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See Release Notes

  • Bug fixes for general core bugs in 3.11.x will end 14 Nov 2022 (12 months plus 6 months extension).
  • Bug fixes for security issues in 3.11.x will end 13 Nov 2023 (18 months plus 12 months extension).
  • PHP version: minimum PHP 7.3.0 Note: minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is supported too.
/calendar/ -> lib.php (source)

Differences Between: [Versions 310 and 311] [Versions 311 and 400] [Versions 311 and 401] [Versions 38 and 311] [Versions 39 and 311]

   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   * Calendar extension
  19   *
  20   * @package    core_calendar
  21   * @copyright  2004 Greek School Network (http://www.sch.gr), Jon Papaioannou,
  22   *             Avgoustos Tsinakos
  23   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24   */
  25  
  26  if (!defined('MOODLE_INTERNAL')) {
  27      die('Direct access to this script is forbidden.');    ///  It must be included from a Moodle page
  28  }
  29  
  30  /**
  31   *  These are read by the administration component to provide default values
  32   */
  33  
  34  /**
  35   * CALENDAR_DEFAULT_UPCOMING_LOOKAHEAD - default value of upcoming event preference
  36   */
  37  define('CALENDAR_DEFAULT_UPCOMING_LOOKAHEAD', 21);
  38  
  39  /**
  40   * CALENDAR_DEFAULT_UPCOMING_MAXEVENTS - default value to display the maximum number of upcoming event
  41   */
  42  define('CALENDAR_DEFAULT_UPCOMING_MAXEVENTS', 10);
  43  
  44  /**
  45   * CALENDAR_DEFAULT_STARTING_WEEKDAY - default value to display the starting weekday
  46   */
  47  define('CALENDAR_DEFAULT_STARTING_WEEKDAY', 1);
  48  
  49  // This is a packed bitfield: day X is "weekend" if $field & (1 << X) is true
  50  // Default value = 65 = 64 + 1 = 2^6 + 2^0 = Saturday & Sunday
  51  
  52  /**
  53   * CALENDAR_DEFAULT_WEEKEND - default value for weekend (Saturday & Sunday)
  54   */
  55  define('CALENDAR_DEFAULT_WEEKEND', 65);
  56  
  57  /**
  58   * CALENDAR_URL - path to calendar's folder
  59   */
  60  define('CALENDAR_URL', $CFG->wwwroot.'/calendar/');
  61  
  62  /**
  63   * CALENDAR_TF_24 - Calendar time in 24 hours format
  64   */
  65  define('CALENDAR_TF_24', '%H:%M');
  66  
  67  /**
  68   * CALENDAR_TF_12 - Calendar time in 12 hours format
  69   */
  70  define('CALENDAR_TF_12', '%I:%M %p');
  71  
  72  /**
  73   * CALENDAR_EVENT_GLOBAL - Site calendar event types
  74   * @deprecated since 3.8
  75   */
  76  define('CALENDAR_EVENT_GLOBAL', 1);
  77  
  78  /**
  79   * CALENDAR_EVENT_SITE - Site calendar event types
  80   */
  81  define('CALENDAR_EVENT_SITE', 1);
  82  
  83  /**
  84   * CALENDAR_EVENT_COURSE - Course calendar event types
  85   */
  86  define('CALENDAR_EVENT_COURSE', 2);
  87  
  88  /**
  89   * CALENDAR_EVENT_GROUP - group calendar event types
  90   */
  91  define('CALENDAR_EVENT_GROUP', 4);
  92  
  93  /**
  94   * CALENDAR_EVENT_USER - user calendar event types
  95   */
  96  define('CALENDAR_EVENT_USER', 8);
  97  
  98  /**
  99   * CALENDAR_EVENT_COURSECAT - Course category calendar event types
 100   */
 101  define('CALENDAR_EVENT_COURSECAT', 16);
 102  
 103  /**
 104   * CALENDAR_IMPORT_FROM_FILE - import the calendar from a file
 105   */
 106  define('CALENDAR_IMPORT_FROM_FILE', 0);
 107  
 108  /**
 109   * CALENDAR_IMPORT_FROM_URL - import the calendar from a URL
 110   */
 111  define('CALENDAR_IMPORT_FROM_URL',  1);
 112  
 113  /**
 114   * CALENDAR_IMPORT_EVENT_UPDATED_SKIPPED - imported event was skipped
 115   */
 116  define('CALENDAR_IMPORT_EVENT_SKIPPED',  -1);
 117  
 118  /**
 119   * CALENDAR_IMPORT_EVENT_UPDATED - imported event was updated
 120   */
 121  define('CALENDAR_IMPORT_EVENT_UPDATED',  1);
 122  
 123  /**
 124   * CALENDAR_IMPORT_EVENT_INSERTED - imported event was added by insert
 125   */
 126  define('CALENDAR_IMPORT_EVENT_INSERTED', 2);
 127  
 128  /**
 129   * CALENDAR_SUBSCRIPTION_UPDATE - Used to represent update action for subscriptions in various forms.
 130   */
 131  define('CALENDAR_SUBSCRIPTION_UPDATE', 1);
 132  
 133  /**
 134   * CALENDAR_SUBSCRIPTION_REMOVE - Used to represent remove action for subscriptions in various forms.
 135   */
 136  define('CALENDAR_SUBSCRIPTION_REMOVE', 2);
 137  
 138  /**
 139   * CALENDAR_EVENT_USER_OVERRIDE_PRIORITY - Constant for the user override priority.
 140   */
 141  define('CALENDAR_EVENT_USER_OVERRIDE_PRIORITY', 0);
 142  
 143  /**
 144   * CALENDAR_EVENT_TYPE_STANDARD - Standard events.
 145   */
 146  define('CALENDAR_EVENT_TYPE_STANDARD', 0);
 147  
 148  /**
 149   * CALENDAR_EVENT_TYPE_ACTION - Action events.
 150   */
 151  define('CALENDAR_EVENT_TYPE_ACTION', 1);
 152  
 153  /**
 154   * Manage calendar events.
 155   *
 156   * This class provides the required functionality in order to manage calendar events.
 157   * It was introduced as part of Moodle 2.0 and was created in order to provide a
 158   * better framework for dealing with calendar events in particular regard to file
 159   * handling through the new file API.
 160   *
 161   * @package    core_calendar
 162   * @category   calendar
 163   * @copyright  2009 Sam Hemelryk
 164   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 165   *
 166   * @property int $id The id within the event table
 167   * @property string $name The name of the event
 168   * @property string $description The description of the event
 169   * @property int $format The format of the description FORMAT_?
 170   * @property int $courseid The course the event is associated with (0 if none)
 171   * @property int $groupid The group the event is associated with (0 if none)
 172   * @property int $userid The user the event is associated with (0 if none)
 173   * @property int $repeatid If this is a repeated event this will be set to the
 174   *                          id of the original
 175   * @property string $component If created by a plugin/component (other than module), the full frankenstyle name of a component
 176   * @property string $modulename If added by a module this will be the module name
 177   * @property int $instance If added by a module this will be the module instance
 178   * @property string $eventtype The event type
 179   * @property int $timestart The start time as a timestamp
 180   * @property int $timeduration The duration of the event in seconds
 181   * @property int $timeusermidnight User midnight for the event
 182   * @property int $visible 1 if the event is visible
 183   * @property int $uuid ?
 184   * @property int $sequence ?
 185   * @property int $timemodified The time last modified as a timestamp
 186   */
 187  class calendar_event {
 188  
 189      /** @var array An object containing the event properties can be accessed via the magic __get/set methods */
 190      protected $properties = null;
 191  
 192      /** @var string The converted event discription with file paths resolved.
 193       *              This gets populated when someone requests description for the first time */
 194      protected $_description = null;
 195  
 196      /** @var array The options to use with this description editor */
 197      protected $editoroptions = array(
 198          'subdirs' => false,
 199          'forcehttps' => false,
 200          'maxfiles' => -1,
 201          'maxbytes' => null,
 202          'trusttext' => false);
 203  
 204      /** @var object The context to use with the description editor */
 205      protected $editorcontext = null;
 206  
 207      /**
 208       * Instantiates a new event and optionally populates its properties with the data provided.
 209       *
 210       * @param \stdClass $data Optional. An object containing the properties to for
 211       *                  an event
 212       */
 213      public function __construct($data = null) {
 214          global $CFG, $USER;
 215  
 216          // First convert to object if it is not already (should either be object or assoc array).
 217          if (!is_object($data)) {
 218              $data = (object) $data;
 219          }
 220  
 221          $this->editoroptions['maxbytes'] = $CFG->maxbytes;
 222  
 223          $data->eventrepeats = 0;
 224  
 225          if (empty($data->id)) {
 226              $data->id = null;
 227          }
 228  
 229          if (!empty($data->subscriptionid)) {
 230              $data->subscription = calendar_get_subscription($data->subscriptionid);
 231          }
 232  
 233          // Default to a user event.
 234          if (empty($data->eventtype)) {
 235              $data->eventtype = 'user';
 236          }
 237  
 238          // Default to the current user.
 239          if (empty($data->userid)) {
 240              $data->userid = $USER->id;
 241          }
 242  
 243          if (!empty($data->timeduration) && is_array($data->timeduration)) {
 244              $data->timeduration = make_timestamp(
 245                      $data->timeduration['year'], $data->timeduration['month'], $data->timeduration['day'],
 246                      $data->timeduration['hour'], $data->timeduration['minute']) - $data->timestart;
 247          }
 248  
 249          if (!empty($data->description) && is_array($data->description)) {
 250              $data->format = $data->description['format'];
 251              $data->description = $data->description['text'];
 252          } else if (empty($data->description)) {
 253              $data->description = '';
 254              $data->format = editors_get_preferred_format();
 255          }
 256  
 257          // Ensure form is defaulted correctly.
 258          if (empty($data->format)) {
 259              $data->format = editors_get_preferred_format();
 260          }
 261  
 262          if (empty($data->component)) {
 263              $data->component = null;
 264          }
 265  
 266          $this->properties = $data;
 267      }
 268  
 269      /**
 270       * Magic set method.
 271       *
 272       * Attempts to call a set_$key method if one exists otherwise falls back
 273       * to simply set the property.
 274       *
 275       * @param string $key property name
 276       * @param mixed $value value of the property
 277       */
 278      public function __set($key, $value) {
 279          if (method_exists($this, 'set_'.$key)) {
 280              $this->{'set_'.$key}($value);
 281          }
 282          $this->properties->{$key} = $value;
 283      }
 284  
 285      /**
 286       * Magic get method.
 287       *
 288       * Attempts to call a get_$key method to return the property and ralls over
 289       * to return the raw property.
 290       *
 291       * @param string $key property name
 292       * @return mixed property value
 293       * @throws \coding_exception
 294       */
 295      public function __get($key) {
 296          if (method_exists($this, 'get_'.$key)) {
 297              return $this->{'get_'.$key}();
 298          }
 299          if (!property_exists($this->properties, $key)) {
 300              throw new \coding_exception('Undefined property requested');
 301          }
 302          return $this->properties->{$key};
 303      }
 304  
 305      /**
 306       * Magic isset method.
 307       *
 308       * PHP needs an isset magic method if you use the get magic method and
 309       * still want empty calls to work.
 310       *
 311       * @param string $key $key property name
 312       * @return bool|mixed property value, false if property is not exist
 313       */
 314      public function __isset($key) {
 315          return !empty($this->properties->{$key});
 316      }
 317  
 318      /**
 319       * Calculate the context value needed for an event.
 320       *
 321       * Event's type can be determine by the available value store in $data
 322       * It is important to check for the existence of course/courseid to determine
 323       * the course event.
 324       * Default value is set to CONTEXT_USER
 325       *
 326       * @return \stdClass The context object.
 327       */
 328      protected function calculate_context() {
 329          global $USER, $DB;
 330  
 331          $context = null;
 332          if (isset($this->properties->categoryid) && $this->properties->categoryid > 0) {
 333              $context = \context_coursecat::instance($this->properties->categoryid);
 334          } else if (isset($this->properties->courseid) && $this->properties->courseid > 0) {
 335              $context = \context_course::instance($this->properties->courseid);
 336          } else if (isset($this->properties->course) && $this->properties->course > 0) {
 337              $context = \context_course::instance($this->properties->course);
 338          } else if (isset($this->properties->groupid) && $this->properties->groupid > 0) {
 339              $group = $DB->get_record('groups', array('id' => $this->properties->groupid));
 340              $context = \context_course::instance($group->courseid);
 341          } else if (isset($this->properties->userid) && $this->properties->userid > 0
 342              && $this->properties->userid == $USER->id) {
 343              $context = \context_user::instance($this->properties->userid);
 344          } else if (isset($this->properties->userid) && $this->properties->userid > 0
 345              && $this->properties->userid != $USER->id &&
 346              !empty($this->properties->modulename) &&
 347              isset($this->properties->instance) && $this->properties->instance > 0) {
 348              $cm = get_coursemodule_from_instance($this->properties->modulename, $this->properties->instance, 0,
 349                  false, MUST_EXIST);
 350              $context = \context_course::instance($cm->course);
 351          } else {
 352              $context = \context_user::instance($this->properties->userid);
 353          }
 354  
 355          return $context;
 356      }
 357  
 358      /**
 359       * Returns the context for this event. The context is calculated
 360       * the first time is is requested and then stored in a member
 361       * variable to be returned each subsequent time.
 362       *
 363       * This is a magical getter function that will be called when
 364       * ever the context property is accessed, e.g. $event->context.
 365       *
 366       * @return context
 367       */
 368      protected function get_context() {
 369          if (!isset($this->properties->context)) {
 370              $this->properties->context = $this->calculate_context();
 371          }
 372  
 373          return $this->properties->context;
 374      }
 375  
 376      /**
 377       * Returns an array of editoroptions for this event.
 378       *
 379       * @return array event editor options
 380       */
 381      protected function get_editoroptions() {
 382          return $this->editoroptions;
 383      }
 384  
 385      /**
 386       * Returns an event description: Called by __get
 387       * Please use $blah = $event->description;
 388       *
 389       * @return string event description
 390       */
 391      protected function get_description() {
 392          global $CFG;
 393  
 394          require_once($CFG->libdir . '/filelib.php');
 395  
 396          if ($this->_description === null) {
 397              // Check if we have already resolved the context for this event.
 398              if ($this->editorcontext === null) {
 399                  // Switch on the event type to decide upon the appropriate context to use for this event.
 400                  $this->editorcontext = $this->get_context();
 401                  if (!calendar_is_valid_eventtype($this->properties->eventtype)) {
 402                      return clean_text($this->properties->description, $this->properties->format);
 403                  }
 404              }
 405  
 406              // Work out the item id for the editor, if this is a repeated event
 407              // then the files will be associated with the original.
 408              if (!empty($this->properties->repeatid) && $this->properties->repeatid > 0) {
 409                  $itemid = $this->properties->repeatid;
 410              } else {
 411                  $itemid = $this->properties->id;
 412              }
 413  
 414              // Convert file paths in the description so that things display correctly.
 415              $this->_description = file_rewrite_pluginfile_urls($this->properties->description, 'pluginfile.php',
 416                  $this->editorcontext->id, 'calendar', 'event_description', $itemid);
 417              // Clean the text so no nasties get through.
 418              $this->_description = clean_text($this->_description, $this->properties->format);
 419          }
 420  
 421          // Finally return the description.
 422          return $this->_description;
 423      }
 424  
 425      /**
 426       * Return the number of repeat events there are in this events series.
 427       *
 428       * @return int number of event repeated
 429       */
 430      public function count_repeats() {
 431          global $DB;
 432          if (!empty($this->properties->repeatid)) {
 433              $this->properties->eventrepeats = $DB->count_records('event',
 434                  array('repeatid' => $this->properties->repeatid));
 435              // We don't want to count ourselves.
 436              $this->properties->eventrepeats--;
 437          }
 438          return $this->properties->eventrepeats;
 439      }
 440  
 441      /**
 442       * Update or create an event within the database
 443       *
 444       * Pass in a object containing the event properties and this function will
 445       * insert it into the database and deal with any associated files
 446       *
 447       * Capability checking should be performed if the user is directly manipulating the event
 448       * and no other capability has been tested. However if the event is not being manipulated
 449       * directly by the user and another capability has been checked for them to do this then
 450       * capabilites should not be checked.
 451       *
 452       * For example if a user is editing an event in the calendar the check should be true,
 453       * but if you are updating an event in an activities settings are changed then the calendar
 454       * capabilites should not be checked.
 455       *
 456       * @see self::create()
 457       * @see self::update()
 458       *
 459       * @param \stdClass $data object of event
 460       * @param bool $checkcapability If Moodle should check the user can manage the calendar events for this call or not.
 461       * @return bool event updated
 462       */
 463      public function update($data, $checkcapability=true) {
 464          global $DB, $USER;
 465  
 466          foreach ($data as $key => $value) {
 467              $this->properties->$key = $value;
 468          }
 469  
 470          $this->properties->timemodified = time();
 471          $usingeditor = (!empty($this->properties->description) && is_array($this->properties->description));
 472  
 473          // Prepare event data.
 474          $eventargs = array(
 475              'context' => $this->get_context(),
 476              'objectid' => $this->properties->id,
 477              'other' => array(
 478                  'repeatid' => empty($this->properties->repeatid) ? 0 : $this->properties->repeatid,
 479                  'timestart' => $this->properties->timestart,
 480                  'name' => $this->properties->name
 481              )
 482          );
 483  
 484          if (empty($this->properties->id) || $this->properties->id < 1) {
 485              if ($checkcapability) {
 486                  if (!calendar_add_event_allowed($this->properties)) {
 487                      print_error('nopermissiontoupdatecalendar');
 488                  }
 489              }
 490  
 491              if ($usingeditor) {
 492                  switch ($this->properties->eventtype) {
 493                      case 'user':
 494                          $this->properties->courseid = 0;
 495                          $this->properties->course = 0;
 496                          $this->properties->groupid = 0;
 497                          $this->properties->userid = $USER->id;
 498                          break;
 499                      case 'site':
 500                          $this->properties->courseid = SITEID;
 501                          $this->properties->course = SITEID;
 502                          $this->properties->groupid = 0;
 503                          $this->properties->userid = $USER->id;
 504                          break;
 505                      case 'course':
 506                          $this->properties->groupid = 0;
 507                          $this->properties->userid = $USER->id;
 508                          break;
 509                      case 'category':
 510                          $this->properties->groupid = 0;
 511                          $this->properties->category = 0;
 512                          $this->properties->userid = $USER->id;
 513                          break;
 514                      case 'group':
 515                          $this->properties->userid = $USER->id;
 516                          break;
 517                      default:
 518                          // We should NEVER get here, but just incase we do lets fail gracefully.
