MDL-51360 core_grades: Improve documentation of grade_get_grades().

[moodle.git] / lib / setup.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/>.

/**
 * setup.php - Sets up sessions, connects to databases and so on
 *
 * Normally this is only called by the main config.php file
 * Normally this file does not need to be edited.
 *
 * @package    core
 * @subpackage lib
 * @copyright  1999 onwards Martin Dougiamas  {@link http://moodle.com}
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

/**
 * Holds the core settings that affect how Moodle works. Some of its fields
 * are set in config.php, and the rest are loaded from the config table.
 *
 * Some typical settings in the $CFG global:
 *  - $CFG->wwwroot  - Path to moodle index directory in url format.
 *  - $CFG->dataroot - Path to moodle data files directory on server's filesystem.
 *  - $CFG->dirroot  - Path to moodle's library folder on server's filesystem.
 *  - $CFG->libdir   - Path to moodle's library folder on server's filesystem.
 *  - $CFG->backuptempdir  - Path to moodle's backup temp file directory on server's filesystem.
 *  - $CFG->tempdir  - Path to moodle's temp file directory on server's filesystem.
 *  - $CFG->cachedir - Path to moodle's cache directory on server's filesystem (shared by cluster nodes).
 *  - $CFG->localcachedir - Path to moodle's local cache directory (not shared by cluster nodes).
 *  - $CFG->localrequestdir - Path to moodle's local temp request directory (not shared by cluster nodes).
 *
 * @global object $CFG
 * @name $CFG
 */
global $CFG; // this should be done much earlier in config.php before creating new $CFG instance

if (!isset($CFG)) {
    if (defined('PHPUNIT_TEST') and PHPUNIT_TEST) {
        echo('There is a missing "global $CFG;" at the beginning of the config.php file.'."\n");
        exit(1);
    } else {
        // this should never happen, maybe somebody is accessing this file directly...
        exit(1);
    }
}

// We can detect real dirroot path reliably since PHP 4.0.2,
// it can not be anything else, there is no point in having this in config.php
$CFG->dirroot = dirname(__DIR__);

// File permissions on created directories in the $CFG->dataroot
if (!isset($CFG->directorypermissions)) {
    $CFG->directorypermissions = 02777;      // Must be octal (that's why it's here)
}
if (!isset($CFG->filepermissions)) {
    $CFG->filepermissions = ($CFG->directorypermissions & 0666); // strip execute flags
}
// Better also set default umask because developers often forget to include directory
// permissions in mkdir() and chmod() after creating new files.
if (!isset($CFG->umaskpermissions)) {
    $CFG->umaskpermissions = (($CFG->directorypermissions & 0777) ^ 0777);
}
umask($CFG->umaskpermissions);

if (defined('BEHAT_SITE_RUNNING')) {
    // We already switched to behat test site previously.

} else if (!empty($CFG->behat_wwwroot) or !empty($CFG->behat_dataroot) or !empty($CFG->behat_prefix)) {
    // The behat is configured on this server, we need to find out if this is the behat test
    // site based on the URL used for access.
    require_once(__DIR__ . '/../lib/behat/lib.php');

    // Update config variables for parallel behat runs.
    behat_update_vars_for_process();

    // If behat is being installed for parallel run, then we modify params for parallel run only.
    if (behat_is_test_site() && !(defined('BEHAT_PARALLEL_UTIL') && empty($CFG->behatrunprocess))) {
        clearstatcache();

        // Checking the integrity of the provided $CFG->behat_* vars and the
        // selected wwwroot to prevent conflicts with production and phpunit environments.
        behat_check_config_vars();

        // Check that the directory does not contains other things.
        if (!file_exists("$CFG->behat_dataroot/behattestdir.txt")) {
            if ($dh = opendir($CFG->behat_dataroot)) {
                while (($file = readdir($dh)) !== false) {
                    if ($file === 'behat' or $file === '.' or $file === '..' or $file === '.DS_Store' or is_numeric($file)) {
                        continue;
                    }
                    behat_error(BEHAT_EXITCODE_CONFIG, "$CFG->behat_dataroot directory is not empty, ensure this is the " .
                        "directory where you want to install behat test dataroot");
                }
                closedir($dh);
                unset($dh);
                unset($file);
            }

            if (defined('BEHAT_UTIL')) {
                // Now we create dataroot directory structure for behat tests.
                testing_initdataroot($CFG->behat_dataroot, 'behat');
            } else {
                behat_error(BEHAT_EXITCODE_INSTALL);
            }
        }

        if (!defined('BEHAT_UTIL') and !defined('BEHAT_TEST')) {
            // Somebody tries to access test site directly, tell them if not enabled.
            $behatdir = preg_replace("#[/|\\\]" . BEHAT_PARALLEL_SITE_NAME . "\d{0,}$#", '', $CFG->behat_dataroot);
            if (!file_exists($behatdir . '/test_environment_enabled.txt')) {
                behat_error(BEHAT_EXITCODE_CONFIG, 'Behat is configured but not enabled on this test site.');
            }
        }

        // Constant used to inform that the behat test site is being used,
        // this includes all the processes executed by the behat CLI command like
        // the site reset, the steps executed by the browser drivers when simulating
        // a user session and a real session when browsing manually to $CFG->behat_wwwroot
        // like the browser driver does automatically.
        // Different from BEHAT_TEST as only this last one can perform CLI
        // actions like reset the site or use data generators.
        define('BEHAT_SITE_RUNNING', true);

        // Clean extra config.php settings.
        behat_clean_init_config();

