<?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/>.


/**
 * external API for mobile web services
 *
 * @package    core_webservice
 * @category   external
 * @copyright  2011 Jerome Mouneyrac <jerome@moodle.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

defined('MOODLE_INTERNAL') || die;

require_once("$CFG->libdir/externallib.php");

/**
 * Web service related functions
 *
 * @package    core_webservice
 * @category   external
 * @copyright  2011 Jerome Mouneyrac <jerome@moodle.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @since Moodle 2.2
 */
class core_webservice_external extends external_api {

    /**
     * Returns description of method parameters
     *
     * @return external_function_parameters
     * @since Moodle 2.2
     */
    public static function get_site_info_parameters() {
        return new external_function_parameters(
            array('serviceshortnames' => new external_multiple_structure (
                new external_value(
                    PARAM_ALPHANUMEXT,
                    'service shortname'),
                    'DEPRECATED PARAMETER - it was a design error in the original implementation. \
                    It is ignored now. (parameter kept for backward compatibility)',
                    VALUE_DEFAULT,
                    array()
                ),
            )
        );
    }

    /**
     * Return user information including profile picture + basic site information
     * Note:
     * - no capability checking because we return only known information about logged user
     *
     * @param array $serviceshortnames - DEPRECATED PARAMETER - values will be ignored -
     * it was an original design error, we keep for backward compatibility.
     * @return array site info
     * @since Moodle 2.2
     */
    public static function get_site_info($serviceshortnames = array()) {
        global $USER, $SITE, $CFG, $DB, $PAGE;

        $params = self::validate_parameters(self::get_site_info_parameters(),
                      array('serviceshortnames'=>$serviceshortnames));

        $context = context_user::instance($USER->id);
        $systemcontext = context_system::instance();

        $userpicture = new user_picture($USER);
        $userpicture->size = 1; // Size f1.
        $profileimageurl = $userpicture->get_url($PAGE);

        // Site information.
        $siteinfo =  array(
            'sitename' => external_format_string($SITE->fullname, $systemcontext),
            'siteurl' => $CFG->wwwroot,
            'username' => $USER->username,
            'firstname' => $USER->firstname,
            'lastname' => $USER->lastname,
            'fullname' => fullname($USER),
            'lang' => clean_param(current_language(), PARAM_LANG),
            'userid' => $USER->id,
            'userpictureurl' => $profileimageurl->out(false),
            'siteid' => SITEID
        );

        // Retrieve the service and functions from the web service linked to the token
        // If you call this function directly from external (not a web service call),
        // then it will still return site info without information about a service
        // Note: wsusername/wspassword ws authentication is not supported.
        $functions = array();
        if ($CFG->enablewebservices) { // No need to check token if web service are disabled and not a ws call.
            $token = optional_param('wstoken', '', PARAM_ALPHANUM);

            if (!empty($token)) { // No need to run if not a ws call.
                // Retrieve service shortname.
                $servicesql = 'SELECT s.*
                               FROM {external_services} s, {external_tokens} t
                               WHERE t.externalserviceid = s.id AND token = ? AND t.userid = ? AND s.enabled = 1';
                $service = $DB->get_record_sql($servicesql, array($token, $USER->id));

                $siteinfo['downloadfiles'] = $service->downloadfiles;
                $siteinfo['uploadfiles'] = $service->uploadfiles;

                if (!empty($service)) {
                    // Return the release and version number for web service users only.
                    $siteinfo['release'] = $CFG->release;
                    $siteinfo['version'] = $CFG->version;
                    // Retrieve the functions.
                    $functionssql = "SELECT f.*
                            FROM {external_functions} f, {external_services_functions} sf
                            WHERE f.name = sf.functionname AND sf.externalserviceid = ?";
                    $functions = $DB->get_records_sql($functionssql, array($service->id));
                } else {
                    throw new coding_exception('No service found in get_site_info: something is buggy, \
                                                it should have fail at the ws server authentication layer.');
                }
            }
        }