 519                          $usingeditor = false;
 520                          break;
 521                  }
 522  
 523                  // If we are actually using the editor, we recalculate the context because some default values
 524                  // were set when calculate_context() was called from the constructor.
 525                  if ($usingeditor) {
 526                      $this->properties->context = $this->calculate_context();
 527                      $this->editorcontext = $this->get_context();
 528                  }
 529  
 530                  $editor = $this->properties->description;
 531                  $this->properties->format = $this->properties->description['format'];
 532                  $this->properties->description = $this->properties->description['text'];
 533              }
 534  
 535              // Insert the event into the database.
 536              $this->properties->id = $DB->insert_record('event', $this->properties);
 537  
 538              if ($usingeditor) {
 539                  $this->properties->description = file_save_draft_area_files(
 540                      $editor['itemid'],
 541                      $this->editorcontext->id,
 542                      'calendar',
 543                      'event_description',
 544                      $this->properties->id,
 545                      $this->editoroptions,
 546                      $editor['text'],
 547                      $this->editoroptions['forcehttps']);
 548                  $DB->set_field('event', 'description', $this->properties->description,
 549                      array('id' => $this->properties->id));
 550              }
 551  
 552              // Log the event entry.
 553              $eventargs['objectid'] = $this->properties->id;
 554              $eventargs['context'] = $this->get_context();
 555              $event = \core\event\calendar_event_created::create($eventargs);
 556              $event->trigger();
 557  
 558              $repeatedids = array();
 559  
 560              if (!empty($this->properties->repeat)) {
 561                  $this->properties->repeatid = $this->properties->id;
 562                  $DB->set_field('event', 'repeatid', $this->properties->repeatid, array('id' => $this->properties->id));
 563  
 564                  $eventcopy = clone($this->properties);
 565                  unset($eventcopy->id);
 566  
 567                  $timestart = new \DateTime('@' . $eventcopy->timestart);
 568                  $timestart->setTimezone(\core_date::get_user_timezone_object());
 569  
 570                  for ($i = 1; $i < $eventcopy->repeats; $i++) {
 571  
 572                      $timestart->add(new \DateInterval('P7D'));
 573                      $eventcopy->timestart = $timestart->getTimestamp();
 574  
 575                      // Get the event id for the log record.
 576                      $eventcopyid = $DB->insert_record('event', $eventcopy);
 577  
 578                      // If the context has been set delete all associated files.
 579                      if ($usingeditor) {
 580                          $fs = get_file_storage();
 581                          $files = $fs->get_area_files($this->editorcontext->id, 'calendar', 'event_description',
 582                              $this->properties->id);
 583                          foreach ($files as $file) {
 584                              $fs->create_file_from_storedfile(array('itemid' => $eventcopyid), $file);
 585                          }
 586                      }
 587  
 588                      $repeatedids[] = $eventcopyid;
 589  
 590                      // Trigger an event.
 591                      $eventargs['objectid'] = $eventcopyid;
 592                      $eventargs['other']['timestart'] = $eventcopy->timestart;
 593                      $event = \core\event\calendar_event_created::create($eventargs);
 594                      $event->trigger();
 595                  }
 596              }
 597  
 598              return true;
 599          } else {
 600  
 601              if ($checkcapability) {
 602                  if (!calendar_edit_event_allowed($this->properties)) {
 603                      print_error('nopermissiontoupdatecalendar');
 604                  }
 605              }
 606  
 607              if ($usingeditor) {
 608                  if ($this->editorcontext !== null) {
 609                      $this->properties->description = file_save_draft_area_files(
 610                          $this->properties->description['itemid'],
 611                          $this->editorcontext->id,
 612                          'calendar',
 613                          'event_description',
 614                          $this->properties->id,
 615                          $this->editoroptions,
 616                          $this->properties->description['text'],
 617                          $this->editoroptions['forcehttps']);
 618                  } else {
 619                      $this->properties->format = $this->properties->description['format'];
 620                      $this->properties->description = $this->properties->description['text'];
 621                  }
 622              }
 623  
 624              $event = $DB->get_record('event', array('id' => $this->properties->id));
 625  
 626              $updaterepeated = (!empty($this->properties->repeatid) && !empty($this->properties->repeateditall));
 627  
 628              if ($updaterepeated) {
 629  
 630                  $sqlset = 'name = ?,
 631                             description = ?,
 632                             timeduration = ?,
 633                             timemodified = ?,
 634                             groupid = ?,
 635                             courseid = ?';
 636  
 637                  // Note: Group and course id may not be set. If not, keep their current values.
 638                  $params = [
 639                      $this->properties->name,
 640                      $this->properties->description,
 641                      $this->properties->timeduration,
 642                      time(),
 643                      isset($this->properties->groupid) ? $this->properties->groupid : $event->groupid,
 644                      isset($this->properties->courseid) ? $this->properties->courseid : $event->courseid,
 645                  ];
 646  
 647                  // Note: Only update start date, if it was changed by the user.
 648                  if ($this->properties->timestart != $event->timestart) {
 649                      $timestartoffset = $this->properties->timestart - $event->timestart;
 650                      $sqlset .= ', timestart = timestart + ?';
 651                      $params[] = $timestartoffset;
 652                  }
 653  
 654                  // Note: Only update location, if it was changed by the user.
 655                  $updatelocation = (!empty($this->properties->location) && $this->properties->location !== $event->location);
 656                  if ($updatelocation) {
 657                      $sqlset .= ', location = ?';
 658                      $params[] = $this->properties->location;
 659                  }
 660  
 661                  // Update all.
 662                  $sql = "UPDATE {event}
 663                             SET $sqlset
 664                           WHERE repeatid = ?";
 665  
 666                  $params[] = $event->repeatid;
 667                  $DB->execute($sql, $params);
 668  
 669                  // Trigger an update event for each of the calendar event.
 670                  $events = $DB->get_records('event', array('repeatid' => $event->repeatid), '', '*');
 671                  foreach ($events as $calendarevent) {
 672                      $eventargs['objectid'] = $calendarevent->id;
 673                      $eventargs['other']['timestart'] = $calendarevent->timestart;
 674                      $event = \core\event\calendar_event_updated::create($eventargs);
 675                      $event->add_record_snapshot('event', $calendarevent);
 676                      $event->trigger();
 677                  }
 678              } else {
 679                  $DB->update_record('event', $this->properties);
 680                  $event = self::load($this->properties->id);
 681                  $this->properties = $event->properties();
 682  
 683                  // Trigger an update event.
 684                  $event = \core\event\calendar_event_updated::create($eventargs);
 685                  $event->add_record_snapshot('event', $this->properties);
 686                  $event->trigger();
 687              }
 688  
 689              return true;
 690          }
 691      }
 692  
 693      /**
 694       * Deletes an event and if selected an repeated events in the same series
 695       *
 696       * This function deletes an event, any associated events if $deleterepeated=true,
 697       * and cleans up any files associated with the events.
 698       *
 699       * @see self::delete()
 700       *
 701       * @param bool $deleterepeated  delete event repeatedly
 702       * @return bool succession of deleting event
 703       */
 704      public function delete($deleterepeated = false) {
 705          global $DB;
 706  
 707          // If $this->properties->id is not set then something is wrong.
 708          if (empty($this->properties->id)) {
 709              debugging('Attempting to delete an event before it has been loaded', DEBUG_DEVELOPER);
 710              return false;
 711          }
 712          $calevent = $DB->get_record('event',  array('id' => $this->properties->id), '*', MUST_EXIST);
 713          // Delete the event.
 714          $DB->delete_records('event', array('id' => $this->properties->id));
 715  
 716          // Trigger an event for the delete action.
 717          $eventargs = array(
 718              'context' => $this->get_context(),
 719              'objectid' => $this->properties->id,
 720              'other' => array(
 721                  'repeatid' => empty($this->properties->repeatid) ? 0 : $this->properties->repeatid,
 722                  'timestart' => $this->properties->timestart,
 723                  'name' => $this->properties->name
 724              ));
 725          $event = \core\event\calendar_event_deleted::create($eventargs);
 726          $event->add_record_snapshot('event', $calevent);
 727          $event->trigger();
 728  
 729          // If we are deleting parent of a repeated event series, promote the next event in the series as parent.
 730          if (($this->properties->id == $this->properties->repeatid) && !$deleterepeated) {
 731              $newparent = $DB->get_field_sql("SELECT id from {event} where repeatid = ? order by id ASC",
 732                  array($this->properties->id), IGNORE_MULTIPLE);
 733              if (!empty($newparent)) {
 734                  $DB->execute("UPDATE {event} SET repeatid = ? WHERE repeatid = ?",
 735                      array($newparent, $this->properties->id));
 736                  // Get all records where the repeatid is the same as the event being removed.
 737                  $events = $DB->get_records('event', array('repeatid' => $newparent));
 738                  // For each of the returned events trigger an update event.
 739                  foreach ($events as $calendarevent) {
 740                      // Trigger an event for the update.
 741                      $eventargs['objectid'] = $calendarevent->id;
 742                      $eventargs['other']['timestart'] = $calendarevent->timestart;
 743                      $event = \core\event\calendar_event_updated::create($eventargs);
 744                      $event->add_record_snapshot('event', $calendarevent);
 745                      $event->trigger();
 746                  }
 747              }
 748          }
 749  
 750          // If the editor context hasn't already been set then set it now.
 751          if ($this->editorcontext === null) {
 752              $this->editorcontext = $this->get_context();
 753          }
 754  
 755          // If the context has been set delete all associated files.
 756          if ($this->editorcontext !== null) {
 757              $fs = get_file_storage();
 758              $files = $fs->get_area_files($this->editorcontext->id, 'calendar', 'event_description', $this->properties->id);
 759              foreach ($files as $file) {
 760                  $file->delete();
 761              }
 762          }
 763  
 764          // If we need to delete repeated events then we will fetch them all and delete one by one.
 765          if ($deleterepeated && !empty($this->properties->repeatid) && $this->properties->repeatid > 0) {
 766              // Get all records where the repeatid is the same as the event being removed.
 767              $events = $DB->get_records('event', array('repeatid' => $this->properties->repeatid));
 768              // For each of the returned events populate an event object and call delete.
 769              // make sure the arg passed is false as we are already deleting all repeats.
 770              foreach ($events as $event) {
 771                  $event = new calendar_event($event);
 772                  $event->delete(false);
 773              }
 774          }
 775  
 776          return true;
 777      }
 778  
 779      /**
 780       * Fetch all event properties.
 781       *
 782       * This function returns all of the events properties as an object and optionally
 783       * can prepare an editor for the description field at the same time. This is
 784       * designed to work when the properties are going to be used to set the default
 785       * values of a moodle forms form.
 786       *
 787       * @param bool $prepareeditor If set to true a editor is prepared for use with
 788       *              the mforms editor element. (for description)
 789       * @return \stdClass Object containing event properties
 790       */
 791      public function properties($prepareeditor = false) {
 792          global $DB;
 793  
 794          // First take a copy of the properties. We don't want to actually change the
 795          // properties or we'd forever be converting back and forwards between an
 796          // editor formatted description and not.
 797          $properties = clone($this->properties);
 798          // Clean the description here.
 799          $properties->description = clean_text($properties->description, $properties->format);
 800  
 801          // If set to true we need to prepare the properties for use with an editor
 802          // and prepare the file area.
 803          if ($prepareeditor) {
 804  
 805              // We may or may not have a property id. If we do then we need to work
 806              // out the context so we can copy the existing files to the draft area.
 807              if (!empty($properties->id)) {
 808  
 809                  if ($properties->eventtype === 'site') {
 810                      // Site context.
 811                      $this->editorcontext = $this->get_context();
 812                  } else if ($properties->eventtype === 'user') {
 813                      // User context.
 814                      $this->editorcontext = $this->get_context();
 815                  } else if ($properties->eventtype === 'group' || $properties->eventtype === 'course') {
 816                      // First check the course is valid.
 817                      $course = $DB->get_record('course', array('id' => $properties->courseid));
 818                      if (!$course) {
 819                          print_error('invalidcourse');
 820                      }
 821                      // Course context.
 822                      $this->editorcontext = $this->get_context();
 823                      // We have a course and are within the course context so we had
 824                      // better use the courses max bytes value.
 825                      $this->editoroptions['maxbytes'] = $course->maxbytes;
 826                  } else if ($properties->eventtype === 'category') {
 827                      // First check the course is valid.
 828                      \core_course_category::get($properties->categoryid, MUST_EXIST, true);
 829                      // Course context.
 830                      $this->editorcontext = $this->get_context();
 831                  } else {
 832                      // If we get here we have a custom event type as used by some
 833                      // modules. In this case the event will have been added by
 834                      // code and we won't need the editor.
 835                      $this->editoroptions['maxbytes'] = 0;
 836                      $this->editoroptions['maxfiles'] = 0;
 837                  }
 838  
 839                  if (empty($this->editorcontext) || empty($this->editorcontext->id)) {
 840                      $contextid = false;
 841                  } else {
 842                      // Get the context id that is what we really want.
 843                      $contextid = $this->editorcontext->id;
 844                  }
 845              } else {
 846  
 847                  // If we get here then this is a new event in which case we don't need a
 848                  // context as there is no existing files to copy to the draft area.
 849                  $contextid = null;
 850              }
 851  
 852              // If the contextid === false we don't support files so no preparing
 853              // a draft area.
 854              if ($contextid !== false) {
 855                  // Just encase it has already been submitted.
 856                  $draftiddescription = file_get_submitted_draft_itemid('description');
 857                  // Prepare the draft area, this copies existing files to the draft area as well.
 858                  $properties->description = file_prepare_draft_area($draftiddescription, $contextid, 'calendar',
 859                      'event_description', $properties->id, $this->editoroptions, $properties->description);
 860              } else {
 861                  $draftiddescription = 0;
 862              }
 863  
 864              // Structure the description field as the editor requires.
 865              $properties->description = array('text' => $properties->description, 'format' => $properties->format,
 866                  'itemid' => $draftiddescription);
 867          }
 868  
 869          // Finally return the properties.
 870          return $properties;
 871      }
 872  
 873      /**
 874       * Toggles the visibility of an event
 875       *
 876       * @param null|bool $force If it is left null the events visibility is flipped,
 877       *                   If it is false the event is made hidden, if it is true it
 878       *                   is made visible.
 879       * @return bool if event is successfully updated, toggle will be visible
 880       */
 881      public function toggle_visibility($force = null) {
 882          global $DB;
 883  
 884          // Set visible to the default if it is not already set.
 885          if (empty($this->properties->visible)) {
 886              $this->properties->visible = 1;
 887          }
 888  
 889          if ($force === true || ($force !== false && $this->properties->visible == 0)) {
 890              // Make this event visible.
 891              $this->properties->visible = 1;
 892          } else {
 893              // Make this event hidden.
 894              $this->properties->visible = 0;
 895          }
 896  
 897          // Update the database to reflect this change.
 898          $success = $DB->set_field('event', 'visible', $this->properties->visible, array('id' => $this->properties->id));
 899          $calendarevent = $DB->get_record('event',  array('id' => $this->properties->id), '*', MUST_EXIST);
 900  
 901          // Prepare event data.
 902          $eventargs = array(
 903              'context' => $this->get_context(),
 904              'objectid' => $this->properties->id,
 905              'other' => array(
 906                  'repeatid' => empty($this->properties->repeatid) ? 0 : $this->properties->repeatid,
 907                  'timestart' => $this->properties->timestart,
 908                  'name' => $this->properties->name
 909              )
 910          );
 911          $event = \core\event\calendar_event_updated::create($eventargs);
 912          $event->add_record_snapshot('event', $calendarevent);
 913          $event->trigger();
 914  
 915          return $success;
 916      }
 917  
 918      /**
 919       * Returns an event object when provided with an event id.
 920       *
 921       * This function makes use of MUST_EXIST, if the event id passed in is invalid
 922       * it will result in an exception being thrown.
 923       *
 924       * @param int|object $param event object or event id
 925       * @return calendar_event
 926       */
 927      public static function load($param) {
 928          global $DB;
 929          if (is_object($param)) {
 930              $event = new calendar_event($param);
 931          } else {
 932              $event = $DB->get_record('event', array('id' => (int)$param), '*', MUST_EXIST);
 933              $event = new calendar_event($event);
 934          }
 935          return $event;
 936      }
 937  
 938      /**
 939       * Creates a new event and returns an event object.
 940       *
 941       * Capability checking should be performed if the user is directly creating the event
 942       * and no other capability has been tested. However if the event is not being created
 943       * directly by the user and another capability has been checked for them to do this then
 944       * capabilites should not be checked.
 945       *
 946       * For example if a user is creating an event in the calendar the check should be true,
 947       * but if you are creating an event in an activity when it is created then the calendar
 948       * capabilites should not be checked.
 949       *
 950       * @param \stdClass|array $properties An object containing event properties
 951       * @param bool $checkcapability If Moodle should check the user can manage the calendar events for this call or not.
 952       * @throws \coding_exception
 953       *
 954       * @return calendar_event|bool The event object or false if it failed
 955       */
 956      public static function create($properties, $checkcapability = true) {
 957          if (is_array($properties)) {
 958              $properties = (object)$properties;
 959          }
 960          if (!is_object($properties)) {
 961              throw new \coding_exception('When creating an event properties should be either an object or an assoc array');
 962          }
 963          $event = new calendar_event($properties);
 964          if ($event->update($properties, $checkcapability)) {
 965              return $event;
 966          } else {
 967              return false;
 968          }
 969      }
 970  
 971      /**
 972       * Format the event name using the external API.
 973       *
 974       * This function should we used when text formatting is required in external functions.
 975       *
 976       * @return string Formatted name.
 977       */
 978      public function format_external_name() {
 979          if ($this->editorcontext === null) {
 980              // Switch on the event type to decide upon the appropriate context to use for this event.
 981              $this->editorcontext = $this->get_context();
 982          }
 983  
 984          return external_format_string($this->properties->name, $this->editorcontext->id);
 985      }
 986  
 987      /**
 988       * Format the text using the external API.
 989       *
 990       * This function should we used when text formatting is required in external functions.
 991       *
 992       * @return array an array containing the text formatted and the text format
 993       */
 994      public function format_external_text() {
 995  
 996          if ($this->editorcontext === null) {
 997              // Switch on the event type to decide upon the appropriate context to use for this event.
