using System;
using System.ComponentModel;

namespace jive
{
  public class WorkerThread : Component, IWorkerThread
  {
    static readonly object do_work_key = new object();
    bool is_running;
    readonly Action background_thread;

    public WorkerThread()
    {
      background_thread = worker_thread_start;
    }

    public event DoWorkEventHandler DoWork
    {
      add { Events.AddHandler(do_work_key, value); }
      remove { Events.RemoveHandler(do_work_key, value); }
    }

    public void begin()
    {
      if (is_running)
      {
        throw new InvalidOperationException("Worker Thread Is Already Running");
      }
      is_running = true;
      background_thread.BeginInvoke(null, null);
    }

    void worker_thread_start()
    {
      try
      {
        var handler = (DoWorkEventHandler) Events[do_work_key];
        if (handler != null)
        {
          handler(this, new DoWorkEventArgs(null));
        }
      }
      catch (Exception e)
      {
        this.log().error(e);
      }
    }
  }
}