Numeración de pedidos secuenciales para Woocommerce con prefijo/sufijo

<?php
// === EMP - Numeración de pedidos Woo con prefijo/sufijo ===
// Snippet para WPCodeBox o functions.php del child theme.
if ( ! defined('ABSPATH') ) { exit; }

if ( ! class_exists('EMP_Custom_Order_Numbering') ) :
class EMP_Custom_Order_Numbering {
    const OPTION_START  = 'emp_con_start_number';
    const OPTION_NEXT   = 'emp_con_next_number';
    const OPTION_PREFIX = 'emp_con_prefix';
    const OPTION_SUFFIX = 'emp_con_suffix';
    const META_KEY      = '_emp_custom_order_number';

    public function __construct() {
        add_action('admin_menu', [$this, 'add_menu']);
        add_action('init', [$this, 'maybe_init_defaults']);

        add_action('woocommerce_new_order', [$this, 'assign_order_number'], 10, 1);
        add_filter('woocommerce_order_number', [$this, 'filter_order_number'], 10, 2);

        add_filter('manage_edit-shop_order_columns', [$this, 'add_admin_column'], 20);
        add_action('manage_shop_order_posts_custom_column', [$this, 'render_admin_column'], 10, 2);

        // Búsqueda en listado de pedidos
        add_filter('request', [$this, 'enable_search_by_custom_number']);
    }

    public function maybe_init_defaults() {
        if ( get_option(self::OPTION_START, null) === null ) {
            add_option(self::OPTION_START, 1000);
        }
        if ( get_option(self::OPTION_NEXT, null) === null ) {
            add_option(self::OPTION_NEXT, (int) get_option(self::OPTION_START, 1000));
        }
        if ( get_option(self::OPTION_PREFIX, null) === null ) {
            add_option(self::OPTION_PREFIX, '');
        }
        if ( get_option(self::OPTION_SUFFIX, null) === null ) {
            add_option(self::OPTION_SUFFIX, '');
        }
    }

    public function add_menu() {
        if ( ! current_user_can('manage_woocommerce') ) return;
        add_submenu_page(
            'woocommerce',
            'Numeración de pedidos',
            'Numeración de pedidos',
            'manage_woocommerce',
            'emp-custom-order-numbering',
            [$this, 'render_settings_page']
        );
    }

    public function render_settings_page() {
        if (
            isset($_POST['emp_con_nonce']) &&
            wp_verify_nonce($_POST['emp_con_nonce'], 'emp_con_save') &&
            current_user_can('manage_woocommerce')
        ) {
            $start  = isset($_POST['emp_con_start'])  ? (int) sanitize_text_field($_POST['emp_con_start'])  : 0;
            $next   = isset($_POST['emp_con_next'])   ? (int) sanitize_text_field($_POST['emp_con_next'])   : 0;
            $prefix = isset($_POST['emp_con_prefix']) ? sanitize_text_field($_POST['emp_con_prefix']) : '';
            $suffix = isset($_POST['emp_con_suffix']) ? sanitize_text_field($_POST['emp_con_suffix']) : '';

            if ( $start > 0 ) {
                update_option(self::OPTION_START, $start);
                if ( (int) get_option(self::OPTION_NEXT, 0) < $start ) {
                    update_option(self::OPTION_NEXT, $start);
                }
            }
            if ( $next > 0 ) {
                update_option(self::OPTION_NEXT, $next);
            }
            update_option(self::OPTION_PREFIX, $prefix);
            update_option(self::OPTION_SUFFIX, $suffix);

            echo '<div class="updated notice"><p>Ajustes guardados.</p></div>';
        }

        $start  = (int) get_option(self::OPTION_START, 1000);
        $next   = (int) get_option(self::OPTION_NEXT, $start);
        $prefix = (string) get_option(self::OPTION_PREFIX, '');
        $suffix = (string) get_option(self::OPTION_SUFFIX, '');

