lib.php

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Plugin library
 *
 * @package local_o365
 * @author  Remote-Learner.net Inc
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @copyright (C) 2016 onwards Microsoft Open Technologies, Inc. (http://msopentech.com/)
 */

defined('MOODLE_INTERNAL') || die();

/**
 * TEAMS_MOODLE_APP_EXTERNAL_ID - app ID used to create Teams Moodle app.
 */
const TEAMS_MOODLE_APP_EXTERNAL_ID = '2e43119b-fcfe-44f8-b3e5-996ffcb7fb95';

// Teams/group course reset site settings.
const COURSE_SYNC_RESET_SITE_SETTING_DO_NOTHING = '1';
const COURSE_SYNC_RESET_SITE_SETTING_PER_COURSE = '2';
const COURSE_SYNC_RESET_SITE_SETTING_DISCONNECT_AND_CREATE_NEW = '3';
const COURSE_SYNC_RESET_SITE_SETTING_DISCONNECT_ONLY = '4';

// Course reset course settings.
const COURSE_SYNC_RESET_COURSE_SETTING_DO_NOTHING = '1';
const COURSE_SYNC_RESET_COURSE_SETTING_DISCONNECT_AND_CREATE_NEW = '2';
const COURSE_SYNC_RESET_COURSE_SETTING_DISCONNECT_ONLY = '3';

// Course sync options.
const MICROSOFT365_COURSE_SYNC_DISABLED = 0;
const MICROSOFT365_COURSE_SYNC_ENABLED = 1;

// Configuration tabs.
const LOCAL_O365_TAB_SETUP = 0; // Setup settings.
const LOCAL_O365_TAB_SYNC = 1; // Sync settings.
const LOCAL_O365_TAB_ADVANCED = 2; // Admin tools + advanced settings.
const LOCAL_O365_TAB_SDS = 3; // School data sync.
const LOCAL_O365_TAB_TEAMS = 5; // Teams integration settings.
const LOCAL_O365_TAB_MOODLE_APP = 6; // Teams Moodle app.

// Group roles.
const MICROSOFT365_GROUP_ROLE_OWNER = 'owner';
const MICROSOFT365_GROUP_ROLE_MEMBER = 'member';

// Team lock status.
const TEAM_LOCKED_STATUS_UNKNOWN = 0;
const TEAM_LOCKED = 1;
const TEAM_UNLOCKED = 2;

// Education license.
const EDUCATION_LICENSE_IDS = ['c33802dd-1b50-4b9a-8bb9-f13d2cdeadac', '500b6a2a-7a50-4f40-b5f9-160e5b8c2f48'];

// SDS sync school disabled actions.
const SDS_SCHOOL_DISABLED_ACTION_KEEP_CONNECTED = 1;
const SDS_SCHOOL_DISABLED_ACTION_DISCONNECT = 2;

/**
 * Check for link connection capabilities.
 *
 * @param int $userid Moodle user id to check permissions for.
 * @param string $mode Mode to check
 *                     'link' to check for connect specific capability
 *                     'unlink' to check for disconnect capability.
 * @param boolean $require Use require_capability rather than has_capability.
 *
 * @return boolean True if has capability.
 */
function local_o365_connectioncapability($userid, $mode = 'link', $require = false) {
    $check = $require ? 'require_capability' : 'has_capability';
    $cap = ($mode == 'link') ? 'local/o365:manageconnectionlink' : 'local/o365:manageconnectionunlink';
    $contextsys = \context_system::instance();
    $contextuser = \context_user::instance($userid);

