using System;
using System.Diagnostics;
using System.Security;
using System.Threading;

namespace HeuristicLab.Services.Hive.Common {
  public class LogFactory {
    public static ILogger GetLogger(string source) {
      return new Logger("HL.Hive", source);
    }
  }

  public interface ILogger {
    void Log(string message);
    void Error(Exception e);
  }

  internal class Logger : ILogger {
    private EventLog log;

    /// <summary>
    /// Creating an EventSource requires certain permissions, which by default a IIS AppPool user does not have.
    /// In this case just ignore security exceptions.
    /// In order to make this work, the eventsource needs to be created manually
    /// </summary>
    public Logger(string name, string source) {
      try {
        if (!EventLog.SourceExists(source)) {
          EventLog.CreateEventSource(source, name);
        }
        log = new EventLog(name);
        log.Source = source;
      }
      catch (SecurityException) { }
    }

    public void Log(string message) {
      try {
        if (log != null) {
          log.WriteEntry(string.Format("{0} (AppDomain: {1}, Thread: {2})", message, AppDomain.CurrentDomain.Id, Thread.CurrentThread.ManagedThreadId), EventLogEntryType.Information);
        }
      }
      catch (SecurityException) { }
    }

    public void Error(Exception e) {
      try {
        if (log != null) {
          log.WriteEntry(string.Format("{0} (AppDomain: {1}, Thread: {2})", e.Message, AppDomain.CurrentDomain.Id, Thread.CurrentThread.ManagedThreadId), EventLogEntryType.Error);
        }
      }
      catch (SecurityException) { }
    }
  }
}