<?php

if (!defined('ABSPATH')) {
    exit;
}

/**
 * Module Registry
 *
 * Allows features to register themselves without modifying
 * core files. Separate add-on plugins register on the
 * 'shadowsync_seo_register_modules' action.
 *
 * Usage:
 *   ShadowSync_SEO_Module_Registry::register([
 *       'id'          => 'keyword_research',
 *       'name'        => 'Keyword Research',
 *       'description' => 'Find keyword opportunities',
 *       'version'     => '1.0',
 *       'class'       => 'ShadowSync_SEO_Keyword_Research',
 *   ]);
 */
class ShadowSync_SEO_Module_Registry {

    private static $modules = [];
    private static $active  = [];

    /**
     * Register a module
     */
    public static function register($config) {

        $required = ['id', 'name', 'class'];
        foreach ($required as $key) {
            if (empty($config[$key])) {
                return new WP_Error('missing_key', 'Module registration missing: ' . $key);
            }
        }

        $defaults = [
            'description' => '',
            'version'     => '1.0',
            'active'      => true,
            'icon'        => '🔧',
            'menu_slug'   => null,
        ];

        self::$modules[$config['id']] = array_merge($defaults, $config);
        return true;
    }

    /**
     * Get all registered modules
     */
    public static function get_all() {
        return self::$modules;
    }

    /**
     * Get a single module by ID
     */
    public static function get($id) {
        return self::$modules[$id] ?? null;
    }

    /**
     * Check if a module is registered
     */
    public static function exists($id) {
        return isset(self::$modules[$id]);
    }

    /**
     * Initialise all registered modules
     */
    public static function init_all() {
        foreach (self::$modules as $id => $module) {
            if (!$module['active']) continue;
            if (class_exists($module['class'])) {
                new $module['class']();
                self::$active[$id] = true;
            }
        }
    }

    /**
     * Get count of active modules
     */
    public static function count_active() {
        return count(self::$active);
    }
}