    return has_capability($cap, $contextsys) || $check($cap, $contextuser);
}

/**
 * Creates json data file for application deployment.
 */
function local_o365_create_deploy_json() {
    global $CFG;
    $data = new stdClass();
    $data->{'$schema'} = 'https://schema.management.azure.com/schemas/2015-01-01/deploymentParameters.json#';
    $data->contentVersion = "1.0.0.0";
    $data->parameters = new stdClass();
    $data->parameters->LUISPricingTier = ['value' => null];
    $data->parameters->LUISRegion = ['value' => null];
    $botappid = get_config('local_o365', 'bot_app_id');
    $botappidval = (empty($botappid) ? null : $botappid);
    $data->parameters->botApplicationID = ['value' => $botappidval];
    $botapppass = get_config('local_o365', 'bot_app_password');
    $botapppassval = (empty($botapppass) ? null : $botapppass);
    $data->parameters->botApplicationPassword = ['value' => $botapppassval];
    $data->parameters->moodleURL = ['value' => $CFG->wwwroot];
    $appid = get_config('auth_oidc', 'clientid');
    $appidval = (empty($appid) ? null : $appid);
    $data->parameters->azureADApplicationID = ['value' => $appidval];
    $appsecret = get_config('auth_oidc', 'clientsecret');
    $appsecretval = (empty($appsecret) ? null : $appsecret);
    $data->parameters->azureADApplicationKey = ['value' => $appsecretval];
    $apptenant = get_config('local_o365', 'aadtenant');
    $apptenantval = (empty($apptenant) ? null : $apptenant);
    $data->parameters->azureADTenant = ['value' => $apptenantval];
    $botsharedsecret = get_config('local_o365', 'bot_sharedsecret');
    $botsharedsecretval = (empty($botsharedsecret) ? null : $botsharedsecret);
    $data->parameters->sharedMoodleSecret = ['value' => $botsharedsecretval];

    return json_encode($data);
}

/**
 * Recursively delete content of the folder and all its contents.
 *
 * @param string $path Path to the deleted
 */
function local_o365_rmdir($path) {
    $it = new RecursiveDirectoryIterator($path, RecursiveDirectoryIterator::SKIP_DOTS);
    $files = new RecursiveIteratorIterator($it,
        RecursiveIteratorIterator::CHILD_FIRST);
    foreach ($files as $file) {
        if ($file->isDir()) {
            rmdir($file->getRealPath());
        } else {
            unlink($file->getRealPath());
        }
    }
    rmdir($path);
}

/**
 * Create manifest file and return its contents in string.
 *
 * @return false|string
 * @throws coding_exception
 * @throws dml_exception
 */
function local_o365_get_manifest_file_content() {
    $filecontent = '';

    $manifestfilepath = local_o365_create_manifest_file();

    if ($manifestfilepath) {
        $filecontent = file_get_contents($manifestfilepath);
    }

    return $filecontent;
}

/**
 * Attempt to create manifest file. Return error details and/or path to the manifest file.
 *
 * @return string
 * @throws coding_exception
 * @throws dml_exception
 */
function local_o365_create_manifest_file() {
    global $CFG;
    require_once($CFG->libdir . '/filestorage/zip_archive.php');

    $error = '';
    $zipfilename = '';

    // Task 1: check if bot settings are consistent.
    $botappid = get_config('local_o365', 'bot_app_id');
    $botfeatureenabled = get_config('local_o365', 'bot_feature_enabled');
    if ($botfeatureenabled) {
        if (!$botappid || $botappid == '00000000-0000-0000-0000-000000000000') {
            // Bot id not configured, cannot create manifest file.
            $error = get_string('error_missing_app_id', 'local_o365');

            return [$error, $zipfilename];
        }

        $botapppassword = get_config('local_o365', 'bot_app_password');
        $botwebhookendpoint = get_config('local_o365', 'bot_webhook_endpoint');
        if (!$botapppassword || !$botwebhookendpoint) {
            $error = get_string('error_missing_bot_settings', 'local_o365');

            return [$error, $zipfilename];
        }
    }

    // Task 2: prepare manifest folder.
    $pathtomanifestfolder = $CFG->dataroot . '/temp/ms_teams_manifest';
    if (file_exists($pathtomanifestfolder)) {
        local_o365_rmdir($pathtomanifestfolder);
    }
    mkdir($pathtomanifestfolder, 0777, true);