 998              $this->editorcontext = $this->get_context();
 999  
1000              if (!calendar_is_valid_eventtype($this->properties->eventtype)) {
1001                  // We don't have a context here, do a normal format_text.
1002                  return external_format_text($this->properties->description, $this->properties->format, $this->editorcontext->id);
1003              }
1004          }
1005  
1006          // Work out the item id for the editor, if this is a repeated event then the files will be associated with the original.
1007          if (!empty($this->properties->repeatid) && $this->properties->repeatid > 0) {
1008              $itemid = $this->properties->repeatid;
1009          } else {
1010              $itemid = $this->properties->id;
1011          }
1012  
1013          return external_format_text($this->properties->description, $this->properties->format, $this->editorcontext->id,
1014              'calendar', 'event_description', $itemid);
1015      }
1016  }
1017  
1018  /**
1019   * Calendar information class
1020   *
1021   * This class is used simply to organise the information pertaining to a calendar
1022   * and is used primarily to make information easily available.
1023   *
1024   * @package core_calendar
1025   * @category calendar
1026   * @copyright 2010 Sam Hemelryk
1027   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1028   */
1029  class calendar_information {
1030  
1031      /**
1032       * @var int The timestamp
1033       *
1034       * Rather than setting the day, month and year we will set a timestamp which will be able
1035       * to be used by multiple calendars.
1036       */
1037      public $time;
1038  
1039      /** @var int A course id */
1040      public $courseid = null;
1041  
1042      /** @var array An array of categories */
1043      public $categories = array();
1044  
1045      /** @var int The current category */
1046      public $categoryid = null;
1047  
1048      /** @var array An array of courses */
1049      public $courses = array();
1050  
1051      /** @var array An array of groups */
1052      public $groups = array();
1053  
1054      /** @var array An array of users */
1055      public $users = array();
1056  
1057      /** @var context The anticipated context that the calendar is viewed in */
1058      public $context = null;
1059  
1060      /**
1061       * Creates a new instance
1062       *
1063       * @param int $day the number of the day
1064       * @param int $month the number of the month
1065       * @param int $year the number of the year
1066       * @param int $time the unixtimestamp representing the date we want to view, this is used instead of $calmonth
1067       *     and $calyear to support multiple calendars
1068       */
1069      public function __construct($day = 0, $month = 0, $year = 0, $time = 0) {
1070          // If a day, month and year were passed then convert it to a timestamp. If these were passed
1071          // then we can assume the day, month and year are passed as Gregorian, as no where in core
1072          // should we be passing these values rather than the time. This is done for BC.
1073          if (!empty($day) || !empty($month) || !empty($year)) {
1074              $date = usergetdate(time());
1075              if (empty($day)) {
1076                  $day = $date['mday'];
1077              }
1078              if (empty($month)) {
1079                  $month = $date['mon'];
1080              }
1081              if (empty($year)) {
1082                  $year =  $date['year'];
1083              }
1084              if (checkdate($month, $day, $year)) {
1085                  $time = make_timestamp($year, $month, $day);
1086              } else {
1087                  $time = time();
1088              }
1089          }
1090  
1091          $this->set_time($time);
1092      }
1093  
1094      /**
1095       * Creates and set up a instance.
1096       *
1097       * @param   int                     $time the unixtimestamp representing the date we want to view.
1098       * @param   int                     $courseid The ID of the course the user wishes to view.
1099       * @param   int                     $categoryid The ID of the category the user wishes to view
1100       *                                  If a courseid is specified, this value is ignored.
1101       * @return  calendar_information
1102       */
1103      public static function create($time, int $courseid, int $categoryid = null) : calendar_information {
1104          $calendar = new static(0, 0, 0, $time);
1105          if ($courseid != SITEID && !empty($courseid)) {
1106              // Course ID must be valid and existing.
1107              $course = get_course($courseid);
1108              $calendar->context = context_course::instance($course->id);
1109  
1110              if (!$course->visible && !is_role_switched($course->id)) {
1111                  require_capability('moodle/course:viewhiddencourses', $calendar->context);
1112              }
1113  
1114              $courses = [$course->id => $course];
1115              $category = (\core_course_category::get($course->category, MUST_EXIST, true))->get_db_record();
1116          } else if (!empty($categoryid)) {
1117              $course = get_site();
1118              $courses = calendar_get_default_courses(null, 'id, category, groupmode, groupmodeforce');
1119  
1120              // Filter available courses to those within this category or it's children.
1121              $ids = [$categoryid];
1122              $category = \core_course_category::get($categoryid);
1123              $ids = array_merge($ids, array_keys($category->get_children()));
1124              $courses = array_filter($courses, function($course) use ($ids) {
1125                  return array_search($course->category, $ids) !== false;
1126              });
1127              $category = $category->get_db_record();
1128  
1129              $calendar->context = context_coursecat::instance($categoryid);
1130          } else {
1131              $course = get_site();
1132              $courses = calendar_get_default_courses(null, 'id, category, groupmode, groupmodeforce');
1133              $category = null;
1134  
1135              $calendar->context = context_system::instance();
1136          }
1137  
1138          $calendar->set_sources($course, $courses, $category);
1139  
1140          return $calendar;
1141      }
1142  
1143      /**
1144       * Set the time period of this instance.
1145       *
1146       * @param   int $time the unixtimestamp representing the date we want to view.
1147       * @return  $this
1148       */
1149      public function set_time($time = null) {
1150          if (empty($time)) {
1151              $this->time = time();
1152          } else {
1153              $this->time = $time;
1154          }
1155  
1156          return $this;
1157      }
1158  
1159      /**
1160       * Initialize calendar information
1161       *
1162       * @deprecated 3.4
1163       * @param stdClass $course object
1164       * @param array $coursestoload An array of courses [$course->id => $course]
1165       * @param bool $ignorefilters options to use filter
1166       */
1167      public function prepare_for_view(stdClass $course, array $coursestoload, $ignorefilters = false) {
1168          debugging('The prepare_for_view() function has been deprecated. Please update your code to use set_sources()',
1169                  DEBUG_DEVELOPER);
1170          $this->set_sources($course, $coursestoload);
1171      }
1172  
1173      /**
1174       * Set the sources for events within the calendar.
1175       *
1176       * If no category is provided, then the category path for the current
1177       * course will be used.
1178       *
1179       * @param   stdClass    $course The current course being viewed.
1180       * @param   stdClass[]  $courses The list of all courses currently accessible.
1181       * @param   stdClass    $category The current category to show.
1182       */
1183      public function set_sources(stdClass $course, array $courses, stdClass $category = null) {
1184          global $USER;
1185  
1186          // A cousre must always be specified.
1187          $this->course = $course;
1188          $this->courseid = $course->id;
1189  
1190          list($courseids, $group, $user) = calendar_set_filters($courses);
1191          $this->courses = $courseids;
1192          $this->groups = $group;
1193          $this->users = $user;
1194  
1195          // Do not show category events by default.
1196          $this->categoryid = null;
1197          $this->categories = null;
1198  
1199          // Determine the correct category information to show.
1200          // When called with a course, the category of that course is usually included too.
1201          // When a category was specifically requested, it should be requested with the site id.
1202          if (SITEID !== $this->courseid) {
1203              // A specific course was requested.
1204              // Fetch the category that this course is in, along with all parents.
1205              // Do not include child categories of this category, as the user many not have enrolments in those siblings or children.
1206              $category = \core_course_category::get($course->category, MUST_EXIST, true);
1207              $this->categoryid = $category->id;
1208  
1209              $this->categories = $category->get_parents();
1210              $this->categories[] = $category->id;
1211          } else if (null !== $category && $category->id > 0) {
1212              // A specific category was requested.
1213              // Fetch all parents of this category, along with all children too.
1214              $category = \core_course_category::get($category->id);
1215              $this->categoryid = $category->id;
1216  
1217              // Build the category list.
1218              // This includes the current category.
1219              $this->categories = $category->get_parents();
1220              $this->categories[] = $category->id;
1221              $this->categories = array_merge($this->categories, $category->get_all_children_ids());
1222          } else if (SITEID === $this->courseid) {
1223              // The site was requested.
1224              // Fetch all categories where this user has any enrolment, and all categories that this user can manage.
1225  
1226              // Grab the list of categories that this user has courses in.
1227              $coursecategories = array_flip(array_map(function($course) {
1228                  return $course->category;
1229              }, $courses));
1230  
1231              $calcatcache = cache::make('core', 'calendar_categories');
1232              $this->categories = $calcatcache->get('site');
1233              if ($this->categories === false) {
1234                  // Use the category id as the key in the following array. That way we do not have to remove duplicates.
1235                  $categories = [];
1236                  foreach (\core_course_category::get_all() as $category) {
1237                      if (isset($coursecategories[$category->id]) ||
1238                              has_capability('moodle/category:manage', $category->get_context(), $USER, false)) {
1239                          // If the user has access to a course in this category or can manage the category,
1240                          // then they can see all parent categories too.
1241                          $categories[$category->id] = true;
1242                          foreach ($category->get_parents() as $catid) {
1243                              $categories[$catid] = true;
1244                          }
1245                      }
1246                  }
1247                  $this->categories = array_keys($categories);
1248                  $calcatcache->set('site', $this->categories);
1249              }
1250          }
1251      }
1252  
1253      /**
1254       * Ensures the date for the calendar is correct and either sets it to now
1255       * or throws a moodle_exception if not
1256       *
1257       * @param bool $defaultonow use current time
1258       * @throws moodle_exception
1259       * @return bool validation of checkdate
1260       */
1261      public function checkdate($defaultonow = true) {
1262          if (!checkdate($this->month, $this->day, $this->year)) {
1263              if ($defaultonow) {
1264                  $now = usergetdate(time());
1265                  $this->day = intval($now['mday']);
1266                  $this->month = intval($now['mon']);
1267                  $this->year = intval($now['year']);
1268                  return true;
1269              } else {
1270                  throw new moodle_exception('invaliddate');
1271              }
1272          }
1273          return true;
1274      }
1275  
1276      /**
1277       * Gets todays timestamp for the calendar
1278       *
1279       * @return int today timestamp
1280       */
1281      public function timestamp_today() {
1282          return $this->time;
1283      }
1284      /**
1285       * Gets tomorrows timestamp for the calendar
1286       *
1287       * @return int tomorrow timestamp
1288       */
1289      public function timestamp_tomorrow() {
1290          return strtotime('+1 day', $this->time);
1291      }
1292      /**
1293       * Adds the pretend blocks for the calendar
1294       *
1295       * @param core_calendar_renderer $renderer
1296       * @param bool $showfilters display filters, false is set as default
1297       * @param string|null $view preference view options (eg: day, month, upcoming)
1298       */
1299      public function add_sidecalendar_blocks(core_calendar_renderer $renderer, $showfilters=false, $view=null) {
1300          global $PAGE;
1301  
1302          if (!has_capability('moodle/block:view', $PAGE->context) ) {
1303              return;
1304          }
1305  
1306          if ($showfilters) {
1307              $filters = new block_contents();
1308              $filters->content = $renderer->event_filter();
1309              $filters->footer = '';
1310              $filters->title = get_string('eventskey', 'calendar');
1311              $renderer->add_pretend_calendar_block($filters, BLOCK_POS_RIGHT);
1312          }
1313          $block = new block_contents;
1314          $block->content = $renderer->fake_block_threemonths($this);
1315          $block->footer = '';
1316          $block->title = get_string('monthlyview', 'calendar');
1317          $renderer->add_pretend_calendar_block($block, BLOCK_POS_RIGHT);
1318      }
1319  }
1320  
1321  /**
1322   * Get calendar events.
1323   *
1324   * @param int $tstart Start time of time range for events
1325   * @param int $tend End time of time range for events
1326   * @param array|int|boolean $users array of users, user id or boolean for all/no user events
1327   * @param array|int|boolean $groups array of groups, group id or boolean for all/no group events
1328   * @param array|int|boolean $courses array of courses, course id or boolean for all/no course events
1329   * @param boolean $withduration whether only events starting within time range selected
1330   *                              or events in progress/already started selected as well
1331   * @param boolean $ignorehidden whether to select only visible events or all events
1332   * @param array|int|boolean $categories array of categories, category id or boolean for all/no course events
1333   * @return array $events of selected events or an empty array if there aren't any (or there was an error)
1334   */
1335  function calendar_get_events($tstart, $tend, $users, $groups, $courses,
1336          $withduration = true, $ignorehidden = true, $categories = []) {
1337      global $DB;
1338  
1339      $whereclause = '';
1340      $params = array();
1341      // Quick test.
1342      if (empty($users) && empty($groups) && empty($courses) && empty($categories)) {
1343          return array();
1344      }
1345  
1346      if ((is_array($users) && !empty($users)) or is_numeric($users)) {
1347          // Events from a number of users
1348          if(!empty($whereclause)) $whereclause .= ' OR';
1349          list($insqlusers, $inparamsusers) = $DB->get_in_or_equal($users, SQL_PARAMS_NAMED);
1350          $whereclause .= " (e.userid $insqlusers AND e.courseid = 0 AND e.groupid = 0 AND e.categoryid = 0)";
1351          $params = array_merge($params, $inparamsusers);
1352      } else if($users === true) {
1353          // Events from ALL users
1354          if(!empty($whereclause)) $whereclause .= ' OR';
1355          $whereclause .= ' (e.userid != 0 AND e.courseid = 0 AND e.groupid = 0 AND e.categoryid = 0)';
1356      } else if($users === false) {
1357          // No user at all, do nothing
1358      }
1359  
1360      if ((is_array($groups) && !empty($groups)) or is_numeric($groups)) {
1361          // Events from a number of groups
1362          if(!empty($whereclause)) $whereclause .= ' OR';
1363          list($insqlgroups, $inparamsgroups) = $DB->get_in_or_equal($groups, SQL_PARAMS_NAMED);
1364          $whereclause .= " e.groupid $insqlgroups ";
1365          $params = array_merge($params, $inparamsgroups);
1366      } else if($groups === true) {
1367          // Events from ALL groups
1368          if(!empty($whereclause)) $whereclause .= ' OR ';
1369          $whereclause .= ' e.groupid != 0';
1370      }
1371      // boolean false (no groups at all): we don't need to do anything
1372  
1373      if ((is_array($courses) && !empty($courses)) or is_numeric($courses)) {
1374          if(!empty($whereclause)) $whereclause .= ' OR';
1375          list($insqlcourses, $inparamscourses) = $DB->get_in_or_equal($courses, SQL_PARAMS_NAMED);
1376          $whereclause .= " (e.groupid = 0 AND e.courseid $insqlcourses)";
1377          $params = array_merge($params, $inparamscourses);
1378      } else if ($courses === true) {
1379          // Events from ALL courses
1380          if(!empty($whereclause)) $whereclause .= ' OR';
1381          $whereclause .= ' (e.groupid = 0 AND e.courseid != 0)';
1382      }
1383  
1384      if ((is_array($categories) && !empty($categories)) || is_numeric($categories)) {
1385          if (!empty($whereclause)) {
1386              $whereclause .= ' OR';
1387          }
1388          list($insqlcategories, $inparamscategories) = $DB->get_in_or_equal($categories, SQL_PARAMS_NAMED);
1389          $whereclause .= " (e.groupid = 0 AND e.courseid = 0 AND e.categoryid $insqlcategories)";
1390          $params = array_merge($params, $inparamscategories);
1391      } else if ($categories === true) {
1392          // Events from ALL categories.
1393          if (!empty($whereclause)) {
1394              $whereclause .= ' OR';
1395          }
1396          $whereclause .= ' (e.groupid = 0 AND e.courseid = 0 AND e.categoryid != 0)';
1397      }
1398  
1399      // Security check: if, by now, we have NOTHING in $whereclause, then it means
1400      // that NO event-selecting clauses were defined. Thus, we won't be returning ANY
1401      // events no matter what. Allowing the code to proceed might return a completely
1402      // valid query with only time constraints, thus selecting ALL events in that time frame!
1403      if(empty($whereclause)) {
1404          return array();
1405      }
1406  
1407      if($withduration) {
1408          $timeclause = '(e.timestart >= '.$tstart.' OR e.timestart + e.timeduration > '.$tstart.') AND e.timestart <= '.$tend;
1409      }
1410      else {
1411          $timeclause = 'e.timestart >= '.$tstart.' AND e.timestart <= '.$tend;
1412      }
1413      if(!empty($whereclause)) {
1414          // We have additional constraints
1415          $whereclause = $timeclause.' AND ('.$whereclause.')';
1416      }
1417      else {
1418          // Just basic time filtering
1419          $whereclause = $timeclause;
1420      }
1421  
1422      if ($ignorehidden) {
1423          $whereclause .= ' AND e.visible = 1';
1424      }
1425  
1426      $sql = "SELECT e.*
1427                FROM {event} e
1428           LEFT JOIN {modules} m ON e.modulename = m.name
1429                  -- Non visible modules will have a value of 0.
1430               WHERE (m.visible = 1 OR m.visible IS NULL) AND $whereclause
1431            ORDER BY e.timestart";
1432      $events = $DB->get_records_sql($sql, $params);
1433  
1434      if ($events === false) {
1435          $events = array();
1436      }
1437      return $events;
1438  }
1439  
1440  /**
1441   * Return the days of the week.
1442   *
1443   * @return array array of days
1444   */
1445  function calendar_get_days() {
1446      $calendartype = \core_calendar\type_factory::get_calendar_instance();
1447      return $calendartype->get_weekdays();
1448  }
1449  
1450  /**
1451   * Get the subscription from a given id.
1452   *
1453   * @since Moodle 2.5
1454   * @param int $id id of the subscription
1455   * @return stdClass Subscription record from DB
1456   * @throws moodle_exception for an invalid id
1457   */
1458  function calendar_get_subscription($id) {
1459      global $DB;
1460  
1461      $cache = \cache::make('core', 'calendar_subscriptions');
1462      $subscription = $cache->get($id);
1463      if (empty($subscription)) {
1464          $subscription = $DB->get_record('event_subscriptions', array('id' => $id), '*', MUST_EXIST);
1465          $cache->set($id, $subscription);
1466      }
1467  
1468      return $subscription;
1469  }
1470  
1471  /**
1472   * Gets the first day of the week.
1473   *
1474   * Used to be define('CALENDAR_STARTING_WEEKDAY', blah);
1475   *
1476   * @return int
1477   */
1478  function calendar_get_starting_weekday() {
1479      $calendartype = \core_calendar\type_factory::get_calendar_instance();
1480      return $calendartype->get_starting_weekday();
1481  }
1482  
1483  /**
1484   * Get a HTML link to a course.
