = $USER;
 233     }
 234
 235     if (!empty($user2)) {
 236         $user2->isblocked = false;
 237     }
 238
 239     $blockedusers = array();
 240
 241     $userfields = user_picture::fields('u', array('lastaccess'));
 242     $blockeduserssql = "SELECT $userfields, COUNT(m.id) AS messagecount
 243                           FROM {message_contacts} mc
 244                           JOIN {user} u ON u.id = mc.contactid
 245                           LEFT OUTER JOIN {message} m ON m.useridfrom = mc.contactid AND m.useridto = :user1id1
 246                          WHERE u.deleted = 0 AND mc.userid = :user1id2 AND mc.blocked = 1
 247                       GROUP BY $userfields
 248                       ORDER BY u.firstname ASC";
 249     $rs =  $DB->get_recordset_sql($blockeduserssql, array('user1id1' => $user1->id, 'user1id2' => $user1->id));
 250
 251     foreach($rs as $rd) {
 252         $blockedusers[] = $rd;
 253
 254         if (!empty($user2) && $user2->id == $rd->id) {
 255             $user2->isblocked = true;
 256         }
 257     }
 258     $rs->close();
 259
 260     return $blockedusers;
 261 }
 262
 263 /**
 264  * Print users blocked by $user1. Called by message_print_contact_selector()
 265  *
 266  * @param array $blockedusers the users blocked by $user1
 267  * @param string $contactselecturl the url to send the user to when a contact's name is clicked
 268  * @param bool $showactionlinks show action links (add/remove contact etc) next to the users
 269  * @param string $titletodisplay Optionally specify a title to display above the participants
 270  * @param object $user2 the user $user1 is talking to. They will be highlighted if they appear in the list of blocked users
 271  * @return void
 272  */
 273 function message_print_blocked_users($blockedusers, $contactselecturl=null, $showactionlinks=true, $titletodisplay=null, $user2=null) {
 274     global $OUTPUT;
 275
 276     $countblocked = count($blockedusers);
 277
 278     echo html_writer::start_tag('div', array('id' => 'message_contacts', 'class' => 'boxaligncenter'));
 279
 280     if (!empty($titletodisplay)) {
 281         echo html_writer::tag('div', $titletodisplay, array('class' => 'heading'));
 282     }
 283
 284     if ($countblocked) {
 285         echo html_writer::tag('div', get_string('blockedusers', 'message', $countblocked), array('class' => 'heading'));
 286
 287         $isuserblocked = true;
 288         $isusercontact = false;
 289         $blockeduserslist = '';
 290         foreach ($blockedusers as $blockeduser) {
 291             $content = message_print_contactlist_user($blockeduser, $isusercontact, $isuserblocked,
 292                 $contactselecturl, $showactionlinks, $user2);
 293             $blockeduserslist .= html_writer::tag('li', $content);
 294         }
 295         echo html_writer::tag('ul', $blockeduserslist, array('id' => 'message-blockedusers', 'class' => 'message-contacts'));
 296     }
 297
 298     echo html_writer::end_tag('div');
 299 }
 300
 301 /**
 302  * Retrieve $user1's contacts (online, offline and strangers)
 303  *
 304  * @param object $user1 the user whose messages are being viewed
 305  * @param object $user2 the user $user1 is talking to. If they are a contact
 306  *                      they will have a variable called 'iscontact' added to their user object
 307  * @return array containing 3 arrays. array($onlinecontacts, $offlinecontacts, $strangers)
 308  */
 309 function message_get_contacts($user1=null, $user2=null) {
 310     global $DB, $CFG, $USER;
 311
 312     if (empty($user1)) {
 313         $user1 = $USER;
 314     }
 315
 316     if (!empty($user2)) {
 317         $user2->iscontact = false;
 318     }
 319
 320     $timetoshowusers = 300; //Seconds default
 321     if (isset($CFG->block_online_users_timetosee)) {
 322         $timetoshowusers = $CFG->block_online_users_timetosee * 60;
 323     }
 324
 325     // time which a user is counting as being active since
 326     $timefrom = time()-$timetoshowusers;
 327
 328     // people in our contactlist who are online
 329     $onlinecontacts  = array();
 330     // people in our contactlist who are offline
 331     $offlinecontacts = array();
 332     // people who are not in our contactlist but have sent us a message
 333     $strangers       = array();
 334
 335     $userfields = user_picture::fields('u', array('lastaccess'));
 336
 337     // get all in our contactlist who are not blocked in our contact list
 338     // and count messages we have waiting from each of them
 339     $contactsql = "SELECT $userfields, COUNT(m.id) AS messagecount
 340                      FROM {message_contacts} mc
 341                      JOIN {user} u ON u.id = mc.contactid
 342                      LEFT OUTER JOIN {message} m ON m.useridfrom = mc.contactid AND m.useridto = ?
 343                     WHERE u.deleted = 0 AND mc.userid = ? AND mc.blocked = 0
 344                  GROUP BY $userfields
 345                  ORDER BY u.firstname ASC";
 346
 347     $rs = $DB->get_recordset_sql($contactsql, array($user1->id, $user1->id));
 348     foreach ($rs as $rd) {
 349         if ($rd->lastaccess >= $timefrom) {
 350             // they have been active recently, so are counted online
 351             $onlinecontacts[] = $rd;
 352
 353         } else {
 354             $offlinecontacts[] = $rd;
 355         }
 356
 357         if (!empty($user2) && $user2->id == $rd->id) {
 358             $user2->iscontact = true;
 359         }
 360     }
 361     $rs->close();
 362
 363     // get messages from anyone who isn't in our contact list and count the number
 364     // of messages we have from each of them
 365     $strangersql = "SELECT $userfields, count(m.id) as messagecount
 366                       FROM {message} m
 367                       JOIN {user} u  ON u.id = m.useridfrom
 368                       LEFT OUTER JOIN {message_contacts} mc ON mc.contactid = m.useridfrom AND mc.userid = m.useridto
 369                      WHERE u.deleted = 0 AND mc.id IS NULL AND m.useridto = ?
 370                   GROUP BY $userfields
 371                   ORDER BY u.firstname ASC";
 372
 373     $rs = $DB->get_recordset_sql($strangersql, array($USER->id));
 374     // Add user id as array index, so supportuser and noreply user don't get duplicated (if they are real users).
 375     foreach ($rs as $rd) {
 376         $strangers[$rd->id] = $rd;
 377     }
 378     $rs->close();
 379
 380     // Add noreply user and support user to the list, if they don't exist.
 381     $supportuser = core_user::get_support_user();
 382     if (!isset($strangers[$supportuser->id])) {
 383         $supportuser->messagecount = message_count_unread_messages($USER, $supportuser);
 384         if ($supportuser->messagecount > 0) {
 385             $strangers[$supportuser->id] = $supportuser;
 386         }
 387     }
 388
 389     $noreplyuser = core_user::get_noreply_user();
 390     if (!isset($strangers[$noreplyuser->id])) {
 391         $noreplyuser->messagecount = message_count_unread_messages($USER, $noreplyuser);
 392         if ($noreplyuser->messagecount > 0) {
 393             $strangers[$noreplyuser->id] = $noreplyuser;
 394         }
 395     }
 396     return array($onlinecontacts, $offlinecontacts, $strangers);
 397 }
 398
 399 /**
 400  * Print $user1's contacts. Called by message_print_contact_selector()
 401  *
 402  * @param array $onlinecontacts $user1's contacts which are online
 403  * @param array $offlinecontacts $user1's contacts which are offline
 404  * @param array $strangers users which are not contacts but who have messaged $user1
 405  * @param string $contactselecturl the url to send the user to when a contact's name is clicked
 406  * @param int $minmessages The minimum number of unread messages required from a user for them to be displayed
 407  *                         Typically 0 (show all contacts) or 1 (only show contacts from whom we have a new message)
 408  * @param bool $showactionlinks show action links (add/remove contact etc) next to the users
 409  * @param string $titletodisplay Optionally specify a title to display above the participants
 410  * @param object $user2 the user $user1 is talking to. They will be highlighted if they appear in the list of contacts
 411  * @return void
 412  */
 413 function message_print_contacts($onlinecontacts, $offlinecontacts, $strangers, $contactselecturl=null, $minmessages=0, $showactionlinks=true, $titletodisplay=null, $user2=null) {
 414     global $CFG, $PAGE, $OUTPUT;
 415
 416     $countonlinecontacts  = count($onlinecontacts);
 417     $countofflinecontacts = count($offlinecontacts);
 418     $countstrangers       = count($strangers);
 419     $isuserblocked = null;
 420
 421     if ($countonlinecontacts + $countofflinecontacts == 0) {
 422         echo html_writer::tag('div', get_string('contactlistempty', 'message'), array('class' => 'heading'));
 423     }
 424
 425     if (!empty($titletodisplay)) {
 426         echo html_writer::tag('div', $titletodisplay, array('class' => 'heading'));
 427     }
 428
 429     if($countonlinecontacts) {
 430         // Print out list of online contacts.
 431
 432         if (empty($titletodisplay)) {
 433             echo html_writer::tag('div',
 434                 get_string('onlinecontacts', 'message', $countonlinecontacts),
 435                 array('class' => 'heading'));
 436         }
 437
 438         $isuserblocked = false;
 439         $isusercontact = true;
 440         $contacts = '';
 441         foreach ($onlinecontacts as $contact) {
 442             if ($minmessages == 0 || $contact->messagecount >= $minmessages) {
 443                 $content = message_print_contactlist_user($contact, $isusercontact, $isuserblocked,
 444                     $contactselecturl, $showactionlinks, $user2);
 445                 $contacts .= html_writer::tag('li', $content);
 446             }
 447         }
 448         if (strlen($contacts) > 0) {
 449             echo html_writer::tag('ul', $contacts, array('id' => 'message-onlinecontacts', 'class' => 'message-contacts'));
 450         }
 451     }
 452
 453     if ($countofflinecontacts) {
 454         // Print out list of offline contacts.
 455
 456         if (empty($titletodisplay)) {
 457             echo html_writer::tag('div',
 458                 get_string('offlinecontacts', 'message', $countofflinecontacts),
 459                 array('class' => 'heading'));
 460         }
 461
 462         $isuserblocked = false;
 463         $isusercontact = true;
 464         $contacts = '';
 465         foreach ($offlinecontacts as $contact) {
 466             if ($minmessages == 0 || $contact->messagecount >= $minmessages) {
 467                 $content = message_print_contactlist_user($contact, $isusercontact, $isuserblocked,
 468                     $contactselecturl, $showactionlinks, $user2);
 469                 $contacts .= html_writer::tag('li', $content);
 470             }
 471         }
 472         if (strlen($contacts) > 0) {
 473             echo html_writer::tag('ul', $contacts, array('id' => 'message-offlinecontacts', 'class' => 'message-contacts'));
 474         }
 475
 476     }
 477
 478     // Print out list of incoming contacts.
 479     if ($countstrangers) {
 480         echo html_writer::tag('div', get_string('incomingcontacts', 'message', $countstrangers), array('class' => 'heading'));
 481
 482         $isuserblocked = false;
 483         $isusercontact = false;
 484         $contacts = '';
 485         foreach ($strangers as $stranger) {
 486             if ($minmessages == 0 || $stranger->messagecount >= $minmessages) {
 487                 $content = message_print_contactlist_user($stranger, $isusercontact, $isuserblocked,
 488                     $contactselecturl, $showactionlinks, $user2);
 489                 $contacts .= html_writer::tag('li', $content);
 490             }
 491         }
 492         if (strlen($contacts) > 0) {
 493             echo html_writer::tag('ul', $contacts, array('id' => 'message-incommingcontacts', 'class' => 'message-contacts'));
 494         }
 495
 496     }
 497
 498     if ($countstrangers && ($countonlinecontacts + $countofflinecontacts == 0)) {  // Extra help
 499         echo html_writer::tag('div','('.get_string('addsomecontactsincoming', 'message').')',array('class' => 'note'));
 500     }
 501 }
 502
 503 /**
 504  * Print a select box allowing the user to choose to view new messages, course participants etc.
 505  *
 506  * Called by message_print_contact_selector()
 507  * @param int $viewing What page is the user viewing ie MESSAGE_VIEW_UNREAD_MESSAGES, MESSAGE_VIEW_RECENT_CONVERSATIONS etc
 508  * @param array $courses array of course objects. The courses the user is enrolled in.
 509  * @param array $coursecontexts array of course contexts. Keyed on course id.
 510  * @param int $countunreadtotal how many unread messages does the user have?
 511  * @param int $countblocked how many users has the current user blocked?
 512  * @param stdClass $user1 The user whose messages we are viewing.
 513  * @param string $strunreadmessages a preconstructed message about the number of unread messages the user has
 514  * @return void
 515  */
 516 function message_print_usergroup_selector($viewing, $courses, $coursecontexts, $countunreadtotal, $countblocked, $strunreadmessages, $user1 = null) {
 517     global $PAGE;
 518     $options = array();
 519
 520     if ($countunreadtotal>0) { //if there are unread messages
 521         $options[MESSAGE_VIEW_UNREAD_MESSAGES] = $strunreadmessages;
 522     }
 523
 524     $str = get_string('contacts', 'message');
 525     $options[MESSAGE_VIEW_CONTACTS] = $str;
 526
 527     $options[MESSAGE_VIEW_RECENT_CONVERSATIONS] = get_string('mostrecentconversations', 'message');
 528     $options[MESSAGE_VIEW_RECENT_NOTIFICATIONS] = get_string('mostrecentnotifications', 'message');
 529
 530     if (!empty($courses)) {
 531         $courses_options = array();
 532
 533         foreach($courses as $course) {
 534             if (has_capability('moodle/course:viewparticipants', $coursecontexts[$course->id])) {
 535                 //Not using short_text() as we want the end of the course name. Not the beginning.
