public async Task ReportErrorsWhenDatesAreInvalid()
        {
            // arrage
            var mediator = new Mock<IMediator>();
            var validator = new CampaignSummaryModelValidator(mediator.Object);
            var model = new CampaignSummaryModel
            {
                StartDate = new DateTimeOffset(new DateTime(2000, 1, 1)),
                EndDate = new DateTimeOffset(new DateTime(1999, 1, 1))
            };

            // act
            var errors = await validator.Validate(model);

            // assert
            Assert.True(errors.ContainsKey("EndDate"));
        }
        public async Task ReportErrorsWhenPostalCodeIsInvalid()
        {
            // arrange
            var mediator = new Mock<IMediator>();
            mediator.Setup(m => m.SendAsync(It.IsAny<CheckValidPostcodeQueryAsync>())).ReturnsAsync(false);

            var validator = new CampaignSummaryModelValidator(mediator.Object);
            var model = new CampaignSummaryModel
            {
                Location = new LocationEditModel { PostalCode = "90210" }
            };

            // act
            var errors = await validator.Validate(model);

            // assert
            mediator.Verify(m => m.SendAsync(It.IsAny<CheckValidPostcodeQueryAsync>()));
            Assert.True(errors.ContainsKey("PostalCode"));
        }
        public async Task<IActionResult> Edit(CampaignSummaryModel campaign, IFormFile fileUpload)
        {
            if (campaign == null)
            {
                return HttpBadRequest();
            }

            if (!User.IsOrganizationAdmin(campaign.OrganizationId))
            {
                return HttpUnauthorized();
            }
            
            var validator = new CampaignSummaryModelValidator(_mediator);
            var errors = await validator.Validate(campaign);
            errors.ToList().ForEach(e => ModelState.AddModelError(e.Key, e.Value));

            if (ModelState.IsValid)
            {
                if (fileUpload != null)
                {
                    if (fileUpload.IsAcceptableImageContentType())
                    {
                        campaign.ImageUrl = await _imageService.UploadCampaignImageAsync(campaign.OrganizationId, campaign.Id, fileUpload);
                    }
                    else
                    {
                        ModelState.AddModelError("ImageUrl", "You must upload a valid image file for the logo (.jpg, .png, .gif)");
                        return View(campaign);
                    }
                }

                var id = await _mediator.SendAsync(new EditCampaignCommand { Campaign = campaign });

                return RedirectToAction(nameof(Details), new { area = "Admin", id = id });
            }

            return View(campaign);
        }