hrynco-notification-service/HrynCo.NotificationService.Web.IntegrationTests/RecordingAdminSmtpMediator.cs

using System.Reflection;
using HrynCo.NotificationService.DAL.Abstract.Providers;
using HrynCo.NotificationService.Services.Core;
using HrynCo.NotificationService.Services.EmailChannels.Get;
using HrynCo.NotificationService.Services.EmailChannels.TestSmtp;
using MediatR;
using ServiceUnit = HrynCo.NotificationService.Services.Core.Unit;

namespace HrynCo.NotificationService.Web.IntegrationTests;

public class RecordingAdminSmtpMediator : DispatchProxy
{
    public EmailChannel? Channel { get; set; }
    public TestSmtpCommand? SentCommand { get; private set; }
    public int LookupCount { get; private set; }

    protected override object Invoke(MethodInfo? targetMethod, object?[]? args)
    {
        if (targetMethod?.Name != nameof(IMediator.Send) || args?.Length is null or 0)
            throw new NotSupportedException();

        return args[0] switch
        {
            GetEmailChannelQuery => RecordLookup(),
            TestSmtpCommand command => RecordSend(command),
            _ => throw new NotSupportedException()
        };
    }

    private Task<ServiceResult<EmailChannel>> RecordLookup()
    {
        LookupCount++;
        return Task.FromResult(Channel is null
            ? ServiceResult<EmailChannel>.Failure("Channel not found.")
            : ServiceResult<EmailChannel>.Success(Channel));
    }

    private Task<ServiceResult<ServiceUnit>> RecordSend(TestSmtpCommand command)
    {
        SentCommand = command;
        return Task.FromResult(ServiceResult<ServiceUnit>.Success(ServiceUnit.Value));
    }
}