Close/CLOSE #13739 Product API route added to get product stock

Using GET /products/{id}/stock user can get product stock from all warehouses. Using warehouse id will get stock of warehouse given.

htdocs/product/class/api_products.class.php

@@ -1793,6 +1793,50 @@ class Products extends DolibarrApi
 		return $result;
 	}
 
+	/**
+	 * Get stock data for the product id given. 
+	 * Optionaly with $selected_warehouse_id parameter user can get stock of specific warehouse
+	 *
+	 * @param  int $id ID of Product
+	 * @param  int $selected_warehouse_id ID of warehouse
+	 * @return int
+	 *
+	 * @throws RestException 500
+	 * @throws RestException 401
+	 * @throws RestException 404
+	 *
+	 * @url GET {id}/stock
+	 */
+	public function getStock($id,$selected_warehouse_id=null){
+
+		if (!DolibarrApiAccess::$user->rights->produit->lire) {
+			throw new RestException(401);
+		}
+
+		if (!DolibarrApi::_checkAccessToResource('product', $id)) {
+			throw new RestException(401, 'Access not allowed for login '.DolibarrApiAccess::$user->login);
+		}		
+
+		$product_model = new Product($this->db);
+		$product_model->fetch($id);
+		$product_model->load_stock();
+
+		$stockData = $this->_cleanObjectDatas($product_model)->stock_warehouse;
+		if($selected_warehouse_id){
+			foreach($stockData as $warehouse_id => $warehouse){
+				if($warehouse_id != $selected_warehouse_id){
+					unset($stockData[$warehouse_id]);
+				}
+			}
+		}
+
+		if(empty($stockData)){
+			throw new RestException(404, 'No stock found');
+		}
+
+		return ['stock_warehouses'=>$stockData];
+	}
+
 	// phpcs:disable PEAR.NamingConventions.ValidFunctionName.PublicUnderscore
 	/**
 	 * Clean sensible object datas