using System.Reactive.Linq;

namespace InnovEnergy.VenusLogger;

internal static class ObservableExtensions
{
    public static IObservable<R> TrySelect<T, R>(this IObservable<T> source, Func<T, R> map) where R : notnull
    {
        return source
              .Select(e => Try(map, e))
              .OfType<R>();
    }

    public static IEnumerable<R> TrySelect<T, R>(this IEnumerable<T> source, Func<T, R> map) where R : notnull
    {
        return source
              .Select(e => Try(map, e))
              .OfType<R>();
    }

    public static IObservable<R> TrySelect<T, R>(this IObservable<T> source, Func<T, R> map, R onError) where R : notnull
    {
        return source
              .Select(e => Try(map, e))
              .Select(e => e is R r ? r : onError);
    }

    public static IEnumerable<R> TrySelect<T, R>(this IEnumerable<T> source, Func<T, R> map, R onError) where R : notnull
    {
        return source
              .Select(e => Try(map, e))
              .Select(e=>e is R r ? r : onError);
    }

    private static Object Try<T, R>(Func<T, R> map, T e) where R : notnull
    {
        try
        {
            return map(e);
        }
        catch (Exception ex)
        {
            return ex;
        }
    }
}