How to create a new product from a custom form and then add it to the cart?

I am trying to develop a custom page on PS 1.6 where a customer could create a new product from a form and then add it to the cart.

Let's say for example, i am selling woodcrafts and i want my customers to fill a form where they need to specify the type of wood, dimensions, ... Depending on these criterias, the price would be modified and it will create a "final" product that will be added to the customer's cart.

I know how i will develop the form and i believe i can add the product to the cart with updateQty() from Cart.php but how do i instanciate my product from the data i get from the form? I am trying to search through all files but i can't seem to find where new products are instanciated from.

Thanks in advance for the help

I'm answering my question since i managed to do it. Here's my solution :

public static function créerProduct($name, $ean13, $category, $price, $description, $reference){
    $product = new Product();
    $languages=Language::getLanguages();
    foreach($languages as $lang){
        $product->name[$lang['id_lang']]=$name;
        $product->link_rewrite[$lang['id_lang']]=$name;
        $product->description[$lang['id_lang']]=$description;
    }
    $product->reference=$reference;
    $product->quantity=0;
    $product->id_category_default=$category;
    $product->id_category[]=$product->id_category_default;
    $product->price=$price;
    $product->id_tax_rules_group=1;
    $product->indexed=0;
    try{
        $product->save();
        } catch (PrestaShopException $e){
        echo $e->displayMessage();
        }
    $product->updateCategories(array_map('intval', $product->id_category));
    StockAvailable::setQuantity($product->id,'',1);
    return $product->id;
}

public static function addProduitauPanier($id_product){
    $context=Context::getContext();
    $result=$context->cart->updateQty(1,$id_product);
}