        // Now we can begin switching $CFG->X for $CFG->behat_X.
        $CFG->wwwroot = $CFG->behat_wwwroot;
        $CFG->prefix = $CFG->behat_prefix;
        $CFG->dataroot = $CFG->behat_dataroot;

        // And we do the same with the optional ones.
        $allowedconfigoverride = ['dbname', 'dbuser', 'dbpass', 'dbhost'];
        foreach ($allowedconfigoverride as $config) {
            $behatconfig = 'behat_' . $config;
            if (!isset($CFG->$behatconfig)) {
                continue;
            }
            $CFG->$config = $CFG->$behatconfig;
        }
    }
}

// Set default warn runtime.
if (!isset($CFG->taskruntimewarn)) {
    $CFG->taskruntimewarn = 12 * 60 * 60;
}

// Set default error runtime.
if (!isset($CFG->taskruntimeerror)) {
    $CFG->taskruntimeerror = 24 * 60 * 60;
}

// Normalise dataroot - we do not want any symbolic links, trailing / or any other weirdness there
if (!isset($CFG->dataroot)) {
    if (isset($_SERVER['REMOTE_ADDR'])) {
        header($_SERVER['SERVER_PROTOCOL'] . ' 500 Internal Server Error ');
    }
    echo('Fatal error: $CFG->dataroot is not specified in config.php! Exiting.'."\n");
    exit(1);
}
$CFG->dataroot = realpath($CFG->dataroot);
if ($CFG->dataroot === false) {
    if (isset($_SERVER['REMOTE_ADDR'])) {
        header($_SERVER['SERVER_PROTOCOL'] . ' 500 Internal Server Error ');
    }
    echo('Fatal error: $CFG->dataroot is not configured properly, directory does not exist or is not accessible! Exiting.'."\n");
    exit(1);
} else if (!is_writable($CFG->dataroot)) {
    if (isset($_SERVER['REMOTE_ADDR'])) {
        header($_SERVER['SERVER_PROTOCOL'] . ' 500 Internal Server Error ');
    }
    echo('Fatal error: $CFG->dataroot is not writable, admin has to fix directory permissions! Exiting.'."\n");
    exit(1);
}

// wwwroot is mandatory
if (!isset($CFG->wwwroot) or $CFG->wwwroot === 'http://example.com/moodle') {
    if (isset($_SERVER['REMOTE_ADDR'])) {
        header($_SERVER['SERVER_PROTOCOL'] . ' 500 Internal Server Error ');
    }
    echo('Fatal error: $CFG->wwwroot is not configured! Exiting.'."\n");
    exit(1);
}

// Make sure there is some database table prefix.
if (!isset($CFG->prefix)) {
    $CFG->prefix = '';
}

// Define admin directory
if (!isset($CFG->admin)) {   // Just in case it isn't defined in config.php
    $CFG->admin = 'admin';   // This is relative to the wwwroot and dirroot
}

// Set up some paths.
$CFG->libdir = $CFG->dirroot .'/lib';

// Allow overriding of tempdir but be backwards compatible
if (!isset($CFG->tempdir)) {
    $CFG->tempdir = $CFG->dataroot . DIRECTORY_SEPARATOR . "temp";
}

// Allow overriding of backuptempdir but be backwards compatible
if (!isset($CFG->backuptempdir)) {
    $CFG->backuptempdir = "$CFG->tempdir/backup";
}

// Allow overriding of cachedir but be backwards compatible
if (!isset($CFG->cachedir)) {
    $CFG->cachedir = "$CFG->dataroot/cache";
}

// Allow overriding of localcachedir.
if (!isset($CFG->localcachedir)) {
    $CFG->localcachedir = "$CFG->dataroot/localcache";
}

// Allow overriding of localrequestdir.
if (!isset($CFG->localrequestdir)) {
    $CFG->localrequestdir = sys_get_temp_dir() . '/requestdir';
}

// Location of all languages except core English pack.
if (!isset($CFG->langotherroot)) {
    $CFG->langotherroot = $CFG->dataroot.'/lang';
}

// Location of local lang pack customisations (dirs with _local suffix).
if (!isset($CFG->langlocalroot)) {
    $CFG->langlocalroot = $CFG->dataroot.'/lang';
}

// The current directory in PHP version 4.3.0 and above isn't necessarily the
// directory of the script when run from the command line. The require_once()
// would fail, so we'll have to chdir()
if (!isset($_SERVER['REMOTE_ADDR']) && isset($_SERVER['argv'][0])) {
    // do it only once - skip the second time when continuing after prevous abort
    if (!defined('ABORT_AFTER_CONFIG') and !defined('ABORT_AFTER_CONFIG_CANCEL')) {
        chdir(dirname($_SERVER['argv'][0]));
    }
}

// sometimes default PHP settings are borked on shared hosting servers, I wonder why they have to do that??
ini_set('precision', 14); // needed for upgrades and gradebook
ini_set('serialize_precision', 17); // Make float serialization consistent on all systems.

