Przerobienie kodu smarty do php prestashop

Witam, posiadam działający kod w smarty w pliku tpl.

potrzebuje go przerobić aby działał w pliku php danego modułu.

Poniżej zamiszczam kod w smarty:

{$db = Db::getInstance()}

{$flag = 0}

{foreach $products as $product}

{$flag = $flag + 1}

{assign var='productId' value=$product.id_product}

{*Height*}

{$sql = "SELECT height FROM ps_product WHERE id_product = $productId"}

{assign var='height' value=$db->getValue($sql)}

{*/Height*}

{*Width*}

{$sql = "SELECT width FROM ps_product WHERE id_product = $productId"}

{assign var='width' value=$db->getValue($sql)}

{*/Width*}

{*DEPTH*}

{$sql = "SELECT depth FROM ps_product WHERE id_product = $productId"}

{assign var='depth' value=$db->getValue($sql)}

{*/DEPTH*}

{assign var='quantity' value=$product.cart_quantity-$ quantityDisplayed}

{assign var='capacity' value=$height*$width*$depth}

{$Arrayquantity.$flag = $quantity}

{$ArrayCapacity.$flag = $capacity}

{$weight = $cart->getTotalWeight()|escape:'htmla ll':'UTF-8'|number_format:2}

{/foreach}

{$capacity = 0}

{foreach $ArrayCapacity as $key => $value}

{$capacity = $capacity + $value*$Arrayquantity[$key]/10 00000}

{/foreach}