        // Build up the returned values of the list of functions.
        $componentversions = array();
        $availablefunctions = array();
        foreach ($functions as $function) {
            $functioninfo = array();
            $functioninfo['name'] = $function->name;
            if ($function->component == 'moodle' || $function->component == 'core') {
                $version = $CFG->version; // Moodle version.
            } else {
                $versionpath = core_component::get_component_directory($function->component).'/version.php';
                if (is_readable($versionpath)) {
                    // We store the component version once retrieved (so we don't load twice the version.php).
                    if (!isset($componentversions[$function->component])) {
                        $plugin = new stdClass();
                        include($versionpath);
                        $componentversions[$function->component] = $plugin->version;
                        $version = $plugin->version;
                    } else {
                        $version = $componentversions[$function->component];
                    }
                } else {
                    // Function component should always have a version.php,
                    // otherwise the function should have been described with component => 'moodle'.
                    throw new moodle_exception('missingversionfile', 'webservice', '', $function->component);
                }
            }
            $functioninfo['version'] = $version;
            $availablefunctions[] = $functioninfo;
        }

        $siteinfo['functions'] = $availablefunctions;

        // Mobile CSS theme and alternative login url.
        $siteinfo['mobilecssurl'] = !empty($CFG->mobilecssurl) ? $CFG->mobilecssurl : '';

        // Retrieve some advanced features. Only enable/disable ones (bool).
        $advancedfeatures = array("usecomments", "usetags", "enablenotes", "messaging", "enableblogs",
                                    "enablecompletion", "enablebadges", "messagingallusers");
        foreach ($advancedfeatures as $feature) {
            if (isset($CFG->{$feature})) {
                $siteinfo['advancedfeatures'][] = array(
                    'name' => $feature,
                    'value' => (int) $CFG->{$feature}
                );
            }
        }
        // Special case mnet_dispatcher_mode.
        $siteinfo['advancedfeatures'][] = array(
            'name' => 'mnet_dispatcher_mode',
            'value' => ($CFG->mnet_dispatcher_mode == 'strict') ? 1 : 0
        );

        // User can manage own files.
        $siteinfo['usercanmanageownfiles'] = has_capability('moodle/user:manageownfiles', $context);

        // User quota. 0 means user can ignore the quota.
        $siteinfo['userquota'] = 0;
        if (!has_capability('moodle/user:ignoreuserquota', $context)) {
            $siteinfo['userquota'] = (int) $CFG->userquota; // Cast to int to ensure value is not higher than PHP_INT_MAX.
        }

        // User max upload file size. -1 means the user can ignore the upload file size.
        // Cast to int to ensure value is not higher than PHP_INT_MAX.
        $siteinfo['usermaxuploadfilesize'] = (int) get_user_max_upload_file_size($context, $CFG->maxbytes);

        // User home page.
        $siteinfo['userhomepage'] = get_home_page();

        // Calendar.
        $siteinfo['sitecalendartype'] = $CFG->calendartype;
        if (empty($USER->calendartype)) {
            $siteinfo['usercalendartype'] = $CFG->calendartype;
        } else {
            $siteinfo['usercalendartype'] = $USER->calendartype;
        }
        $siteinfo['userissiteadmin'] = is_siteadmin();

        // User key, to avoid using the WS token for fetching assets.
        $siteinfo['userprivateaccesskey'] = get_user_key('core_files', $USER->id);

        // Current theme.
        $siteinfo['theme'] = clean_param($PAGE->theme->name, PARAM_THEME);  // We always clean to avoid problem with old sites.

        $siteinfo['limitconcurrentlogins'] = (int) $CFG->limitconcurrentlogins;
        if (!empty($CFG->limitconcurrentlogins)) {
            // For performance, only when enabled.
            $siteinfo['usersessionscount'] = $DB->count_records('sessions', ['userid' => $USER->id]);
        }

