hrynco-notification-service/HrynCo.NotificationService.Services/EmailChannels/TestSmtp/TestSmtpHandler.cs

using System.Net;
using System.Net.Mail;
using HrynCo.NotificationService.DAL.Abstract;
using HrynCo.NotificationService.Services.Core;
using HrynCo.NotificationService.Services.Logging;
using static HrynCo.NotificationService.Services.Core.ServiceResultHelper;

namespace HrynCo.NotificationService.Services.EmailChannels.TestSmtp;

internal sealed class TestSmtpHandler
    : RequestHandler<TestSmtpCommand, ServiceResult<Unit>>
{
    public TestSmtpHandler(
        IContextualSerilogLogger<TestSmtpCommand> logger,
        IUnitOfWork unitOfWork)
        : base(logger, unitOfWork)
    {
    }

    protected override async Task<ServiceResult<Unit>> DoOnHandle(
        TestSmtpCommand request, CancellationToken cancellationToken)
    {
        try
        {
            using var client = new SmtpClient(request.Host, request.Port)
            {
                EnableSsl = request.UseSsl,
                Credentials = string.IsNullOrWhiteSpace(request.Username)
                    ? null
                    : new NetworkCredential(request.Username, request.Password)
            };

            using var mail = new MailMessage
            {
                From = new MailAddress(request.FromEmail, request.FromName),
                Subject = "✅ Test email from Notification Service",
                Body = "<p>This is a test email sent from the <b>Notification Service</b> admin panel to verify the channel settings.</p>",
                IsBodyHtml = true
            };
            mail.To.Add(new MailAddress(request.ToEmail));

            await client.SendMailAsync(mail, cancellationToken);
        }
        catch (Exception ex)
        {
            Logger.Error(ex, "Ad-hoc SMTP test failed for host {Host}", request.Host);
            return Failure<Unit>(ex.Message);
        }

        return Success(Unit.Value);
    }
}