// Scripts may request no debug and error messages in output
// please note it must be defined before including the config.php script
// and in some cases you also need to set custom default exception handler
if (!defined('NO_DEBUG_DISPLAY')) {
    if (defined('AJAX_SCRIPT') and AJAX_SCRIPT) {
        // Moodle AJAX scripts are expected to return json data, any PHP notices or errors break it badly,
        // developers simply must learn to watch error log.
        define('NO_DEBUG_DISPLAY', true);
    } else {
        define('NO_DEBUG_DISPLAY', false);
    }
}

// Some scripts such as upgrade may want to prevent output buffering
if (!defined('NO_OUTPUT_BUFFERING')) {
    define('NO_OUTPUT_BUFFERING', false);
}

// PHPUnit tests need custom init
if (!defined('PHPUNIT_TEST')) {
    define('PHPUNIT_TEST', false);
}

// Performance tests needs to always display performance info, even in redirections;
// MDL_PERF_TEST is used in https://github.com/moodlehq/moodle-performance-comparison scripts.
if (!defined('MDL_PERF_TEST')) {
    define('MDL_PERF_TEST', false);
}
// Make sure all MDL_PERF* constants are always defined.
if (!defined('MDL_PERF')) {
    define('MDL_PERF', MDL_PERF_TEST);
}
if (!defined('MDL_PERFTOFOOT')) {
    define('MDL_PERFTOFOOT', MDL_PERF_TEST);
}
if (!defined('MDL_PERFTOLOG')) {
    define('MDL_PERFTOLOG', false);
}
if (!defined('MDL_PERFINC')) {
    define('MDL_PERFINC', false);
}
// Note that PHPUnit and Behat tests should pass with both MDL_PERF true and false.

// When set to true MUC (Moodle caching) will be disabled as much as possible.
// A special cache factory will be used to handle this situation and will use special "disabled" equivalents objects.
// This ensure we don't attempt to read or create the config file, don't use stores, don't provide persistence or
// storage of any kind.
if (!defined('CACHE_DISABLE_ALL')) {
    define('CACHE_DISABLE_ALL', false);
}

// When set to true MUC (Moodle caching) will not use any of the defined or default stores.
// The Cache API will continue to function however this will force the use of the cachestore_dummy so all requests
// will be interacting with a static property and will never go to the proper cache stores.
// Useful if you need to avoid the stores for one reason or another.
if (!defined('CACHE_DISABLE_STORES')) {
    define('CACHE_DISABLE_STORES', false);
}

// Servers should define a default timezone in php.ini, but if they don't then make sure no errors are shown.
date_default_timezone_set(@date_default_timezone_get());

// Detect CLI scripts - CLI scripts are executed from command line, do not have session and we do not want HTML in output
// In your new CLI scripts just add "define('CLI_SCRIPT', true);" before requiring config.php.
// Please note that one script can not be accessed from both CLI and web interface.
if (!defined('CLI_SCRIPT')) {
    define('CLI_SCRIPT', false);
}
if (defined('WEB_CRON_EMULATED_CLI')) {
    if (!isset($_SERVER['REMOTE_ADDR'])) {
        echo('Web cron can not be executed as CLI script any more, please use admin/cli/cron.php instead'."\n");
        exit(1);
    }
} else if (isset($_SERVER['REMOTE_ADDR'])) {
    if (CLI_SCRIPT) {
        echo('Command line scripts can not be executed from the web interface');
        exit(1);
    }
} else {
    if (!CLI_SCRIPT) {
        echo('Command line scripts must define CLI_SCRIPT before requiring config.php'."\n");
        exit(1);
    }
}

// All web service requests have WS_SERVER == true.
if (!defined('WS_SERVER')) {
    define('WS_SERVER', false);
}

// Detect CLI maintenance mode - this is useful when you need to mess with database, such as during upgrades
if (file_exists("$CFG->dataroot/climaintenance.html")) {
    if (!CLI_SCRIPT) {
        header($_SERVER['SERVER_PROTOCOL'] . ' 503 Moodle under maintenance');
        header('Status: 503 Moodle under maintenance');
        header('Retry-After: 300');
        header('Content-type: text/html; charset=utf-8');
        header('X-UA-Compatible: IE=edge');
        /// Headers to make it not cacheable and json
        header('Cache-Control: no-store, no-cache, must-revalidate');
        header('Cache-Control: post-check=0, pre-check=0', false);
        header('Pragma: no-cache');
        header('Expires: Mon, 20 Aug 1969 09:23:00 GMT');
        header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');
        header('Accept-Ranges: none');
        readfile("$CFG->dataroot/climaintenance.html");
        die;
    } else {
        if (!defined('CLI_MAINTENANCE')) {
            define('CLI_MAINTENANCE', true);
        }
    }
} else {
    if (!defined('CLI_MAINTENANCE')) {
        define('CLI_MAINTENANCE', false);
    }
}

// Some core parts of Moodle may make use of language features not available in older PHP versions.s
// When this happens as part of our core bootstrap, we can end up having confusing and spurious error
// messages which are hard to diagnose.
// This check allows us to insert a very basic check for the absolute minimum version of PHP for the
// Moodle core to be able to load the environment and error pages.
// It should only be updated in these circumstances, not with every PHP version.
if (version_compare(PHP_VERSION, '8.1.0') < 0) {
    $phpversion = PHP_VERSION;
    // Do NOT localise - lang strings would not work here and we CAN NOT move it to later place.
    echo "Moodle 4.4 or later requires at least PHP 8.1 (currently using version $phpversion).\n";
    echo "Some servers may have multiple PHP versions installed, are you using the correct executable?\n";
    exit(1);
}

// Detect ajax scripts - they are similar to CLI because we can not redirect, output html, etc.
if (!defined('AJAX_SCRIPT')) {
    define('AJAX_SCRIPT', false);
}

// Exact version of currently used yui2 and 3 library.
$CFG->yui2version = '2.9.0';
$CFG->yui3version = '3.18.1';

// Patching the upstream YUI release.
// If we need to patch a YUI modules between official YUI releases, the yuipatchlevel will need to be manually
// incremented here. The module will also need to be listed in the yuipatchedmodules.
// When upgrading to a subsequent version of YUI, these should be reset back to 0 and an empty array.
$CFG->yuipatchlevel = 0;
$CFG->yuipatchedmodules = array(
);

if (!empty($CFG->disableonclickaddoninstall)) {
    // This config.php flag has been merged into another one.
    $CFG->disableupdateautodeploy = true;
}