        return $siteinfo;
    }

    /**
     * Returns description of method result value
     *
     * @return external_single_structure
     * @since Moodle 2.2
     */
    public static function get_site_info_returns() {
        return new external_single_structure(
            array(
                'sitename'       => new external_value(PARAM_RAW, 'site name'),
                'username'       => new external_value(PARAM_RAW, 'username'),
                'firstname'      => new external_value(PARAM_TEXT, 'first name'),
                'lastname'       => new external_value(PARAM_TEXT, 'last name'),
                'fullname'       => new external_value(PARAM_TEXT, 'user full name'),
                'lang'           => new external_value(PARAM_LANG, 'Current language.'),
                'userid'         => new external_value(PARAM_INT, 'user id'),
                'siteurl'        => new external_value(PARAM_RAW, 'site url'),
                'userpictureurl' => new external_value(PARAM_URL, 'the user profile picture.
                    Warning: this url is the public URL that only works when forcelogin is set to NO and guestaccess is set to YES.
                    In order to retrieve user profile pictures independently of the Moodle config, replace "pluginfile.php" by
                    "webservice/pluginfile.php?token=WSTOKEN&file="
                    Of course the user can only see profile picture depending
                    on his/her permissions. Moreover it is recommended to use HTTPS too.'),
                'functions'      => new external_multiple_structure(
                    new external_single_structure(
                        array(
                            'name' => new external_value(PARAM_RAW, 'function name'),
                            'version' => new external_value(PARAM_TEXT,
                                        'The version number of the component to which the function belongs')
                        ), 'functions that are available')
                    ),
                'downloadfiles'  => new external_value(PARAM_INT, '1 if users are allowed to download files, 0 if not',
                                                       VALUE_OPTIONAL),
                'uploadfiles'  => new external_value(PARAM_INT, '1 if users are allowed to upload files, 0 if not',
                                                       VALUE_OPTIONAL),
                'release'  => new external_value(PARAM_TEXT, 'Moodle release number', VALUE_OPTIONAL),
                'version'  => new external_value(PARAM_TEXT, 'Moodle version number', VALUE_OPTIONAL),
                'mobilecssurl'  => new external_value(PARAM_URL, 'Mobile custom CSS theme', VALUE_OPTIONAL),
                'advancedfeatures' => new external_multiple_structure(
                    new external_single_structure(
                        array(
                            'name'  => new external_value(PARAM_ALPHANUMEXT, 'feature name'),
                            'value' => new external_value(PARAM_INT, 'feature value. Usually 1 means enabled.')
                        ),
                        'Advanced features availability'
                    ),
                    'Advanced features availability',
                    VALUE_OPTIONAL
                ),
                'usercanmanageownfiles' => new external_value(PARAM_BOOL,
                                            'true if the user can manage his own files', VALUE_OPTIONAL),
                'userquota' => new external_value(PARAM_INT,
                                    'user quota (bytes). 0 means user can ignore the quota', VALUE_OPTIONAL),
                'usermaxuploadfilesize' => new external_value(PARAM_INT,
                                            'user max upload file size (bytes). -1 means the user can ignore the upload file size',
                                            VALUE_OPTIONAL),
                'userhomepage' => new external_value(PARAM_INT,
                                                        'the default home page for the user: 0 for the site home, 1 for dashboard',
                                                        VALUE_OPTIONAL),
                'userprivateaccesskey'  => new external_value(PARAM_ALPHANUM, 'Private user access key for fetching files.',
                    VALUE_OPTIONAL),
                'siteid'  => new external_value(PARAM_INT, 'Site course ID', VALUE_OPTIONAL),
                'sitecalendartype'  => new external_value(PARAM_PLUGIN, 'Calendar type set in the site.', VALUE_OPTIONAL),
                'usercalendartype'  => new external_value(PARAM_PLUGIN, 'Calendar typed used by the user.', VALUE_OPTIONAL),
                'userissiteadmin'  => new external_value(PARAM_BOOL, 'Whether the user is a site admin or not.', VALUE_OPTIONAL),
                'theme'  => new external_value(PARAM_THEME, 'Current theme for the user.', VALUE_OPTIONAL),
                'limitconcurrentlogins' => new external_value(PARAM_INT, 'Number of concurrent sessions allowed', VALUE_OPTIONAL),
                'usersessionscount' => new external_value(PARAM_INT, 'Number of active sessions for current user.
                    Only returned when limitconcurrentlogins is used.', VALUE_OPTIONAL),
            )
        );
    }
}