 536                 $shortname = format_string($course->shortname, true, array('context' => $coursecontexts[$course->id]));
 537                 if (core_text::strlen($shortname) > MESSAGE_MAX_COURSE_NAME_LENGTH) {
 538                     $courses_options[MESSAGE_VIEW_COURSE.$course->id] = '...'.core_text::substr($shortname, -MESSAGE_MAX_COURSE_NAME_LENGTH);
 539                 } else {
 540                     $courses_options[MESSAGE_VIEW_COURSE.$course->id] = $shortname;
 541                 }
 542             }
 543         }
 544
 545         if (!empty($courses_options)) {
 546             $options[] = array(get_string('courses') => $courses_options);
 547         }
 548     }
 549
 550     if ($countblocked>0) {
 551         $str = get_string('blockedusers','message', $countblocked);
 552         $options[MESSAGE_VIEW_BLOCKED] = $str;
 553     }
 554
 555     $select = new single_select($PAGE->url, 'viewing', $options, $viewing, false);
 556     $select->set_label(get_string('messagenavigation', 'message'));
 557
 558     $renderer = $PAGE->get_renderer('core');
 559     echo $renderer->render($select);
 560 }
 561
 562 /**
 563  * Load the course contexts for all of the users courses
 564  *
 565  * @param array $courses array of course objects. The courses the user is enrolled in.
 566  * @return array of course contexts
 567  */
 568 function message_get_course_contexts($courses) {
 569     $coursecontexts = array();
 570
 571     foreach($courses as $course) {
 572         $coursecontexts[$course->id] = context_course::instance($course->id);
 573     }
 574
 575     return $coursecontexts;
 576 }
 577
 578 /**
 579  * strip off action parameters like 'removecontact'
 580  *
 581  * @param moodle_url/string $moodleurl a URL. Typically the current page URL.
 582  * @return string the URL minus parameters that perform actions (like adding/removing/blocking a contact).
 583  */
 584 function message_remove_url_params($moodleurl) {
 585     $newurl = new moodle_url($moodleurl);
 586     $newurl->remove_params('addcontact','removecontact','blockcontact','unblockcontact');
 587     return $newurl->out();
 588 }
 589
 590 /**
 591  * Count the number of messages with a field having a specified value.
 592  * if $field is empty then return count of the whole array
 593  * if $field is non-existent then return 0
 594  *
 595  * @param array $messagearray array of message objects
 596  * @param string $field the field to inspect on the message objects
 597  * @param string $value the value to test the field against
 598  */
 599 function message_count_messages($messagearray, $field='', $value='') {
 600     if (!is_array($messagearray)) return 0;
 601     if ($field == '' or empty($messagearray)) return count($messagearray);
 602
 603     $count = 0;
 604     foreach ($messagearray as $message) {
 605         $count += ($message->$field == $value) ? 1 : 0;
 606     }
 607     return $count;
 608 }
 609
 610 /**
 611  * Returns the count of unread messages for user. Either from a specific user or from all users.
 612  *
 613  * @param object $user1 the first user. Defaults to $USER
 614  * @param object $user2 the second user. If null this function will count all of user 1's unread messages.
 615  * @return int the count of $user1's unread messages
 616  */
 617 function message_count_unread_messages($user1=null, $user2=null) {
 618     global $USER, $DB;
 619
 620     if (empty($user1)) {
 621         $user1 = $USER;
 622     }
 623
 624     if (!empty($user2)) {
 625         return $DB->count_records_select('message', "useridto = ? AND useridfrom = ?",
 626             array($user1->id, $user2->id), "COUNT('id')");
 627     } else {
 628         return $DB->count_records_select('message', "useridto = ?",
 629             array($user1->id), "COUNT('id')");
 630     }
 631 }
 632
 633 /**
 634  * Count the number of users blocked by $user1
 635  *
 636  * @param object $user1 user object
 637  * @return int the number of blocked users
 638  */
 639 function message_count_blocked_users($user1=null) {
 640     global $USER, $DB;
 641
 642     if (empty($user1)) {
 643         $user1 = $USER;
 644     }
 645
 646     $sql = "SELECT count(mc.id)
 647             FROM {message_contacts} mc
 648             WHERE mc.userid = :userid AND mc.blocked = 1";
 649     $params = array('userid' => $user1->id);
 650
 651     return $DB->count_records_sql($sql, $params);
 652 }
 653
 654 /**
 655  * Print the search form and search results if a search has been performed
 656  *
 657  * @param  boolean $advancedsearch show basic or advanced search form
 658  * @param  object $user1 the current user
 659  * @return boolean true if a search was performed
 660  */
 661 function message_print_search($advancedsearch = false, $user1=null) {
 662     $frm = data_submitted();
 663
 664     $doingsearch = false;
 665     if ($frm) {
 666         if (confirm_sesskey()) {
 667             $doingsearch = !empty($frm->combinedsubmit) || !empty($frm->keywords) || (!empty($frm->personsubmit) and !empty($frm->name));
 668         } else {
 669             $frm = false;
 670         }
 671     }
 672
 673     if (!empty($frm->combinedsearch)) {
 674         $combinedsearchstring = $frm->combinedsearch;
 675     } else {
 676         //$combinedsearchstring = get_string('searchcombined','message').'...';
 677         $combinedsearchstring = '';
 678     }
 679
 680     if ($doingsearch) {
 681         if ($advancedsearch) {
 682
 683             $messagesearch = '';
 684             if (!empty($frm->keywords)) {
 685                 $messagesearch = $frm->keywords;
 686             }
 687             $personsearch = '';
 688             if (!empty($frm->name)) {
 689                 $personsearch = $frm->name;
 690             }
 691             include('search_advanced.html');
 692         } else {
 693             include('search.html');
 694         }
 695
 696         $showicontext = false;
 697         message_print_search_results($frm, $showicontext, $user1);
 698
 699         return true;
 700     } else {
 701
 702         if ($advancedsearch) {
 703             $personsearch = $messagesearch = '';
 704             include('search_advanced.html');
 705         } else {
 706             include('search.html');
 707         }
 708         return false;
 709     }
 710 }
 711
 712 /**
 713  * Get the users recent conversations meaning all the people they've recently
 714  * sent or received a message from plus the most recent message sent to or received from each other user
 715  *
 716  * @param object $user the current user
 717  * @param int $limitfrom can be used for paging
 718  * @param int $limitto can be used for paging
 719  * @return array
 720  */
 721 function message_get_recent_conversations($user, $limitfrom=0, $limitto=100) {
 722     global $DB;
 723
 724     $userfields = user_picture::fields('otheruser', array('lastaccess'));
 725
 726     // This query retrieves the most recent message received from or sent to
 727     // seach other user.
 728     //
 729     // If two messages have the same timecreated, we take the one with the
 730     // larger id.
 731     //
 732     // There is a separate query for read and unread messages as they are stored
 733     // in different tables. They were originally retrieved in one query but it
 734     // was so large that it was difficult to be confident in its correctness.
 735     $uniquefield = $DB->sql_concat('message.useridfrom', "'-'", 'message.useridto');
 736     $sql = "SELECT $uniquefield, $userfields,
 737                    message.id as mid, message.notification, message.smallmessage, message.fullmessage,
 738                    message.fullmessagehtml, message.fullmessageformat, message.timecreated,
 739                    contact.id as contactlistid, contact.blocked
 740               FROM {message_read} message
 741               JOIN (
 742                         SELECT MAX(id) AS messageid,
 743                                matchedmessage.useridto,
 744                                matchedmessage.useridfrom
 745                          FROM {message_read} matchedmessage
 746                    INNER JOIN (
 747                                SELECT MAX(recentmessages.timecreated) timecreated,
 748                                       recentmessages.useridfrom,
 749                                       recentmessages.useridto
 750                                  FROM {message_read} recentmessages
 751                                 WHERE (
 752                                       (recentmessages.useridfrom = :userid1 AND recentmessages.timeuserfromdeleted = 0) OR
 753                                       (recentmessages.useridto = :userid2   AND recentmessages.timeusertodeleted = 0)
 754                                       )
 755                              GROUP BY recentmessages.useridfrom, recentmessages.useridto
 756                               ) recent ON matchedmessage.useridto     = recent.useridto
 757                            AND matchedmessage.useridfrom   = recent.useridfrom
 758                            AND matchedmessage.timecreated  = recent.timecreated
 759                            WHERE (
 760                                  (matchedmessage.useridfrom = :userid6 AND matchedmessage.timeuserfromdeleted = 0) OR
 761                                  (matchedmessage.useridto = :userid7   AND matchedmessage.timeusertodeleted = 0)
 762                                  )
 763                       GROUP BY matchedmessage.useridto, matchedmessage.useridfrom
 764                    ) messagesubset ON messagesubset.messageid = message.id
 765               JOIN {user} otheruser ON (message.useridfrom = :userid4 AND message.useridto = otheruser.id)
 766                 OR (message.useridto   = :userid5 AND message.useridfrom   = otheruser.id)
 767          LEFT JOIN {message_contacts} contact ON contact.userid  = :userid3 AND contact.userid = otheruser.id
 768              WHERE otheruser.deleted = 0 AND message.notification = 0
 769           ORDER BY message.timecreated DESC";
 770     $params = array(
 771             'userid1' => $user->id,
 772             'userid2' => $user->id,
 773             'userid3' => $user->id,
 774             'userid4' => $user->id,
 775             'userid5' => $user->id,
 776             'userid6' => $user->id,
 777             'userid7' => $user->id
 778         );
 779     $read = $DB->get_records_sql($sql, $params, $limitfrom, $limitto);
 780
 781     // We want to get the messages that have not been read. These are stored in the 'message' table. It is the
 782     // exact same query as the one above, except for the table we are querying. So, simply replace references to
 783     // the 'message_read' table with the 'message' table.
 784     $sql = str_replace('{message_read}', '{message}', $sql);
 785     $unread = $DB->get_records_sql($sql, $params, $limitfrom, $limitto);
 786
 787     // Union the 2 result sets together looking for the message with the most
 788     // recent timecreated for each other user.
 789     // $conversation->id (the array key) is the other user's ID.
 790     $conversations = array();
 791     $conversation_arrays = array($unread, $read);
 792     foreach ($conversation_arrays as $conversation_array) {
 793         foreach ($conversation_array as $conversation) {
 794             if (!isset($conversations[$conversation->id])) {
 795                 $conversations[$conversation->id] = $conversation;
 796             } else {
 797                 $current = $conversations[$conversation->id];
 798                 if ($current->timecreated < $conversation->timecreated) {
 799                     $conversations[$conversation->id] = $conversation;
 800                 } else if ($current->timecreated == $conversation->timecreated) {
 801                     if ($current->mid < $conversation->mid) {
 802                         $conversations[$conversation->id] = $conversation;
 803                     }
 804                 }
 805             }
 806         }
 807     }
 808
 809     // Sort the conversations by $conversation->timecreated, newest to oldest
 810     // There may be multiple conversations with the same timecreated
 811     // The conversations array contains both read and unread messages (different tables) so sorting by ID won't work
 812     $result = core_collator::asort_objects_by_property($conversations, 'timecreated', core_collator::SORT_NUMERIC);
 813     $conversations = array_reverse($conversations);
 814
 815     return $conversations;
 816 }
 817
 818 /**
 819  * Get the users recent event notifications
 820  *
 821  * @param object $user the current user
 822  * @param int $limitfrom can be used for paging
 823  * @param int $limitto can be used for paging
 824  * @return array
 825  */
 826 function message_get_recent_notifications($user, $limitfrom=0, $limitto=100) {
 827     global $DB;
 828
 829     $userfields = user_picture::fields('u', array('lastaccess'));
 830     $sql = "SELECT mr.id AS message_read_id, $userfields, mr.notification, mr.smallmessage, mr.fullmessage, mr.fullmessagehtml, mr.fullmessageformat, mr.timecreated as timecreated, mr.contexturl, mr.contexturlname
 831               FROM {message_read} mr
 832                    JOIN {user} u ON u.id=mr.useridfrom
 833              WHERE mr.useridto = :userid1 AND u.deleted = '0' AND mr.notification = :notification
 834              ORDER BY mr.timecreated DESC";
 835     $params = array('userid1' => $user->id, 'notification' => 1);
 836
 837     $notifications =  $DB->get_records_sql($sql, $params, $limitfrom, $limitto);
 838     return $notifications;
 839 }
 840
 841 /**
 842  * Print the user's recent conversations
 843  *
 844  * @param stdClass $user the current user
 845  * @param bool $showicontext flag indicating whether or not to show text next to the action icons
 846  */
 847 function message_print_recent_conversations($user1 = null, $showicontext = false, $showactionlinks = true) {
 848     global $USER;
 849
 850     echo html_writer::start_tag('p', array('class' => 'heading'));
 851     echo get_string('mostrecentconversations', 'message');
 852     echo html_writer::end_tag('p');
 853
 854     if (empty($user1)) {
 855         $user1 = $USER;
 856     }
 857
 858     $conversations = message_get_recent_conversations($user1);
 859
 860     // Attach context url information to create the "View this conversation" type links
 861     foreach($conversations as $conversation) {
 862         $conversation->contexturl = new moodle_url("/message/index.php?user1={$user1->id}&user2={$conversation->id}");
 863         $conversation->contexturlname = get_string('thisconversation', 'message');
 864     }
 865
 866     $showotheruser = true;
 867     message_print_recent_messages_table($conversations, $user1, $showotheruser, $showicontext, false, $showactionlinks);
 868 }
 869
 870 /**
 871  * Print the user's recent notifications
 872  *
 873  * @param stdClass $user the current user
 874  */
 875 function message_print_recent_notifications($user=null) {
 876     global $USER;
 877
 878     echo html_writer::start_tag('p', array('class' => 'heading'));
 879     echo get_string('mostrecentnotifications', 'message');
 880     echo html_writer::end_tag('p');
 881
 882     if (empty($user)) {
 883         $user = $USER;
 884     }
 885
 886     $notifications = message_get_recent_notifications($user);
 887
 888     $showicontext = false;
 889     $showotheruser = false;
 890     message_print_recent_messages_table($notifications, $user, $showotheruser, $showicontext, true);
 891 }
 892
 893 /**
 894  * Print a list of recent messages
 895  *
 896  * @access private
 897  *
 898  * @param array $messages the messages to display
 899  * @param stdClass $user the current user
 900  * @param bool $showotheruser display information on the other user?