// Store settings from config.php in array in $CFG - we can use it later to detect problems and overrides.
if (!isset($CFG->config_php_settings)) {
    $CFG->config_php_settings = (array)$CFG;
    // Forced plugin settings override values from config_plugins table.
    unset($CFG->config_php_settings['forced_plugin_settings']);
    if (!isset($CFG->forced_plugin_settings)) {
        $CFG->forced_plugin_settings = array();
    }
}

if (isset($CFG->debug)) {
    $CFG->debug = (int)$CFG->debug;
} else {
    $CFG->debug = 0;
}
$CFG->debugdeveloper = (($CFG->debug & (E_ALL | E_STRICT)) === (E_ALL | E_STRICT)); // DEBUG_DEVELOPER is not available yet.

if (!defined('MOODLE_INTERNAL')) { // Necessary because cli installer has to define it earlier.
    /** Used by library scripts to check they are being called by Moodle. */
    define('MOODLE_INTERNAL', true);
}

// core_component can be used in any scripts, it does not need anything else.
require_once($CFG->libdir .'/classes/component.php');

// special support for highly optimised scripts that do not need libraries and DB connection
if (defined('ABORT_AFTER_CONFIG')) {
    if (!defined('ABORT_AFTER_CONFIG_CANCEL')) {
        // hide debugging if not enabled in config.php - we do not want to disclose sensitive info
        error_reporting($CFG->debug);
        if (NO_DEBUG_DISPLAY) {
            // Some parts of Moodle cannot display errors and debug at all.
            ini_set('display_errors', '0');
            ini_set('log_errors', '1');
        } else if (empty($CFG->debugdisplay)) {
            ini_set('display_errors', '0');
            ini_set('log_errors', '1');
        } else {
            ini_set('display_errors', '1');
        }
        require_once("$CFG->dirroot/lib/configonlylib.php");
        return;
    }
}

// Early profiling start, based exclusively on config.php $CFG settings
if (!empty($CFG->earlyprofilingenabled)) {
    require_once($CFG->libdir . '/xhprof/xhprof_moodle.php');
    profiling_start();
}

/**
 * Database connection. Used for all access to the database.
 * @global moodle_database $DB
 * @name $DB
 */
global $DB;

/**
 * Moodle's wrapper round PHP's $_SESSION.
 *
 * @global object $SESSION
 * @name $SESSION
 */
global $SESSION;

/**
 * Holds the user table record for the current user. Will be the 'guest'
 * user record for people who are not logged in.
 *
 * $USER is stored in the session.
 *
 * Items found in the user record:
 *  - $USER->email - The user's email address.
 *  - $USER->id - The unique integer identified of this user in the 'user' table.
 *  - $USER->email - The user's email address.
 *  - $USER->firstname - The user's first name.
 *  - $USER->lastname - The user's last name.
 *  - $USER->username - The user's login username.
 *  - $USER->secret - The user's ?.
 *  - $USER->lang - The user's language choice.
 *
 * @global object $USER
 * @name $USER
 */
global $USER;

/**
 * Frontpage course record
 */
global $SITE;

/**
 * A central store of information about the current page we are
 * generating in response to the user's request.
 *
 * @global moodle_page $PAGE
 * @name $PAGE
 */
global $PAGE;

/**
 * The current course. An alias for $PAGE->course.
 * @global object $COURSE
 * @name $COURSE
 */
global $COURSE;

/**
 * $OUTPUT is an instance of core_renderer or one of its subclasses. Use
 * it to generate HTML for output.
 *
 * $OUTPUT is initialised the first time it is used. See {@link bootstrap_renderer}
 * for the magic that does that. After $OUTPUT has been initialised, any attempt
 * to change something that affects the current theme ($PAGE->course, logged in use,
 * httpsrequried ... will result in an exception.)
 *
 * Please note the $OUTPUT is replacing the old global $THEME object.
 *
 * @global object $OUTPUT
 * @name $OUTPUT
 */
global $OUTPUT;

/**
 * Full script path including all params, slash arguments, scheme and host.
 *
 * Note: Do NOT use for getting of current page URL or detection of https,
 * instead use $PAGE->url or is_https().
 *
 * @global string $FULLME
 * @name $FULLME
 */
global $FULLME;

/**
 * Script path including query string and slash arguments without host.
 * @global string $ME
 * @name $ME
 */
global $ME;

/**
 * $FULLME without slasharguments and query string.
 * @global string $FULLSCRIPT
 * @name $FULLSCRIPT
 */
global $FULLSCRIPT;

/**
 * Relative moodle script path '/course/view.php'
 * @global string $SCRIPT
 * @name $SCRIPT
 */
global $SCRIPT;

// The httpswwwroot has been deprecated, we keep it as an alias for backwards compatibility with plugins only.
$CFG->httpswwwroot = $CFG->wwwroot;

require_once($CFG->libdir .'/setuplib.php');        // Functions that MUST be loaded first

if (NO_OUTPUT_BUFFERING) {
    // we have to call this always before starting session because it discards headers!
    disable_output_buffering();
}

// Increase memory limits if possible
raise_memory_limit(MEMORY_STANDARD);

// Time to start counting
init_performance_info();

// Put $OUTPUT in place, so errors can be displayed.
$OUTPUT = new bootstrap_renderer();

