public async Task <IActionResult> UpdateCoupon(string couponId, [FromBody] CouponForModalDto input)
        {
            if (ModelState.IsValid)
            {
                var couponInDB = await _couponService.GetCouponById(couponId);

                if (couponInDB == null)
                {
                    return(NotFound(couponId));
                }

                var result = await _couponService.UpdateCoupon(_mapper.Map(input, couponInDB));

                if (result)
                {
                    return(Ok());
                }
            }
            return(BadRequest(ModelState));
        }
        public async Task <IActionResult> CreateCoupon([FromBody] CouponForModalDto input)
        {
            if (ModelState.IsValid)
            {
                var couponInDB = await _couponService.GetCouponById(input.CouponID);

                if (couponInDB != null)
                {
                    return(BadRequest(new { message = "Coupon already exists" }));
                }
                var coupon = _mapper.Map <Coupon>(input);
                var result = await _couponService.CreateCoupon(coupon);

                if (result)
                {
                    return(Ok());
                }
            }
            return(BadRequest(new { message = ModelState.Values.First().Errors[0].ErrorMessage }));
        }