 901  * @param bool $showicontext show text next to the action icons?
 902  * @param bool $forcetexttohtml Force text to go through @see text_to_html() via @see format_text()
 903  * @param bool $showactionlinks
 904  * @return void
 905  */
 906 function message_print_recent_messages_table($messages, $user = null, $showotheruser = true, $showicontext = false, $forcetexttohtml = false, $showactionlinks = true) {
 907     global $OUTPUT;
 908     static $dateformat;
 909
 910     if (empty($dateformat)) {
 911         $dateformat = get_string('strftimedatetimeshort');
 912     }
 913
 914     echo html_writer::start_tag('div', array('class' => 'messagerecent'));
 915     foreach ($messages as $message) {
 916         echo html_writer::start_tag('div', array('class' => 'singlemessage'));
 917
 918         if ($showotheruser) {
 919             $strcontact = $strblock = $strhistory = null;
 920
 921             if ($showactionlinks) {
 922                 if ( $message->contactlistid )  {
 923                     if ($message->blocked == 0) { // The other user isn't blocked.
 924                         $strcontact = message_contact_link($message->id, 'remove', true, null, $showicontext);
 925                         $strblock   = message_contact_link($message->id, 'block', true, null, $showicontext);
 926                     } else { // The other user is blocked.
 927                         $strcontact = message_contact_link($message->id, 'add', true, null, $showicontext);
 928                         $strblock   = message_contact_link($message->id, 'unblock', true, null, $showicontext);
 929                     }
 930                 } else {
 931                     $strcontact = message_contact_link($message->id, 'add', true, null, $showicontext);
 932                     $strblock   = message_contact_link($message->id, 'block', true, null, $showicontext);
 933                 }
 934
 935                 //should we show just the icon or icon and text?
 936                 $histicontext = 'icon';
 937                 if ($showicontext) {
 938                     $histicontext = 'both';
 939                 }
 940                 $strhistory = message_history_link($user->id, $message->id, true, '', '', $histicontext);
 941             }
 942             echo html_writer::start_tag('span', array('class' => 'otheruser'));
 943
 944             echo html_writer::start_tag('span', array('class' => 'pix'));
 945             echo $OUTPUT->user_picture($message, array('size' => 20, 'courseid' => SITEID));
 946             echo html_writer::end_tag('span');
 947
 948             echo html_writer::start_tag('span', array('class' => 'contact'));
 949
 950             $link = new moodle_url("/message/index.php?user1={$user->id}&user2=$message->id");
 951             $action = null;
 952             echo $OUTPUT->action_link($link, fullname($message), $action, array('title' => get_string('sendmessageto', 'message', fullname($message))));
 953
 954             echo html_writer::end_tag('span');//end contact
 955
 956             if ($showactionlinks) {
 957                 echo $strcontact.$strblock.$strhistory;
 958             }
 959             echo html_writer::end_tag('span');//end otheruser
 960         }
 961
 962         $messagetext = message_format_message_text($message, $forcetexttohtml);
 963
 964         echo html_writer::tag('span', userdate($message->timecreated, $dateformat), array('class' => 'messagedate'));
 965         echo html_writer::tag('span', $messagetext, array('class' => 'themessage'));
 966         echo message_format_contexturl($message);
 967         echo html_writer::end_tag('div');//end singlemessage
 968     }
 969     echo html_writer::end_tag('div');//end messagerecent
 970 }
 971
 972 /**
 973  * Try to guess how to convert the message to html.
 974  *
 975  * @access private
 976  *
 977  * @param stdClass $message
 978  * @param bool $forcetexttohtml
 979  * @return string html fragment
 980  */
 981 function message_format_message_text($message, $forcetexttohtml = false) {
 982     // Note: this is a very nasty hack that tries to work around the weird messaging rules and design.
 983
 984     $options = new stdClass();
 985     $options->para = false;
 986
 987     $format = $message->fullmessageformat;
 988
 989     if (strval($message->smallmessage) !== '') {
 990         if ($message->notification == 1) {
 991             if (strval($message->fullmessagehtml) !== '' or strval($message->fullmessage) !== '') {
 992                 $format = FORMAT_PLAIN;
 993             }
 994         }
 995         $messagetext = $message->smallmessage;
 996
 997     } else if ($message->fullmessageformat == FORMAT_HTML) {
 998         if (strval($message->fullmessagehtml) !== '') {
 999             $messagetext = $message->fullmessagehtml;
1000         } else {
1001             $messagetext = $message->fullmessage;
1002             $format = FORMAT_MOODLE;
1003         }
1004
1005     } else {
1006         if (strval($message->fullmessage) !== '') {
1007             $messagetext = $message->fullmessage;
1008         } else {
1009             $messagetext = $message->fullmessagehtml;
1010             $format = FORMAT_HTML;
1011         }
1012     }
1013
1014     if ($forcetexttohtml) {
1015         // This is a crazy hack, why not set proper format when creating the notifications?
1016         if ($format === FORMAT_PLAIN) {
1017             $format = FORMAT_MOODLE;
1018         }
1019     }
1020     return format_text($messagetext, $format, $options);
1021 }
1022
1023 /**
1024  * Add the selected user as a contact for the current user
1025  *
1026  * @param int $contactid the ID of the user to add as a contact
1027  * @param int $blocked 1 if you wish to block the contact
1028  * @return bool/int false if the $contactid isnt a valid user id. True if no changes made.
1029  *                  Otherwise returns the result of update_record() or insert_record()
1030  */
1031 function message_add_contact($contactid, $blocked=0) {
1032     global $USER, $DB;
1033
1034     if (!$DB->record_exists('user', array('id' => $contactid))) { // invalid userid
1035         return false;
1036     }
1037
1038     // Check if a record already exists as we may be changing blocking status.
1039     if (($contact = $DB->get_record('message_contacts', array('userid' => $USER->id, 'contactid' => $contactid))) !== false) {
1040         // Check if blocking status has been changed.
1041         if ($contact->blocked != $blocked) {
1042             $contact->blocked = $blocked;
1043             $DB->update_record('message_contacts', $contact);
1044
1045             if ($blocked == 1) {
1046                 // Trigger event for blocking a contact.
1047                 $event = \core\event\message_contact_blocked::create(array(
1048                     'objectid' => $contact->id,
1049                     'userid' => $contact->userid,
1050                     'relateduserid' => $contact->contactid,
1051                     'context'  => context_user::instance($contact->userid)
1052                 ));
1053                 $event->add_record_snapshot('message_contacts', $contact);
1054                 $event->trigger();
1055             } else {
1056                 // Trigger event for unblocking a contact.
1057                 $event = \core\event\message_contact_unblocked::create(array(
1058                     'objectid' => $contact->id,
1059                     'userid' => $contact->userid,
1060                     'relateduserid' => $contact->contactid,
1061                     'context'  => context_user::instance($contact->userid)
1062                 ));
1063                 $event->add_record_snapshot('message_contacts', $contact);
1064                 $event->trigger();
1065             }
1066
1067             return true;
1068         } else {
1069             // No change to blocking status.
1070             return true;
1071         }
1072
1073     } else {
1074         // New contact record.
1075         $contact = new stdClass();
1076         $contact->userid = $USER->id;
1077         $contact->contactid = $contactid;
1078         $contact->blocked = $blocked;
1079         $contact->id = $DB->insert_record('message_contacts', $contact);
1080
1081         $eventparams = array(
1082             'objectid' => $contact->id,
1083             'userid' => $contact->userid,
1084             'relateduserid' => $contact->contactid,
1085             'context'  => context_user::instance($contact->userid)
1086         );
1087
1088         if ($blocked) {
1089             $event = \core\event\message_contact_blocked::create($eventparams);
1090         } else {
1091             $event = \core\event\message_contact_added::create($eventparams);
1092         }
1093         // Trigger event.
1094         $event->trigger();
1095
1096         return true;
1097     }
1098 }
1099
1100 /**
1101  * remove a contact
1102  *
1103  * @param int $contactid the user ID of the contact to remove
1104  * @return bool returns the result of delete_records()
1105  */
1106 function message_remove_contact($contactid) {
1107     global $USER, $DB;
1108
1109     if ($contact = $DB->get_record('message_contacts', array('userid' => $USER->id, 'contactid' => $contactid))) {
1110         $DB->delete_records('message_contacts', array('id' => $contact->id));
1111
1112         // Trigger event for removing a contact.
1113         $event = \core\event\message_contact_removed::create(array(
1114             'objectid' => $contact->id,
1115             'userid' => $contact->userid,
1116             'relateduserid' => $contact->contactid,
1117             'context'  => context_user::instance($contact->userid)
1118         ));
1119         $event->add_record_snapshot('message_contacts', $contact);
1120         $event->trigger();
1121
1122         return true;
1123     }
1124
1125     return false;
1126 }
1127
1128 /**
1129  * Unblock a contact. Note that this reverts the previously blocked user back to a non-contact.
1130  *
1131  * @param int $contactid the user ID of the contact to unblock
1132  * @return bool returns the result of delete_records()
1133  */
1134 function message_unblock_contact($contactid) {
1135     return message_add_contact($contactid, 0);
1136 }
1137
1138 /**
1139  * Block a user.
1140  *
1141  * @param int $contactid the user ID of the user to block
1142  * @return bool
1143  */
1144 function message_block_contact($contactid) {
1145     return message_add_contact($contactid, 1);
1146 }
1147
1148 /**
1149  * Checks if a user can delete a message.
1150  *
1151  * @param stdClass $message the message to delete
1152  * @param string $userid the user id of who we want to delete the message for (this may be done by the admin
1153  *  but will still seem as if it was by the user)
1154  * @return bool Returns true if a user can delete the message, false otherwise.
1155  */
1156 function message_can_delete_message($message, $userid) {
1157     global $USER;
1158
1159     if ($message->useridfrom == $userid) {
1160         $userdeleting = 'useridfrom';
1161     } else if ($message->useridto == $userid) {
1162         $userdeleting = 'useridto';
1163     } else {
1164         return false;
1165     }
1166
1167     $systemcontext = context_system::instance();
1168
1169     // Let's check if the user is allowed to delete this message.
1170     if (has_capability('moodle/site:deleteanymessage', $systemcontext) ||
1171         ((has_capability('moodle/site:deleteownmessage', $systemcontext) &&
1172             $USER->id == $message->$userdeleting))) {
1173         return true;
1174     }
1175
1176     return false;
1177 }
1178
1179 /**
1180  * Deletes a message.
1181  *
1182  * This function does not verify any permissions.
1183  *
1184  * @param stdClass $message the message to delete
1185  * @param string $userid the user id of who we want to delete the message for (this may be done by the admin
1186  *  but will still seem as if it was by the user)
1187  * @return bool
1188  */
1189 function message_delete_message($message, $userid) {
1190     global $DB;
1191
1192     // The column we want to alter.
1193     if ($message->useridfrom == $userid) {
1194         $coltimedeleted = 'timeuserfromdeleted';
1195     } else if ($message->useridto == $userid) {
1196         $coltimedeleted = 'timeusertodeleted';
1197     } else {
1198         return false;
1199     }
1200
1201     // Don't update it if it's already been deleted.
1202     if ($message->$coltimedeleted > 0) {
1203         return false;
1204     }
1205
1206     // Get the table we want to update.
1207     if (isset($message->timeread)) {
1208         $messagetable = 'message_read';
1209     } else {
1210         $messagetable = 'message';
1211     }
1212
1213     // Mark the message as deleted.
1214     $updatemessage = new stdClass();
1215     $updatemessage->id = $message->id;
1216     $updatemessage->$coltimedeleted = time();
1217     $success = $DB->update_record($messagetable, $updatemessage);
1218
1219     if ($success) {
1220         // Trigger event for deleting a message.
1221         \core\event\message_deleted::create_from_ids($message->useridfrom, $message->useridto,
1222             $userid, $messagetable, $message->id)->trigger();
1223     }
1224
1225     return $success;
1226 }
1227
1228 /**
1229  * Load a user's contact record
1230  *
1231  * @param int $contactid the user ID of the user whose contact record you want
1232  * @return array message contacts
1233  */
1234 function message_get_contact($contactid) {
1235     global $USER, $DB;
1236     return $DB->get_record('message_contacts', array('userid' => $USER->id, 'contactid' => $contactid));
1237 }
1238
1239 /**
1240  * Print the results of a message search
1241  *
1242  * @param mixed $frm submitted form data
1243  * @param bool $showicontext show text next to action icons?
1244  * @param object $currentuser the current user
1245  * @return void
1246  */
1247 function message_print_search_results($frm, $showicontext=false, $currentuser=null) {
1248     global $USER, $DB, $OUTPUT;
1249
1250     if (empty($currentuser)) {
1251         $currentuser = $USER;
1252     }
1253
1254     echo html_writer::start_tag('div', array('class' => 'mdl-left'));
1255
1256     $personsearch = false;
1257     $personsearchstring = null;
1258     if (!empty($frm->personsubmit) and !empty($frm->name)) {
1259         $personsearch = true;
1260         $personsearchstring = $frm->name;
1261     } else if (!empty($frm->combinedsubmit) and !empty($frm->combinedsearch)) {
1262         $personsearch = true;
1263         $personsearchstring = $frm->combinedsearch;
1264     }
1265
1266     // Search for person.