    // Task 2.1: prepare manifest params.
    $teamsmoodleappexternalid = get_config('local_o365', 'teams_moodle_app_external_id');
    if (!$teamsmoodleappexternalid) {
        $teamsmoodleappexternalid = TEAMS_MOODLE_APP_EXTERNAL_ID;
    }

    $teamsmoodleappnameshortname = get_config('local_o365', 'teams_moodle_app_short_name');
    if (!$teamsmoodleappnameshortname) {
        $teamsmoodleappnameshortname = 'Moodle';
    }

    // Task 3: prepare manifest file.
    $manifest = array(
        '$schema' => 'https://developer.microsoft.com/en-us/json-schemas/teams/v1.7/MicrosoftTeams.schema.json',
        'manifestVersion' => '1.7',
        'version' => '1.3',
        'id' => $teamsmoodleappexternalid,
        'packageName' => 'ie.enovation.microsoft.o365',
        'developer' => array(
            'name' => 'Enovation Solutions',
            'websiteUrl' => 'https://enovation.ie',
            'privacyUrl' => 'https://enovation.ie/moodleteamsapp-privacy',
            'termsOfUseUrl' => 'https://enovation.ie/moodleteamsapp-termsofuse',
            'mpnId' => '1718735',
        ),
        'icons' => array(
            'color' => 'color.png',
            'outline' => 'outline.png',
        ),
        'name' => array(
            'short' => $teamsmoodleappnameshortname,
            'full' => 'Moodle integration with Microsoft Teams for ' . $CFG->wwwroot,
        ),
        'description' => array(
            'short' => 'Access your Moodle courses and ask questions to your Moodle Assistant in Teams.',
            'full' => 'The Moodle app for Microsoft Teams allows you to easily access and collaborate around your Moodle ' .
                'courses from within your teams through tabs. You can also get regular notifications from Moodle and ask ' .
                'questions about your courses, assignments, grades and students using the Moodle Assistant bot.',
        ),
        'accentColor' => '#FF7A00',
        'configurableTabs' => array(
            array(
                'configurationUrl' => $CFG->wwwroot . '/local/o365/teams_tab_configuration.php',
                'canUpdateConfiguration' => false,
                'scopes' => array(
                    'team',
                ),
            ),
        ),
        'permissions' => array(
            'identity',
            'messageTeamMembers',
        ),
        'validDomains' => array(
            parse_url($CFG->wwwroot, PHP_URL_HOST),
            'token.botframework.com',
        ),
        'webApplicationInfo' => array(
            'id' => get_config('auth_oidc', 'clientid'),
            'resource' => 'api://' . preg_replace("(^https?://)", "", $CFG->wwwroot) . '/' . get_config('auth_oidc', 'clientid'),
        )
    );

    // Task 4: add bot part to manifest if enabled.
    if ($botfeatureenabled) {
        $manifest['bots'] = array(
            array(
                'botId' => $botappid,
                'needsChannelSelector' => false,
                'isNotificationOnly' => false,
                'scopes' => array(
                    'team',
                    'personal',
                ),
                'commandLists' => array(
                    array(
                        'scopes' => array(
                            'team',
                            'personal',
                        ),
                        'commands' => array(
                            array(
                                'title' => 'Help',
                                'description' => 'Displays help dialog'
                            ),
                            array(
                                'title' => 'Feedback',
                                'description' => 'Displays feedback dialog'
                            ),
                        ),
                    ),
                ),
            ),
        );
    }

    $file = $pathtomanifestfolder . '/manifest.json';
    file_put_contents($file, json_encode($manifest, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES));

    // Task 5: prepare icons.
    copy($CFG->dirroot . '/local/o365/pix/color.png', $pathtomanifestfolder . '/color.png');
    copy($CFG->dirroot . '/local/o365/pix/outline.png', $pathtomanifestfolder . '/outline.png');

