public async Task <IActionResult> UpdateCartItem(int bookId, [FromBody] CartItemForUserUpdateDto input) { if (ModelState.IsValid) { var userId = GetUserId(); if (userId == "error") { return(Unauthorized()); } var cartItemInDB = await _cartItemService.GetCartItemById(bookId, userId); var result = await _cartItemService.UpdateCartItem(_mapper.Map(input, cartItemInDB)); if (result) { return(RedirectToAction("GetCartItemsByUserId")); } } return(BadRequest(new { message = ModelState.Values.First().Errors[0].ErrorMessage })); }