1267     if ($personsearch) {
1268         if (optional_param('mycourses', 0, PARAM_BOOL)) {
1269             $users = array();
1270             $mycourses = enrol_get_my_courses('id');
1271             $mycoursesids = array();
1272             foreach ($mycourses as $mycourse) {
1273                 $mycoursesids[] = $mycourse->id;
1274             }
1275             $susers = message_search_users($mycoursesids, $personsearchstring);
1276             foreach ($susers as $suser) {
1277                 $users[$suser->id] = $suser;
1278             }
1279         } else {
1280             $users = message_search_users(SITEID, $personsearchstring);
1281         }
1282
1283         if (!empty($users)) {
1284             echo html_writer::start_tag('p', array('class' => 'heading searchresultcount'));
1285             echo get_string('userssearchresults', 'message', count($users));
1286             echo html_writer::end_tag('p');
1287
1288             echo html_writer::start_tag('table', array('class' => 'messagesearchresults'));
1289             foreach ($users as $user) {
1290
1291                 if ( $user->contactlistid )  {
1292                     if ($user->blocked == 0) { // User is not blocked.
1293                         $strcontact = message_contact_link($user->id, 'remove', true, null, $showicontext);
1294                         $strblock   = message_contact_link($user->id, 'block', true, null, $showicontext);
1295                     } else { // blocked
1296                         $strcontact = message_contact_link($user->id, 'add', true, null, $showicontext);
1297                         $strblock   = message_contact_link($user->id, 'unblock', true, null, $showicontext);
1298                     }
1299                 } else {
1300                     $strcontact = message_contact_link($user->id, 'add', true, null, $showicontext);
1301                     $strblock   = message_contact_link($user->id, 'block', true, null, $showicontext);
1302                 }
1303
1304                 // Should we show just the icon or icon and text?
1305                 $histicontext = 'icon';
1306                 if ($showicontext) {
1307                     $histicontext = 'both';
1308                 }
1309                 $strhistory = message_history_link($USER->id, $user->id, true, '', '', $histicontext);
1310
1311                 echo html_writer::start_tag('tr');
1312
1313                 echo html_writer::start_tag('td', array('class' => 'pix'));
1314                 echo $OUTPUT->user_picture($user, array('size' => 20, 'courseid' => SITEID));
1315                 echo html_writer::end_tag('td');
1316
1317                 echo html_writer::start_tag('td',array('class' => 'contact'));
1318                 $action = null;
1319                 $link = new moodle_url("/message/index.php?id=$user->id");
1320                 echo $OUTPUT->action_link($link, fullname($user), $action, array('title' => get_string('sendmessageto', 'message', fullname($user))));
1321                 echo html_writer::end_tag('td');
1322
1323                 echo html_writer::tag('td', $strcontact, array('class' => 'link'));
1324                 echo html_writer::tag('td', $strblock, array('class' => 'link'));
1325                 echo html_writer::tag('td', $strhistory, array('class' => 'link'));
1326
1327                 echo html_writer::end_tag('tr');
1328             }
1329             echo html_writer::end_tag('table');
1330
1331         } else {
1332             echo html_writer::start_tag('p', array('class' => 'heading searchresultcount'));
1333             echo get_string('userssearchresults', 'message', 0).'<br /><br />';
1334             echo html_writer::end_tag('p');
1335         }
1336     }
1337
1338     // search messages for keywords
1339     $messagesearch = false;
1340     $messagesearchstring = null;
1341     if (!empty($frm->keywords)) {
1342         $messagesearch = true;
1343         $messagesearchstring = clean_text(trim($frm->keywords));
1344     } else if (!empty($frm->combinedsubmit) and !empty($frm->combinedsearch)) {
1345         $messagesearch = true;
1346         $messagesearchstring = clean_text(trim($frm->combinedsearch));
1347     }
1348
1349     if ($messagesearch) {
1350         if ($messagesearchstring) {
1351             $keywords = explode(' ', $messagesearchstring);
1352         } else {
1353             $keywords = array();
1354         }
1355         $tome     = false;
1356         $fromme   = false;
1357         $courseid = 'none';
1358
1359         if (empty($frm->keywordsoption)) {
1360             $frm->keywordsoption = 'allmine';
1361         }
1362
1363         switch ($frm->keywordsoption) {
1364             case 'tome':
1365                 $tome   = true;
1366                 break;
1367             case 'fromme':
1368                 $fromme = true;
1369                 break;
1370             case 'allmine':
1371                 $tome   = true;
1372                 $fromme = true;
1373                 break;
1374             case 'allusers':
1375                 $courseid = SITEID;
1376                 break;
1377             case 'courseusers':
1378                 $courseid = $frm->courseid;
1379                 break;
1380             default:
1381                 $tome   = true;
1382                 $fromme = true;
1383         }
1384
1385         if (($messages = message_search($keywords, $fromme, $tome, $courseid)) !== false) {
1386
1387             // Get a list of contacts.
1388             if (($contacts = $DB->get_records('message_contacts', array('userid' => $USER->id), '', 'contactid, blocked') ) === false) {
1389                 $contacts = array();
1390             }
1391
1392             // Print heading with number of results.
1393             echo html_writer::start_tag('p', array('class' => 'heading searchresultcount'));
1394             $countresults = count($messages);
1395             if ($countresults == MESSAGE_SEARCH_MAX_RESULTS) {
1396                 echo get_string('keywordssearchresultstoomany', 'message', $countresults).' ("'.s($messagesearchstring).'")';
1397             } else {
1398                 echo get_string('keywordssearchresults', 'message', $countresults);
1399             }
1400             echo html_writer::end_tag('p');
1401
1402             // Print table headings.
1403             echo html_writer::start_tag('table', array('class' => 'messagesearchresults', 'cellspacing' => '0'));
1404
1405             $headertdstart = html_writer::start_tag('td', array('class' => 'messagesearchresultscol'));
1406             $headertdend   = html_writer::end_tag('td');
1407             echo html_writer::start_tag('tr');
1408             echo $headertdstart.get_string('from').$headertdend;
1409             echo $headertdstart.get_string('to').$headertdend;
1410             echo $headertdstart.get_string('message', 'message').$headertdend;
1411             echo $headertdstart.get_string('timesent', 'message').$headertdend;
1412             echo html_writer::end_tag('tr');
1413
1414             $blockedcount = 0;
1415             $dateformat = get_string('strftimedatetimeshort');
1416             $strcontext = get_string('context', 'message');
1417             foreach ($messages as $message) {
1418
1419                 // Ignore messages to and from blocked users unless $frm->includeblocked is set.
1420                 if (!optional_param('includeblocked', 0, PARAM_BOOL) and (
1421                       ( isset($contacts[$message->useridfrom]) and ($contacts[$message->useridfrom]->blocked == 1)) or
1422                       ( isset($contacts[$message->useridto]  ) and ($contacts[$message->useridto]->blocked   == 1))
1423                                                 )
1424                    ) {
1425                     $blockedcount ++;
1426                     continue;
1427                 }
1428
1429                 // Load user-to record.
1430                 if ($message->useridto !== $USER->id) {
1431                     $userto = core_user::get_user($message->useridto);
1432                     $tocontact = (array_key_exists($message->useridto, $contacts) and
1433                                     ($contacts[$message->useridto]->blocked == 0) );
1434                     $toblocked = (array_key_exists($message->useridto, $contacts) and
1435                                     ($contacts[$message->useridto]->blocked == 1) );
1436                 } else {
1437                     $userto = false;
1438                     $tocontact = false;
1439                     $toblocked = false;
1440                 }
1441
1442                 // Load user-from record.
1443                 if ($message->useridfrom !== $USER->id) {
1444                     $userfrom = core_user::get_user($message->useridfrom);
1445                     $fromcontact = (array_key_exists($message->useridfrom, $contacts) and
1446                                     ($contacts[$message->useridfrom]->blocked == 0) );
1447                     $fromblocked = (array_key_exists($message->useridfrom, $contacts) and
1448                                     ($contacts[$message->useridfrom]->blocked == 1) );
1449                 } else {
1450                     $userfrom = false;
1451                     $fromcontact = false;
1452                     $fromblocked = false;
1453                 }
1454
1455                 // Find date string for this message.
1456                 $date = usergetdate($message->timecreated);
1457                 $datestring = $date['year'].$date['mon'].$date['mday'];
1458
1459                 // Print out message row.
1460                 echo html_writer::start_tag('tr', array('valign' => 'top'));
1461
1462                 echo html_writer::start_tag('td', array('class' => 'contact'));
1463                 message_print_user($userfrom, $fromcontact, $fromblocked, $showicontext);
1464                 echo html_writer::end_tag('td');
1465
1466                 echo html_writer::start_tag('td', array('class' => 'contact'));
1467                 message_print_user($userto, $tocontact, $toblocked, $showicontext);
1468                 echo html_writer::end_tag('td');
1469
1470                 echo html_writer::start_tag('td', array('class' => 'summary'));
1471                 echo message_get_fragment($message->smallmessage, $keywords);
1472                 echo html_writer::start_tag('div', array('class' => 'link'));
1473
1474                 // If the user clicks the context link display message sender on the left.
1475                 // EXCEPT if the current user is in the conversation. Current user == always on the left.
1476                 $leftsideuserid = $rightsideuserid = null;
1477                 if ($currentuser->id == $message->useridto) {
1478                     $leftsideuserid = $message->useridto;
1479                     $rightsideuserid = $message->useridfrom;
1480                 } else {
1481                     $leftsideuserid = $message->useridfrom;
1482                     $rightsideuserid = $message->useridto;
1483                 }
1484                 message_history_link($leftsideuserid, $rightsideuserid, false,
1485                                      $messagesearchstring, 'm'.$message->id, $strcontext);
1486                 echo html_writer::end_tag('div');
1487                 echo html_writer::end_tag('td');
1488
1489                 echo html_writer::tag('td', userdate($message->timecreated, $dateformat), array('class' => 'date'));
1490
1491                 echo html_writer::end_tag('tr');
1492             }
1493
1494
1495             if ($blockedcount > 0) {
1496                 echo html_writer::start_tag('tr');
1497                 echo html_writer::tag('td', get_string('blockedmessages', 'message', $blockedcount), array('colspan' => 4, 'align' => 'center'));
1498                 echo html_writer::end_tag('tr');
1499             }
1500             echo html_writer::end_tag('table');
1501
1502         } else {
1503             echo html_writer::tag('p', get_string('keywordssearchresults', 'message', 0), array('class' => 'heading'));
1504         }
1505     }
1506
1507     if (!$personsearch && !$messagesearch) {
1508         //they didn't enter any search terms
1509         echo $OUTPUT->notification(get_string('emptysearchstring', 'message'));
1510     }
1511
1512     echo html_writer::end_tag('div');
1513 }
1514
1515 /**
1516  * Print information on a user. Used when printing search results.
1517  *
1518  * @param object/bool $user the user to display or false if you just want $USER
1519  * @param bool $iscontact is the user being displayed a contact?
1520  * @param bool $isblocked is the user being displayed blocked?
1521  * @param bool $includeicontext include text next to the action icons?
1522  * @return void
1523  */
1524 function message_print_user ($user=false, $iscontact=false, $isblocked=false, $includeicontext=false) {
1525     global $USER, $OUTPUT;
1526
1527     $userpictureparams = array('size' => 20, 'courseid' => SITEID);
1528
1529     if ($user === false) {
1530         echo $OUTPUT->user_picture($USER, $userpictureparams);
1531     } else if (core_user::is_real_user($user->id)) { // If not real user, then don't show any links.
1532         $userpictureparams['link'] = false;
1533         echo $OUTPUT->user_picture($USER, $userpictureparams);
1534         echo fullname($user);
1535     } else {
1536         echo $OUTPUT->user_picture($user, $userpictureparams);
1537
1538         $link = new moodle_url("/message/index.php?id=$user->id");
1539         echo $OUTPUT->action_link($link, fullname($user), null, array('title' =>
1540                 get_string('sendmessageto', 'message', fullname($user))));
1541
1542         $return = false;
1543         $script = null;
1544         if ($iscontact) {
1545             message_contact_link($user->id, 'remove', $return, $script, $includeicontext);
1546         } else {
1547             message_contact_link($user->id, 'add', $return, $script, $includeicontext);
1548         }
1549
1550         if ($isblocked) {
1551             message_contact_link($user->id, 'unblock', $return, $script, $includeicontext);
1552         } else {
1553             message_contact_link($user->id, 'block', $return, $script, $includeicontext);
1554         }
1555     }
1556 }
1557
1558 /**
1559  * Print a message contact link
1560  *
1561  * @param int $userid the ID of the user to apply to action to
1562  * @param string $linktype can be add, remove, block or unblock
1563  * @param bool $return if true return the link as a string. If false echo the link.
1564  * @param string $script the URL to send the user to when the link is clicked. If null, the current page.
1565  * @param bool $text include text next to the icons?
1566  * @param bool $icon include a graphical icon?
