<?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/>.

/**
 * Defines classes used for plugin info.
 *
 * @package    core_antivirus
 * @copyright  2015 Ruslan Kabalin, Lancaster University.
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
namespace core\plugininfo;

use admin_settingpage;
use moodle_url;
use part_of_admin_tree;

/**
 * Class for Antiviruses
 *
 * @package    core_antivirus
 * @copyright  2015 Ruslan Kabalin, Lancaster University.
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class antivirus extends base {

    public static function plugintype_supports_disabling(): bool {
        return true;
    }

    /**
     * Finds all enabled plugins, the result may include missing plugins.
     * @return array|null of enabled plugins $pluginname=>$pluginname, null means unknown
     */
    public static function get_enabled_plugins() {
        global $CFG;

        if (empty($CFG->antiviruses)) {
            return array();
        }

        $enabled = array();
        foreach (explode(',', $CFG->antiviruses) as $antivirus) {
            $enabled[$antivirus] = $antivirus;
        }

        return $enabled;
    }

    public static function enable_plugin(string $pluginname, int $enabled): bool {
        global $CFG;

        $haschanged = false;
        $plugins = [];
        if (!empty($CFG->antiviruses)) {
            $plugins = array_flip(explode(',', $CFG->antiviruses));
        }
        // Only set visibility if it's different from the current value.
        if ($enabled && !array_key_exists($pluginname, $plugins)) {
            $plugins[$pluginname] = $pluginname;
            $haschanged = true;
        } else if (!$enabled && array_key_exists($pluginname, $plugins)) {
            unset($plugins[$pluginname]);
            $haschanged = true;
        }

        if ($haschanged) {
            $new = implode(',', array_flip($plugins));
            add_to_config_log('antiviruses', $CFG->antiviruses, $new, 'core');
            set_config('antiviruses', $new);
            // Reset caches.
            \core_plugin_manager::reset_caches();
        }

        return $haschanged;
    }

    /**
     * Return the node name to use in admin settings menu for this plugin.
     *
     * @return string node name
     */
    public function get_settings_section_name() {
        return 'antivirussettings' . $this->name;
    }

    /**
     * Loads plugin settings to the settings tree
     *
     * This function usually includes settings.php file in plugins folder.
     * Alternatively it can create a link to some settings page (instance of admin_externalpage)
     *
     * @param \part_of_admin_tree $adminroot
     * @param string $parentnodename
     * @param bool $hassiteconfig whether the current user has moodle/site:config capability
     */
    public function load_settings(part_of_admin_tree $adminroot, $parentnodename, $hassiteconfig) {
        global $CFG, $USER, $DB, $OUTPUT, $PAGE; // In case settings.php wants to refer to them.
        /** @var \admin_root $ADMIN */
        $ADMIN = $adminroot; // May be used in settings.php.
        $plugininfo = $this; // Also can be used inside settings.php.
        $antivirus = $this;  // Also can be used inside settings.php.

        if (!$this->is_installed_and_upgraded()) {
            return;
        }

        if (!$hassiteconfig or !file_exists($this->full_path('settings.php'))) {
            return;
        }

        $section = $this->get_settings_section_name();

        $settings = new admin_settingpage($section, $this->displayname, 'moodle/site:config', $this->is_enabled() === false);
        include($this->full_path('settings.php')); // This may also set $settings to null.

        if ($settings) {
            $ADMIN->add($parentnodename, $settings);
        }
    }

    /**
     * Clamav antivirus can not be uninstalled.
     */
    public function is_uninstall_allowed() {
        if ($this->name === 'clamav') {
            return false;
        } else {
            return true;
        }
    }

    /**
     * Return URL used for management of plugins of this type.
     * @return moodle_url
     */
    public static function get_manage_url() {
        return new moodle_url('/admin/settings.php', array('section' => 'manageantiviruses'));
    }

    /**
     * Pre-uninstall hook.
     */
    public function uninstall_cleanup() {
        global $CFG;

        if (!empty($CFG->antiviruses)) {
            $antiviruses = explode(',', $CFG->antiviruses);
            $antiviruses = array_unique($antiviruses);
        } else {
            $antiviruses = array();
        }
        if (($key = array_search($this->name, $antiviruses)) !== false) {
            unset($antiviruses[$key]);
            set_config('antiviruses', implode(',', $antiviruses));
        }
        parent::uninstall_cleanup();
    }
}