1485   *
1486   * @param int|stdClass $course the course id or course object
1487   * @return string a link to the course (as HTML); empty if the course id is invalid
1488   */
1489  function calendar_get_courselink($course) {
1490      if (!$course) {
1491          return '';
1492      }
1493  
1494      if (!is_object($course)) {
1495          $course = calendar_get_course_cached($coursecache, $course);
1496      }
1497      $context = \context_course::instance($course->id);
1498      $fullname = format_string($course->fullname, true, array('context' => $context));
1499      $url = new \moodle_url('/course/view.php', array('id' => $course->id));
1500      $link = \html_writer::link($url, $fullname);
1501  
1502      return $link;
1503  }
1504  
1505  /**
1506   * Get current module cache.
1507   *
1508   * Only use this method if you do not know courseid. Otherwise use:
1509   * get_fast_modinfo($courseid)->instances[$modulename][$instance]
1510   *
1511   * @param array $modulecache in memory module cache
1512   * @param string $modulename name of the module
1513   * @param int $instance module instance number
1514   * @return stdClass|bool $module information
1515   */
1516  function calendar_get_module_cached(&$modulecache, $modulename, $instance) {
1517      if (!isset($modulecache[$modulename . '_' . $instance])) {
1518          $modulecache[$modulename . '_' . $instance] = get_coursemodule_from_instance($modulename, $instance);
1519      }
1520  
1521      return $modulecache[$modulename . '_' . $instance];
1522  }
1523  
1524  /**
1525   * Get current course cache.
1526   *
1527   * @param array $coursecache list of course cache
1528   * @param int $courseid id of the course
1529   * @return stdClass $coursecache[$courseid] return the specific course cache
1530   */
1531  function calendar_get_course_cached(&$coursecache, $courseid) {
1532      if (!isset($coursecache[$courseid])) {
1533          $coursecache[$courseid] = get_course($courseid);
1534      }
1535      return $coursecache[$courseid];
1536  }
1537  
1538  /**
1539   * Get group from groupid for calendar display
1540   *
1541   * @param int $groupid
1542   * @return stdClass group object with fields 'id', 'name' and 'courseid'
1543   */
1544  function calendar_get_group_cached($groupid) {
1545      static $groupscache = array();
1546      if (!isset($groupscache[$groupid])) {
1547          $groupscache[$groupid] = groups_get_group($groupid, 'id,name,courseid');
1548      }
1549      return $groupscache[$groupid];
1550  }
1551  
1552  /**
1553   * Add calendar event metadata
1554   *
1555   * @deprecated since 3.9
1556   *
1557   * @param stdClass $event event info
1558   * @return stdClass $event metadata
1559   */
1560  function calendar_add_event_metadata($event) {
1561      debugging('This function is no longer used', DEBUG_DEVELOPER);
1562      global $CFG, $OUTPUT;
1563  
1564      // Support multilang in event->name.
1565      $event->name = format_string($event->name, true);
1566  
1567      if (!empty($event->modulename)) { // Activity event.
1568          // The module name is set. I will assume that it has to be displayed, and
1569          // also that it is an automatically-generated event. And of course that the
1570          // instace id and modulename are set correctly.
1571          $instances = get_fast_modinfo($event->courseid)->get_instances_of($event->modulename);
1572          if (!array_key_exists($event->instance, $instances)) {
1573              return;
1574          }
1575          $module = $instances[$event->instance];
1576  
1577          $modulename = $module->get_module_type_name(false);
1578          if (get_string_manager()->string_exists($event->eventtype, $event->modulename)) {
1579              // Will be used as alt text if the event icon.
1580              $eventtype = get_string($event->eventtype, $event->modulename);
1581          } else {
1582              $eventtype = '';
1583          }
1584  
1585          $event->icon = '<img src="' . s($module->get_icon_url()) . '" alt="' . s($eventtype) .
1586              '" title="' . s($modulename) . '" class="icon" />';
1587          $event->referer = html_writer::link($module->url, $event->name);
1588          $event->courselink = calendar_get_courselink($module->get_course());
1589          $event->cmid = $module->id;
1590      } else if ($event->courseid == SITEID) { // Site event.
1591          $event->icon = '<img src="' . $OUTPUT->image_url('i/siteevent') . '" alt="' .
1592              get_string('siteevent', 'calendar') . '" class="icon" />';
1593          $event->cssclass = 'calendar_event_site';
1594      } else if ($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) { // Course event.
1595          $event->icon = '<img src="' . $OUTPUT->image_url('i/courseevent') . '" alt="' .
1596              get_string('courseevent', 'calendar') . '" class="icon" />';
1597          $event->courselink = calendar_get_courselink($event->courseid);
1598          $event->cssclass = 'calendar_event_course';
1599      } else if ($event->groupid) { // Group event.
1600          if ($group = calendar_get_group_cached($event->groupid)) {
1601              $groupname = format_string($group->name, true, \context_course::instance($group->courseid));
1602          } else {
1603              $groupname = '';
1604          }
1605          $event->icon = \html_writer::empty_tag('image', array('src' => $OUTPUT->image_url('i/groupevent'),
1606              'alt' => get_string('groupevent', 'calendar'), 'title' => $groupname, 'class' => 'icon'));
1607          $event->courselink = calendar_get_courselink($event->courseid) . ', ' . $groupname;
1608          $event->cssclass = 'calendar_event_group';
1609      } else if ($event->userid) { // User event.
1610          $event->icon = '<img src="' . $OUTPUT->image_url('i/userevent') . '" alt="' .
1611              get_string('userevent', 'calendar') . '" class="icon" />';
1612          $event->cssclass = 'calendar_event_user';
1613      }
1614  
1615      return $event;
1616  }
1617  
1618  /**
1619   * Get calendar events by id.
1620   *
1621   * @since Moodle 2.5
1622   * @param array $eventids list of event ids
1623   * @return array Array of event entries, empty array if nothing found
1624   */
1625  function calendar_get_events_by_id($eventids) {
1626      global $DB;
1627  
1628      if (!is_array($eventids) || empty($eventids)) {
1629          return array();
1630      }
1631  
1632      list($wheresql, $params) = $DB->get_in_or_equal($eventids);
1633      $wheresql = "id $wheresql";
1634  
1635      return $DB->get_records_select('event', $wheresql, $params);
1636  }
1637  
1638  /**
1639   * Get control options for calendar.
1640   *
1641   * @param string $type of calendar
1642   * @param array $data calendar information
1643   * @return string $content return available control for the calender in html
1644   */
1645  function calendar_top_controls($type, $data) {
1646      global $PAGE, $OUTPUT;
1647  
1648      // Get the calendar type we are using.
1649      $calendartype = \core_calendar\type_factory::get_calendar_instance();
1650  
1651      $content = '';
1652  
1653      // Ensure course id passed if relevant.
1654      $courseid = '';
1655      if (!empty($data['id'])) {
1656          $courseid = '&amp;course=' . $data['id'];
1657      }
1658  
1659      // If we are passing a month and year then we need to convert this to a timestamp to
1660      // support multiple calendars. No where in core should these be passed, this logic
1661      // here is for third party plugins that may use this function.
1662      if (!empty($data['m']) && !empty($date['y'])) {
1663          if (!isset($data['d'])) {
1664              $data['d'] = 1;
1665          }
1666          if (!checkdate($data['m'], $data['d'], $data['y'])) {
1667              $time = time();
1668          } else {
1669              $time = make_timestamp($data['y'], $data['m'], $data['d']);
1670          }
1671      } else if (!empty($data['time'])) {
1672          $time = $data['time'];
1673      } else {
1674          $time = time();
1675      }
1676  
1677      // Get the date for the calendar type.
1678      $date = $calendartype->timestamp_to_date_array($time);
1679  
1680      $urlbase = $PAGE->url;
1681  
1682      // We need to get the previous and next months in certain cases.
1683      if ($type == 'frontpage' || $type == 'course' || $type == 'month') {
1684          $prevmonth = calendar_sub_month($date['mon'], $date['year']);
1685          $prevmonthtime = $calendartype->convert_to_gregorian($prevmonth[1], $prevmonth[0], 1);
1686          $prevmonthtime = make_timestamp($prevmonthtime['year'], $prevmonthtime['month'], $prevmonthtime['day'],
1687              $prevmonthtime['hour'], $prevmonthtime['minute']);
1688  
1689          $nextmonth = calendar_add_month($date['mon'], $date['year']);
1690          $nextmonthtime = $calendartype->convert_to_gregorian($nextmonth[1], $nextmonth[0], 1);
1691          $nextmonthtime = make_timestamp($nextmonthtime['year'], $nextmonthtime['month'], $nextmonthtime['day'],
1692              $nextmonthtime['hour'], $nextmonthtime['minute']);
1693      }
1694  
1695      switch ($type) {
1696          case 'frontpage':
1697              $prevlink = calendar_get_link_previous(get_string('monthprev', 'calendar'), $urlbase, false, false, false,
1698                  true, $prevmonthtime);
1699              $nextlink = calendar_get_link_next(get_string('monthnext', 'calendar'), $urlbase, false, false, false, true,
1700                  $nextmonthtime);
1701              $calendarlink = calendar_get_link_href(new \moodle_url(CALENDAR_URL . 'view.php', array('view' => 'month')),
1702                  false, false, false, $time);
1703  
1704              if (!empty($data['id'])) {
1705                  $calendarlink->param('course', $data['id']);
1706              }
1707  
1708              $right = $nextlink;
1709  
1710              $content .= \html_writer::start_tag('div', array('class' => 'calendar-controls'));
1711              $content .= $prevlink . '<span class="hide"> | </span>';
1712              $content .= \html_writer::tag('span', \html_writer::link($calendarlink,
1713                  userdate($time, get_string('strftimemonthyear')), array('title' => get_string('monththis', 'calendar'))
1714              ), array('class' => 'current'));
1715              $content .= '<span class="hide"> | </span>' . $right;
1716              $content .= "<span class=\"clearer\"><!-- --></span>\n";
1717              $content .= \html_writer::end_tag('div');
1718  
1719              break;
1720          case 'course':
1721              $prevlink = calendar_get_link_previous(get_string('monthprev', 'calendar'), $urlbase, false, false, false,
1722                  true, $prevmonthtime);
1723              $nextlink = calendar_get_link_next(get_string('monthnext', 'calendar'), $urlbase, false, false, false,
1724                  true, $nextmonthtime);
1725              $calendarlink = calendar_get_link_href(new \moodle_url(CALENDAR_URL . 'view.php', array('view' => 'month')),
1726                  false, false, false, $time);
1727  
1728              if (!empty($data['id'])) {
1729                  $calendarlink->param('course', $data['id']);
1730              }
1731  
1732              $content .= \html_writer::start_tag('div', array('class' => 'calendar-controls'));
1733              $content .= $prevlink . '<span class="hide"> | </span>';
1734              $content .= \html_writer::tag('span', \html_writer::link($calendarlink,
1735                  userdate($time, get_string('strftimemonthyear')), array('title' => get_string('monththis', 'calendar'))
1736              ), array('class' => 'current'));
1737              $content .= '<span class="hide"> | </span>' . $nextlink;
1738              $content .= "<span class=\"clearer\"><!-- --></span>";
1739              $content .= \html_writer::end_tag('div');
1740              break;
1741          case 'upcoming':
1742              $calendarlink = calendar_get_link_href(new \moodle_url(CALENDAR_URL . 'view.php', array('view' => 'upcoming')),
1743                  false, false, false, $time);
1744              if (!empty($data['id'])) {
1745                  $calendarlink->param('course', $data['id']);
1746              }
1747              $calendarlink = \html_writer::link($calendarlink, userdate($time, get_string('strftimemonthyear')));
1748              $content .= \html_writer::tag('div', $calendarlink, array('class' => 'centered'));
1749              break;
1750          case 'display':
1751              $calendarlink = calendar_get_link_href(new \moodle_url(CALENDAR_URL . 'view.php', array('view' => 'month')),
1752                  false, false, false, $time);
1753              if (!empty($data['id'])) {
1754                  $calendarlink->param('course', $data['id']);
1755              }
1756              $calendarlink = \html_writer::link($calendarlink, userdate($time, get_string('strftimemonthyear')));
1757              $content .= \html_writer::tag('h3', $calendarlink);
1758              break;
1759          case 'month':
1760              $prevlink = calendar_get_link_previous(userdate($prevmonthtime, get_string('strftimemonthyear')),
1761                  'view.php?view=month' . $courseid . '&amp;', false, false, false, false, $prevmonthtime);
1762              $nextlink = calendar_get_link_next(userdate($nextmonthtime, get_string('strftimemonthyear')),
1763                  'view.php?view=month' . $courseid . '&amp;', false, false, false, false, $nextmonthtime);
1764  
1765              $content .= \html_writer::start_tag('div', array('class' => 'calendar-controls'));
1766              $content .= $prevlink . '<span class="hide"> | </span>';
1767              $content .= $OUTPUT->heading(userdate($time, get_string('strftimemonthyear')), 2, 'current');
1768              $content .= '<span class="hide"> | </span>' . $nextlink;
1769              $content .= '<span class="clearer"><!-- --></span>';
1770              $content .= \html_writer::end_tag('div')."\n";
1771              break;
1772          case 'day':
1773              $days = calendar_get_days();
1774  
1775              $prevtimestamp = strtotime('-1 day', $time);
1776              $nexttimestamp = strtotime('+1 day', $time);
1777  
1778              $prevdate = $calendartype->timestamp_to_date_array($prevtimestamp);
1779              $nextdate = $calendartype->timestamp_to_date_array($nexttimestamp);
1780  
1781              $prevname = $days[$prevdate['wday']]['fullname'];
1782              $nextname = $days[$nextdate['wday']]['fullname'];
1783              $prevlink = calendar_get_link_previous($prevname, 'view.php?view=day' . $courseid . '&amp;', false, false,
1784                  false, false, $prevtimestamp);
1785              $nextlink = calendar_get_link_next($nextname, 'view.php?view=day' . $courseid . '&amp;', false, false, false,
1786                  false, $nexttimestamp);
1787  
1788              $content .= \html_writer::start_tag('div', array('class' => 'calendar-controls'));
1789              $content .= $prevlink;
1790              $content .= '<span class="hide"> | </span><span class="current">' .userdate($time,
1791                      get_string('strftimedaydate')) . '</span>';
1792              $content .= '<span class="hide"> | </span>' . $nextlink;
1793              $content .= "<span class=\"clearer\"><!-- --></span>";
1794              $content .= \html_writer::end_tag('div') . "\n";
1795  
1796              break;
1797      }
1798  
1799      return $content;
1800  }
1801  
1802  /**
1803   * Return the representation day.
1804   *
1805   * @param int $tstamp Timestamp in GMT
1806   * @param int|bool $now current Unix timestamp
1807   * @param bool $usecommonwords
1808   * @return string the formatted date/time
1809   */
1810  function calendar_day_representation($tstamp, $now = false, $usecommonwords = true) {
1811      static $shortformat;
1812  
1813      if (empty($shortformat)) {
1814          $shortformat = get_string('strftimedayshort');
1815      }
1816  
1817      if ($now === false) {
1818          $now = time();
1819      }
1820  
1821      // To have it in one place, if a change is needed.
1822      $formal = userdate($tstamp, $shortformat);
1823  
1824      $datestamp = usergetdate($tstamp);
1825      $datenow = usergetdate($now);
1826  
1827      if ($usecommonwords == false) {
1828          // We don't want words, just a date.
1829          return $formal;
1830      } else if ($datestamp['year'] == $datenow['year'] && $datestamp['yday'] == $datenow['yday']) {
1831          return get_string('today', 'calendar');
1832      } else if (($datestamp['year'] == $datenow['year'] && $datestamp['yday'] == $datenow['yday'] - 1 ) ||
1833          ($datestamp['year'] == $datenow['year'] - 1 && $datestamp['mday'] == 31 && $datestamp['mon'] == 12
1834              && $datenow['yday'] == 1)) {
1835          return get_string('yesterday', 'calendar');
1836      } else if (($datestamp['year'] == $datenow['year'] && $datestamp['yday'] == $datenow['yday'] + 1 ) ||
1837          ($datestamp['year'] == $datenow['year'] + 1 && $datenow['mday'] == 31 && $datenow['mon'] == 12
1838              && $datestamp['yday'] == 1)) {
1839          return get_string('tomorrow', 'calendar');
1840      } else {
1841          return $formal;
1842      }
1843  }
1844  
1845  /**
1846   * return the formatted representation time.
1847   *
1848  
1849   * @param int $time the timestamp in UTC, as obtained from the database
1850   * @return string the formatted date/time
1851   */
1852  function calendar_time_representation($time) {
1853      static $langtimeformat = null;
1854  
1855      if ($langtimeformat === null) {
1856          $langtimeformat = get_string('strftimetime');
1857      }
1858  
1859      $timeformat = get_user_preferences('calendar_timeformat');
1860      if (empty($timeformat)) {
1861          $timeformat = get_config(null, 'calendar_site_timeformat');
1862      }
1863  
1864      // Allow language customization of selected time format.
1865      if ($timeformat === CALENDAR_TF_12) {
1866          $timeformat = get_string('strftimetime12', 'langconfig');
1867      } else if ($timeformat === CALENDAR_TF_24) {
1868          $timeformat = get_string('strftimetime24', 'langconfig');
1869      }
1870  
1871      return userdate($time, empty($timeformat) ? $langtimeformat : $timeformat);
1872  }
1873  
1874  /**
1875   * Adds day, month, year arguments to a URL and returns a moodle_url object.
1876   *
1877   * @param string|moodle_url $linkbase
1878   * @param int $d The number of the day.
1879   * @param int $m The number of the month.
1880   * @param int $y The number of the year.
1881   * @param int $time the unixtime, used for multiple calendar support. The values $d,
1882   *     $m and $y are kept for backwards compatibility.
1883   * @return moodle_url|null $linkbase
1884   */
1885  function calendar_get_link_href($linkbase, $d, $m, $y, $time = 0) {
1886      if (empty($linkbase)) {
1887          return null;
1888      }
1889  
1890      if (!($linkbase instanceof \moodle_url)) {
1891          $linkbase = new \moodle_url($linkbase);
1892      }
1893  
1894      $linkbase->param('time', calendar_get_timestamp($d, $m, $y, $time));
1895  
1896      return $linkbase;
1897  }
1898  
1899  /**
1900   * Build and return a previous month HTML link, with an arrow.
1901   *
1902   * @param string $text The text label.
1903   * @param string|moodle_url $linkbase The URL stub.
