prestashop update meta title , description and image tag

<?php
if (!defined('_PS_ADMIN_DIR_')) {
    define('_PS_ADMIN_DIR_', __DIR__);
}
include _PS_ADMIN_DIR_.'/../config/config.inc.php';

$id_lang=2;
$start=3001;
$limit=4000;
$order_by='id_product';
$order_way='DESC';
$id_category = false; 
$only_active =true;
$context = null;

$all_products=Product::getProducts($id_lang, $start, $limit, $order_by, $order_way, $id_category,$only_active ,  $context );

foreach ($all_products as $keyall_products => $valueall_products) {
	echo $valueall_products['id_product'];
	$product = new Product($valueall_products['id_product'], false, $id_lang);
	//if($valueall_products['id_product']==32611){
	/*echo "<pre>";
	print_r($product->name);
	echo "</pre>";*/
	$product->description=$product->name;
	$product->meta_description=$product->name;
	$product->save();
	$productImages = $product->getImages((int) $id_lang);
	//$image = Image::getCover($valueall_products['id_product']);
	//print_r($productImages);
	if(!empty($productImages)){
		foreach($productImages as $val_productImages){
			$sql = 'UPDATE '._DB_PREFIX_.'image_lang SET legend="'.pSQL($product->name).'" WHERE id_image='.$val_productImages['id_image'];
			if (!Db::getInstance()->execute($sql))
			    die('error!');
		}
	}
	
	//}
}