1567  * @return string  if $return is true otherwise bool
1568  */
1569 function message_contact_link($userid, $linktype='add', $return=false, $script=null, $text=false, $icon=true) {
1570     global $OUTPUT, $PAGE;
1571
1572     //hold onto the strings as we're probably creating a bunch of links
1573     static $str;
1574
1575     if (empty($script)) {
1576         //strip off previous action params like 'removecontact'
1577         $script = message_remove_url_params($PAGE->url);
1578     }
1579
1580     if (empty($str->blockcontact)) {
1581        $str = new stdClass();
1582        $str->blockcontact   =  get_string('blockcontact', 'message');
1583        $str->unblockcontact =  get_string('unblockcontact', 'message');
1584        $str->removecontact  =  get_string('removecontact', 'message');
1585        $str->addcontact     =  get_string('addcontact', 'message');
1586     }
1587
1588     $command = $linktype.'contact';
1589     $string  = $str->{$command};
1590
1591     $safealttext = s($string);
1592
1593     $safestring = '';
1594     if (!empty($text)) {
1595         $safestring = $safealttext;
1596     }
1597
1598     $img = '';
1599     if ($icon) {
1600         $iconpath = null;
1601         switch ($linktype) {
1602             case 'block':
1603                 $iconpath = 't/block';
1604                 break;
1605             case 'unblock':
1606                 $iconpath = 't/unblock';
1607                 break;
1608             case 'remove':
1609                 $iconpath = 't/removecontact';
1610                 break;
1611             case 'add':
1612             default:
1613                 $iconpath = 't/addcontact';
1614         }
1615
1616         $img = '<img src="'.$OUTPUT->pix_url($iconpath).'" class="iconsmall" alt="'.$safealttext.'" />';
1617     }
1618
1619     $output = '<span class="'.$linktype.'contact">'.
1620               '<a href="'.$script.'&amp;'.$command.'='.$userid.
1621               '&amp;sesskey='.sesskey().'" title="'.$safealttext.'">'.
1622               $img.
1623               $safestring.'</a></span>';
1624
1625     if ($return) {
1626         return $output;
1627     } else {
1628         echo $output;
1629         return true;
1630     }
1631 }
1632
1633 /**
1634  * echo or return a link to take the user to the full message history between themselves and another user
1635  *
1636  * @param int $userid1 the ID of the user displayed on the left (usually the current user)
1637  * @param int $userid2 the ID of the other user
1638  * @param bool $return true to return the link as a string. False to echo the link.
1639  * @param string $keywords any keywords to highlight in the message history
1640  * @param string $position anchor name to jump to within the message history
1641  * @param string $linktext optionally specify the link text
1642  * @return string|bool. Returns a string if $return is true. Otherwise returns a boolean.
1643  */
1644 function message_history_link($userid1, $userid2, $return=false, $keywords='', $position='', $linktext='') {
1645     global $OUTPUT, $PAGE;
1646     static $strmessagehistory;
1647
1648     if (empty($strmessagehistory)) {
1649         $strmessagehistory = get_string('messagehistory', 'message');
1650     }
1651
1652     if ($position) {
1653         $position = "#$position";
1654     }
1655     if ($keywords) {
1656         $keywords = "&search=".urlencode($keywords);
1657     }
1658
1659     if ($linktext == 'icon') {  // Icon only
1660         $fulllink = '<img src="'.$OUTPUT->pix_url('t/messages') . '" class="iconsmall" alt="'.$strmessagehistory.'" />';
1661     } else if ($linktext == 'both') {  // Icon and standard name
1662         $fulllink = '<img src="'.$OUTPUT->pix_url('t/messages') . '" class="iconsmall" alt="" />';
1663         $fulllink .= '&nbsp;'.$strmessagehistory;
1664     } else if ($linktext) {    // Custom name
1665         $fulllink = $linktext;
1666     } else {                   // Standard name only
1667         $fulllink = $strmessagehistory;
1668     }
1669
1670     $popupoptions = array(
1671             'height' => 500,
1672             'width' => 500,
1673             'menubar' => false,
1674             'location' => false,
1675             'status' => true,
1676             'scrollbars' => true,
1677             'resizable' => true);
1678
1679     $link = new moodle_url('/message/index.php?history='.MESSAGE_HISTORY_ALL."&user1=$userid1&user2=$userid2$keywords$position");
1680     if ($PAGE->url && $PAGE->url->get_param('viewing')) {
1681         $link->param('viewing', $PAGE->url->get_param('viewing'));
1682     }
1683     $action = null;
1684     $str = $OUTPUT->action_link($link, $fulllink, $action, array('title' => $strmessagehistory));
1685
1686     $str = '<span class="history">'.$str.'</span>';
1687
1688     if ($return) {
1689         return $str;
1690     } else {
1691         echo $str;
1692         return true;
1693     }
1694 }
1695
1696
1697 /**
1698  * Search through course users.
1699  *
1700  * If $courseids contains the site course then this function searches
1701  * through all undeleted and confirmed users.
1702  *
1703  * @param int|array $courseids Course ID or array of course IDs.
1704  * @param string $searchtext the text to search for.
1705  * @param string $sort the column name to order by.
1706  * @param string|array $exceptions comma separated list or array of user IDs to exclude.
1707  * @return array An array of {@link $USER} records.
1708  */
1709 function message_search_users($courseids, $searchtext, $sort='', $exceptions='') {
1710     global $CFG, $USER, $DB;
1711
1712     // Basic validation to ensure that the parameter $courseids is not an empty array or an empty value.
1713     if (!$courseids) {
1714         $courseids = array(SITEID);
1715     }
1716
1717     // Allow an integer to be passed.
1718     if (!is_array($courseids)) {
1719         $courseids = array($courseids);
1720     }
1721
1722     $fullname = $DB->sql_fullname();
1723     $ufields = user_picture::fields('u');
1724
1725     if (!empty($sort)) {
1726         $order = ' ORDER BY '. $sort;
1727     } else {
1728         $order = '';
1729     }
1730
1731     $params = array(
1732         'userid' => $USER->id,
1733         'query' => "%$searchtext%"
1734     );
1735
1736     if (empty($exceptions)) {
1737         $exceptions = array();
1738     } else if (!empty($exceptions) && is_string($exceptions)) {
1739         $exceptions = explode(',', $exceptions);
1740     }
1741
1742     // Ignore self and guest account.
1743     $exceptions[] = $USER->id;
1744     $exceptions[] = $CFG->siteguest;
1745
1746     // Exclude exceptions from the search result.
1747     list($except, $params_except) = $DB->get_in_or_equal($exceptions, SQL_PARAMS_NAMED, 'param', false);
1748     $except = ' AND u.id ' . $except;
1749     $params = array_merge($params_except, $params);
1750
1751     if (in_array(SITEID, $courseids)) {
1752         // Search on site level.
1753         return $DB->get_records_sql("SELECT $ufields, mc.id as contactlistid, mc.blocked
1754                                        FROM {user} u
1755                                        LEFT JOIN {message_contacts} mc
1756                                             ON mc.contactid = u.id AND mc.userid = :userid
1757                                       WHERE u.deleted = '0' AND u.confirmed = '1'
1758                                             AND (".$DB->sql_like($fullname, ':query', false).")
1759                                             $except
1760                                      $order", $params);
1761     } else {
1762         // Search in courses.
1763
1764         // Getting the context IDs or each course.
1765         $contextids = array();
1766         foreach ($courseids as $courseid) {
1767             $context = context_course::instance($courseid);
1768             $contextids = array_merge($contextids, $context->get_parent_context_ids(true));
1769         }
1770         list($contextwhere, $contextparams) = $DB->get_in_or_equal(array_unique($contextids), SQL_PARAMS_NAMED, 'context');
1771         $params = array_merge($params, $contextparams);
1772
1773         // Everyone who has a role assignment in this course or higher.
1774         // TODO: add enabled enrolment join here (skodak)
1775         $users = $DB->get_records_sql("SELECT DISTINCT $ufields, mc.id as contactlistid, mc.blocked
1776                                          FROM {user} u
1777                                          JOIN {role_assignments} ra ON ra.userid = u.id
1778                                          LEFT JOIN {message_contacts} mc
1779                                               ON mc.contactid = u.id AND mc.userid = :userid
1780                                         WHERE u.deleted = '0' AND u.confirmed = '1'
1781                                               AND (".$DB->sql_like($fullname, ':query', false).")
1782                                               AND ra.contextid $contextwhere
1783                                               $except
1784                                        $order", $params);
1785
1786         return $users;
1787     }
1788 }
1789
1790 /**
1791  * Search a user's messages
1792  *
1793  * Returns a list of posts found using an array of search terms
1794  * eg   word  +word -word
1795  *
1796  * @param array $searchterms an array of search terms (strings)
1797  * @param bool $fromme include messages from the user?
1798  * @param bool $tome include messages to the user?
1799  * @param mixed $courseid SITEID for admins searching all messages. Other behaviour not yet implemented
1800  * @param int $userid the user ID of the current user
1801  * @return mixed An array of messages or false if no matching messages were found
1802  */
1803 function message_search($searchterms, $fromme=true, $tome=true, $courseid='none', $userid=0) {
1804     global $CFG, $USER, $DB;
1805
1806     // If user is searching all messages check they are allowed to before doing anything else.
1807     if ($courseid == SITEID && !has_capability('moodle/site:readallmessages', context_system::instance())) {
1808         print_error('accessdenied','admin');
1809     }
1810
1811     // If no userid sent then assume current user.
1812     if ($userid == 0) $userid = $USER->id;
1813
1814     // Some differences in SQL syntax.
1815     if ($DB->sql_regex_supported()) {
1816         $REGEXP    = $DB->sql_regex(true);
1817         $NOTREGEXP = $DB->sql_regex(false);
1818     }
1819
1820     $searchcond = array();
1821     $params = array();
1822     $i = 0;
1823
1824     // Preprocess search terms to check whether we have at least 1 eligible search term.
1825     // If we do we can drop words around it like 'a'.
1826     $dropshortwords = false;
1827     foreach ($searchterms as $searchterm) {
1828         if (strlen($searchterm) >= 2) {
1829             $dropshortwords = true;
1830         }
1831     }
1832
1833     foreach ($searchterms as $searchterm) {
1834         $i++;
1835
1836         $NOT = false; // Initially we aren't going to perform NOT LIKE searches, only MSSQL and Oracle.
1837
1838         if ($dropshortwords && strlen($searchterm) < 2) {
1839             continue;
1840         }
1841         // Under Oracle and MSSQL, trim the + and - operators and perform simpler LIKE search.
1842         if (!$DB->sql_regex_supported()) {
1843             if (substr($searchterm, 0, 1) == '-') {
1844                 $NOT = true;
1845             }
1846             $searchterm = trim($searchterm, '+-');
1847         }
1848
1849         if (substr($searchterm,0,1) == "+") {
1850             $searchterm = substr($searchterm,1);
1851             $searchterm = preg_quote($searchterm, '|');
1852             $searchcond[] = "m.fullmessage $REGEXP :ss$i";
1853             $params['ss'.$i] = "(^|[^a-zA-Z0-9])$searchterm([^a-zA-Z0-9]|$)";
1854
1855         } else if (substr($searchterm,0,1) == "-") {
1856             $searchterm = substr($searchterm,1);
1857             $searchterm = preg_quote($searchterm, '|');
1858             $searchcond[] = "m.fullmessage $NOTREGEXP :ss$i";
1859             $params['ss'.$i] = "(^|[^a-zA-Z0-9])$searchterm([^a-zA-Z0-9]|$)";
1860
1861         } else {
1862             $searchcond[] = $DB->sql_like("m.fullmessage", ":ss$i", false, true, $NOT);
1863             $params['ss'.$i] = "%$searchterm%";
1864         }
1865     }
1866
1867     if (empty($searchcond)) {
1868         $searchcond = " ".$DB->sql_like('m.fullmessage', ':ss1', false);
1869         $params['ss1'] = "%";
1870     } else {
1871         $searchcond = implode(" AND ", $searchcond);
1872     }
1873
1874     // There are several possibilities
1875     // 1. courseid = SITEID : The admin is searching messages by all users
1876     // 2. courseid = ??     : A teacher is searching messages by users in
1877     //                        one of their courses - currently disabled
1878     // 3. courseid = none   : User is searching their own messages;
1879     //    a.  Messages from user
1880     //    b.  Messages to user
1881     //    c.  Messages to and from user
1882
1883     if ($fromme && $tome) {
1884         $searchcond .= " AND ((useridto = :useridto AND timeusertodeleted = 0) OR
1885             (useridfrom = :useridfrom AND timeuserfromdeleted = 0))";
1886         $params['useridto'] = $userid;
1887         $params['useridfrom'] = $userid;
1888     } else if ($fromme) {
1889         $searchcond .= " AND (useridfrom = :useridfrom AND timeuserfromdeleted = 0)";
1890         $params['useridfrom'] = $userid;
1891     } else if ($tome) {
1892         $searchcond .= " AND (useridto = :useridto AND timeusertodeleted = 0)";
1893         $params['useridto'] = $userid;
1894     }
1895     if ($courseid == SITEID) { // Admin is searching all messages.
1896         $m_read   = $DB->get_records_sql("SELECT m.id, m.useridto, m.useridfrom, m.smallmessage, m.fullmessage, m.timecreated
1897                                             FROM {message_read} m
1898                                            WHERE $searchcond", $params, 0, MESSAGE_SEARCH_MAX_RESULTS);
1899         $m_unread = $DB->get_records_sql("SELECT m.id, m.useridto, m.useridfrom, m.smallmessage, m.fullmessage, m.timecreated
1900                                             FROM {message} m
1901                                            WHERE $searchcond", $params, 0, MESSAGE_SEARCH_MAX_RESULTS);
1902
1903     } else if ($courseid !== 'none') {
1904         // This has not been implemented due to security concerns.
