Do not allow smartstone skus to be added to cart without character selection (#168)

Current behavior (before this PR, as my mistake and lack of knowledge)
smartstone can be added to cart without selecting a character (from the
catologue of costumes or others from the smartstone), which leads people
buying costumes and not getting them because there's no character
associated. This fixes the current issue for the current implementation
(for character unlock the service, if this get changed to account bound,
we change smartstone impelemtnation then).

This will redirect them to the page (of "add cart") and ask them to
select the character

This is hasn't be tested, and can't test it for now.

And i tried submitting this fix on the same night of invesgiating, I
couldn't update `acore-cms` within my `chormiecraft-cms` in my WSL, lack
of linux and git together maybe.

---------

Co-authored-by: Yehonal <[email protected]>
Co-authored-by: Copilot <[email protected]>

Author: 3 people

src/acore-wp-plugin/src/Hooks/WooCommerce/Smartstone.php

@@ -26,6 +26,30 @@ public static function init() {
         add_action('woocommerce_checkout_order_processed', self::sprefix() . 'checkout_order_processed', 20, 2);
         add_action('woocommerce_add_order_item_meta', self::sprefix() . 'add_order_item_meta', 1, 3);
         add_action('woocommerce_payment_complete', self::sprefix() . 'payment_complete');
+        add_action('woocommerce_add_to_cart_validation', [__CLASS__, 'add_to_cart_validation'], 10, 5);
+    }
+
+     // Validator for add to cart from external sources (no character selected) or logged in required from "CartValidation")    
+    public static function add_to_cart_validation($passed, $product_id, $quantity, $variation_id = null, $variations = null) {
+        $product = $variation_id ? \wc_get_product($variation_id) : \wc_get_product($product_id);
+        $sku = $product->get_sku();
+        if (strpos($sku, 'smartstone') !== 0) {
+            return $passed;
+        }
+
+        $current_user = wp_get_current_user();
+        if (!is_user_logged_in()) {
+            \wc_add_notice(__('You must be logged in to buy it!', 'acore-wp-plugin'), 'error');
+            return false;
+        }
+
+        $guid = intval($_REQUEST['acore_char_sel'] ?? 0);
+        if ($guid === 0) {
+            \wc_add_notice(__('No character selected. Please select a character and try again.', 'acore-wp-plugin'), 'error');
+            return false;
+        }
+
+        return $passed;
     }
 
     // LIST