<?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: activate / recheck / deactivate MeetLet site registration.
 *
 * @package    mod_meetletacbfree
 * @copyright  2026 MeetLet <info@meetlet.net>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

namespace mod_meetletacbfree\external;

use core_external\external_api;
use core_external\external_function_parameters;
use core_external\external_single_structure;
use core_external\external_value;
use mod_meetletacbfree\registration\error_mapper;
use mod_meetletacbfree\registration\manager;
use mod_meetletacbfree\registration\registration_exception;

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

/**
 * Ajax-capable registration actions for admin settings.
 */
class registration_action extends external_api {
    public static function execute_parameters(): external_function_parameters {
        return new external_function_parameters([
            'action' => new external_value(PARAM_ALPHA, 'activate|recheck|deactivate|status'),
            'registration_api_url' => new external_value(PARAM_URL, 'Optional API base URL', VALUE_DEFAULT, ''),
        ]);
    }

    public static function execute(string $action, string $registrationapiurl = ''): array {
        $params = self::validate_parameters(self::execute_parameters(), [
            'action' => $action,
            'registration_api_url' => $registrationapiurl,
        ]);

        $context = \context_system::instance();
        self::validate_context($context);
        require_capability('moodle/site:config', $context);

        try {
            if ($params['registration_api_url'] !== '') {
                set_config(manager::CONFIG_API_URL, rtrim($params['registration_api_url'], '/'), 'meetletacbfree');
            }

            $message = '';
            if ($params['action'] === 'activate') {
                manager::activate();
                $message = get_string('registration_activated', 'meetletacbfree');
            } else if (in_array($params['action'], ['recheck', 'refresh', 'validate'], true)) {
                manager::recheck(true);
                $message = get_string('registration_rechecked', 'meetletacbfree');
            } else if ($params['action'] === 'deactivate') {
                manager::deactivate();
                $message = get_string('registration_deactivated', 'meetletacbfree');
            } else if ($params['action'] === 'status') {
                $message = '';
            } else {
                throw new \moodle_exception('invalidparameter');
            }

            return self::pack_response(true, $message, '');
        } catch (\Throwable $e) {
            $ex = registration_exception::from_throwable($e);
            $mapped = error_mapper::from_exception($ex);
            return self::pack_response(
                false,
                '',
                (string)($mapped['message'] ?? $ex->get_api_message())
            );
        }
    }

    /**
     * @return array<string,mixed>
     */
    protected static function pack_response(bool $success, string $message, string $error): array {
        $summary = manager::status_summary();
        return [
            'success' => $success,
            'message' => $message,
            'error' => $error,
            'active' => !empty($summary['active']),
            'status' => (string)($summary['status'] ?? ''),
            'status_label' => (string)($summary['status_label'] ?? ''),
            'product_label' => (string)($summary['product_label'] ?? ''),
            'domain' => (string)($summary['domain'] ?? ''),
            'installation_id' => (string)($summary['installation_id'] ?? ''),
            'can_deactivate' => !empty($summary['can_deactivate']),
        ];
    }

    public static function execute_returns(): external_single_structure {
        return new external_single_structure([
            'success' => new external_value(PARAM_BOOL, 'Whether the action succeeded'),
            'message' => new external_value(PARAM_TEXT, 'Success message'),
            'error' => new external_value(PARAM_TEXT, 'Error message when unsuccessful'),
            'active' => new external_value(PARAM_BOOL, 'Whether activation is active'),
            'status' => new external_value(PARAM_ALPHANUMEXT, 'Raw status code'),
            'status_label' => new external_value(PARAM_TEXT, 'Human status label'),
            'product_label' => new external_value(PARAM_TEXT, 'Product label'),
            'domain' => new external_value(PARAM_TEXT, 'Site domain'),
            'installation_id' => new external_value(PARAM_TEXT, 'Installation id'),
            'can_deactivate' => new external_value(PARAM_BOOL, 'Whether deactivate is allowed'),
        ]);
    }
}