1905         $m_read   = array();
1906         $m_unread = array();
1907
1908     } else {
1909
1910         if ($fromme and $tome) {
1911             $searchcond .= " AND (m.useridfrom=:userid1 OR m.useridto=:userid2)";
1912             $params['userid1'] = $userid;
1913             $params['userid2'] = $userid;
1914
1915         } else if ($fromme) {
1916             $searchcond .= " AND m.useridfrom=:userid";
1917             $params['userid'] = $userid;
1918
1919         } else if ($tome) {
1920             $searchcond .= " AND m.useridto=:userid";
1921             $params['userid'] = $userid;
1922         }
1923
1924         $m_read   = $DB->get_records_sql("SELECT m.id, m.useridto, m.useridfrom, m.smallmessage, m.fullmessage, m.timecreated
1925                                             FROM {message_read} m
1926                                            WHERE $searchcond", $params, 0, MESSAGE_SEARCH_MAX_RESULTS);
1927         $m_unread = $DB->get_records_sql("SELECT m.id, m.useridto, m.useridfrom, m.smallmessage, m.fullmessage, m.timecreated
1928                                             FROM {message} m
1929                                            WHERE $searchcond", $params, 0, MESSAGE_SEARCH_MAX_RESULTS);
1930
1931     }
1932
1933     /// The keys may be duplicated in $m_read and $m_unread so we can't
1934     /// do a simple concatenation
1935     $messages = array();
1936     foreach ($m_read as $m) {
1937         $messages[] = $m;
1938     }
1939     foreach ($m_unread as $m) {
1940         $messages[] = $m;
1941     }
1942
1943     return (empty($messages)) ? false : $messages;
1944 }
1945
1946 /**
1947  * Given a message object that we already know has a long message
1948  * this function truncates the message nicely to the first
1949  * sane place between $CFG->forum_longpost and $CFG->forum_shortpost
1950  *
1951  * @param string $message the message
1952  * @param int $minlength the minimum length to trim the message to
1953  * @return string the shortened message
1954  */
1955 function message_shorten_message($message, $minlength = 0) {
1956     $i = 0;
1957     $tag = false;
1958     $length = strlen($message);
1959     $count = 0;
1960     $stopzone = false;
1961     $truncate = 0;
1962     if ($minlength == 0) $minlength = MESSAGE_SHORTLENGTH;
1963
1964
1965     for ($i=0; $i<$length; $i++) {
1966         $char = $message[$i];
1967
1968         switch ($char) {
1969             case "<":
1970                 $tag = true;
1971                 break;
1972             case ">":
1973                 $tag = false;
1974                 break;
1975             default:
1976                 if (!$tag) {
1977                     if ($stopzone) {
1978                         if ($char == '.' or $char == ' ') {
1979                             $truncate = $i+1;
1980                             break 2;
1981                         }
1982                     }
1983                     $count++;
1984                 }
1985                 break;
1986         }
1987         if (!$stopzone) {
1988             if ($count > $minlength) {
1989                 $stopzone = true;
1990             }
1991         }
1992     }
1993
1994     if (!$truncate) {
1995         $truncate = $i;
1996     }
1997
1998     return substr($message, 0, $truncate);
1999 }
2000
2001
2002 /**
2003  * Given a string and an array of keywords, this function looks
2004  * for the first keyword in the string, and then chops out a
2005  * small section from the text that shows that word in context.
2006  *
2007  * @param string $message the text to search
2008  * @param array $keywords array of keywords to find
2009  */
2010 function message_get_fragment($message, $keywords) {
2011
2012     $fullsize = 160;
2013     $halfsize = (int)($fullsize/2);
2014
2015     $message = strip_tags($message);
2016
2017     foreach ($keywords as $keyword) {  // Just get the first one
2018         if ($keyword !== '') {
2019             break;
2020         }
2021     }
2022     if (empty($keyword)) {   // None found, so just return start of message
2023         return message_shorten_message($message, 30);
2024     }
2025
2026     $leadin = $leadout = '';
2027
2028 /// Find the start of the fragment
2029     $start = 0;
2030     $length = strlen($message);
2031
2032     $pos = strpos($message, $keyword);
2033     if ($pos > $halfsize) {
2034         $start = $pos - $halfsize;
2035         $leadin = '...';
2036     }
2037 /// Find the end of the fragment
2038     $end = $start + $fullsize;
2039     if ($end > $length) {
2040         $end = $length;
2041     } else {
2042         $leadout = '...';
2043     }
2044
2045 /// Pull out the fragment and format it
2046
2047     $fragment = substr($message, $start, $end - $start);
2048     $fragment = $leadin.highlight(implode(' ',$keywords), $fragment).$leadout;
2049     return $fragment;
2050 }
2051
2052 /**
2053  * Retrieve the messages between two users
2054  *
2055  * @param object $user1 the current user
2056  * @param object $user2 the other user
2057  * @param int $limitnum the maximum number of messages to retrieve
2058  * @param bool $viewingnewmessages are we currently viewing new messages?
2059  */
2060 function message_get_history($user1, $user2, $limitnum=0, $viewingnewmessages=false) {
2061     global $DB, $CFG;
2062
2063     $messages = array();
2064
2065     //we want messages sorted oldest to newest but if getting a subset of messages we need to sort
2066     //desc to get the last $limitnum messages then flip the order in php
2067     $sort = 'asc';
2068     if ($limitnum>0) {
2069         $sort = 'desc';
2070     }
2071
2072     $notificationswhere = null;
2073     //we have just moved new messages to read. If theyre here to see new messages dont hide notifications
2074     if (!$viewingnewmessages && $CFG->messaginghidereadnotifications) {
2075         $notificationswhere = 'AND notification=0';
2076     }
2077
2078     //prevent notifications of your own actions appearing in your own message history
2079     $ownnotificationwhere = ' AND NOT (useridfrom=? AND notification=1)';
2080
2081     $sql = "((useridto = ? AND useridfrom = ? AND timeusertodeleted = 0) OR
2082         (useridto = ? AND useridfrom = ? AND timeuserfromdeleted = 0))";
2083     if ($messages_read = $DB->get_records_select('message_read', $sql . $notificationswhere . $ownnotificationwhere,
2084                                                     array($user1->id, $user2->id, $user2->id, $user1->id, $user1->id),
2085                                                     "timecreated $sort", '*', 0, $limitnum)) {
2086         foreach ($messages_read as $message) {
2087             $messages[] = $message;
2088         }
2089     }
2090     if ($messages_new = $DB->get_records_select('message', $sql . $ownnotificationwhere,
2091                                                     array($user1->id, $user2->id, $user2->id, $user1->id, $user1->id),
2092                                                     "timecreated $sort", '*', 0, $limitnum)) {
2093         foreach ($messages_new as $message) {
2094             $messages[] = $message;
2095         }
2096     }
2097
2098     $result = core_collator::asort_objects_by_property($messages, 'timecreated', core_collator::SORT_NUMERIC);
2099
2100     //if we only want the last $limitnum messages
2101     $messagecount = count($messages);
2102     if ($limitnum > 0 && $messagecount > $limitnum) {
2103         $messages = array_slice($messages, $messagecount - $limitnum, $limitnum, true);
2104     }
2105
2106     return $messages;
2107 }
2108
2109 /**
2110  * Print the message history between two users
2111  *
2112  * @param object $user1 the current user
2113  * @param object $user2 the other user
2114  * @param string $search search terms to highlight
2115  * @param int $messagelimit maximum number of messages to return
2116  * @param string $messagehistorylink the html for the message history link or false
2117  * @param bool $viewingnewmessages are we currently viewing new messages?
2118  */
2119 function message_print_message_history($user1, $user2 ,$search = '', $messagelimit = 0, $messagehistorylink = false, $viewingnewmessages = false, $showactionlinks = true) {
2120     global $OUTPUT, $PAGE;
2121
2122     $PAGE->requires->yui_module(
2123         array('moodle-core_message-toolbox'),
2124         'M.core_message.toolbox.deletemsg.init',
2125         array(array())
2126     );
2127
2128     echo $OUTPUT->box_start('center', 'message_user_pictures');
2129     echo $OUTPUT->box_start('user');
2130     echo $OUTPUT->box_start('generalbox', 'user1');
2131     echo $OUTPUT->user_picture($user1, array('size' => 100, 'courseid' => SITEID));
2132     echo html_writer::tag('div', fullname($user1), array('class' => 'heading'));
2133     echo $OUTPUT->box_end();
2134     echo $OUTPUT->box_end();
2135
2136     $imgattr = array('src' => $OUTPUT->pix_url('i/twoway'), 'alt' => '', 'width' => 16, 'height' => 16);
2137     echo $OUTPUT->box(html_writer::empty_tag('img', $imgattr), 'between');
2138
2139     echo $OUTPUT->box_start('user');
2140     echo $OUTPUT->box_start('generalbox', 'user2');
2141     // Show user picture with link is real user else without link.
2142     if (core_user::is_real_user($user2->id)) {
2143         echo $OUTPUT->user_picture($user2, array('size' => 100, 'courseid' => SITEID));
2144     } else {
2145         echo $OUTPUT->user_picture($user2, array('size' => 100, 'courseid' => SITEID, 'link' => false));
2146     }
2147     echo html_writer::tag('div', fullname($user2), array('class' => 'heading'));
2148
2149     if ($showactionlinks && isset($user2->iscontact) && isset($user2->isblocked)) {
2150
2151         $script = null;
2152         $text = true;
2153         $icon = false;
2154
2155         $strcontact = message_get_contact_add_remove_link($user2->iscontact, $user2->isblocked, $user2, $script, $text, $icon);
2156         $strblock   = message_get_contact_block_link($user2->iscontact, $user2->isblocked, $user2, $script, $text, $icon);
2157         $useractionlinks = $strcontact.'&nbsp;|&nbsp;'.$strblock;
2158
2159         echo html_writer::tag('div', $useractionlinks, array('class' => 'useractionlinks'));
2160     }
2161     echo $OUTPUT->box_end();
2162     echo $OUTPUT->box_end();
2163     echo $OUTPUT->box_end();
2164
2165     if (!empty($messagehistorylink)) {
2166         echo $messagehistorylink;
2167     }
2168
2169     /// Get all the messages and print them
2170     if ($messages = message_get_history($user1, $user2, $messagelimit, $viewingnewmessages)) {
2171         $tablecontents = '';
2172
2173         $current = new stdClass();
2174         $current->mday = '';
2175         $current->month = '';
2176         $current->year = '';
2177         $messagedate = get_string('strftimetime');
2178         $blockdate   = get_string('strftimedaydate');
2179         $messagenumber = 0;
2180         foreach ($messages as $message) {
2181             $messagenumber++;
2182             if ($message->notification) {
2183                 $notificationclass = ' notification';
2184             } else {
2185                 $notificationclass = null;
2186             }
2187             $date = usergetdate($message->timecreated);
2188             if ($current->mday != $date['mday'] | $current->month != $date['month'] | $current->year != $date['year']) {
2189                 $current->mday = $date['mday'];
2190                 $current->month = $date['month'];
2191                 $current->year = $date['year'];
2192
2193                 $datestring = html_writer::empty_tag('a', array('name' => $date['year'].$date['mon'].$date['mday']));
2194                 $tablecontents .= html_writer::tag('div', $datestring, array('class' => 'mdl-align heading'));
2195
2196                 $tablecontents .= $OUTPUT->heading(userdate($message->timecreated, $blockdate), 4, 'mdl-align');
2197             }
2198
2199             if ($message->useridfrom == $user1->id) {
2200                 $formatted_message = message_format_message($message, $messagedate, $search, 'me');
2201                 $side = 'left';
2202             } else {
2203                 $formatted_message = message_format_message($message, $messagedate, $search, 'other');
2204                 $side = 'right';
2205             }
2206
2207             // Check if it is a read message or not.
