public JsonResult AddCoffeeDevice(string appUserId)
        {
            Random       random       = new Random();
            CoffeeDevice coffeeDevice = new CoffeeDevice()
            {
                Id                  = Guid.NewGuid(),
                AppUserId           = appUserId,
                CurrentCoffeeAmount = random.Next(0, 100),
                CurrentMilkAmount   = random.Next(0, 100),
                CurrentWaterAmount  = random.Next(0, 100)
            };

            bool isAdded = _coffeeRepository.AddCoffeeDevice(coffeeDevice);

            if (isAdded)
            {
                return(new JsonResult(new { message = "ok", coffeDeviceState = GetCurrentUserCoffeeDeviceState(appUserId) }));
            }
            else
            {
                return(new JsonResult(new { message = "error", coffeDeviceState = GetCurrentUserCoffeeDeviceState(appUserId) }));
            }
        }