// Set handler for uncaught exceptions - equivalent to throw new \moodle_exception() call.
if (!PHPUNIT_TEST or PHPUNIT_UTIL) {
    set_exception_handler('default_exception_handler');
    set_error_handler('default_error_handler', E_ALL | E_STRICT);
}

// Acceptance tests needs special output to capture the errors,
// but not necessary for behat CLI command and init script.
if (defined('BEHAT_SITE_RUNNING') && !defined('BEHAT_TEST') && !defined('BEHAT_UTIL')) {
    require_once(__DIR__ . '/behat/lib.php');
    set_error_handler('behat_error_handler', E_ALL | E_STRICT);
}

if (defined('WS_SERVER') && WS_SERVER) {
    require_once($CFG->dirroot . '/webservice/lib.php');
    set_exception_handler('early_ws_exception_handler');
}

// If there are any errors in the standard libraries we want to know!
error_reporting(E_ALL | E_STRICT);

// Just say no to link prefetching (Moz prefetching, Google Web Accelerator, others)
// http://www.google.com/webmasters/faq.html#prefetchblock
if (!empty($_SERVER['HTTP_X_moz']) && $_SERVER['HTTP_X_moz'] === 'prefetch'){
    header($_SERVER['SERVER_PROTOCOL'] . ' 404 Prefetch Forbidden');
    echo('Prefetch request forbidden.');
    exit(1);
}

//point pear include path to moodles lib/pear so that includes and requires will search there for files before anywhere else
//the problem is that we need specific version of quickforms and hacked excel files :-(
ini_set('include_path', $CFG->libdir.'/pear' . PATH_SEPARATOR . ini_get('include_path'));

// Register our classloader, in theory somebody might want to replace it to load other hacked core classes.
if (defined('COMPONENT_CLASSLOADER')) {
    spl_autoload_register(COMPONENT_CLASSLOADER);
} else {
    spl_autoload_register('core_component::classloader');
}

// Remember the default PHP timezone, we will need it later.
core_date::store_default_php_timezone();

// Load up standard libraries
require_once($CFG->libdir .'/filterlib.php');       // Functions for filtering test as it is output
require_once($CFG->libdir .'/ajax/ajaxlib.php');    // Functions for managing our use of JavaScript and YUI
require_once($CFG->libdir .'/weblib.php');          // Functions relating to HTTP and content
require_once($CFG->libdir .'/outputlib.php');       // Functions for generating output
require_once($CFG->libdir .'/navigationlib.php');   // Class for generating Navigation structure
require_once($CFG->libdir .'/dmllib.php');          // Database access
require_once($CFG->libdir .'/datalib.php');         // Legacy lib with a big-mix of functions.
require_once($CFG->libdir .'/accesslib.php');       // Access control functions
require_once($CFG->libdir .'/deprecatedlib.php');   // Deprecated functions included for backward compatibility
require_once($CFG->libdir .'/moodlelib.php');       // Other general-purpose functions
require_once($CFG->libdir .'/enrollib.php');        // Enrolment related functions
require_once($CFG->libdir .'/pagelib.php');         // Library that defines the moodle_page class, used for $PAGE
require_once($CFG->libdir .'/blocklib.php');        // Library for controlling blocks
require_once($CFG->libdir .'/grouplib.php');        // Groups functions
require_once($CFG->libdir .'/sessionlib.php');      // All session and cookie related stuff
require_once($CFG->libdir .'/editorlib.php');       // All text editor related functions and classes
require_once($CFG->libdir .'/messagelib.php');      // Messagelib functions
require_once($CFG->libdir .'/modinfolib.php');      // Cached information on course-module instances
require_once($CFG->dirroot.'/cache/lib.php');       // Cache API

// make sure PHP is not severly misconfigured
setup_validate_php_configuration();

// Connect to the database
setup_DB();

if (PHPUNIT_TEST and !PHPUNIT_UTIL) {
    // Make sure tests do not run in parallel.
    $suffix = '';
    if (phpunit_util::is_in_isolated_process()) {
        $suffix = '.isolated';
    }
    test_lock::acquire('phpunit', $suffix);
    $dbhash = null;
    try {
        if ($dbhash = $DB->get_field('config', 'value', array('name'=>'phpunittest'))) {
            // reset DB tables
            phpunit_util::reset_database();
        }
    } catch (Exception $e) {
        if ($dbhash) {
            // we ned to reinit if reset fails
            $DB->set_field('config', 'value', 'na', array('name'=>'phpunittest'));
        }
    }
    unset($dbhash);
}

// Load any immutable bootstrap config from local cache.
$bootstrapcachefile = $CFG->localcachedir . '/bootstrap.php';
if (is_readable($bootstrapcachefile)) {
    try {
        require_once($bootstrapcachefile);
        // Verify the file is not stale.
        if (!isset($CFG->bootstraphash) || $CFG->bootstraphash !== hash_local_config_cache()) {
            // Something has changed, the bootstrap.php file is stale.
            unset($CFG->siteidentifier);
            @unlink($bootstrapcachefile);
        }
    } catch (Throwable $e) {
        // If it is corrupted then attempt to delete it and it will be rebuilt.
        @unlink($bootstrapcachefile);
    }
}

// Load up any configuration from the config table or MUC cache.
if (PHPUNIT_TEST) {
    phpunit_util::initialise_cfg();
} else {
    initialise_cfg();
}

if (isset($CFG->debug)) {
    $CFG->debug = (int)$CFG->debug;
    error_reporting($CFG->debug);
}  else {
    $CFG->debug = 0;
}
$CFG->debugdeveloper = (($CFG->debug & DEBUG_DEVELOPER) === DEBUG_DEVELOPER);