2208             if (isset($message->timeread)) {
2209                 $type = 'message_read';
2210             } else {
2211                 $type = 'message';
2212             }
2213
2214             if (message_can_delete_message($message, $user1->id)) {
2215                 $usergroup = optional_param('usergroup', MESSAGE_VIEW_UNREAD_MESSAGES, PARAM_ALPHANUMEXT);
2216                 $viewing = optional_param('viewing', $usergroup, PARAM_ALPHANUMEXT);
2217                 $deleteurl = new moodle_url('/message/index.php', array('user1' => $user1->id, 'user2' => $user2->id,
2218                     'viewing' => $viewing, 'deletemessageid' => $message->id, 'deletemessagetype' => $type,
2219                     'sesskey' => sesskey()));
2220
2221                 $deleteicon = $OUTPUT->action_icon($deleteurl, new pix_icon('t/delete', get_string('delete')));
2222                 $deleteicon = html_writer::tag('div', $deleteicon, array('class' => 'deleteicon accesshide'));
2223                 $formatted_message .= $deleteicon;
2224             }
2225
2226             $tablecontents .= html_writer::tag('div', $formatted_message, array('class' => "mdl-left messagecontent
2227                 $side $notificationclass", 'id' => 'message_' . $messagenumber));
2228         }
2229
2230         echo html_writer::nonempty_tag('div', $tablecontents, array('class' => 'mdl-left messagehistory'));
2231     } else {
2232         echo html_writer::nonempty_tag('div', '('.get_string('nomessagesfound', 'message').')', array('class' => 'mdl-align messagehistory'));
2233     }
2234 }
2235
2236 /**
2237  * Format a message for display in the message history
2238  *
2239  * @param object $message the message object
2240  * @param string $format optional date format
2241  * @param string $keywords keywords to highlight
2242  * @param string $class CSS class to apply to the div around the message
2243  * @return string the formatted message
2244  */
2245 function message_format_message($message, $format='', $keywords='', $class='other') {
2246
2247     static $dateformat;
2248
2249     //if we haven't previously set the date format or they've supplied a new one
2250     if ( empty($dateformat) || (!empty($format) && $dateformat != $format) ) {
2251         if ($format) {
2252             $dateformat = $format;
2253         } else {
2254             $dateformat = get_string('strftimedatetimeshort');
2255         }
2256     }
2257     $time = userdate($message->timecreated, $dateformat);
2258
2259     $messagetext = message_format_message_text($message, false);
2260
2261     if ($keywords) {
2262         $messagetext = highlight($keywords, $messagetext);
2263     }
2264
2265     $messagetext .= message_format_contexturl($message);
2266
2267     $messagetext = clean_text($messagetext, FORMAT_HTML);
2268
2269     return <<<TEMPLATE
2270 <div class='message $class'>
2271     <a name="m{$message->id}"></a>
2272     <span class="message-meta"><span class="time">$time</span></span>: <span class="text">$messagetext</span>
2273 </div>
2274 TEMPLATE;
2275 }
2276
2277 /**
2278  * Format a the context url and context url name of a message for display
2279  *
2280  * @param object $message the message object
2281  * @return string the formatted string
2282  */
2283 function message_format_contexturl($message) {
2284     $s = null;
2285
2286     if (!empty($message->contexturl)) {
2287         $displaytext = null;
2288         if (!empty($message->contexturlname)) {
2289             $displaytext= $message->contexturlname;
2290         } else {
2291             $displaytext= $message->contexturl;
2292         }
2293         $s .= html_writer::start_tag('div',array('class' => 'messagecontext'));
2294             $s .= get_string('view').': '.html_writer::tag('a', $displaytext, array('href' => $message->contexturl));
2295         $s .= html_writer::end_tag('div');
2296     }
2297
2298     return $s;
2299 }
2300
2301 /**
2302  * Send a message from one user to another. Will be delivered according to the message recipients messaging preferences
2303  *
2304  * @param object $userfrom the message sender
2305  * @param object $userto the message recipient
2306  * @param string $message the message
2307  * @param int $format message format such as FORMAT_PLAIN or FORMAT_HTML
2308  * @return int|false the ID of the new message or false
2309  */
2310 function message_post_message($userfrom, $userto, $message, $format) {
2311     global $SITE, $CFG, $USER;
2312
2313     $eventdata = new stdClass();
2314     $eventdata->component        = 'moodle';
2315     $eventdata->name             = 'instantmessage';
2316     $eventdata->userfrom         = $userfrom;
2317     $eventdata->userto           = $userto;
2318
2319     //using string manager directly so that strings in the message will be in the message recipients language rather than the senders
2320     $eventdata->subject          = get_string_manager()->get_string('unreadnewmessage', 'message', fullname($userfrom), $userto->lang);
2321
2322     if ($format == FORMAT_HTML) {
2323         $eventdata->fullmessagehtml  = $message;
2324         //some message processors may revert to sending plain text even if html is supplied
2325         //so we keep both plain and html versions if we're intending to send html
2326         $eventdata->fullmessage = html_to_text($eventdata->fullmessagehtml);
2327     } else {
2328         $eventdata->fullmessage      = $message;
2329         $eventdata->fullmessagehtml  = '';
2330     }
2331
2332     $eventdata->fullmessageformat = $format;
2333     $eventdata->smallmessage     = $message;//store the message unfiltered. Clean up on output.
2334
2335     $s = new stdClass();
2336     $s->sitename = format_string($SITE->shortname, true, array('context' => context_course::instance(SITEID)));
2337     $s->url = $CFG->wwwroot.'/message/index.php?user='.$userto->id.'&id='.$userfrom->id;
2338
2339     $emailtagline = get_string_manager()->get_string('emailtagline', 'message', $s, $userto->lang);
2340     if (!empty($eventdata->fullmessage)) {
2341         $eventdata->fullmessage .= "\n\n---------------------------------------------------------------------\n".$emailtagline;
2342     }
2343     if (!empty($eventdata->fullmessagehtml)) {
2344         $eventdata->fullmessagehtml .= "<br /><br />---------------------------------------------------------------------<br />".$emailtagline;
2345     }
2346
2347     $eventdata->timecreated     = time();
2348     $eventdata->notification    = 0;
2349     return message_send($eventdata);
2350 }
2351
2352 /**
2353  * Print a row of contactlist displaying user picture, messages waiting and
2354  * block links etc
2355  *
2356  * @param object $contact contact object containing all fields required for $OUTPUT->user_picture()
2357  * @param bool $incontactlist is the user a contact of ours?
2358  * @param bool $isblocked is the user blocked?
2359  * @param string $selectcontacturl the url to send the user to when a contact's name is clicked
2360  * @param bool $showactionlinks display action links next to the other users (add contact, block user etc)
2361  * @param object $selecteduser the user the current user is viewing (if any). They will be highlighted.
2362  * @return void
2363  */
2364 function message_print_contactlist_user($contact, $incontactlist = true, $isblocked = false, $selectcontacturl = null, $showactionlinks = true, $selecteduser=null) {
2365     global $OUTPUT, $USER, $COURSE;
2366     $fullname  = fullname($contact);
2367     $fullnamelink  = $fullname;
2368     $output = '';
2369
2370     $linkclass = '';
2371     if (!empty($selecteduser) && $contact->id == $selecteduser->id) {
2372         $linkclass = 'messageselecteduser';
2373     }
2374
2375     // Are there any unread messages for this contact?
2376     if ($contact->messagecount > 0 ){
2377         $fullnamelink = '<strong>'.$fullnamelink.' ('.$contact->messagecount.')</strong>';
2378     }
2379
2380     $strcontact = $strblock = $strhistory = null;
2381
2382     if ($showactionlinks) {
2383         // Show block and delete links if user is real user.
2384         if (core_user::is_real_user($contact->id)) {
2385             $strcontact = message_get_contact_add_remove_link($incontactlist, $isblocked, $contact);
2386             $strblock   = message_get_contact_block_link($incontactlist, $isblocked, $contact);
2387         }
2388         $strhistory = message_history_link($USER->id, $contact->id, true, '', '', 'icon');
2389     }
2390
2391     $output .= html_writer::start_tag('div', array('class' => 'pix'));
2392     $output .= $OUTPUT->user_picture($contact, array('size' => 20, 'courseid' => $COURSE->id));
2393     $output .= html_writer::end_tag('div');
2394
2395     $popupoptions = array(
2396             'height' => MESSAGE_DISCUSSION_HEIGHT,
2397             'width' => MESSAGE_DISCUSSION_WIDTH,
2398             'menubar' => false,
2399             'location' => false,
2400             'status' => true,
2401             'scrollbars' => true,
2402             'resizable' => true);
2403
2404     $link = $action = null;
2405     if (!empty($selectcontacturl)) {
2406         $link = new moodle_url($selectcontacturl.'&user2='.$contact->id);
2407     } else {
2408         //can $selectcontacturl be removed and maybe the be removed and hardcoded?
2409         $link = new moodle_url("/message/index.php?id=$contact->id");
2410         $action = new popup_action('click', $link, "message_$contact->id", $popupoptions);
2411     }
2412
2413
2414     if (strlen($strcontact . $strblock . $strhistory) > 0) {
2415         $output .= html_writer::tag('div', $strcontact . $strblock . $strhistory, array('class' => 'link'));
2416
2417         $output .= html_writer::start_tag('div', array('class' => 'contact'));
2418         $linkattr = array('class' => $linkclass, 'title' => get_string('sendmessageto', 'message', $fullname));
2419         $output .= $OUTPUT->action_link($link, $fullnamelink, $action, $linkattr);
2420         $output .= html_writer::end_tag('div');
2421     } else {
2422         $output .= html_writer::start_tag('div', array('class' => 'contact nolinks'));
2423         $linkattr = array('class' => $linkclass, 'title' => get_string('sendmessageto', 'message', $fullname));
2424         $output .= $OUTPUT->action_link($link, $fullnamelink, $action, $linkattr);
2425         $output .= html_writer::end_tag('div');
2426     }
2427
2428     return $output;
2429 }
2430
2431 /**
2432  * Constructs the add/remove contact link to display next to other users
2433  *
2434  * @param bool $incontactlist is the user a contact
2435  * @param bool $isblocked is the user blocked
2436  * @param stdClass $contact contact object
2437  * @param string $script the URL to send the user to when the link is clicked. If null, the current page.
2438  * @param bool $text include text next to the icons?
2439  * @param bool $icon include a graphical icon?
2440  * @return string
2441  */
2442 function message_get_contact_add_remove_link($incontactlist, $isblocked, $contact, $script=null, $text=false, $icon=true) {
2443     $strcontact = '';
2444
2445     if($incontactlist){
2446         $strcontact = message_contact_link($contact->id, 'remove', true, $script, $text, $icon);
2447     } else if ($isblocked) {
2448         $strcontact = message_contact_link($contact->id, 'add', true, $script, $text, $icon);
2449     } else{
2450         $strcontact = message_contact_link($contact->id, 'add', true, $script, $text, $icon);
2451     }
2452
2453     return $strcontact;
2454 }
2455
2456 /**
2457  * Constructs the block contact link to display next to other users
2458  *
2459  * @param bool $incontactlist is the user a contact?
2460  * @param bool $isblocked is the user blocked?
2461  * @param stdClass $contact contact object
2462  * @param string $script the URL to send the user to when the link is clicked. If null, the current page.
2463  * @param bool $text include text next to the icons?
2464  * @param bool $icon include a graphical icon?
2465  * @return string
2466  */
2467 function message_get_contact_block_link($incontactlist, $isblocked, $contact, $script=null, $text=false, $icon=true) {
2468     $strblock   = '';
2469
2470     //commented out to allow the user to block a contact without having to remove them first
2471     /*if ($incontactlist) {
2472         //$strblock = '';
2473     } else*/
2474     if ($isblocked) {
2475         $strblock   = message_contact_link($contact->id, 'unblock', true, $script, $text, $icon);
2476     } else{
2477         $strblock   = message_contact_link($contact->id, 'block', true, $script, $text, $icon);
2478     }
2479
2480     return $strblock;
2481 }
2482
2483 /**
2484  * Moves messages from a particular user from the message table (unread messages) to message_read
2485  * This is typically only used when a user is deleted
2486  *
2487  * @param object $userid User id
2488  * @return boolean success
2489  */
2490 function message_move_userfrom_unread2read($userid) {
2491     global $DB;
2492
2493     // move all unread messages from message table to message_read
2494     if ($messages = $DB->get_records_select('message', 'useridfrom = ?', array($userid), 'timecreated')) {
2495         foreach ($messages as $message) {
2496             message_mark_message_read($message, 0); //set timeread to 0 as the message was never read
2497         }
2498     }
2499     return true;
2500 }
2501
2502 /**
2503  * marks ALL messages being sent from $fromuserid to $touserid as read
2504  *
2505  * @param int $touserid the id of the message recipient
2506  * @param int $fromuserid the id of the message sender
2507  * @return void
2508  */
2509 function message_mark_messages_read($touserid, $fromuserid) {
2510     global $DB;
2511
2512     $sql = 'SELECT m.* FROM {message} m WHERE m.useridto=:useridto AND m.useridfrom=:useridfrom';
2513     $messages = $DB->get_recordset_sql($sql, array('useridto' => $touserid,'useridfrom' => $fromuserid));
2514
2515     foreach ($messages as $message) {
2516         message_mark_message_read($message, time());
2517     }
2518
2519     $messages->close();
2520 }
2521
2522 /**
2523  * Mark a single message as read
2524  *
2525  * @param stdClass $message An object with an object property ie $message->id which is an id in the message table
2526  * @param int $timeread the timestamp for when the message should be marked read. Usually time().
2527  * @param bool $messageworkingempty Is the message_working table already confirmed empty for this message?
2528  * @return int the ID of the message in the message_read table
2529  */
2530 function message_mark_message_read($message, $timeread, $messageworkingempty=false) {
2531     global $DB;
2532
2533     $message->timeread = $timeread;
2534
2535     $messageid = $message->id;
2536     unset($message->id);//unset because it will get a new id on insert into message_read
2537
2538     //If any processors have pending actions abort them
2539     if (!$messageworkingempty) {
2540         $DB->delete_records('message_working', array('unreadmessageid' => $messageid));
2541     }
2542     $messagereadid = $DB->insert_record('message_read', $message);
2543
2544     $DB->delete_records('message', array('id' => $messageid));
2545
2546     // Get the context for the user who received the message.
2547     $context = context_user::instance($message->useridto, IGNORE_MISSING);
2548     // If the user no longer exists the context value will be false, in this case use the system context.
2549     if ($context === false) {
2550         $context = context_system::instance();
2551     }
2552
2553     // Trigger event for reading a message.
2554     $event = \core\event\message_viewed::create(array(
2555         'objectid' => $messagereadid,
2556         'userid' => $message->useridto, // Using the user who read the message as they are the ones performing the action.