1904   * @param int $d The number of the date.
1905   * @param int $m The number of the month.
1906   * @param int $y year The number of the year.
1907   * @param bool $accesshide Default visible, or hide from all except screenreaders.
1908   * @param int $time the unixtime, used for multiple calendar support. The values $d,
1909   *     $m and $y are kept for backwards compatibility.
1910   * @return string HTML string.
1911   */
1912  function calendar_get_link_previous($text, $linkbase, $d, $m, $y, $accesshide = false, $time = 0) {
1913      $href = calendar_get_link_href(new \moodle_url($linkbase), $d, $m, $y, $time);
1914  
1915      if (empty($href)) {
1916          return $text;
1917      }
1918  
1919      $attrs = [
1920          'data-time' => calendar_get_timestamp($d, $m, $y, $time),
1921          'data-drop-zone' => 'nav-link',
1922      ];
1923  
1924      return link_arrow_left($text, $href->out(false), $accesshide, 'previous', $attrs);
1925  }
1926  
1927  /**
1928   * Build and return a next month HTML link, with an arrow.
1929   *
1930   * @param string $text The text label.
1931   * @param string|moodle_url $linkbase The URL stub.
1932   * @param int $d the number of the Day
1933   * @param int $m The number of the month.
1934   * @param int $y The number of the year.
1935   * @param bool $accesshide Default visible, or hide from all except screenreaders.
1936   * @param int $time the unixtime, used for multiple calendar support. The values $d,
1937   *     $m and $y are kept for backwards compatibility.
1938   * @return string HTML string.
1939   */
1940  function calendar_get_link_next($text, $linkbase, $d, $m, $y, $accesshide = false, $time = 0) {
1941      $href = calendar_get_link_href(new \moodle_url($linkbase), $d, $m, $y, $time);
1942  
1943      if (empty($href)) {
1944          return $text;
1945      }
1946  
1947      $attrs = [
1948          'data-time' => calendar_get_timestamp($d, $m, $y, $time),
1949          'data-drop-zone' => 'nav-link',
1950      ];
1951  
1952      return link_arrow_right($text, $href->out(false), $accesshide, 'next', $attrs);
1953  }
1954  
1955  /**
1956   * Return the number of days in month.
1957   *
1958   * @param int $month the number of the month.
1959   * @param int $year the number of the year
1960   * @return int
1961   */
1962  function calendar_days_in_month($month, $year) {
1963      $calendartype = \core_calendar\type_factory::get_calendar_instance();
1964      return $calendartype->get_num_days_in_month($year, $month);
1965  }
1966  
1967  /**
1968   * Get the next following month.
1969   *
1970   * @param int $month the number of the month.
1971   * @param int $year the number of the year.
1972   * @return array the following month
1973   */
1974  function calendar_add_month($month, $year) {
1975      $calendartype = \core_calendar\type_factory::get_calendar_instance();
1976      return $calendartype->get_next_month($year, $month);
1977  }
1978  
1979  /**
1980   * Get the previous month.
1981   *
1982   * @param int $month the number of the month.
1983   * @param int $year the number of the year.
1984   * @return array previous month
1985   */
1986  function calendar_sub_month($month, $year) {
1987      $calendartype = \core_calendar\type_factory::get_calendar_instance();
1988      return $calendartype->get_prev_month($year, $month);
1989  }
1990  
1991  /**
1992   * Get per-day basis events
1993   *
1994   * @param array $events list of events
1995   * @param int $month the number of the month
1996   * @param int $year the number of the year
1997   * @param array $eventsbyday event on specific day
1998   * @param array $durationbyday duration of the event in days
1999   * @param array $typesbyday event type (eg: site, course, user, or group)
2000   * @param array $courses list of courses
2001   * @return void
2002   */
2003  function calendar_events_by_day($events, $month, $year, &$eventsbyday, &$durationbyday, &$typesbyday, &$courses) {
2004      $calendartype = \core_calendar\type_factory::get_calendar_instance();
2005  
2006      $eventsbyday = array();
2007      $typesbyday = array();
2008      $durationbyday = array();
2009  
2010      if ($events === false) {
2011          return;
2012      }
2013  
2014      foreach ($events as $event) {
2015          $startdate = $calendartype->timestamp_to_date_array($event->timestart);
2016          if ($event->timeduration) {
2017              $enddate = $calendartype->timestamp_to_date_array($event->timestart + $event->timeduration - 1);
2018          } else {
2019              $enddate = $startdate;
2020          }
2021  
2022          // Simple arithmetic: $year * 13 + $month is a distinct integer for each distinct ($year, $month) pair.
2023          if (!($startdate['year'] * 13 + $startdate['mon'] <= $year * 13 + $month) &&
2024              ($enddate['year'] * 13 + $enddate['mon'] >= $year * 13 + $month)) {
2025              continue;
2026          }
2027  
2028          $eventdaystart = intval($startdate['mday']);
2029  
2030          if ($startdate['mon'] == $month && $startdate['year'] == $year) {
2031              // Give the event to its day.
2032              $eventsbyday[$eventdaystart][] = $event->id;
2033  
2034              // Mark the day as having such an event.
2035              if ($event->courseid == SITEID && $event->groupid == 0) {
2036                  $typesbyday[$eventdaystart]['startsite'] = true;
2037                  // Set event class for site event.
2038                  $events[$event->id]->class = 'calendar_event_site';
2039              } else if ($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) {
2040                  $typesbyday[$eventdaystart]['startcourse'] = true;
2041                  // Set event class for course event.
2042                  $events[$event->id]->class = 'calendar_event_course';
2043              } else if ($event->groupid) {
2044                  $typesbyday[$eventdaystart]['startgroup'] = true;
2045                  // Set event class for group event.
2046                  $events[$event->id]->class = 'calendar_event_group';
2047              } else if ($event->userid) {
2048                  $typesbyday[$eventdaystart]['startuser'] = true;
2049                  // Set event class for user event.
2050                  $events[$event->id]->class = 'calendar_event_user';
2051              }
2052          }
2053  
2054          if ($event->timeduration == 0) {
2055              // Proceed with the next.
2056              continue;
2057          }
2058  
2059          // The event starts on $month $year or before.
2060          if ($startdate['mon'] == $month && $startdate['year'] == $year) {
2061              $lowerbound = intval($startdate['mday']);
2062          } else {
2063              $lowerbound = 0;
2064          }
2065  
2066          // Also, it ends on $month $year or later.
2067          if ($enddate['mon'] == $month && $enddate['year'] == $year) {
2068              $upperbound = intval($enddate['mday']);
2069          } else {
2070              $upperbound = calendar_days_in_month($month, $year);
2071          }
2072  
2073          // Mark all days between $lowerbound and $upperbound (inclusive) as duration.
2074          for ($i = $lowerbound + 1; $i <= $upperbound; ++$i) {
2075              $durationbyday[$i][] = $event->id;
2076              if ($event->courseid == SITEID && $event->groupid == 0) {
2077                  $typesbyday[$i]['durationsite'] = true;
2078              } else if ($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) {
2079                  $typesbyday[$i]['durationcourse'] = true;
2080              } else if ($event->groupid) {
2081                  $typesbyday[$i]['durationgroup'] = true;
2082              } else if ($event->userid) {
2083                  $typesbyday[$i]['durationuser'] = true;
2084              }
2085          }
2086  
2087      }
2088      return;
2089  }
2090  
2091  /**
2092   * Returns the courses to load events for.
2093   *
2094   * @param array $courseeventsfrom An array of courses to load calendar events for
2095   * @param bool $ignorefilters specify the use of filters, false is set as default
2096   * @param stdClass $user The user object. This defaults to the global $USER object.
2097   * @return array An array of courses, groups, and user to load calendar events for based upon filters
2098   */
2099  function calendar_set_filters(array $courseeventsfrom, $ignorefilters = false, stdClass $user = null) {
2100      global $CFG, $USER;
2101  
2102      if (is_null($user)) {
2103          $user = $USER;
2104      }
2105  
2106      $courses = array();
2107      $userid = false;
2108      $group = false;
2109  
2110      // Get the capabilities that allow seeing group events from all groups.
2111      $allgroupscaps = array('moodle/site:accessallgroups', 'moodle/calendar:manageentries');
2112  
2113      $isvaliduser = !empty($user->id);
2114  
2115      if ($ignorefilters || calendar_show_event_type(CALENDAR_EVENT_COURSE, $user)) {
2116          $courses = array_keys($courseeventsfrom);
2117      }
2118      if ($ignorefilters || calendar_show_event_type(CALENDAR_EVENT_SITE, $user)) {
2119          $courses[] = SITEID;
2120      }
2121      $courses = array_unique($courses);
2122      sort($courses);
2123  
2124      if (!empty($courses) && in_array(SITEID, $courses)) {
2125          // Sort courses for consistent colour highlighting.
2126          // Effectively ignoring SITEID as setting as last course id.
2127          $key = array_search(SITEID, $courses);
2128          unset($courses[$key]);
2129          $courses[] = SITEID;
2130      }
2131  
2132      if ($ignorefilters || ($isvaliduser && calendar_show_event_type(CALENDAR_EVENT_USER, $user))) {
2133          $userid = $user->id;
2134      }
2135  
2136      if (!empty($courseeventsfrom) && (calendar_show_event_type(CALENDAR_EVENT_GROUP, $user) || $ignorefilters)) {
2137  
2138          if (count($courseeventsfrom) == 1) {
2139              $course = reset($courseeventsfrom);
2140              if (has_any_capability($allgroupscaps, \context_course::instance($course->id))) {
2141                  $coursegroups = groups_get_all_groups($course->id, 0, 0, 'g.id');
2142                  $group = array_keys($coursegroups);
2143              }
2144          }
2145          if ($group === false) {
2146              if (!empty($CFG->calendar_adminseesall) && has_any_capability($allgroupscaps, \context_system::instance())) {
2147                  $group = true;
2148              } else if ($isvaliduser) {
2149                  $groupids = array();
2150                  foreach ($courseeventsfrom as $courseid => $course) {
2151                      if ($course->groupmode != NOGROUPS || !$course->groupmodeforce) {
2152                          // If this course has groups, show events from all of those related to the current user.
2153                          $coursegroups = groups_get_user_groups($course->id, $user->id);
2154                          $groupids = array_merge($groupids, $coursegroups['0']);
2155                      }
2156                  }
2157                  if (!empty($groupids)) {
2158                      $group = $groupids;
2159                  }
2160              }
2161          }
2162      }
2163      if (empty($courses)) {
2164          $courses = false;
2165      }
2166  
2167      return array($courses, $group, $userid);
2168  }
2169  
2170  /**
2171   * Can current user manage a non user event in system context.
2172   *
2173   * @param calendar_event|stdClass $event event object
2174   * @return boolean
2175   */
2176  function calendar_can_manage_non_user_event_in_system($event) {
2177      $sitecontext = \context_system::instance();
2178      $isuserevent = $event->eventtype == 'user';
2179      $canmanageentries = has_capability('moodle/calendar:manageentries', $sitecontext);
2180      // If user has manageentries at site level and it's not user event, return true.
2181      if ($canmanageentries && !$isuserevent) {
2182          return true;
2183      }
2184  
2185      return false;
2186  }
2187  
2188  /**
2189   * Return the capability for viewing a calendar event.
2190   *
2191   * @param calendar_event $event event object
2192   * @return boolean
2193   */
2194  function calendar_view_event_allowed(calendar_event $event) {
2195      global $USER;
2196  
2197      // Anyone can see site events.
2198      if ($event->courseid && $event->courseid == SITEID) {
2199          return true;
2200      }
2201  
2202      if (calendar_can_manage_non_user_event_in_system($event)) {
2203          return true;
2204      }
2205  
2206      if (!empty($event->groupid)) {
2207          // If it is a group event we need to be able to manage events in the course, or be in the group.
2208          if (has_capability('moodle/calendar:manageentries', $event->context) ||
2209                  has_capability('moodle/calendar:managegroupentries', $event->context)) {
2210              return true;
2211          }
2212  
2213          $mycourses = enrol_get_my_courses('id');
2214          return isset($mycourses[$event->courseid]) && groups_is_member($event->groupid);
2215      } else if ($event->modulename) {
2216          // If this is a module event we need to be able to see the module.
2217          $coursemodules = [];
2218          $courseid = 0;
2219          // Override events do not have the courseid set.
2220          if ($event->courseid) {
2221              $courseid = $event->courseid;
2222              $coursemodules = get_fast_modinfo($event->courseid)->instances;
2223          } else {
2224              $cmraw = get_coursemodule_from_instance($event->modulename, $event->instance, 0, false, MUST_EXIST);
2225              $courseid = $cmraw->course;
2226              $coursemodules = get_fast_modinfo($cmraw->course)->instances;
2227          }
2228          $hasmodule = isset($coursemodules[$event->modulename]);
2229          $hasinstance = isset($coursemodules[$event->modulename][$event->instance]);
2230  
2231          // If modinfo doesn't know about the module, return false to be safe.
2232          if (!$hasmodule || !$hasinstance) {
2233              return false;
2234          }
2235  
2236          // Must be able to see the course and the module - MDL-59304.
2237          $cm = $coursemodules[$event->modulename][$event->instance];
2238          if (!$cm->uservisible) {
2239              return false;
2240          }
2241          $mycourses = enrol_get_my_courses('id');
2242          return isset($mycourses[$courseid]);
2243      } else if ($event->categoryid) {
2244          // If this is a category we need to be able to see the category.
2245          $cat = \core_course_category::get($event->categoryid, IGNORE_MISSING);
2246          if (!$cat) {
2247              return false;
2248          }
2249          return true;
2250      } else if (!empty($event->courseid)) {
2251          // If it is a course event we need to be able to manage events in the course, or be in the course.
2252          if (has_capability('moodle/calendar:manageentries', $event->context)) {
2253              return true;
2254          }
2255  
2256          return can_access_course(get_course($event->courseid));
2257      } else if ($event->userid) {
2258          return calendar_can_manage_user_event($event);
2259      } else {
2260          throw new moodle_exception('unknown event type');
2261      }
2262  
2263      return false;
2264  }
2265  
2266  /**
2267   * Return the capability for editing calendar event.
2268   *
2269   * @param calendar_event $event event object
2270   * @param bool $manualedit is the event being edited manually by the user
2271   * @return bool capability to edit event
2272   */
2273  function calendar_edit_event_allowed($event, $manualedit = false) {
2274      global $USER, $DB;
2275  
2276      // Must be logged in.
2277      if (!isloggedin()) {
2278          return false;
2279      }
2280  
2281      // Can not be using guest account.
2282      if (isguestuser()) {
2283          return false;
2284      }
2285  
2286      if ($manualedit && !empty($event->modulename)) {
2287          $hascallback = component_callback_exists(
2288              'mod_' . $event->modulename,
2289              'core_calendar_event_timestart_updated'
2290          );
2291  
2292          if (!$hascallback) {
2293              // If the activity hasn't implemented the correct callback
2294              // to handle changes to it's events then don't allow any
2295              // manual changes to them.
2296              return false;
2297          }
2298  
2299          $coursemodules = get_fast_modinfo($event->courseid)->instances;
2300          $hasmodule = isset($coursemodules[$event->modulename]);
2301          $hasinstance = isset($coursemodules[$event->modulename][$event->instance]);
2302  
2303          // If modinfo doesn't know about the module, return false to be safe.
2304          if (!$hasmodule || !$hasinstance) {
2305              return false;
2306          }
2307  
2308          $coursemodule = $coursemodules[$event->modulename][$event->instance];
2309          $context = context_module::instance($coursemodule->id);
2310          // This is the capability that allows a user to modify the activity
2311          // settings. Since the activity generated this event we need to check
2312          // that the current user has the same capability before allowing them
2313          // to update the event because the changes to the event will be
2314          // reflected within the activity.
2315          return has_capability('moodle/course:manageactivities', $context);
2316      }
2317  
2318      if ($manualedit && !empty($event->component)) {
2319          // TODO possibly we can later add a callback similar to core_calendar_event_timestart_updated in the modules.
2320          return false;
2321      }
2322  
2323      // You cannot edit URL based calendar subscription events presently.
2324      if (!empty($event->subscriptionid)) {
2325          if (!empty($event->subscription->url)) {
2326              // This event can be updated externally, so it cannot be edited.
2327              return false;
2328          }
2329      }
2330  
2331      if (calendar_can_manage_non_user_event_in_system($event)) {
2332          return true;
2333      }
2334  
2335      // If groupid is set, it's definitely a group event.
2336      if (!empty($event->groupid)) {
2337          // Allow users to add/edit group events if -
2338          // 1) They have manageentries for the course OR
2339          // 2) They have managegroupentries AND are in the group.
2340          $group = $DB->get_record('groups', array('id' => $event->groupid));
2341          return $group && (
2342                  has_capability('moodle/calendar:manageentries', $event->context) ||
2343                  (has_capability('moodle/calendar:managegroupentries', $event->context)
2344                      && groups_is_member($event->groupid)));
2345      } else if (!empty($event->courseid)) {
2346          // If groupid is not set, but course is set, it's definitely a course event.
2347          return has_capability('moodle/calendar:manageentries', $event->context);
2348      } else if (!empty($event->categoryid)) {
2349          // If groupid is not set, but category is set, it's definitely a category event.
2350          return has_capability('moodle/calendar:manageentries', $event->context);
2351      } else if (!empty($event->userid) && $event->userid == $USER->id) {
2352          // If course is not set, but userid id set, it's a user event.
2353          return (has_capability('moodle/calendar:manageownentries', $event->context));
2354      } else if (!empty($event->userid)) {
2355          return calendar_can_manage_user_event($event);
2356      }
2357  
2358      return false;
2359  }
2360  
2361  /**
2362   * Can current user edit/delete/add an user event?
2363   *
2364   * @param calendar_event|stdClass $event event object
2365   * @return bool
2366   */
2367  function calendar_can_manage_user_event($event): bool {
2368      global $USER;
2369  
2370      if (!($event instanceof \calendar_event)) {
2371          $event = new \calendar_event(clone($event));
2372      }
2373  
2374      $canmanage = has_capability('moodle/calendar:manageentries', $event->context);
2375      $canmanageown = has_capability('moodle/calendar:manageownentries', $event->context);
2376      $ismyevent = $event->userid == $USER->id;
2377      $isadminevent = is_siteadmin($event->userid);
2378  
2379      if ($canmanageown && $ismyevent) {
2380          return true;
2381      }
2382  
2383      // In site context, user must have login and calendar:manageentries permissions
2384      // ... to manage other user's events except admin users.
