Woocommerce. Show a message if the user bought product but didn't leave a review (does not work for variable products)

I use the code (Thanks to the author of the code):Check if customer wrote a review for a product in Woocommerce It works great only for a simple product. Unfortunately, if a variable product was purchased, the message is not shown.

For example: T-shirt in different sizes. 40, 41, 42. The client bought size 41. But when he goes to the product card to write a review, he does not see the message. (I tried setting or clearing the default size value - but it doesn't help)

Can you please tell me how to display a message for variable products too? Thanks for the help.

The code I am using

// Utility function to check if a customer has posted a review in a product
function has_reviewed_product( $product_id ) {
    global $wpdb;

    $user = wp_get_current_user();

    if( $user->ID == 0 )
        return false;

    // Count the number of products
    $count = $wpdb->get_var( "
        SELECT COUNT(comment_ID) FROM {$wpdb->prefix}comments
        WHERE comment_post_ID = $product_id
        AND comment_author_email = '{$user->user_email}'
    " );

    return $count > 0 ? true : false;
}
// Utility function to check if a customer has bought a product (Order with "completed" status only)
function customer_has_bought_product( $product_id, $user_id = 0 ) {
    global $wpdb;
    $customer_id = $user_id == 0 || $user_id == '' ? get_current_user_id() : $user_id;
    $status      = 'wc-completed';

    if( ! $customer_id )
        return false;

    // Count the number of products
    $count = $wpdb->get_var( "
        SELECT COUNT(woim.meta_value) FROM {$wpdb->prefix}posts AS p
        INNER JOIN {$wpdb->prefix}postmeta AS pm ON p.ID = pm.post_id
        INNER JOIN {$wpdb->prefix}woocommerce_order_items AS woi ON p.ID = woi.order_id
        INNER JOIN {$wpdb->prefix}woocommerce_order_itemmeta AS woim ON woi.order_item_id = woim.order_item_id
        WHERE p.post_status = '$status'
        AND pm.meta_key = '_customer_user'
        AND pm.meta_value = $customer_id
        AND woim.meta_key IN ( '_product_id', '_variation_id' )
        AND woim.meta_value = $product_id
    " );

    // Return a boolean value if count is higher than 0
    return $count > 0 ? true : false;
}

add_action( 'woocommerce_before_single_product_summary', 'woo_review_discount_message');
function woo_review_discount_message() {
    global $product;

    if ( customer_has_bought_product( $product->get_id() ) && ! $product->is_type('variable') && ! has_reviewed_product( $product->get_id() ) ) {
        $user = wp_get_current_user();
        echo '<div class="user-bought"><span style="color:#CA364D;font-weight:bold;font-size:18px;"><i class="wishlist-icon icon-heart-o"></i></span> Hi ' . $user->first_name . '! Please write a review below.</a></div>';
    }
}

The reason your code does not show the message for variable products is because of the && ! $product->is_type('variable'). This means that only not (!) variable products will display the message. My best guess is to remove the && ! $product->is_type('variable') part.

Hope this helps!