2557         'context' => $context,
2558         'relateduserid' => $message->useridfrom,
2559         'other' => array(
2560             'messageid' => $messageid
2561         )
2562     ));
2563     $event->trigger();
2564
2565     return $messagereadid;
2566 }
2567
2568 /**
2569  * Get all message processors, validate corresponding plugin existance and
2570  * system configuration
2571  *
2572  * @param bool $ready only return ready-to-use processors
2573  * @param bool $reset Reset list of message processors (used in unit tests)
2574  * @param bool $resetonly Just reset, then exit
2575  * @return mixed $processors array of objects containing information on message processors
2576  */
2577 function get_message_processors($ready = false, $reset = false, $resetonly = false) {
2578     global $DB, $CFG;
2579
2580     static $processors;
2581     if ($reset) {
2582         $processors = array();
2583
2584         if ($resetonly) {
2585             return $processors;
2586         }
2587     }
2588
2589     if (empty($processors)) {
2590         // Get all processors, ensure the name column is the first so it will be the array key
2591         $processors = $DB->get_records('message_processors', null, 'name DESC', 'name, id, enabled');
2592         foreach ($processors as &$processor){
2593             $processorfile = $CFG->dirroot. '/message/output/'.$processor->name.'/message_output_'.$processor->name.'.php';
2594             if (is_readable($processorfile)) {
2595                 include_once($processorfile);
2596                 $processclass = 'message_output_' . $processor->name;
2597                 if (class_exists($processclass)) {
2598                     $pclass = new $processclass();
2599                     $processor->object = $pclass;
2600                     $processor->configured = 0;
2601                     if ($pclass->is_system_configured()) {
2602                         $processor->configured = 1;
2603                     }
2604                     $processor->hassettings = 0;
2605                     if (is_readable($CFG->dirroot.'/message/output/'.$processor->name.'/settings.php')) {
2606                         $processor->hassettings = 1;
2607                     }
2608                     $processor->available = 1;
2609                 } else {
2610                     print_error('errorcallingprocessor', 'message');
2611                 }
2612             } else {
2613                 $processor->available = 0;
2614             }
2615         }
2616     }
2617     if ($ready) {
2618         // Filter out enabled and system_configured processors
2619         $readyprocessors = $processors;
2620         foreach ($readyprocessors as $readyprocessor) {
2621             if (!($readyprocessor->enabled && $readyprocessor->configured)) {
2622                 unset($readyprocessors[$readyprocessor->name]);
2623             }
2624         }
2625         return $readyprocessors;
2626     }
2627
2628     return $processors;
2629 }
2630
2631 /**
2632  * Get all message providers, validate their plugin existance and
2633  * system configuration
2634  *
2635  * @return mixed $processors array of objects containing information on message processors
2636  */
2637 function get_message_providers() {
2638     global $CFG, $DB;
2639
2640     $pluginman = core_plugin_manager::instance();
2641
2642     $providers = $DB->get_records('message_providers', null, 'name');
2643
2644     // Remove all the providers whose plugins are disabled or don't exist
2645     foreach ($providers as $providerid => $provider) {
2646         $plugin = $pluginman->get_plugin_info($provider->component);
2647         if ($plugin) {
2648             if ($plugin->get_status() === core_plugin_manager::PLUGIN_STATUS_MISSING) {
2649                 unset($providers[$providerid]);   // Plugins does not exist
2650                 continue;
2651             }
2652             if ($plugin->is_enabled() === false) {
2653                 unset($providers[$providerid]);   // Plugin disabled
2654                 continue;
2655             }
2656         }
2657     }
2658     return $providers;
2659 }
2660
2661 /**
2662  * Get an instance of the message_output class for one of the output plugins.
2663  * @param string $type the message output type. E.g. 'email' or 'jabber'.
2664  * @return message_output message_output the requested class.
2665  */
2666 function get_message_processor($type) {
2667     global $CFG;
2668
2669     // Note, we cannot use the get_message_processors function here, becaues this
2670     // code is called during install after installing each messaging plugin, and
2671     // get_message_processors caches the list of installed plugins.
2672
2673     $processorfile = $CFG->dirroot . "/message/output/{$type}/message_output_{$type}.php";
2674     if (!is_readable($processorfile)) {
2675         throw new coding_exception('Unknown message processor type ' . $type);
2676     }
2677
2678     include_once($processorfile);
2679
2680     $processclass = 'message_output_' . $type;
2681     if (!class_exists($processclass)) {
2682         throw new coding_exception('Message processor ' . $type .
2683                 ' does not define the right class');
2684     }
2685
2686     return new $processclass();
2687 }
2688
2689 /**
2690  * Get messaging outputs default (site) preferences
2691  *
2692  * @return object $processors object containing information on message processors
2693  */
2694 function get_message_output_default_preferences() {
2695     return get_config('message');
2696 }
2697
2698 /**
2699  * Translate message default settings from binary value to the array of string
2700  * representing the settings to be stored. Also validate the provided value and
2701  * use default if it is malformed.
2702  *
2703  * @param  int    $plugindefault Default setting suggested by plugin
2704  * @param  string $processorname The name of processor
2705  * @return array  $settings array of strings in the order: $permitted, $loggedin, $loggedoff.
2706  */
2707 function translate_message_default_setting($plugindefault, $processorname) {
2708     // Preset translation arrays
2709     $permittedvalues = array(
2710         0x04 => 'disallowed',
2711         0x08 => 'permitted',
2712         0x0c => 'forced',
2713     );
2714
2715     $loggedinstatusvalues = array(
2716         0x00 => null, // use null if loggedin/loggedoff is not defined
2717         0x01 => 'loggedin',
2718         0x02 => 'loggedoff',
2719     );
2720
2721     // define the default setting
2722     $processor = get_message_processor($processorname);
2723     $default = $processor->get_default_messaging_settings();
2724
2725     // Validate the value. It should not exceed the maximum size
2726     if (!is_int($plugindefault) || ($plugindefault > 0x0f)) {
2727         debugging(get_string('errortranslatingdefault', 'message'));
2728         $plugindefault = $default;
2729     }
2730     // Use plugin default setting of 'permitted' is 0
2731     if (!($plugindefault & MESSAGE_PERMITTED_MASK)) {
2732         $plugindefault = $default;
2733     }
2734
2735     $permitted = $permittedvalues[$plugindefault & MESSAGE_PERMITTED_MASK];
2736     $loggedin = $loggedoff = null;
2737
2738     if (($plugindefault & MESSAGE_PERMITTED_MASK) == MESSAGE_PERMITTED) {
2739         $loggedin = $loggedinstatusvalues[$plugindefault & MESSAGE_DEFAULT_LOGGEDIN];
2740         $loggedoff = $loggedinstatusvalues[$plugindefault & MESSAGE_DEFAULT_LOGGEDOFF];
2741     }
2742
2743     return array($permitted, $loggedin, $loggedoff);
2744 }
2745
2746 /**
2747  * Return a list of page types
2748  * @param string $pagetype current page type
2749  * @param stdClass $parentcontext Block's parent context
2750  * @param stdClass $currentcontext Current context of block
2751  */
2752 function message_page_type_list($pagetype, $parentcontext, $currentcontext) {
2753     return array('messages-*'=>get_string('page-message-x', 'message'));
2754 }
2755
2756 /**
2757  * Get messages sent or/and received by the specified users.
2758  * Please note that this function return deleted messages too.
2759  *
2760  * @param  int      $useridto       the user id who received the message
2761  * @param  int      $useridfrom     the user id who sent the message. -10 or -20 for no-reply or support user
2762  * @param  int      $notifications  1 for retrieving notifications, 0 for messages, -1 for both
2763  * @param  bool     $read           true for retrieving read messages, false for unread
2764  * @param  string   $sort           the column name to order by including optionally direction
2765  * @param  int      $limitfrom      limit from
2766  * @param  int      $limitnum       limit num
2767  * @return external_description
2768  * @since  2.8
2769  */
2770 function message_get_messages($useridto, $useridfrom = 0, $notifications = -1, $read = true,
2771                                 $sort = 'mr.timecreated DESC', $limitfrom = 0, $limitnum = 0) {
2772     global $DB;
2773
2774     $messagetable = $read ? '{message_read}' : '{message}';
2775     $params = array('deleted' => 0);
2776
2777     // Empty useridto means that we are going to retrieve messages send by the useridfrom to any user.
2778     if (empty($useridto)) {
2779         $userfields = get_all_user_name_fields(true, 'u', '', 'userto');
2780         $joinsql = "JOIN {user} u ON u.id = mr.useridto";
2781         $usersql = "mr.useridfrom = :useridfrom AND u.deleted = :deleted";
2782         $params['useridfrom'] = $useridfrom;
2783     } else {
2784         $userfields = get_all_user_name_fields(true, 'u', '', 'userfrom');
2785         // Left join because useridfrom may be -10 or -20 (no-reply and support users).
2786         $joinsql = "LEFT JOIN {user} u ON u.id = mr.useridfrom";
2787         $usersql = "mr.useridto = :useridto AND (u.deleted IS NULL OR u.deleted = :deleted)";
2788         $params['useridto'] = $useridto;
2789         if (!empty($useridfrom)) {
2790             $usersql .= " AND mr.useridfrom = :useridfrom";
2791             $params['useridfrom'] = $useridfrom;
2792         }
2793     }
2794
2795     // Now, if retrieve notifications, conversations or both.
2796     $typesql = "";
2797     if ($notifications !== -1) {
2798         $typesql = "AND mr.notification = :notification";
2799         $params['notification'] = ($notifications) ? 1 : 0;
2800     }
2801
2802     $sql = "SELECT mr.*, $userfields
2803               FROM $messagetable mr
2804                    $joinsql
2805              WHERE $usersql
2806                    $typesql
2807              ORDER BY $sort";
2808
2809     $messages = $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
2810     return $messages;
2811 }
2812
2813 /**
2814  * Requires the JS libraries to send a message using a dialog.
2815  *
2816  * @return void
2817  */
2818 function message_messenger_requirejs() {
2819     global $PAGE;
2820
2821     static $done = false;
2822     if ($done) {
2823         return;
2824     }
2825
2826     $PAGE->requires->yui_module(
2827         array('moodle-core_message-messenger'),
2828         'Y.M.core_message.messenger.init',
2829         array(array())
2830     );
2831     $PAGE->requires->strings_for_js(array(
2832         'errorwhilesendingmessage',
2833         'messagesent',
2834         'messagetosend',
2835         'sendingmessage',
2836         'sendmessage',
2837         'viewconversation',
2838     ), 'core_message');
2839     $PAGE->requires->strings_for_js(array(
2840         'userisblockingyou',
2841         'userisblockingyounoncontact'
2842     ), 'message');
2843     $PAGE->requires->string_for_js('error', 'core');
2844
2845     $done = true;
2846 }
2847
2848 /**
2849  * Returns the attributes to place on a link to open the 'Send message' dialog.
2850  *
2851  * @param object $user User object.
2852  * @return void
2853  */
2854 function message_messenger_sendmessage_link_params($user) {
2855     $params = array(
2856         'data-trigger' => 'core_message-messenger::sendmessage',
2857         'data-fullname' => fullname($user),
2858         'data-userid' => $user->id,
2859         'role' => 'button'
2860     );
2861
2862     if (message_is_user_non_contact_blocked($user)) {
2863         $params['data-blocked-string'] = 'userisblockingyounoncontact';
2864     } else if (message_is_user_blocked($user)) {
2865         $params['data-blocked-string'] = 'userisblockingyou';
2866     }
2867
2868     return $params;
2869 }
2870
2871 /**
2872  * Determines if a user is permitted to send another user a private message.
2873  * If no sender is provided then it defaults to the logged in user.
2874  *
2875  * @param object $recipient User object.
2876  * @param object $sender User object.
2877  * @return bool true if user is permitted, false otherwise.
2878  */
2879 function message_can_post_message($recipient, $sender = null) {
2880     global $USER, $DB;
2881
2882     if (is_null($sender)) {
2883         // The message is from the logged in user, unless otherwise specified.
2884         $sender = $USER;
2885     }
2886
2887     if (!has_capability('moodle/site:sendmessage', context_system::instance(), $sender)) {
2888         return false;
2889     }
2890
2891     // The recipient blocks messages from non-contacts and the
2892     // sender isn't a contact.
2893     if (message_is_user_non_contact_blocked($recipient, $sender)) {
2894         return false;
2895     }
2896
2897     // The recipient has specifically blocked this sender.
2898     if (message_is_user_blocked($recipient, $sender)) {
2899         return false;
2900     }
2901
2902     return true;
2903 }
2904
2905 /**
2906  * Checks if the recipient is allowing messages from users that aren't a
2907  * contact. If not then it checks to make sure the sender is in the
2908  * recipient's contacts.
2909  *
2910  * @param object $recipient User object.
2911  * @param object $sender User object.
2912  * @return bool true if $sender is blocked, false otherwise.
2913  */
2914 function message_is_user_non_contact_blocked($recipient, $sender = null) {
2915     global $USER, $DB;
2916
2917     if (is_null($sender)) {
2918         // The message is from the logged in user, unless otherwise specified.
2919         $sender = $USER;
2920     }
2921
2922     $blockednoncontacts = get_user_preferences('message_blocknoncontacts', '', $recipient->id);
2923     if (!empty($blockednoncontacts)) {
2924         // Confirm the sender is a contact of the recipient.
2925         $exists = $DB->record_exists('message_contacts', array('userid' => $recipient->id, 'contactid' => $sender->id));
2926         if ($exists) {
2927             // All good, the recipient is a contact of the sender.
2928             return false;
2929         } else {
2930             // Oh no, the recipient is not a contact. Looks like we can't send the message.
2931             return true;
2932         }
2933     }
2934
2935     return false;
2936 }
2937
2938 /**
2939  * Checks if the recipient has specifically blocked the sending user.
2940  *
2941  * Note: This function will always return false if the sender has the
2942  * readallmessages capability at the system context level.
2943  *
2944  * @param object $recipient User object.
2945  * @param object $sender User object.
2946  * @return bool true if $sender is blocked, false otherwise.
2947  */
2948 function message_is_user_blocked($recipient, $sender = null) {
2949     global $USER, $DB;
2950
2951     if (is_null($sender)) {
2952         // The message is from the logged in user, unless otherwise specified.
2953         $sender = $USER;
2954     }
2955
2956     $systemcontext = context_system::instance();
2957     if (has_capability('moodle/site:readallmessages', $systemcontext, $sender)) {
2958         return false;
2959     }
2960
2961     if ($contact = $DB->get_record('message_contacts', array('userid' => $recipient->id, 'contactid' => $sender->id))) {
2962         if ($contact->blocked) {
2963             return true;
2964         }
2965     }
2966
2967     return false;
2968 }