<?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/>.

/**
 * Class for availability plugins.
 *
 * @package core
 * @copyright 2014 The Open University
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
namespace core\plugininfo;

use admin_settingpage;

/**
 * Class for availability plugins.
 *
 * @package core
 * @copyright 2014 The Open University
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class availability extends base {

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

    public static function get_enabled_plugins() {
        global $DB;

        // Get all available plugins.
        $plugins = \core_plugin_manager::instance()->get_installed_plugins('availability');
        if (!$plugins) {
            return array();
        }

        // Check they are enabled using get_config (which is cached and hopefully fast).
        $enabled = array();
        foreach ($plugins as $plugin => $version) {
            $disabled = get_config('availability_' . $plugin, 'disabled');
            if (empty($disabled)) {
                $enabled[$plugin] = $plugin;
            }
        }

        return $enabled;
    }

    public static function enable_plugin(string $pluginname, int $enabled): bool {
        $haschanged = false;

        $plugin = 'availability_' . $pluginname;
        $oldvalue = get_config($plugin, 'disabled');
        $disabled = !$enabled;
        // Only set value if there is no config setting or if the value is different from the previous one.
        if ($oldvalue == false && $disabled) {
            set_config('disabled', $disabled, $plugin);
            $haschanged = true;
        } else if ($oldvalue != false && !$disabled) {
            unset_config('disabled', $plugin);
            $haschanged = true;
        }

        if ($haschanged) {
            add_to_config_log('disabled', $oldvalue, $disabled, $plugin);
            \core_plugin_manager::reset_caches();
        }

        return $haschanged;
    }

    /**
     * Update the display mode for a specific plugin based on `$displaymode` parameter.
     *
     * @param string $pluginname The plugin name.
     * @param bool $displaymode whether the eye icon of display mode is enabled or disabled.
     * @return bool Returns true if the configuration has been changed, false otherwise.
     */
    public static function update_display_mode(string $pluginname, bool $displaymode): bool {
        $haschanged = false;

        $plugin = 'availability_' . $pluginname;
        $oldvalue = get_config($plugin, 'defaultdisplaymode');
        $disabled = !$displaymode;
        // Only set value if there is no config setting or if the value is different from the previous one.
        if ($oldvalue == false && $disabled) {
            set_config('defaultdisplaymode', $disabled, $plugin);
            $haschanged = true;
        } else if ($oldvalue != false && !$disabled) {
            unset_config('defaultdisplaymode', $plugin);
            $haschanged = true;
        }

        if ($haschanged) {
            add_to_config_log('defaultdisplaymode', $oldvalue, $disabled, $plugin);
            \core_plugin_manager::reset_caches();
        }

        return $haschanged;
    }

    /**
     * Defines if there should be a way to uninstall the plugin via the administration UI.
     *
     * @return bool
     */
    public function is_uninstall_allowed() {
        return true;
    }

    /**
     * Get the name for the settings section.
     *
     * @return string
     */
    public function get_settings_section_name() {
        return 'availabilitysetting' . $this->name;
    }

    /**
     * Load the global settings for a particular availability plugin (if there are any)
     *
     * @param \part_of_admin_tree $adminroot
     * @param string $parentnodename
     * @param bool $hassiteconfig
     */
    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
        $availability = $this; // Also to be used inside settings.php.

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

        if (!$hassiteconfig) {
            return;
        }

        $section = $this->get_settings_section_name();

        $settings = null;
        if (file_exists($this->full_path('settings.php'))) {
            $settings = new admin_settingpage($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);
        }
    }
}
