NLogSink for Avalonia

NLogSink.cs

using Avalonia.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using NLog;
using Splat;
using NLog.Fluent;
using DynamicData.Binding;

namespace Logging
{
    public class NLogSink : ILogSink
    {
        private readonly LogEventLevel _level;
        private readonly IList<string>? _areas;

        public NLogSink(
            LogEventLevel minimumLevel,
            IList<string>? areas = null)
        {
            _level = minimumLevel;
            _areas = areas?.Count > 0 ? areas : null;
        }

        public bool IsEnabled(LogEventLevel level, string area)
        {
            return level >= _level && (_areas?.Contains(area) ?? true);
        }

        public void Log(LogEventLevel level, string area, object? source, string messageTemplate)
        {
            if (IsEnabled(level, area))
            {
                NLog.ILogger? logger = null;
                if (source is not null)
                    logger = Resolve(source.GetType());
                else
                    logger = Resolve(typeof(NLogSink));

                logger.Log(LogLevelToNLogLevel(level), $"{area}: {messageTemplate}");
            }
        }

        public void Log(LogEventLevel level, string area, object? source, string messageTemplate, params object?[] propertyValues)
        {
            if (IsEnabled(level, area))
            {
                NLog.ILogger? logger = null;
                if (source is not null)
                    logger = Resolve(source.GetType());
                else
                    logger = Resolve(typeof(NLogSink));

                logger.Log(LogLevelToNLogLevel(level), $"{area}: {messageTemplate}", propertyValues);
            }
        }

        private const int MaxCacheSize = 16;
        private static readonly MemoizingMRUCache<Type, NLog.ILogger> _loggerCache = new(
            (type, _) => LogManager.GetLogger(type.ToString()),
            MaxCacheSize);

        public static NLog.ILogger Resolve(Type type) => _loggerCache.Get(type, null);

        private static NLog.LogLevel LogLevelToNLogLevel(LogEventLevel level)
        {
            switch (level)
            {
                case LogEventLevel.Verbose:
                    return NLog.LogLevel.Trace;
                case LogEventLevel.Debug:
                    return NLog.LogLevel.Debug;
                case LogEventLevel.Information:
                    return NLog.LogLevel.Info;
                case LogEventLevel.Warning:
                    return NLog.LogLevel.Warn;
                case LogEventLevel.Error:
                    return NLog.LogLevel.Error;
                case LogEventLevel.Fatal:
                    return NLog.LogLevel.Fatal;
                default:
                    return NLog.LogLevel.Trace;
            }
        }
    }
    public static class NLogSinkExtensions
    {
        public static AppBuilder LogToNLog(
            this AppBuilder builder,
            LogEventLevel level = LogEventLevel.Warning,
            params string[] areas)
        {
            Logger.Sink = new NLogSink(level, areas);
            return builder;
        }
    }
}