设置gallery相册字段的第一个图片作为缩略图

function set_featured_image_from_product_gallery() {
    $args = array(
        'post_type'      => 'product',  // Change if using a different post type
        'posts_per_page' => -1,         // Get all products
        'meta_query'     => array(
            array(
                'key'     => 'product_gallery',
                'compare' => 'EXISTS',
            ),
        ),
    );

    $query = new WP_Query($args);

    if ($query->have_posts()) {
        while ($query->have_posts()) {
            $query->the_post();
            $post_id = get_the_ID();
            $gallery = get_post_meta($post_id, 'product_gallery', true);

            if (!empty($gallery) && is_array($gallery)) {
                $image_url = $gallery[0]->Url ?? ''; // Get the first image URL

                if (!empty($image_url)) {
                    $attachment_id = insert_attachment_from_url($image_url, $post_id);
                    if ($attachment_id) {
                        set_post_thumbnail($post_id, $attachment_id);
                    }
                }
            }
        }
        wp_reset_postdata();
    }
}
add_action('init', 'set_featured_image_from_product_gallery');

function insert_attachment_from_url($image_url, $post_id) {
    require_once ABSPATH . 'wp-admin/includes/image.php';
    require_once ABSPATH . 'wp-admin/includes/file.php';
    require_once ABSPATH . 'wp-admin/includes/media.php';

    $image_name = basename($image_url);
    $upload_dir = wp_upload_dir();
    $image_data = file_get_contents($image_url);

    if (!$image_data) {
        return false;
    }

    $file_path = $upload_dir['path'] . '/' . $image_name;
    file_put_contents($file_path, $image_data);

    $file_type = wp_check_filetype($file_path);
    $attachment = array(
        'post_mime_type' => $file_type['type'],
        'post_title'     => sanitize_file_name($image_name),
        'post_content'   => '',
        'post_status'    => 'inherit',
    );

    $attach_id = wp_insert_attachment($attachment, $file_path, $post_id);
    $attach_data = wp_generate_attachment_metadata($attach_id, $file_path);
    wp_update_attachment_metadata($attach_id, $attach_data);

    return $attach_id;
}