// Set a default value for whether to show exceptions in a pretty format.
if (!property_exists($CFG, 'debug_developer_use_pretty_exceptions')) {
    $CFG->debug_developer_use_pretty_exceptions = true;

}

// Find out if PHP configured to display warnings,
// this is a security problem because some moodle scripts may
// disclose sensitive information.
if (ini_get_bool('display_errors')) {
    define('WARN_DISPLAY_ERRORS_ENABLED', true);
}
// If we want to display Moodle errors, then try and set PHP errors to match.
if (!isset($CFG->debugdisplay)) {
    // Keep it "as is" during installation.
} else if (NO_DEBUG_DISPLAY) {
    // Some parts of Moodle cannot display errors and debug at all.
    ini_set('display_errors', '0');
    ini_set('log_errors', '1');
} else if (empty($CFG->debugdisplay)) {
    ini_set('display_errors', '0');
    ini_set('log_errors', '1');
} else {
    // This is very problematic in XHTML strict mode!
    ini_set('display_errors', '1');
}

// Register our shutdown manager, do NOT use register_shutdown_function().
core_shutdown_manager::initialize();

// Verify upgrade is not running unless we are in a script that needs to execute in any case
if (!defined('NO_UPGRADE_CHECK') and isset($CFG->upgraderunning)) {
    if ($CFG->upgraderunning < time()) {
        unset_config('upgraderunning');
    } else {
        throw new \moodle_exception('upgraderunning');
    }
}

// enable circular reference collector in PHP 5.3,
// it helps a lot when using large complex OOP structures such as in amos or gradebook
if (function_exists('gc_enable')) {
    gc_enable();
}

// detect unsupported upgrade jump as soon as possible - do not change anything, do not use system functions
if (!empty($CFG->version) and $CFG->version < 2007101509) {
    throw new \moodle_exception('upgraderequires19', 'error');
    die;
}

// Calculate and set $CFG->ostype to be used everywhere. Possible values are:
// - WINDOWS: for any Windows flavour.
// - UNIX: for the rest
// Also, $CFG->os can continue being used if more specialization is required
if (stristr(PHP_OS, 'win') && !stristr(PHP_OS, 'darwin')) {
    $CFG->ostype = 'WINDOWS';
} else {
    $CFG->ostype = 'UNIX';
}
$CFG->os = PHP_OS;

// Configure ampersands in URLs
ini_set('arg_separator.output', '&amp;');

// Work around for a PHP bug   see MDL-11237
ini_set('pcre.backtrack_limit', 20971520);  // 20 MB

// Set PHP default timezone to server timezone.
core_date::set_default_server_timezone();

// Location of standard files
$CFG->wordlist = $CFG->libdir .'/wordlist.txt';
$CFG->moddata  = 'moddata';

// neutralise nasty chars in PHP_SELF
if (isset($_SERVER['PHP_SELF'])) {
    $phppos = strpos($_SERVER['PHP_SELF'], '.php');
    if ($phppos !== false) {
        $_SERVER['PHP_SELF'] = substr($_SERVER['PHP_SELF'], 0, $phppos+4);
    }
    unset($phppos);
}

// initialise ME's - this must be done BEFORE starting of session!
initialise_fullme();

// SYSCONTEXTID is cached in local cache to eliminate 1 query per page.
if (!defined('SYSCONTEXTID')) {
    context_system::instance();
}

// Defining the site - aka frontpage course
try {
    $SITE = get_site();
} catch (moodle_exception $e) {
    $SITE = null;
    if (empty($CFG->version)) {
        $SITE = new stdClass();
        $SITE->id = 1;
        $SITE->shortname = null;
    } else {
        throw $e;
    }
}
// And the 'default' course - this will usually get reset later in require_login() etc.
$COURSE = clone($SITE);
// Id of the frontpage course.
define('SITEID', $SITE->id);

// init session prevention flag - this is defined on pages that do not want session
if (CLI_SCRIPT) {
    // no sessions in CLI scripts possible
    define('NO_MOODLE_COOKIES', true);

} else if (WS_SERVER) {
    // No sessions possible in web services.
    define('NO_MOODLE_COOKIES', true);

} else if (!defined('NO_MOODLE_COOKIES')) {
    if (empty($CFG->version) or $CFG->version < 2009011900) {
        // no session before sessions table gets created
        define('NO_MOODLE_COOKIES', true);
    } else if (CLI_SCRIPT) {
        // CLI scripts can not have session
        define('NO_MOODLE_COOKIES', true);
    } else {
        define('NO_MOODLE_COOKIES', false);
    }
}

// Start session and prepare global $SESSION, $USER.
if (empty($CFG->sessiontimeout)) {
    $CFG->sessiontimeout = 8 * 60 * 60;
}
// Set sessiontimeoutwarning 20 minutes.
if (empty($CFG->sessiontimeoutwarning)) {
    $CFG->sessiontimeoutwarning = 20 * 60;
}

// Allow plugins to callback just before the session is started.
$pluginswithfunction = get_plugins_with_function('before_session_start', 'lib.php');
foreach ($pluginswithfunction as $plugins) {
    foreach ($plugins as $function) {
        try {
            $function();
        } catch (Throwable $e) {
            debugging("Exception calling '$function'", DEBUG_DEVELOPER, $e->getTrace());
        }
    }
}

\core\session\manager::start();
// Prevent ignoresesskey hack from getting carried over to a next page.
unset($USER->ignoresesskey);

if (!empty($CFG->proxylogunsafe) || !empty($CFG->proxyfixunsafe)) {
    if (!empty($CFG->proxyfixunsafe)) {
        require_once($CFG->libdir.'/filelib.php');