2385      if ($canmanage && !$isadminevent) {
2386          return true;
2387      }
2388  
2389      return false;
2390  }
2391  
2392  /**
2393   * Return the capability for deleting a calendar event.
2394   *
2395   * @param calendar_event $event The event object
2396   * @return bool Whether the user has permission to delete the event or not.
2397   */
2398  function calendar_delete_event_allowed($event) {
2399      // Only allow delete if you have capabilities and it is not an module or component event.
2400      return (calendar_edit_event_allowed($event) && empty($event->modulename) && empty($event->component));
2401  }
2402  
2403  /**
2404   * Returns the default courses to display on the calendar when there isn't a specific
2405   * course to display.
2406   *
2407   * @param int $courseid (optional) If passed, an additional course can be returned for admins (the current course).
2408   * @param string $fields Comma separated list of course fields to return.
2409   * @param bool $canmanage If true, this will return the list of courses the user can create events in, rather
2410   *                        than the list of courses they see events from (an admin can always add events in a course
2411   *                        calendar, even if they are not enrolled in the course).
2412   * @param int $userid (optional) The user which this function returns the default courses for.
2413   *                        By default the current user.
2414   * @return array $courses Array of courses to display
2415   */
2416  function calendar_get_default_courses($courseid = null, $fields = '*', $canmanage = false, int $userid = null) {
2417      global $CFG, $USER;
2418  
2419      if (!$userid) {
2420          if (!isloggedin()) {
2421              return array();
2422          }
2423          $userid = $USER->id;
2424      }
2425  
2426      if ((!empty($CFG->calendar_adminseesall) || $canmanage) &&
2427              has_capability('moodle/calendar:manageentries', context_system::instance(), $userid)) {
2428  
2429          // Add a c. prefix to every field as expected by get_courses function.
2430          $fieldlist = explode(',', $fields);
2431  
2432          $prefixedfields = array_map(function($value) {
2433              return 'c.' . trim(strtolower($value));
2434          }, $fieldlist);
2435  
2436          $courses = get_courses('all', 'c.shortname', implode(',', $prefixedfields));
2437      } else {
2438          $courses = enrol_get_users_courses($userid, true, $fields);
2439      }
2440  
2441      if ($courseid && $courseid != SITEID) {
2442          if (empty($courses[$courseid]) && has_capability('moodle/calendar:manageentries', context_system::instance(), $userid)) {
2443              // Allow a site admin to see calendars from courses he is not enrolled in.
2444              // This will come from $COURSE.
2445              $courses[$courseid] = get_course($courseid);
2446          }
2447      }
2448  
2449      return $courses;
2450  }
2451  
2452  /**
2453   * Get event format time.
2454   *
2455   * @param calendar_event $event event object
2456   * @param int $now current time in gmt
2457   * @param array $linkparams list of params for event link
2458   * @param bool $usecommonwords the words as formatted date/time.
2459   * @param int $showtime determine the show time GMT timestamp
2460   * @return string $eventtime link/string for event time
2461   */
2462  function calendar_format_event_time($event, $now, $linkparams = null, $usecommonwords = true, $showtime = 0) {
2463      $starttime = $event->timestart;
2464      $endtime = $event->timestart + $event->timeduration;
2465  
2466      if (empty($linkparams) || !is_array($linkparams)) {
2467          $linkparams = array();
2468      }
2469  
2470      $linkparams['view'] = 'day';
2471  
2472      // OK, now to get a meaningful display.
2473      // Check if there is a duration for this event.
2474      if ($event->timeduration) {
2475          // Get the midnight of the day the event will start.
2476          $usermidnightstart = usergetmidnight($starttime);
2477          // Get the midnight of the day the event will end.
2478          $usermidnightend = usergetmidnight($endtime);
2479          // Check if we will still be on the same day.
2480          if ($usermidnightstart == $usermidnightend) {
2481              // Check if we are running all day.
2482              if ($event->timeduration == DAYSECS) {
2483                  $time = get_string('allday', 'calendar');
2484              } else { // Specify the time we will be running this from.
2485                  $datestart = calendar_time_representation($starttime);
2486                  $dateend = calendar_time_representation($endtime);
2487                  $time = $datestart . ' <strong>&raquo;</strong> ' . $dateend;
2488              }
2489  
2490              // Set printable representation.
2491              if (!$showtime) {
2492                  $day = calendar_day_representation($event->timestart, $now, $usecommonwords);
2493                  $url = calendar_get_link_href(new \moodle_url(CALENDAR_URL . 'view.php', $linkparams), 0, 0, 0, $endtime);
2494                  $eventtime = \html_writer::link($url, $day) . ', ' . $time;
2495              } else {
2496                  $eventtime = $time;
2497              }
2498          } else { // It must spans two or more days.
2499              $daystart = calendar_day_representation($event->timestart, $now, $usecommonwords) . ', ';
2500              if ($showtime == $usermidnightstart) {
2501                  $daystart = '';
2502              }
2503              $timestart = calendar_time_representation($event->timestart);
2504              $dayend = calendar_day_representation($event->timestart + $event->timeduration, $now, $usecommonwords) . ', ';
2505              if ($showtime == $usermidnightend) {
2506                  $dayend = '';
2507              }
2508              $timeend = calendar_time_representation($event->timestart + $event->timeduration);
2509  
2510              // Set printable representation.
2511              if ($now >= $usermidnightstart && $now < strtotime('+1 day', $usermidnightstart)) {
2512                  $url = calendar_get_link_href(new \moodle_url(CALENDAR_URL . 'view.php', $linkparams), 0, 0, 0, $endtime);
2513                  $eventtime = $timestart . ' <strong>&raquo;</strong> ' . \html_writer::link($url, $dayend) . $timeend;
2514              } else {
2515                  // The event is in the future, print start and end links.
2516                  $url = calendar_get_link_href(new \moodle_url(CALENDAR_URL . 'view.php', $linkparams), 0, 0, 0, $starttime);
2517                  $eventtime = \html_writer::link($url, $daystart) . $timestart . ' <strong>&raquo;</strong> ';
2518  
2519                  $url = calendar_get_link_href(new \moodle_url(CALENDAR_URL . 'view.php', $linkparams),  0, 0, 0, $endtime);
2520                  $eventtime .= \html_writer::link($url, $dayend) . $timeend;
2521              }
2522          }
2523      } else { // There is no time duration.
2524          $time = calendar_time_representation($event->timestart);
2525          // Set printable representation.
2526          if (!$showtime) {
2527              $day = calendar_day_representation($event->timestart, $now, $usecommonwords);
2528              $url = calendar_get_link_href(new \moodle_url(CALENDAR_URL . 'view.php', $linkparams),  0, 0, 0, $starttime);
2529              $eventtime = \html_writer::link($url, $day) . ', ' . trim($time);
2530          } else {
2531              $eventtime = $time;
2532          }
2533      }
2534  
2535      // Check if It has expired.
2536      if ($event->timestart + $event->timeduration < $now) {
2537          $eventtime = '<span class="dimmed_text">' . str_replace(' href=', ' class="dimmed" href=', $eventtime) . '</span>';
2538      }
2539  
2540      return $eventtime;
2541  }
2542  
2543  /**
2544   * Checks to see if the requested type of event should be shown for the given user.
2545   *
2546   * @param int $type The type to check the display for (default is to display all)
2547   * @param stdClass|int|null $user The user to check for - by default the current user
2548   * @return bool True if the tyep should be displayed false otherwise
2549   */
2550  function calendar_show_event_type($type, $user = null) {
2551      $default = CALENDAR_EVENT_SITE + CALENDAR_EVENT_COURSE + CALENDAR_EVENT_GROUP + CALENDAR_EVENT_USER;
2552  
2553      if (get_user_preferences('calendar_persistflt', 0, $user) === 0) {
2554          global $SESSION;
2555          if (!isset($SESSION->calendarshoweventtype)) {
2556              $SESSION->calendarshoweventtype = $default;
2557          }
2558          return $SESSION->calendarshoweventtype & $type;
2559      } else {
2560          return get_user_preferences('calendar_savedflt', $default, $user) & $type;
2561      }
2562  }
2563  
2564  /**
2565   * Sets the display of the event type given $display.
2566   *
2567   * If $display = true the event type will be shown.
2568   * If $display = false the event type will NOT be shown.
2569   * If $display = null the current value will be toggled and saved.
2570   *
2571   * @param int $type object of CALENDAR_EVENT_XXX
2572   * @param bool $display option to display event type
2573   * @param stdClass|int $user moodle user object or id, null means current user
2574   */
2575  function calendar_set_event_type_display($type, $display = null, $user = null) {
2576      $persist = get_user_preferences('calendar_persistflt', 0, $user);
2577      $default = CALENDAR_EVENT_SITE + CALENDAR_EVENT_COURSE + CALENDAR_EVENT_GROUP
2578              + CALENDAR_EVENT_USER + CALENDAR_EVENT_COURSECAT;
2579      if ($persist === 0) {
2580          global $SESSION;
2581          if (!isset($SESSION->calendarshoweventtype)) {
2582              $SESSION->calendarshoweventtype = $default;
2583          }
2584          $preference = $SESSION->calendarshoweventtype;
2585      } else {
2586          $preference = get_user_preferences('calendar_savedflt', $default, $user);
2587      }
2588      $current = $preference & $type;
2589      if ($display === null) {
2590          $display = !$current;
2591      }
2592      if ($display && !$current) {
2593          $preference += $type;
2594      } else if (!$display && $current) {
2595          $preference -= $type;
2596      }
2597      if ($persist === 0) {
2598          $SESSION->calendarshoweventtype = $preference;
2599      } else {
2600          if ($preference == $default) {
2601              unset_user_preference('calendar_savedflt', $user);
2602          } else {
2603              set_user_preference('calendar_savedflt', $preference, $user);
2604          }
2605      }
2606  }
2607  
2608  /**
2609   * Get calendar's allowed types.
2610   *
2611   * @param stdClass $allowed list of allowed edit for event  type
2612   * @param stdClass|int $course object of a course or course id
2613   * @param array $groups array of groups for the given course
2614   * @param stdClass|int $category object of a category
2615   */
2616  function calendar_get_allowed_types(&$allowed, $course = null, $groups = null, $category = null) {
2617      global $USER, $DB;
2618  
2619      $allowed = new \stdClass();
2620      $allowed->user = has_capability('moodle/calendar:manageownentries', \context_system::instance());
2621      $allowed->groups = false;
2622      $allowed->courses = false;
2623      $allowed->categories = false;
2624      $allowed->site = has_capability('moodle/calendar:manageentries', \context_course::instance(SITEID));
2625      $getgroupsfunc = function($course, $context, $user) use ($groups) {
2626          if ($course->groupmode != NOGROUPS || !$course->groupmodeforce) {
2627              if (has_capability('moodle/site:accessallgroups', $context)) {
2628                  return is_null($groups) ? groups_get_all_groups($course->id) : $groups;
2629              } else {
2630                  if (is_null($groups)) {
2631                      return groups_get_all_groups($course->id, $user->id);
2632                  } else {
2633                      return array_filter($groups, function($group) use ($user) {
2634                          return isset($group->members[$user->id]);
2635                      });
2636                  }
2637              }
2638          }
2639  
2640          return false;
2641      };
2642  
2643      if (!empty($course)) {
2644          if (!is_object($course)) {
2645              $course = $DB->get_record('course', array('id' => $course), 'id, groupmode, groupmodeforce', MUST_EXIST);
2646          }
2647          if ($course->id != SITEID) {
2648              $coursecontext = \context_course::instance($course->id);
2649              $allowed->user = has_capability('moodle/calendar:manageownentries', $coursecontext);
2650  
2651              if (has_capability('moodle/calendar:manageentries', $coursecontext)) {
2652                  $allowed->courses = array($course->id => 1);
2653                  $allowed->groups = $getgroupsfunc($course, $coursecontext, $USER);
2654              } else if (has_capability('moodle/calendar:managegroupentries', $coursecontext)) {
2655                  $allowed->groups = $getgroupsfunc($course, $coursecontext, $USER);
2656              }
2657          }
2658      }
2659  
2660      if (!empty($category)) {
2661          $catcontext = \context_coursecat::instance($category->id);
2662          if (has_capability('moodle/category:manage', $catcontext)) {
2663              $allowed->categories = [$category->id => 1];
2664          }
2665      }
2666  }
2667  
2668  /**
2669   * See if user can add calendar entries at all used to print the "New Event" button.
2670   *
2671   * @param stdClass $course object of a course or course id
2672   * @return bool has the capability to add at least one event type
2673   */
2674  function calendar_user_can_add_event($course) {
2675      if (!isloggedin() || isguestuser()) {
2676          return false;
2677      }
2678  
2679      calendar_get_allowed_types($allowed, $course);
2680  
2681      return (bool)($allowed->user || $allowed->groups || $allowed->courses || $allowed->categories || $allowed->site);
2682  }
2683  
2684  /**
2685   * Check wether the current user is permitted to add events.
2686   *
2687   * @param stdClass $event object of event
2688   * @return bool has the capability to add event
2689   */
2690  function calendar_add_event_allowed($event) {
2691      global $USER, $DB;
2692  
2693      // Can not be using guest account.
2694      if (!isloggedin() or isguestuser()) {
2695          return false;
2696      }
2697  
2698      if (calendar_can_manage_non_user_event_in_system($event)) {
2699          return true;
2700      }
2701  
2702      switch ($event->eventtype) {
2703          case 'category':
2704              return has_capability('moodle/category:manage', $event->context);
2705          case 'course':
2706              return has_capability('moodle/calendar:manageentries', $event->context);
2707          case 'group':
2708              // Allow users to add/edit group events if -
2709              // 1) They have manageentries (= entries for whole course).
2710              // 2) They have managegroupentries AND are in the group.
2711              $group = $DB->get_record('groups', array('id' => $event->groupid));
2712              return $group && (
2713                      has_capability('moodle/calendar:manageentries', $event->context) ||
2714                      (has_capability('moodle/calendar:managegroupentries', $event->context)
2715                          && groups_is_member($event->groupid)));
2716          case 'user':
2717              return calendar_can_manage_user_event($event);
2718          case 'site':
2719              return has_capability('moodle/calendar:manageentries', $event->context);
2720          default:
2721              return has_capability('moodle/calendar:manageentries', $event->context);
2722      }
2723  }
2724  
2725  /**
2726   * Returns option list for the poll interval setting.
2727   *
2728   * @return array An array of poll interval options. Interval => description.
2729   */
2730  function calendar_get_pollinterval_choices() {
2731      return array(
2732          '0' => new \lang_string('never', 'calendar'),
2733          HOURSECS => new \lang_string('hourly', 'calendar'),
2734          DAYSECS => new \lang_string('daily', 'calendar'),
2735          WEEKSECS => new \lang_string('weekly', 'calendar'),
2736          '2628000' => new \lang_string('monthly', 'calendar'),
2737          YEARSECS => new \lang_string('annually', 'calendar')
2738      );
2739  }
2740  
2741  /**
2742   * Returns option list of available options for the calendar event type, given the current user and course.
2743   *
2744   * @param int $courseid The id of the course
2745   * @return array An array containing the event types the user can create.
2746   */
2747  function calendar_get_eventtype_choices($courseid) {
2748      $choices = array();
2749      $allowed = new \stdClass;
2750      calendar_get_allowed_types($allowed, $courseid);
2751  
2752      if ($allowed->user) {
2753          $choices['user'] = get_string('userevents', 'calendar');
2754      }
2755      if ($allowed->site) {
2756          $choices['site'] = get_string('siteevents', 'calendar');
2757      }
2758      if (!empty($allowed->courses)) {
2759          $choices['course'] = get_string('courseevents', 'calendar');
2760      }
2761      if (!empty($allowed->categories)) {
2762          $choices['category'] = get_string('categoryevents', 'calendar');
2763      }
2764      if (!empty($allowed->groups) and is_array($allowed->groups)) {
2765          $choices['group'] = get_string('group');
2766      }
2767  
2768      return array($choices, $allowed->groups);
2769  }
2770  
2771  /**
2772   * Add an iCalendar subscription to the database.
2773   *
2774   * @param stdClass $sub The subscription object (e.g. from the form)
2775   * @return int The insert ID, if any.
2776   */
2777  function calendar_add_subscription($sub) {
2778      global $DB, $USER, $SITE;
2779  
2780      // Undo the form definition work around to allow us to have two different
2781      // course selectors present depending on which event type the user selects.
2782      if (!empty($sub->groupcourseid)) {
2783          $sub->courseid = $sub->groupcourseid;
2784          unset($sub->groupcourseid);
2785      }
2786  
2787      // Default course id if none is set.
2788      if (empty($sub->courseid)) {
2789          if ($sub->eventtype === 'site') {
2790              $sub->courseid = SITEID;
2791          } else {
2792              $sub->courseid = 0;
2793          }
2794      }
2795  
2796      if ($sub->eventtype === 'site') {
2797          $sub->courseid = $SITE->id;
2798      } else if ($sub->eventtype === 'group' || $sub->eventtype === 'course') {
2799          $sub->courseid = $sub->courseid;
2800      } else if ($sub->eventtype === 'category') {
2801          $sub->categoryid = $sub->categoryid;
2802      } else {
2803          // User events.
2804          $sub->courseid = 0;
2805      }
2806      $sub->userid = $USER->id;
2807  
2808      // File subscriptions never update.
2809      if (empty($sub->url)) {
2810          $sub->pollinterval = 0;
2811      }
2812  
2813      if (!empty($sub->name)) {
2814          if (empty($sub->id)) {
2815              $id = $DB->insert_record('event_subscriptions', $sub);
2816              // We cannot cache the data here because $sub is not complete.
2817              $sub->id = $id;
2818              // Trigger event, calendar subscription added.
2819              $eventparams = array('objectid' => $sub->id,
2820                  'context' => calendar_get_calendar_context($sub),
2821                  'other' => array(
2822                      'eventtype' => $sub->eventtype,
2823                  )
2824              );
2825              switch ($sub->eventtype) {
2826                  case 'category':
2827                      $eventparams['other']['categoryid'] = $sub->categoryid;
2828                      break;
2829                  case 'course':
2830                      $eventparams['other']['courseid'] = $sub->courseid;
2831                      break;
2832                  case 'group':
2833                      $eventparams['other']['courseid'] = $sub->courseid;
2834                      $eventparams['other']['groupid'] = $sub->groupid;
2835                      break;
2836                  default:
2837                      $eventparams['other']['courseid'] = $sub->courseid;
2838              }
2839  
2840              $event = \core\event\calendar_subscription_created::create($eventparams);
2841              $event->trigger();
2842              return $id;
2843          } else {
2844              // Why are we doing an update here?
