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