        $proxyurl = get_moodle_proxy_url();
        // This fixes stream handlers inside php.
        $defaults = stream_context_set_default([
            'http' => [
                'user_agent' => \core_useragent::get_moodlebot_useragent(),
                'proxy' => $proxyurl
            ],
        ]);

        // Attempt to tell other web clients to use the proxy too. This only
        // works for clients written in php in the same process, it will not
        // work for with requests done in another process from an exec call.
        putenv('http_proxy=' . $proxyurl);
        putenv('https_proxy=' . $proxyurl);
        putenv('HTTPS_PROXY=' . $proxyurl);
    } else {
        $defaults = stream_context_get_default();
    }

    if (!empty($CFG->proxylogunsafe)) {
        stream_context_set_params($defaults, ['notification' => 'proxy_log_callback']);
    }

}

// Set default content type and encoding, developers are still required to use
// echo $OUTPUT->header() everywhere, anything that gets set later should override these headers.
// This is intended to mitigate some security problems.
if (AJAX_SCRIPT) {
    if (!core_useragent::supports_json_contenttype()) {
        // Some bloody old IE.
        @header('Content-type: text/plain; charset=utf-8');
        @header('X-Content-Type-Options: nosniff');
    } else if (!empty($_FILES)) {
        // Some ajax code may have problems with json and file uploads.
        @header('Content-type: text/plain; charset=utf-8');
    } else {
        @header('Content-type: application/json; charset=utf-8');
    }
} else if (!CLI_SCRIPT) {
    @header('Content-type: text/html; charset=utf-8');
}

// Initialise some variables that are supposed to be set in config.php only.
if (!isset($CFG->filelifetime)) {
    $CFG->filelifetime = 60*60*6;
}

// Late profiling, only happening if early one wasn't started
if (!empty($CFG->profilingenabled)) {
    require_once($CFG->libdir . '/xhprof/xhprof_moodle.php');
    profiling_start();
}

// Hack to get around max_input_vars restrictions,
// we need to do this after session init to have some basic DDoS protection.
workaround_max_input_vars();

// Process theme change in the URL.
if (!empty($CFG->allowthemechangeonurl) and !empty($_GET['theme'])) {
    // we have to use _GET directly because we do not want this to interfere with _POST
    $urlthemename = optional_param('theme', '', PARAM_PLUGIN);
    try {
        $themeconfig = theme_config::load($urlthemename);
        // Makes sure the theme can be loaded without errors.
        if ($themeconfig->name === $urlthemename) {
            $SESSION->theme = $urlthemename;
        } else {
            unset($SESSION->theme);
        }
        unset($themeconfig);
        unset($urlthemename);
    } catch (Exception $e) {
        debugging('Failed to set the theme from the URL.', DEBUG_DEVELOPER, $e->getTrace());
    }
}
unset($urlthemename);

// Ensure a valid theme is set.
if (!isset($CFG->theme)) {
    $CFG->theme = 'boost';
}

// Set language/locale of printed times.  If user has chosen a language that
// that is different from the site language, then use the locale specified
// in the language file.  Otherwise, if the admin hasn't specified a locale
// then use the one from the default language.  Otherwise (and this is the
// majority of cases), use the stored locale specified by admin.
// note: do not accept lang parameter from POST
if (isset($_GET['lang']) and ($lang = optional_param('lang', '', PARAM_SAFEDIR))) {
    if (get_string_manager()->translation_exists($lang, false)) {
        $SESSION->lang = $lang;
        \core_courseformat\base::session_cache_reset_all();
    }
}
unset($lang);

// PARAM_SAFEDIR used instead of PARAM_LANG because using PARAM_LANG results
// in an empty string being returned when a non-existant language is specified,
// which would make it necessary to log out to undo the forcelang setting.
// With PARAM_SAFEDIR, it's possible to specify ?forcelang=none to drop the forcelang effect.
if ($forcelang = optional_param('forcelang', '', PARAM_SAFEDIR)) {
    if (isloggedin()
        && get_string_manager()->translation_exists($forcelang, false)
        && has_capability('moodle/site:forcelanguage', context_system::instance())) {
        $SESSION->forcelang = $forcelang;
    } else if (isset($SESSION->forcelang)) {
        unset($SESSION->forcelang);
    }
}
unset($forcelang);

setup_lang_from_browser();

if (empty($CFG->lang)) {
    if (empty($SESSION->lang)) {
        $CFG->lang = 'en';
    } else {
        $CFG->lang = $SESSION->lang;
    }
}

// Set the default site locale, a lot of the stuff may depend on this
// it is definitely too late to call this first in require_login()!
moodle_setlocale();

// Create the $PAGE global - this marks the PAGE and OUTPUT fully initialised, this MUST be done at the end of setup!
if (!empty($CFG->moodlepageclass)) {
    if (!empty($CFG->moodlepageclassfile)) {
        require_once($CFG->moodlepageclassfile);
    }
    $classname = $CFG->moodlepageclass;
} else {
    $classname = 'moodle_page';
}
$PAGE = new $classname();
unset($classname);


if (!empty($CFG->debugvalidators) and !empty($CFG->guestloginbutton)) {
    if ($CFG->theme == 'standard') {    // Temporary measure to help with XHTML validation
        if (isset($_SERVER['HTTP_USER_AGENT']) and empty($USER->id)) {      // Allow W3CValidator in as user called w3cvalidator (or guest)
            if ((strpos($_SERVER['HTTP_USER_AGENT'], 'W3C_Validator') !== false) or
                (strpos($_SERVER['HTTP_USER_AGENT'], 'Cynthia') !== false )) {
                if ($user = get_complete_user_data("username", "w3cvalidator")) {
                    $user->ignoresesskey = true;
                } else {
                    $user = guest_user();
                }
                \core\session\manager::set_user($user);
            }
        }
    }
}