2845              calendar_update_subscription($sub);
2846              return $sub->id;
2847          }
2848      } else {
2849          print_error('errorbadsubscription', 'importcalendar');
2850      }
2851  }
2852  
2853  /**
2854   * Add an iCalendar event to the Moodle calendar.
2855   *
2856   * @param stdClass $event The RFC-2445 iCalendar event
2857   * @param int $unused Deprecated
2858   * @param int $subscriptionid The iCalendar subscription ID
2859   * @param string $timezone The X-WR-TIMEZONE iCalendar property if provided
2860   * @throws dml_exception A DML specific exception is thrown for invalid subscriptionids.
2861   * @return int Code: CALENDAR_IMPORT_EVENT_UPDATED = updated,  CALENDAR_IMPORT_EVENT_INSERTED = inserted, 0 = error
2862   */
2863  function calendar_add_icalendar_event($event, $unused, $subscriptionid, $timezone='UTC') {
2864      global $DB;
2865  
2866      // Probably an unsupported X-MICROSOFT-CDO-BUSYSTATUS event.
2867      if (empty($event->properties['SUMMARY'])) {
2868          return 0;
2869      }
2870  
2871      $name = $event->properties['SUMMARY'][0]->value;
2872      $name = str_replace('\n', '<br />', $name);
2873      $name = str_replace('\\', '', $name);
2874      $name = preg_replace('/\s+/u', ' ', $name);
2875  
2876      $eventrecord = new \stdClass;
2877      $eventrecord->name = clean_param($name, PARAM_NOTAGS);
2878  
2879      if (empty($event->properties['DESCRIPTION'][0]->value)) {
2880          $description = '';
2881      } else {
2882          $description = $event->properties['DESCRIPTION'][0]->value;
2883          $description = clean_param($description, PARAM_NOTAGS);
2884          $description = str_replace('\n', '<br />', $description);
2885          $description = str_replace('\\', '', $description);
2886          $description = preg_replace('/\s+/u', ' ', $description);
2887      }
2888      $eventrecord->description = $description;
2889  
2890      // Probably a repeating event with RRULE etc. TODO: skip for now.
2891      if (empty($event->properties['DTSTART'][0]->value)) {
2892          return 0;
2893      }
2894  
2895      if (isset($event->properties['DTSTART'][0]->parameters['TZID'])) {
2896          $tz = $event->properties['DTSTART'][0]->parameters['TZID'];
2897      } else {
2898          $tz = $timezone;
2899      }
2900      $tz = \core_date::normalise_timezone($tz);
2901      $eventrecord->timestart = strtotime($event->properties['DTSTART'][0]->value . ' ' . $tz);
2902      if (empty($event->properties['DTEND'])) {
2903          $eventrecord->timeduration = 0; // No duration if no end time specified.
2904      } else {
2905          if (isset($event->properties['DTEND'][0]->parameters['TZID'])) {
2906              $endtz = $event->properties['DTEND'][0]->parameters['TZID'];
2907          } else {
2908              $endtz = $timezone;
2909          }
2910          $endtz = \core_date::normalise_timezone($endtz);
2911          $eventrecord->timeduration = strtotime($event->properties['DTEND'][0]->value . ' ' . $endtz) - $eventrecord->timestart;
2912      }
2913  
2914      // Check to see if it should be treated as an all day event.
2915      if ($eventrecord->timeduration == DAYSECS) {
2916          // Check to see if the event started at Midnight on the imported calendar.
2917          date_default_timezone_set($timezone);
2918          if (date('H:i:s', $eventrecord->timestart) === "00:00:00") {
2919              // This event should be an all day event. This is not correct, we don't do anything differently for all day events.
2920              // See MDL-56227.
2921              $eventrecord->timeduration = 0;
2922          }
2923          \core_date::set_default_server_timezone();
2924      }
2925  
2926      $eventrecord->location = empty($event->properties['LOCATION'][0]->value) ? '' :
2927              trim(str_replace('\\', '', $event->properties['LOCATION'][0]->value));
2928      $eventrecord->uuid = $event->properties['UID'][0]->value;
2929      $eventrecord->timemodified = time();
2930  
2931      // Add the iCal subscription details if required.
2932      // We should never do anything with an event without a subscription reference.
2933      $sub = calendar_get_subscription($subscriptionid);
2934      $eventrecord->subscriptionid = $subscriptionid;
2935      $eventrecord->userid = $sub->userid;
2936      $eventrecord->groupid = $sub->groupid;
2937      $eventrecord->courseid = $sub->courseid;
2938      $eventrecord->categoryid = $sub->categoryid;
2939      $eventrecord->eventtype = $sub->eventtype;
2940  
2941      if ($updaterecord = $DB->get_record('event', array('uuid' => $eventrecord->uuid,
2942          'subscriptionid' => $eventrecord->subscriptionid))) {
2943  
2944          // Compare iCal event data against the moodle event to see if something has changed.
2945          $result = array_diff((array) $eventrecord, (array) $updaterecord);
2946  
2947          // Unset timemodified field because it's always going to be different.
2948          unset($result['timemodified']);
2949  
2950          if (count($result)) {
2951              $eventrecord->id = $updaterecord->id;
2952              $return = CALENDAR_IMPORT_EVENT_UPDATED; // Update.
2953          } else {
2954              return CALENDAR_IMPORT_EVENT_SKIPPED;
2955          }
2956      } else {
2957          $return = CALENDAR_IMPORT_EVENT_INSERTED; // Insert.
2958      }
2959  
2960      if ($createdevent = \calendar_event::create($eventrecord, false)) {
2961          if (!empty($event->properties['RRULE'])) {
2962              // Repeating events.
2963              date_default_timezone_set($tz); // Change time zone to parse all events.
2964              $rrule = new \core_calendar\rrule_manager($event->properties['RRULE'][0]->value);
2965              $rrule->parse_rrule();
2966              $rrule->create_events($createdevent);
2967              \core_date::set_default_server_timezone(); // Change time zone back to what it was.
2968          }
2969          return $return;
2970      } else {
2971          return 0;
2972      }
2973  }
2974  
2975  /**
2976   * Update a subscription from the form data in one of the rows in the existing subscriptions table.
2977   *
2978   * @param int $subscriptionid The ID of the subscription we are acting upon.
2979   * @param int $pollinterval The poll interval to use.
2980   * @param int $action The action to be performed. One of update or remove.
2981   * @throws dml_exception if invalid subscriptionid is provided
2982   * @return string A log of the import progress, including errors
2983   */
2984  function calendar_process_subscription_row($subscriptionid, $pollinterval, $action) {
2985      // Fetch the subscription from the database making sure it exists.
2986      $sub = calendar_get_subscription($subscriptionid);
2987  
2988      // Update or remove the subscription, based on action.
2989      switch ($action) {
2990          case CALENDAR_SUBSCRIPTION_UPDATE:
2991              // Skip updating file subscriptions.
2992              if (empty($sub->url)) {
2993                  break;
2994              }
2995              $sub->pollinterval = $pollinterval;
2996              calendar_update_subscription($sub);
2997  
2998              // Update the events.
2999              return "<p>" . get_string('subscriptionupdated', 'calendar', $sub->name) . "</p>" .
3000                  calendar_update_subscription_events($subscriptionid);
3001          case CALENDAR_SUBSCRIPTION_REMOVE:
3002              calendar_delete_subscription($subscriptionid);
3003              return get_string('subscriptionremoved', 'calendar', $sub->name);
3004              break;
3005          default:
3006              break;
3007      }
3008      return '';
3009  }
3010  
3011  /**
3012   * Delete subscription and all related events.
3013   *
3014   * @param int|stdClass $subscription subscription or it's id, which needs to be deleted.
3015   */
3016  function calendar_delete_subscription($subscription) {
3017      global $DB;
3018  
3019      if (!is_object($subscription)) {
3020          $subscription = $DB->get_record('event_subscriptions', array('id' => $subscription), '*', MUST_EXIST);
3021      }
3022  
3023      // Delete subscription and related events.
3024      $DB->delete_records('event', array('subscriptionid' => $subscription->id));
3025      $DB->delete_records('event_subscriptions', array('id' => $subscription->id));
3026      \cache_helper::invalidate_by_definition('core', 'calendar_subscriptions', array(), array($subscription->id));
3027  
3028      // Trigger event, calendar subscription deleted.
3029      $eventparams = array('objectid' => $subscription->id,
3030          'context' => calendar_get_calendar_context($subscription),
3031          'other' => array(
3032              'eventtype' => $subscription->eventtype,
3033          )
3034      );
3035      switch ($subscription->eventtype) {
3036          case 'category':
3037              $eventparams['other']['categoryid'] = $subscription->categoryid;
3038              break;
3039          case 'course':
3040              $eventparams['other']['courseid'] = $subscription->courseid;
3041              break;
3042          case 'group':
3043              $eventparams['other']['courseid'] = $subscription->courseid;
3044              $eventparams['other']['groupid'] = $subscription->groupid;
3045              break;
3046          default:
3047              $eventparams['other']['courseid'] = $subscription->courseid;
3048      }
3049      $event = \core\event\calendar_subscription_deleted::create($eventparams);
3050      $event->trigger();
3051  }
3052  
3053  /**
3054   * From a URL, fetch the calendar and return an iCalendar object.
3055   *
3056   * @param string $url The iCalendar URL
3057   * @return iCalendar The iCalendar object
3058   */
3059  function calendar_get_icalendar($url) {
3060      global $CFG;
3061  
3062      require_once($CFG->libdir . '/filelib.php');
3063  
3064      $curl = new \curl();
3065      $curl->setopt(array('CURLOPT_FOLLOWLOCATION' => 1, 'CURLOPT_MAXREDIRS' => 5));
3066      $calendar = $curl->get($url);
3067  
3068      // Http code validation should actually be the job of curl class.
3069      if (!$calendar || $curl->info['http_code'] != 200 || !empty($curl->errorno)) {
3070          throw new \moodle_exception('errorinvalidicalurl', 'calendar');
3071      }
3072  
3073      $ical = new \iCalendar();
3074      $ical->unserialize($calendar);
3075  
3076      return $ical;
3077  }
3078  
3079  /**
3080   * Import events from an iCalendar object into a course calendar.
3081   *
3082   * @param iCalendar $ical The iCalendar object.
3083   * @param int $unused Deprecated
3084   * @param int $subscriptionid The subscription ID.
3085   * @return string A log of the import progress, including errors.
3086   */
3087  function calendar_import_icalendar_events($ical, $unused = null, $subscriptionid = null) {
3088      global $DB;
3089  
3090      $return = '';
3091      $eventcount = 0;
3092      $updatecount = 0;
3093      $skippedcount = 0;
3094  
3095      // Large calendars take a while...
3096      if (!CLI_SCRIPT) {
3097          \core_php_time_limit::raise(300);
3098      }
3099  
3100      // Grab the timezone from the iCalendar file to be used later.
3101      if (isset($ical->properties['X-WR-TIMEZONE'][0]->value)) {
3102          $timezone = $ical->properties['X-WR-TIMEZONE'][0]->value;
3103      } else {
3104          $timezone = 'UTC';
3105      }
3106  
3107      $icaluuids = [];
3108      foreach ($ical->components['VEVENT'] as $event) {
3109          $icaluuids[] = $event->properties['UID'][0]->value;
3110          $res = calendar_add_icalendar_event($event, null, $subscriptionid, $timezone);
3111          switch ($res) {
3112              case CALENDAR_IMPORT_EVENT_UPDATED:
3113                  $updatecount++;
3114                  break;
3115              case CALENDAR_IMPORT_EVENT_INSERTED:
3116                  $eventcount++;
3117                  break;
3118              case CALENDAR_IMPORT_EVENT_SKIPPED:
3119                  $skippedcount++;
3120                  break;
3121              case 0:
3122                  $return .= '<p>' . get_string('erroraddingevent', 'calendar') . ': ';
3123                  if (empty($event->properties['SUMMARY'])) {
3124                      $return .= '(' . get_string('notitle', 'calendar') . ')';
3125                  } else {
3126                      $return .= $event->properties['SUMMARY'][0]->value;
3127                  }
3128                  $return .= "</p>\n";
3129                  break;
3130          }
3131      }
3132  
3133      $existing = $DB->get_field('event_subscriptions', 'lastupdated', ['id' => $subscriptionid]);
3134      if (!empty($existing)) {
3135          $eventsuuids = $DB->get_records_menu('event', ['subscriptionid' => $subscriptionid], '', 'id, uuid');
3136  
3137          $icaleventscount = count($icaluuids);
3138          $tobedeleted = [];
3139          if (count($eventsuuids) > $icaleventscount) {
3140              foreach ($eventsuuids as $eventid => $eventuuid) {
3141                  if (!in_array($eventuuid, $icaluuids)) {
3142                      $tobedeleted[] = $eventid;
3143                  }
3144              }
3145              if (!empty($tobedeleted)) {
3146                  $DB->delete_records_list('event', 'id', $tobedeleted);
3147                  $return .= "<p> " . get_string('eventsdeleted', 'calendar') . ": " . count($tobedeleted) . "</p> ";
3148              }
3149          }
3150      }
3151  
3152      $return .= "<p>" . get_string('eventsimported', 'calendar', $eventcount) . "</p> ";
3153      $return .= "<p>" . get_string('eventsskipped', 'calendar', $skippedcount) . "</p> ";
3154      $return .= "<p>" . get_string('eventsupdated', 'calendar', $updatecount) . "</p>";
3155      return $return;
3156  }
3157  
3158  /**
3159   * Fetch a calendar subscription and update the events in the calendar.
3160   *
3161   * @param int $subscriptionid The course ID for the calendar.
3162   * @return string A log of the import progress, including errors.
3163   */
3164  function calendar_update_subscription_events($subscriptionid) {
3165      $sub = calendar_get_subscription($subscriptionid);
3166  
3167      // Don't update a file subscription.
3168      if (empty($sub->url)) {
3169          return 'File subscription not updated.';
3170      }
3171  
3172      $ical = calendar_get_icalendar($sub->url);
3173      $return = calendar_import_icalendar_events($ical, null, $subscriptionid);
3174      $sub->lastupdated = time();
3175  
3176      calendar_update_subscription($sub);
3177  
3178      return $return;
3179  }
3180  
3181  /**
3182   * Update a calendar subscription. Also updates the associated cache.
3183   *
3184   * @param stdClass|array $subscription Subscription record.
3185   * @throws coding_exception If something goes wrong
3186   * @since Moodle 2.5
3187   */
3188  function calendar_update_subscription($subscription) {
3189      global $DB;
3190  
3191      if (is_array($subscription)) {
3192          $subscription = (object)$subscription;
3193      }
3194      if (empty($subscription->id) || !$DB->record_exists('event_subscriptions', array('id' => $subscription->id))) {
3195          throw new \coding_exception('Cannot update a subscription without a valid id');
3196      }
3197  
3198      $DB->update_record('event_subscriptions', $subscription);
3199  
3200      // Update cache.
3201      $cache = \cache::make('core', 'calendar_subscriptions');
3202      $cache->set($subscription->id, $subscription);
3203  
3204      // Trigger event, calendar subscription updated.
3205      $eventparams = array('userid' => $subscription->userid,
3206          'objectid' => $subscription->id,
3207          'context' => calendar_get_calendar_context($subscription),
3208          'other' => array(
3209              'eventtype' => $subscription->eventtype,
3210          )
3211      );
3212      switch ($subscription->eventtype) {
3213          case 'category':
3214              $eventparams['other']['categoryid'] = $subscription->categoryid;
3215              break;
3216          case 'course':
3217              $eventparams['other']['courseid'] = $subscription->courseid;
3218              break;
3219          case 'group':
3220              $eventparams['other']['courseid'] = $subscription->courseid;
3221              $eventparams['other']['groupid'] = $subscription->groupid;
3222              break;
3223          default:
3224              $eventparams['other']['courseid'] = $subscription->courseid;
3225      }
3226      $event = \core\event\calendar_subscription_updated::create($eventparams);
3227      $event->trigger();
3228  }
3229  
3230  /**
3231   * Checks to see if the user can edit a given subscription feed.
3232   *
3233   * @param mixed $subscriptionorid Subscription object or id
3234   * @return bool true if current user can edit the subscription else false
3235   */
3236  function calendar_can_edit_subscription($subscriptionorid) {
3237      global $USER;
3238      if (is_array($subscriptionorid)) {
3239          $subscription = (object)$subscriptionorid;
3240      } else if (is_object($subscriptionorid)) {
3241          $subscription = $subscriptionorid;
3242      } else {
3243          $subscription = calendar_get_subscription($subscriptionorid);
3244      }
3245  
3246      $allowed = new \stdClass;
3247      $courseid = $subscription->courseid;
3248      $categoryid = $subscription->categoryid;
3249      $groupid = $subscription->groupid;
3250      $category = null;
3251  
3252      if (!empty($categoryid)) {
3253          $category = \core_course_category::get($categoryid);
3254      }
3255      calendar_get_allowed_types($allowed, $courseid, null, $category);
3256      switch ($subscription->eventtype) {
3257          case 'user':
3258              return ($USER->id == $subscription->userid && $allowed->user);
3259          case 'course':
3260              if (isset($allowed->courses[$courseid])) {
3261                  return $allowed->courses[$courseid];
3262              } else {
3263                  return false;
3264              }
3265          case 'category':
3266              if (isset($allowed->categories[$categoryid])) {
3267                  return $allowed->categories[$categoryid];
3268              } else {
3269                  return false;
3270              }
3271          case 'site':
3272              return $allowed->site;
3273          case 'group':
3274              if (isset($allowed->groups[$groupid])) {
3275                  return $allowed->groups[$groupid];
3276              } else {
3277                  return false;
3278              }
3279          default:
3280              return false;
3281      }
3282  }
3283  
3284  /**
3285   * Helper function to determine the context of a calendar subscription.
3286   * Subscriptions can be created in two contexts COURSE, or USER.
3287   *
3288   * @param stdClass $subscription
3289   * @return context instance
3290   */
3291  function calendar_get_calendar_context($subscription) {
3292      // Determine context based on calendar type.
