How to get "id_image" of CoverImage for each Shops

[aleh250]

By saving Product in context "All Shops" I want to get id_image of "CoverImage" of "this"-product for each shop.

For instance we have Multistore of 3 Shops, each of shops has Product_id "8" but with diferent Cover Image. (id_image: 23,35,36)

Edit product "8" in context "All Shops" and Save:

public function hookActionProductUpdate()
{
...
    if (Shop::getContext() == Shop::CONTEXT_SHOP) {
        $shops[] = $this->context->shop->id;
    } else {
        foreach (Shop::getCompleteListOfShopsID() as $key => $shop) {
            $shops[] = (int)$shop;
        }
    }
    ...
    foreach ($shops as $key => $id_shop) {
        ...
        $image = Product::getCover((int)($id_product));
        $params = array(
            'id_image' => (int)$image['id_image'],
        ...
    ...
    }
...
}

But this code returns the same id_image of CoverImage. (for first(default) Shop)

Can someone help?
Thanks in advance.

[aleh250]

function getCover in Product.php:

public static function getCover($id_product, Context $context = null)

Someone know what should be second parameter ($context) ? I tried pass there $id_shop, but nothing changed