using System;

LogFile.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using DnsUpdater.ExtensionsMethods;

namespace DnsUpdater
{
    public enum LogSeverity
    {
        INFO,
        ERROR,
        SUCCESS,
        FAILURE,
        IP_CHANGED
    }
    
    class LogFile
    {
        public delegate void Log(string value);
        public string LogFilePath { get { return _logFilePath; } }
        private string _logFilePath { get; set; }

        public LogFile(string logFilePath)
        {
            _logFilePath = logFilePath;
        }

        public void LogWriter(Log logFunction, string value)
        {
            logFunction(value);
        }

        public void WriteInfo(string entry)
        {
            File.AppendAllText(
                _logFilePath,
                entry.AddLogFileTimestamp(LogSeverity.INFO)
                );
        }
    }
}

namespace DnsUpdater.ExtensionsMethods
{
    public static class ToTimestamps
    {
        public static string AddLogFileTimestamp(this String str, LogSeverity severity)
        {
            return string.Format(
                "[[{0}][{1}]] {2}",
                severity,
                DateTime.Now.ToString("MM/dd/yyyy@hh:mm:sstt"),
                str
                ) + Environment.NewLine;
        }
    }
}