3293      if ($subscription->eventtype === 'site') {
3294          $context = \context_course::instance(SITEID);
3295      } else if ($subscription->eventtype === 'group' || $subscription->eventtype === 'course') {
3296          $context = \context_course::instance($subscription->courseid);
3297      } else {
3298          $context = \context_user::instance($subscription->userid);
3299      }
3300      return $context;
3301  }
3302  
3303  /**
3304   * Implements callback user_preferences, lists preferences that users are allowed to update directly
3305   *
3306   * Used in {@see core_user::fill_preferences_cache()}, see also {@see useredit_update_user_preference()}
3307   *
3308   * @return array
3309   */
3310  function core_calendar_user_preferences() {
3311      $preferences = [];
3312      $preferences['calendar_timeformat'] = array('type' => PARAM_NOTAGS, 'null' => NULL_NOT_ALLOWED, 'default' => '0',
3313          'choices' => array('0', CALENDAR_TF_12, CALENDAR_TF_24)
3314      );
3315      $preferences['calendar_startwday'] = array('type' => PARAM_INT, 'null' => NULL_NOT_ALLOWED, 'default' => 0,
3316          'choices' => array(0, 1, 2, 3, 4, 5, 6));
3317      $preferences['calendar_maxevents'] = array('type' => PARAM_INT, 'choices' => range(1, 20));
3318      $preferences['calendar_lookahead'] = array('type' => PARAM_INT, 'null' => NULL_NOT_ALLOWED, 'default' => 365,
3319          'choices' => array(365, 270, 180, 150, 120, 90, 60, 30, 21, 14, 7, 6, 5, 4, 3, 2, 1));
3320      $preferences['calendar_persistflt'] = array('type' => PARAM_INT, 'null' => NULL_NOT_ALLOWED, 'default' => 0,
3321          'choices' => array(0, 1));
3322      return $preferences;
3323  }
3324  
3325  /**
3326   * Get legacy calendar events
3327   *
3328   * @param int $tstart Start time of time range for events
3329   * @param int $tend End time of time range for events
3330   * @param array|int|boolean $users array of users, user id or boolean for all/no user events
3331   * @param array|int|boolean $groups array of groups, group id or boolean for all/no group events
3332   * @param array|int|boolean $courses array of courses, course id or boolean for all/no course events
3333   * @param boolean $withduration whether only events starting within time range selected
3334   *                              or events in progress/already started selected as well
3335   * @param boolean $ignorehidden whether to select only visible events or all events
3336   * @param array $categories array of category ids and/or objects.
3337   * @param int $limitnum Number of events to fetch or zero to fetch all.
3338   *
3339   * @return array $events of selected events or an empty array if there aren't any (or there was an error)
3340   */
3341  function calendar_get_legacy_events($tstart, $tend, $users, $groups, $courses,
3342          $withduration = true, $ignorehidden = true, $categories = [], $limitnum = 0) {
3343      // Normalise the users, groups and courses parameters so that they are compliant with \core_calendar\local\api::get_events().
3344      // Existing functions that were using the old calendar_get_events() were passing a mixture of array, int, boolean for these
3345      // parameters, but with the new API method, only null and arrays are accepted.
3346      list($userparam, $groupparam, $courseparam, $categoryparam) = array_map(function($param) {
3347          // If parameter is true, return null.
3348          if ($param === true) {
3349              return null;
3350          }
3351  
3352          // If parameter is false, return an empty array.
3353          if ($param === false) {
3354              return [];
3355          }
3356  
3357          // If the parameter is a scalar value, enclose it in an array.
3358          if (!is_array($param)) {
3359              return [$param];
3360          }
3361  
3362          // No normalisation required.
3363          return $param;
3364      }, [$users, $groups, $courses, $categories]);
3365  
3366      // If a single user is provided, we can use that for capability checks.
3367      // Otherwise current logged in user is used - See MDL-58768.
3368      if (is_array($userparam) && count($userparam) == 1) {
3369          \core_calendar\local\event\container::set_requesting_user($userparam[0]);
3370      }
3371      $mapper = \core_calendar\local\event\container::get_event_mapper();
3372      $events = \core_calendar\local\api::get_events(
3373          $tstart,
3374          $tend,
3375          null,
3376          null,
3377          null,
3378          null,
3379          $limitnum,
3380          null,
3381          $userparam,
3382          $groupparam,
3383          $courseparam,
3384          $categoryparam,
3385          $withduration,
3386          $ignorehidden
3387      );
3388  
3389      return array_reduce($events, function($carry, $event) use ($mapper) {
3390          return $carry + [$event->get_id() => $mapper->from_event_to_stdclass($event)];
3391      }, []);
3392  }
3393  
3394  
3395  /**
3396   * Get the calendar view output.
3397   *
3398   * @param   \calendar_information $calendar The calendar being represented
3399   * @param   string  $view The type of calendar to have displayed
3400   * @param   bool    $includenavigation Whether to include navigation
3401   * @param   bool    $skipevents Whether to load the events or not
3402   * @param   int     $lookahead Overwrites site and users's lookahead setting.
3403   * @return  array[array, string]
3404   */
3405  function calendar_get_view(\calendar_information $calendar, $view, $includenavigation = true, bool $skipevents = false,
3406          ?int $lookahead = null) {
3407      global $PAGE, $CFG;
3408  
3409      $renderer = $PAGE->get_renderer('core_calendar');
3410      $type = \core_calendar\type_factory::get_calendar_instance();
3411  
3412      // Calculate the bounds of the month.
3413      $calendardate = $type->timestamp_to_date_array($calendar->time);
3414  
3415      $date = new \DateTime('now', core_date::get_user_timezone_object(99));
3416      $eventlimit = 0;
3417  
3418      if ($view === 'day') {
3419          $tstart = $type->convert_to_timestamp($calendardate['year'], $calendardate['mon'], $calendardate['mday']);
3420          $date->setTimestamp($tstart);
3421          $date->modify('+1 day');
3422      } else if ($view === 'upcoming' || $view === 'upcoming_mini') {
3423          // Number of days in the future that will be used to fetch events.
3424          if (!$lookahead) {
3425              if (isset($CFG->calendar_lookahead)) {
3426                  $defaultlookahead = intval($CFG->calendar_lookahead);
3427              } else {
3428                  $defaultlookahead = CALENDAR_DEFAULT_UPCOMING_LOOKAHEAD;
3429              }
3430              $lookahead = get_user_preferences('calendar_lookahead', $defaultlookahead);
3431          }
3432  
3433          // Maximum number of events to be displayed on upcoming view.
3434          $defaultmaxevents = CALENDAR_DEFAULT_UPCOMING_MAXEVENTS;
3435          if (isset($CFG->calendar_maxevents)) {
3436              $defaultmaxevents = intval($CFG->calendar_maxevents);
3437          }
3438          $eventlimit = get_user_preferences('calendar_maxevents', $defaultmaxevents);
3439  
3440          $tstart = $type->convert_to_timestamp($calendardate['year'], $calendardate['mon'], $calendardate['mday'],
3441                  $calendardate['hours']);
3442          $date->setTimestamp($tstart);
3443          $date->modify('+' . $lookahead . ' days');
3444      } else {
3445          $tstart = $type->convert_to_timestamp($calendardate['year'], $calendardate['mon'], 1);
3446          $monthdays = $type->get_num_days_in_month($calendardate['year'], $calendardate['mon']);
3447          $date->setTimestamp($tstart);
3448          $date->modify('+' . $monthdays . ' days');
3449  
3450          if ($view === 'mini' || $view === 'minithree') {
3451              $template = 'core_calendar/calendar_mini';
3452          } else {
3453              $template = 'core_calendar/calendar_month';
3454          }
3455      }
3456  
3457      // We need to extract 1 second to ensure that we don't get into the next day.
3458      $date->modify('-1 second');
3459      $tend = $date->getTimestamp();
3460  
3461      list($userparam, $groupparam, $courseparam, $categoryparam) = array_map(function($param) {
3462          // If parameter is true, return null.
3463          if ($param === true) {
3464              return null;
3465          }
3466  
3467          // If parameter is false, return an empty array.
3468          if ($param === false) {
3469              return [];
3470          }
3471  
3472          // If the parameter is a scalar value, enclose it in an array.
3473          if (!is_array($param)) {
3474              return [$param];
3475          }
3476  
3477          // No normalisation required.
3478          return $param;
3479      }, [$calendar->users, $calendar->groups, $calendar->courses, $calendar->categories]);
3480  
3481      if ($skipevents) {
3482          $events = [];
3483      } else {
3484          $events = \core_calendar\local\api::get_events(
3485              $tstart,
3486              $tend,
3487              null,
3488              null,
3489              null,
3490              null,
3491              $eventlimit,
3492              null,
3493              $userparam,
3494              $groupparam,
3495              $courseparam,
3496              $categoryparam,
3497              true,
3498              true,
3499              function ($event) {
3500                  if ($proxy = $event->get_course_module()) {
3501                      $cminfo = $proxy->get_proxied_instance();
3502                      return $cminfo->uservisible;
3503                  }
3504  
3505                  if ($proxy = $event->get_category()) {
3506                      $category = $proxy->get_proxied_instance();
3507  
3508                      return $category->is_uservisible();
3509                  }
3510  
3511                  return true;
3512              }
3513          );
3514      }
3515  
3516      $related = [
3517          'events' => $events,
3518          'cache' => new \core_calendar\external\events_related_objects_cache($events),
3519          'type' => $type,
3520      ];
3521  
3522      $data = [];
3523      if ($view == "month" || $view == "mini" || $view == "minithree") {
3524          $month = new \core_calendar\external\month_exporter($calendar, $type, $related);
3525          $month->set_includenavigation($includenavigation);
3526          $month->set_initialeventsloaded(!$skipevents);
3527          $month->set_showcoursefilter($view == "month");
3528          $data = $month->export($renderer);
3529          $data->viewingmonth = true;
3530      } else if ($view == "day") {
3531          $day = new \core_calendar\external\calendar_day_exporter($calendar, $related);
3532          $data = $day->export($renderer);
3533          $data->viewingday = true;
3534          $template = 'core_calendar/calendar_day';
3535      } else if ($view == "upcoming" || $view == "upcoming_mini") {
3536          $upcoming = new \core_calendar\external\calendar_upcoming_exporter($calendar, $related);
3537          $data = $upcoming->export($renderer);
3538  
3539          if ($view == "upcoming") {
3540              $template = 'core_calendar/calendar_upcoming';
3541              $data->viewingupcoming = true;
3542          } else if ($view == "upcoming_mini") {
3543              $template = 'core_calendar/calendar_upcoming_mini';
3544          }
3545      }
3546  
3547      return [$data, $template];
3548  }
3549  
3550  /**
3551   * Request and render event form fragment.
3552   *
3553   * @param array $args The fragment arguments.
3554   * @return string The rendered mform fragment.
3555   */
3556  function calendar_output_fragment_event_form($args) {
3557      global $CFG, $OUTPUT, $USER;
3558      require_once($CFG->libdir . '/grouplib.php');
3559      $html = '';
3560      $data = [];
3561      $eventid = isset($args['eventid']) ? clean_param($args['eventid'], PARAM_INT) : null;
3562      $starttime = isset($args['starttime']) ? clean_param($args['starttime'], PARAM_INT) : null;
3563      $courseid = (isset($args['courseid']) && $args['courseid'] != SITEID) ? clean_param($args['courseid'], PARAM_INT) : null;
3564      $categoryid = isset($args['categoryid']) ? clean_param($args['categoryid'], PARAM_INT) : null;
3565      $event = null;
3566      $hasformdata = isset($args['formdata']) && !empty($args['formdata']);
3567      $context = \context_user::instance($USER->id);
3568      $editoroptions = \core_calendar\local\event\forms\create::build_editor_options($context);
3569      $formoptions = ['editoroptions' => $editoroptions, 'courseid' => $courseid];
3570      $draftitemid = 0;
3571  
3572      if ($hasformdata) {
3573          parse_str(clean_param($args['formdata'], PARAM_TEXT), $data);
3574          if (isset($data['description']['itemid'])) {
3575              $draftitemid = $data['description']['itemid'];
3576          }
3577      }
3578  
3579      if ($starttime) {
3580          $formoptions['starttime'] = $starttime;
3581      }
3582      // Let's check first which event types user can add.
3583      $eventtypes = calendar_get_allowed_event_types($courseid);
3584      $formoptions['eventtypes'] = $eventtypes;
3585  
3586      if (is_null($eventid)) {
3587          if (!empty($courseid)) {
3588              $groupcoursedata = groups_get_course_data($courseid);
3589              $formoptions['groups'] = [];
3590              foreach ($groupcoursedata->groups as $groupid => $groupdata) {
3591                  $formoptions['groups'][$groupid] = $groupdata->name;
3592              }
3593          }
3594  
3595          $mform = new \core_calendar\local\event\forms\create(
3596              null,
3597              $formoptions,
3598              'post',
3599              '',
3600              null,
3601              true,
3602              $data
3603          );
3604  
3605          // If the user is on course context and is allowed to add course events set the event type default to course.
3606          if (!empty($courseid) && !empty($eventtypes['course'])) {
3607              $data['eventtype'] = 'course';
3608              $data['courseid'] = $courseid;
3609              $data['groupcourseid'] = $courseid;
3610          } else if (!empty($categoryid) && !empty($eventtypes['category'])) {
3611              $data['eventtype'] = 'category';
3612              $data['categoryid'] = $categoryid;
3613          } else if (!empty($groupcoursedata) && !empty($eventtypes['group'])) {
3614              $data['groupcourseid'] = $courseid;
3615              $data['groups'] = $groupcoursedata->groups;
3616          }
3617          $mform->set_data($data);
3618      } else {
3619          $event = calendar_event::load($eventid);
3620  
3621          if (!calendar_edit_event_allowed($event)) {
3622              print_error('nopermissiontoupdatecalendar');
3623          }
3624  
3625          $mapper = new \core_calendar\local\event\mappers\create_update_form_mapper();
3626          $eventdata = $mapper->from_legacy_event_to_data($event);
3627          $data = array_merge((array) $eventdata, $data);
3628          $event->count_repeats();
3629          $formoptions['event'] = $event;
3630  
3631          if (!empty($event->courseid)) {
3632              $groupcoursedata = groups_get_course_data($event->courseid);
3633              $formoptions['groups'] = [];
3634              foreach ($groupcoursedata->groups as $groupid => $groupdata) {
3635                  $formoptions['groups'][$groupid] = $groupdata->name;
3636              }
3637          }
3638  
3639          $data['description']['text'] = file_prepare_draft_area(
3640              $draftitemid,
3641              $event->context->id,
3642              'calendar',
3643              'event_description',
3644              $event->id,
3645              null,
3646              $data['description']['text']
3647          );
3648          $data['description']['itemid'] = $draftitemid;
3649  
3650          $mform = new \core_calendar\local\event\forms\update(
3651              null,
3652              $formoptions,
3653              'post',
3654              '',
3655              null,
3656              true,
3657              $data
3658          );
3659          $mform->set_data($data);
3660  
3661          // Check to see if this event is part of a subscription or import.
3662          // If so display a warning on edit.
3663          if (isset($event->subscriptionid) && ($event->subscriptionid != null)) {
3664              $renderable = new \core\output\notification(
3665                  get_string('eventsubscriptioneditwarning', 'calendar'),
3666                  \core\output\notification::NOTIFY_INFO
3667              );
3668  
3669              $html .= $OUTPUT->render($renderable);
3670          }
3671      }
3672  
3673      if ($hasformdata) {
3674          $mform->is_validated();
3675      }
3676  
3677      $html .= $mform->render();
3678      return $html;
3679  }
3680  
3681  /**
3682   * Calculate the timestamp from the supplied Gregorian Year, Month, and Day.
3683   *
3684   * @param   int     $d The day
3685   * @param   int     $m The month
3686   * @param   int     $y The year
3687   * @param   int     $time The timestamp to use instead of a separate y/m/d.
3688   * @return  int     The timestamp
3689   */
3690  function calendar_get_timestamp($d, $m, $y, $time = 0) {
3691      // If a day, month and year were passed then convert it to a timestamp. If these were passed
3692      // then we can assume the day, month and year are passed as Gregorian, as no where in core
3693      // should we be passing these values rather than the time.
3694      if (!empty($d) && !empty($m) && !empty($y)) {
3695          if (checkdate($m, $d, $y)) {
3696              $time = make_timestamp($y, $m, $d);
3697          } else {
3698              $time = time();
3699          }
3700      } else if (empty($time)) {
3701          $time = time();
3702      }
3703  
3704      return $time;
3705  }
3706  
3707  /**
3708   * Get the calendar footer options.
3709   *
3710   * @param calendar_information $calendar The calendar information object.
3711   * @return array The data for template and template name.
3712   */
3713  function calendar_get_footer_options($calendar) {
3714      global $CFG, $USER, $PAGE;
3715  
3716      // Generate hash for iCal link.
3717      $authtoken = calendar_get_export_token($USER);
3718  
3719      $renderer = $PAGE->get_renderer('core_calendar');
3720      $footer = new \core_calendar\external\footer_options_exporter($calendar, $USER->id, $authtoken);
3721      $data = $footer->export($renderer);
3722      $template = 'core_calendar/footer_options';
3723  
3724      return [$data, $template];
3725  }
3726  
3727  /**
3728   * Get the list of potential calendar filter types as a type => name
3729   * combination.
3730   *
3731   * @return array
3732   */
3733  function calendar_get_filter_types() {
3734      $types = [
3735          'site',
3736          'category',
3737          'course',
3738          'group',
3739          'user',
3740          'other'
3741      ];
3742  
3743      return array_map(function($type) {
3744          return [
3745              'eventtype' => $type,
3746              'name' => get_string("eventtype{$type}", "calendar"),
3747              'icon' => true,
3748              'key' => 'i/' . $type . 'event',
3749              'component' => 'core'
3750          ];
3751      }, $types);
3752  }
3753  
3754  /**
3755   * Check whether the specified event type is valid.
3756   *
3757   * @param string $type
3758   * @return bool
3759   */
3760  function calendar_is_valid_eventtype($type) {
3761      $validtypes = [
3762          'user',
3763          'group',
3764          'course',
3765          'category',
3766          'site',
3767      ];
3768      return in_array($type, $validtypes);
3769  }
3770  
3771  /**
3772   * Get event types the user can create event based on categories, courses and groups
3773   * the logged in user belongs to.
3774   *
3775   * @param int|null $courseid The course id.
3776   * @return array The array of allowed types.
3777   */
3778  function calendar_get_allowed_event_types(int $courseid = null) {
3779      global $DB, $CFG, $USER;
3780  
3781      $types = [
3782          'user' => false,
3783          'site' => false,
3784          'course' => false,
3785          'group' => false,
3786          'category' => false
3787      ];
3788  
3789      if (!empty($courseid) && $courseid != SITEID) {
3790          $context = \context_course::instanc