// Apache log integration. In apache conf file one can use ${MOODULEUSER}n in
// LogFormat to get the current logged in username in moodle.
// Alternatvely for other web servers a header X-MOODLEUSER can be set which
// can be using in the logfile and stripped out if needed.
set_access_log_user();

if (CLI_SCRIPT && !empty($CFG->version)) {
    // Allow auth plugins to optionally authenticate users on the CLI.
    require_once($CFG->libdir. '/authlib.php');
    auth_plugin_base::login_cli_admin_user();
}

// Ensure the urlrewriteclass is setup correctly (to avoid crippling site).
if (isset($CFG->urlrewriteclass)) {
    if (!class_exists($CFG->urlrewriteclass)) {
        debugging("urlrewriteclass {$CFG->urlrewriteclass} was not found, disabling.");
        unset($CFG->urlrewriteclass);
    } else if (!in_array('core\output\url_rewriter', class_implements($CFG->urlrewriteclass))) {
        debugging("{$CFG->urlrewriteclass} does not implement core\output\url_rewriter, disabling.", DEBUG_DEVELOPER);
        unset($CFG->urlrewriteclass);
    }
}

// Use a custom script replacement if one exists
if (!empty($CFG->customscripts)) {
    if (($customscript = custom_script_path()) !== false) {
        require ($customscript);
    }
}

if (PHPUNIT_TEST) {
    // no ip blocking, these are CLI only
} else if (CLI_SCRIPT and !defined('WEB_CRON_EMULATED_CLI')) {
    // no ip blocking
} else if (!empty($CFG->allowbeforeblock)) { // allowed list processed before blocked list?
    // in this case, ip in allowed list will be performed first
    // for example, client IP is 192.168.1.1
    // 192.168 subnet is an entry in allowed list
    // 192.168.1.1 is banned in blocked list
    // This ip will be banned finally
    if (!empty($CFG->allowedip)) {
        if (!remoteip_in_list($CFG->allowedip)) {
            die(get_string('ipblocked', 'admin'));
        }
    }
    // need further check, client ip may a part of
    // allowed subnet, but a IP address are listed
    // in blocked list.
    if (!empty($CFG->blockedip)) {
        if (remoteip_in_list($CFG->blockedip)) {
            die(get_string('ipblocked', 'admin'));
        }
    }

} else {
    // in this case, IPs in blocked list will be performed first
    // for example, client IP is 192.168.1.1
    // 192.168 subnet is an entry in blocked list
    // 192.168.1.1 is allowed in allowed list
    // This ip will be allowed finally
    if (!empty($CFG->blockedip)) {
        if (remoteip_in_list($CFG->blockedip)) {
            // if the allowed ip list is not empty
            // IPs are not included in the allowed list will be
            // blocked too
            if (!empty($CFG->allowedip)) {
                if (!remoteip_in_list($CFG->allowedip)) {
                    die(get_string('ipblocked', 'admin'));
                }
            } else {
                die(get_string('ipblocked', 'admin'));
            }
        }
    }
    // if blocked list is null
    // allowed list should be tested
    if(!empty($CFG->allowedip)) {
        if (!remoteip_in_list($CFG->allowedip)) {
            die(get_string('ipblocked', 'admin'));
        }
    }

}

// // try to detect IE6 and prevent gzip because it is extremely buggy browser
if (!empty($_SERVER['HTTP_USER_AGENT']) and strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE 6') !== false) {
    ini_set('zlib.output_compression', 'Off');
    if (function_exists('apache_setenv')) {
        apache_setenv('no-gzip', 1);
    }
}

// Switch to CLI maintenance mode if required, we need to do it here after all the settings are initialised.
if (isset($CFG->maintenance_later) and $CFG->maintenance_later <= time()) {
    if (!file_exists("$CFG->dataroot/climaintenance.html")) {
        require_once("$CFG->libdir/adminlib.php");
        enable_cli_maintenance_mode();
    }
    unset_config('maintenance_later');
    if (AJAX_SCRIPT) {
        die;
    } else if (!CLI_SCRIPT) {
        redirect(new moodle_url('/'));
    }
}

// Add behat_shutdown_function to shutdown manager, so we can capture php errors,
// but not necessary for behat CLI command as it's being captured by behat process.
if (defined('BEHAT_SITE_RUNNING') && !defined('BEHAT_TEST')) {
    core_shutdown_manager::register_function('behat_shutdown_function');
}

// note: we can not block non utf-8 installations here, because empty mysql database
// might be converted to utf-8 in admin/index.php during installation



// this is a funny trick to make Eclipse believe that $OUTPUT and other globals
// contains an instance of core_renderer, etc. which in turn fixes autocompletion ;-)
if (false) {
    $DB = new moodle_database();
    $OUTPUT = new core_renderer(null, null);
    $PAGE = new moodle_page();
}

// Cache any immutable config locally to avoid constant DB lookups.
initialise_local_config_cache();

// Allow plugins to callback as soon possible after setup.php is loaded.
$pluginswithfunction = get_plugins_with_function('after_config', 'lib.php');
foreach ($pluginswithfunction as $plugins) {
    foreach ($plugins as $function) {
        try {
            $function();
        } catch (Throwable $e) {
            debugging("Exception calling '$function'", DEBUG_DEVELOPER, $e->getTrace());
        }
    }
}