using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.ServiceProcess;
using System.Text;
using System.Runtime.InteropServices;
using System.Timers;

namespace Watchdog
{


	public partial class Watchdog : ServiceBase
	{
		public enum ServiceState
		{
				SERVICE_STOPPED = 0x00000001,
				SERVICE_START_PENDING = 0x00000002,
				SERVICE_STOP_PENDING = 0x00000003,
				SERVICE_RUNNING = 0x00000004,
				SERVICE_CONTINUE_PENDING = 0x00000005,
				SERVICE_PAUSE_PENDING = 0x00000006,
				SERVICE_PAUSED = 0x00000007,
		}

		[StructLayout(LayoutKind.Sequential)]
		public struct ServiceStatus
		{
				public int dwServiceType;
				public ServiceState dwCurrentState;
				public int dwControlsAccepted;
				public int dwWin32ExitCode;
				public int dwServiceSpecificExitCode;
				public int dwCheckPoint;
				public int dwWaitHint;
		};

	  private EventLog eventLog=null;
		private Timer timer=null;
		private int eventId=1;
		public Watchdog()
		{
			InitializeComponent(); 

			eventLog = new System.Diagnostics.EventLog();
			if (!System.Diagnostics.EventLog.SourceExists("WatchdogSource"))
			{
					System.Diagnostics.EventLog.CreateEventSource(
							"WatchdogSource","WatchdogLog");
			}
			eventLog.Source = "WatchdogSource";
			eventLog.Log = "WatchdogLog";
		}
		[DllImport("advapi32.dll", SetLastError = true)]
		private static extern bool SetServiceStatus(System.IntPtr handle, ref ServiceStatus serviceStatus);
		protected override void OnStart(string[] args)
		{
			ServiceStatus serviceStatus = new ServiceStatus();
			serviceStatus.dwCurrentState = ServiceState.SERVICE_START_PENDING;
			serviceStatus.dwWaitHint = 100000;
			SetServiceStatus(this.ServiceHandle, ref serviceStatus);

		  eventLog.WriteEntry("Watchdog OnStop");

			timer = new Timer();
			timer.Interval = 1000; // 60 seconds
			timer.Elapsed += new ElapsedEventHandler(this.OnTimer);
			timer.Start();

			serviceStatus.dwCurrentState = ServiceState.SERVICE_RUNNING;
			SetServiceStatus(this.ServiceHandle, ref serviceStatus);
		}

		protected override void OnStop()
		{
			ServiceStatus serviceStatus = new ServiceStatus();
			serviceStatus.dwCurrentState = ServiceState.SERVICE_STOP_PENDING;
			serviceStatus.dwWaitHint = 100000;
			SetServiceStatus(this.ServiceHandle, ref serviceStatus);

		  eventLog.WriteEntry("Watchdog OnStop");

			serviceStatus.dwCurrentState = ServiceState.SERVICE_STOPPED;
			SetServiceStatus(this.ServiceHandle, ref serviceStatus);
		}
		protected override void OnContinue()
		{
		  eventLog.WriteEntry("Watchdog OnContinue");
		}

		private void OnTimer(Object sender,ElapsedEventArgs elapsedEventArgs)
		{
		  if(1==eventId)timer.Interval=60000;
		  eventLog.WriteEntry(String.Format("Watchdog monitoring: {0}",eventId++));
		  List<ManagedProcess> managedProcessList=null;
			managedProcessList=ProcessManager.GetManagedProceses(); 
			ProcessManager.ManageProcesses(managedProcessList, eventLog);

		}
	}
}