        ?>
        <div class="wrap">
            <h1>Numeración personalizada de pedidos</h1>
            <form method="post">
                <?php wp_nonce_field('emp_con_save', 'emp_con_nonce'); ?>
                <table class="form-table" role="presentation">
                    <tr>
                        <th scope="row"><label for="emp_con_start">Número de inicio</label></th>
                        <td>
                            <input name="emp_con_start" id="emp_con_start" type="number" min="1" value="<?php echo esc_attr($start); ?>" class="regular-text" />
                            <p class="description">Mínimo de la secuencia. Si lo subes, el siguiente número se ajusta si hace falta.</p>
                        </td>
                    </tr>
                    <tr>
                        <th scope="row"><label for="emp_con_next">Número del próximo pedido</label></th>
                        <td>
                            <input name="emp_con_next" id="emp_con_next" type="number" min="1" value="<?php echo esc_attr($next); ?>" class="regular-text" />
                            <p class="description">Úsalo solo si quieres saltar la secuencia aun número mayor manualmente.</p>
                        </td>
                    </tr>
                    <tr>
                        <th scope="row"><label for="emp_con_prefix">Prefijo (opcional)</label></th>
                        <td>
                            <input name="emp_con_prefix" id="emp_con_prefix" type="text" value="<?php echo esc_attr($prefix); ?>" class="regular-text" />
                            <p class="description">Ej.: <code>EMP-</code> o <code>2025-</code></p>
                        </td>
                    </tr>
                    <tr>
                        <th scope="row"><label for="emp_con_suffix">Sufijo (opcional)</label></th>
                        <td>
                            <input name="emp_con_suffix" id="emp_con_suffix" type="text" value="<?php echo esc_attr($suffix); ?>" class="regular-text" />
                            <p class="description">Ej.: <code>-ES</code></p>
                        </td>
                    </tr>
                </table>
                <?php submit_button('Guardar cambios'); ?>
            </form>
        </div>
        <?php
    }

    public function assign_order_number( $order_id ) {
        if ( ! $order_id ) return;

        if ( get_post_meta($order_id, self::META_KEY, true) ) return; // ya asignado

        $start = (int) get_option(self::OPTION_START, 1000);
        $next  = (int) get_option(self::OPTION_NEXT, $start);
        if ( $next < $start ) $next = $start;

        update_post_meta($order_id, self::META_KEY, $next);
        update_option(self::OPTION_NEXT, $next + 1);
    }

    public function filter_order_number( $order_number, $order ) {
        $id     = is_a($order, 'WC_Order') ? $order->get_id() : (int) $order;
        $raw    = get_post_meta($id, self::META_KEY, true);
        return $raw ? $this->format_number((int) $raw) : $order_number;
    }

    private function format_number( $n ) {
        $prefix = (string) get_option(self::OPTION_PREFIX, '');
        $suffix = (string) get_option(self::OPTION_SUFFIX, '');
        return $prefix . $n . $suffix;
    }

    public function add_admin_column( $columns ) {
        $new = [];
        foreach ( $columns as $key => $label ) {
            $new[$key] = $label;
            if ( 'order_number' === $key ) {
                $new['emp_con_number'] = 'Nº personalizado';
            }
        }
        return $new;
    }

    public function render_admin_column( $column, $post_id ) {
        if ( 'emp_con_number' === $column ) {
            $raw = get_post_meta($post_id, self::META_KEY, true);
            echo $raw ? esc_html( $this->format_number((int)$raw) ) : '—';
        }
    }

    public function enable_search_by_custom_number( $vars ) {
        global $pagenow, $typenow;
        if ( 'edit.php' === $pagenow && 'shop_order' === $typenow && ! empty($_GET['s']) ) {
            $term = trim(wp_unslash($_GET['s']));

            // 1) Si es solo dígitos, busca por número crudo.
            if ( ctype_digit($term) ) {
                $order_id = $this->get_order_id_by_custom_number( (int) $term );
                if ( $order_id ) {
                    $vars['post__in'] = [$order_id];
                    $vars['s'] = '';
                    return $vars;
                }
            }

            // 2) Intentar “prefijo + número + sufijo”
            $prefix = (string) get_option(self::OPTION_PREFIX, '');
            $suffix = (string) get_option(self::OPTION_SUFFIX, '');

            $p = preg_quote($prefix, '/');
            $s = preg_quote($suffix, '/');
            $pattern = '/^' . $p . '(\d+)' . $s . '$/';

            if ( preg_match($pattern, $term, $m) ) {
                $num = (int) $m[1];
                $order_id = $this->get_order_id_by_custom_number( $num );
                if ( $order_id ) {
                    $vars['post__in'] = [$order_id];
                    $vars['s'] = '';
                }
            }
        }
        return $vars;
    }

    private function get_order_id_by_custom_number( $number ) {
        global $wpdb;
        $meta = $wpdb->get_var( $wpdb->prepare(
            "SELECT post_id FROM {$wpdb->postmeta} WHERE meta_key = %s AND meta_value = %s LIMIT 1",
            self::META_KEY,
            (string) $number
        ) );
        return $meta ? (int) $meta : 0;
    }
}
new EMP_Custom_Order_Numbering();
endif;