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   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   * Contains the import_strategy_file class.
  18   *
  19   * @package tool_moodlenet
  20   * @copyright 2020 Jake Dallimore <jrhdallimore@gmail.com>
  21   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  22   */
  23  namespace tool_moodlenet\local;
  24  
  25  use core\antivirus\manager as avmanager;
  26  
  27  /**
  28   * The import_strategy_file class.
  29   *
  30   * The import_strategy_file objects contains the setup steps needed to prepare a resource for import as a file into Moodle. This
  31   * ensures the remote_resource is first downloaded and put in a draft file area, ready for use as a file by the handling module.
  32   *
  33   * @copyright 2020 Jake Dallimore <jrhdallimore@gmail.com>
  34   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  35   */
  36  class import_strategy_file implements import_strategy {
  37  
  38      /**
  39       * Get an array of import_handler_info objects representing modules supporting import of this file type.
  40       *
  41       * @param array $registrydata the fully populated registry.
  42       * @param remote_resource $resource the remote resource.
  43       * @return import_handler_info[] the array of import_handler_info objects.
  44       */
  45      public function get_handlers(array $registrydata, remote_resource $resource): array {
  46          $handlers = [];
  47          foreach ($registrydata['files'] as $index => $items) {
  48              foreach ($items as $item) {
  49                  if ($index === $resource->get_extension() || $index === '*') {
  50                      $handlers[] = new import_handler_info($item['module'], $item['message'], $this);
  51                  }
  52              }
  53          }
  54          return $handlers;
  55      }
  56  
  57      /**
  58       * Import the remote resource according to the rules of this strategy.
  59       *
  60       * @param remote_resource $resource the resource to import.
  61       * @param \stdClass $user the user to import on behalf of.
  62       * @param \stdClass $course the course into which the remote_resource is being imported.
  63       * @param int $section the section into which the remote_resource is being imported.
  64       * @return \stdClass the module data.
  65       * @throws \moodle_exception if the file size means the upload limit is exceeded for the user.
  66       */
  67      public function import(remote_resource $resource, \stdClass $user, \stdClass $course, int $section): \stdClass {
  68          // Before starting a potentially lengthy download, try to ensure the file size does not exceed the upload size restrictions
  69          // for the user. This is a time saving measure.
  70          // This is a naive check, that serves only to catch files if they provide the content length header.
  71          // Because of potential content encoding (compression), the stored file will be checked again after download as well.
  72          $size = $resource->get_download_size() ?? -1;
  73          $useruploadlimit = $this->get_user_upload_limit($user, $course);
  74          if ($this->size_exceeds_upload_limit($size, $useruploadlimit)) {
  75              throw new \moodle_exception('uploadlimitexceeded', 'tool_moodlenet', '', ['filesize' => $size,
  76                  'uploadlimit' => $useruploadlimit]);
  77          }
  78  
  79          // Download the file into a request directory and scan it.
  80          [$filepath, $filename] = $resource->download_to_requestdir();
  81          avmanager::scan_file($filepath, $filename, true);
  82  
  83          // Check the final size of file against the user upload limits.
  84          $localsize = filesize(sprintf('%s/%s', $filepath, $filename));
  85          if ($this->size_exceeds_upload_limit($localsize, $useruploadlimit)) {
  86              throw new \moodle_exception('uploadlimitexceeded', 'tool_moodlenet', '', ['filesize' => $localsize,
  87                  'uploadlimit' => $useruploadlimit]);
  88          }
  89  
  90          // Store in the user draft file area.
  91          $storedfile = $this->create_user_draft_stored_file($user, $filename, $filepath);
  92  
  93          // Prepare the data to be sent to the modules dndupload_handle hook.
  94          return $this->prepare_module_data($course, $resource, $storedfile->get_itemid());
  95      }
  96  
  97  
  98      /**
  99       * Creates the data to pass to the dndupload_handle() hooks.
 100       *
 101       * @param \stdClass $course the course record.
 102       * @param remote_resource $resource the resource being imported as a file.
 103       * @param int $draftitemid the itemid of the draft file.
 104       * @return \stdClass the data object.
 105       */
 106      protected function prepare_module_data(\stdClass $course, remote_resource $resource, int $draftitemid): \stdClass {
 107          $data = new \stdClass();
 108          $data->type = 'Files';
 109          $data->course = $course;
 110          $data->draftitemid = $draftitemid;
 111          $data->displayname = $resource->get_name();
 112          return $data;
 113      }
 114  
 115      /**
 116       * Get the max file size limit for the user in the course.
 117       *
 118       * @param \stdClass $user the user to check.
 119       * @param \stdClass $course the course to check in.
 120       * @return int the file size limit, in bytes.
 121       */
 122      protected function get_user_upload_limit(\stdClass $user, \stdClass $course): int {
 123          return get_user_max_upload_file_size(\context_course::instance($course->id), get_config('core', 'maxbytes'),
 124              $course->maxbytes, 0, $user);
 125      }
 126  
 127      /**
 128       * Does the size exceed the upload limit for the current import, taking into account user and core settings.
 129       *
 130       * @param int $sizeinbytes the size, in bytes.
 131       * @param int $useruploadlimit the upload limit, in bytes.
 132       * @return bool true if exceeded, false otherwise.
 133       * @throws \dml_exception
 134       */
 135      protected function size_exceeds_upload_limit(int $sizeinbytes, int $useruploadlimit): bool {
 136          if ($useruploadlimit != USER_CAN_IGNORE_FILE_SIZE_LIMITS && $sizeinbytes > $useruploadlimit) {
 137              return true;
 138          }
 139          return false;
 140      }
 141  
 142      /**
 143       * Create a file in the user drafts ready for use by plugins implementing dndupload_handle().
 144       *
 145       * @param \stdClass $user the user object.
 146       * @param string $filename the name of the file on disk
 147       * @param string $path the path where the file is stored on disk
 148       * @return \stored_file
 149       */
 150      protected function create_user_draft_stored_file(\stdClass $user, string $filename, string $path): \stored_file {
 151          global $CFG;
 152  
 153          $record = new \stdClass();
 154          $record->filearea = 'draft';
 155          $record->component = 'user';
 156          $record->filepath = '/';
 157          $record->itemid   = file_get_unused_draft_itemid();
 158          $record->license  = $CFG->sitedefaultlicense;
 159          $record->author   = '';
 160          $record->filename = clean_param($filename, PARAM_FILE);
 161          $record->contextid = \context_user::instance($user->id)->id;
 162          $record->userid = $user->id;
 163  
 164          $fullpathwithname = sprintf('%s/%s', $path, $filename);
 165  
 166          $fs = get_file_storage();
 167  
 168          return  $fs->create_file_from_pathname($record, $fullpathwithname);
 169      }
 170  }