    // Task 6: compress the folder.
    $ziparchive = new zip_archive();
    $zipfilename = $pathtomanifestfolder . '/manifest.zip';
    $ziparchive->open($zipfilename);
    $filenames = array('manifest.json', 'color.png', 'outline.png');
    foreach ($filenames as $filename) {
        $ziparchive->add_file_from_pathname($filename, $pathtomanifestfolder . '/' . $filename);
    }
    $ziparchive->close();

    return [$error, $zipfilename];
}

/**
 * Decodes JWT token elements
 *
 * @param string $data - encoded string
 *
 * @return string - decoded string
 */
function local_o365_base64urldecode($data) {
    $urlunsafedata = strtr($data, '-_', '+/');
    $paddeddata = str_pad($urlunsafedata, strlen($data) % 4, '=', STR_PAD_RIGHT);

    return base64_decode($paddeddata);
}

/**
 *  Checks if bot shared secret is set and if not generates new secret
 */
function local_o365_check_sharedsecret() {
    $sharedsecret = get_config('local_o365', 'bot_sharedsecret');
    if (empty($sharedsecret)) {
        $secret = local_o365_generate_sharedsecret();
        set_config('bot_sharedsecret', $secret, 'local_o365');
    }
}

/**
 * Generates shared secret of random symbols
 *
 * @param int $length
 *
 * @return string
 */
function local_o365_generate_sharedsecret($length = 36) {
    $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789`-=~!@#$%^&*()_+,./<>?;:[]{}\|';
    $sharedsecret = '';
    $max = strlen($chars) - 1;
    for ($i = 0; $i < $length; $i++) {
        $sharedsecret .= $chars[random_int(0, $max)];
    }

    return $sharedsecret;
}

/**
 * Determine if "Teams Moodle app ID" tab needs to appear.
 *
 * @return bool
 */
function local_o365_show_teams_moodle_app_id_tab() {
    return (get_config('local_o365', 'manifest_downloaded'));
}

/**
 * Attempt to get authorization token from request header.
 *
 * @return false|string|null
 */
function local_o365_get_auth_token() {
    global $_SERVER;

    $authtoken = null;

    if (function_exists('apache_request_headers')) {
        $headers = apache_request_headers();
        if (isset($headers['Authorization'])) {
            $authtoken = substr($headers['Authorization'], 7);
        }
    }

    if (!$authtoken) {
        if (isset($_SERVER['HTTP_AUTHORIZATION'])) {
            $authtoken = substr($_SERVER['HTTP_AUTHORIZATION'], 7);
        }
    }

    return $authtoken;
}

/**
 * Check Moodle and local_o365 versions to see if LTI feature is included in the plugin.
 *
 * @return bool
 */
function local_o365_is_lti_feature_included() {
    global $CFG;

    $hasltifeature = false;

    $releaseparts = explode(' ', $CFG->release);
    $release = $releaseparts[0];
    $localo365version = get_config('local_o365', 'version');
    switch ($release) {
        case '3.10':
            if ($localo365version >= 2020110935) {
                $hasltifeature = true;
            }
            break;
        case '3.11':
            if ($localo365version >= 2021051720) {
                $hasltifeature = true;
            }
            break;
        default:
            if (substr($release, 0, 1) >= 4) {
                $hasltifeature = true;
            }
    }

    return $hasltifeature;
}

/**
 * Check if the suspension feature schedule in the user sync task has been set, and set the default value if not.
 *
 * @return void
 */
function local_o365_set_default_user_sync_suspension_feature_schedule() {
    if (get_config('local_o365', 'usersync_suspension_h') === false) {
        set_config('usersync_suspension_h', 2, 'local_o365');
    }
    if (get_config('local_o365', 'usersync_suspension_m') === false) {
        set_config('usersync_suspension_m', 30, 'local_o365');
    }
}

/**
 * Return all active users' duplicate email addresses.
 *
 * @return array
 */
function local_o365_get_duplicate_emails() {
    global $DB;

    $sql = 'SELECT DISTINCT LOWER(a.email)
              FROM {user} a
              JOIN {user} b ON a.email LIKE b.email
             WHERE a.id < b.id 
               AND a.deleted = 0
               AND b.deleted = 0
               AND a.suspended = 0
               AND b.suspended = 0';

    $records = $DB->get_records_sql($sql);
    return array_keys($records);
}