Moamen Elbarky

// Custom Result<T> Monad — Deterministic Control Flow Without Exception Overhead
public readonly struct Result<TValue>
{
    private readonly TValue? _value;
    public bool IsSuccess { get; }
    public Error Error { get; }

    public TValue Value => IsSuccess 
        ? _value! 
        : throw new InvalidOperationException("Cannot access value of a failed result.");

    private Result(TValue value)
    {
        IsSuccess = true;
        _value = value;
        Error = Error.None;
    }

    public static Result<TValue> Success(TValue value) => new(value);
    public static Result<TValue> Failure(Error error) => new(error);
}

// Push-based Outbox Wakeup: PostgreSQL LISTEN/NOTIFY Replaces 500ms Polling
public async Task ListenToOutboxAsync(CancellationToken ct)
{
    await using var connection = new NpgsqlConnection(_connectionString);
    await connection.OpenAsync(ct);
    
    connection.Notification += async (o, e) => {
        // Immediate event-driven dispatch without polling overhead
        await _channelWriter.WriteAsync(e.Payload, ct);
    };

    await using var cmd = new NpgsqlCommand("LISTEN outbox_events_channel;", connection);
    await cmd.ExecuteNonQueryAsync(ct);
}