Watch Dog

using System;
using System.Runtime.InteropServices;
using WatchDogPile;
using System.Diagnostics;


namespace WatchDogPile
{
	#region ProcessStatusEventArgs: Fires when Queue Engine starts or stops
	public class ProcessStatusEventArgs: EventArgs 
	{
		public ProcessStatusEventArgs(Process queueEngineProcess, bool isRunning)
		{
			QueueEngineProcess = queueEngineProcess;
			IsRunning = isRunning;
		}
		public Process QueueEngineProcess;
		public bool IsRunning;
	}    
	#endregion

	/// <summary>
	/// Summary description for AppWrapper.
	/// </summary>
	public class AppWrapper: ITrainingDog
	{
		#region override FindProcess
		/// <summary>
		/// Overrided find the spinning engine process
		/// </summary>
		/// <returns>The first process found with SpinningEngine.exe name </returns>
		public Process FindProcess()
		{
			if(PID>=0)
			{
				try
				{
					Process TheProcess = GetProcessByID();
					if(TheProcess == null)
					{
						OnProcessStatusChangedEvent(this, new ProcessStatusEventArgs( null, false) );
						return null;
					}
					else
					{
						OnProcessStatusChangedEvent(this, new ProcessStatusEventArgs( TheProcess, true) );
						return TheProcess;
					}
				}
				catch(Exception ex)
				{
					Console.Write("ISpin", "FindProcess: "+ex.Message, 
						System.Diagnostics.EventLogEntryType.Error, 0);
					return null;
				}
			}
			else
			{
				OnProcessStatusChangedEvent(this, new ProcessStatusEventArgs( null, false) );
				return null;
			}
		}
		#endregion

		#region override SuspectedSmell
		/// <summary>
		/// Is being used by a watch dog thread
		/// </summary>
		/// <returns>if the process is dead (Suspected) then return null </returns>
		public object SuspectedSmell()
		{
			try
			{
				Process TheProcess = GetProcessByID();
				if(TheProcess==null)
					return (bool)false;
				else
					return null;
			}
			catch
			{
				return (bool)true;
			}
		}
		#endregion 

		#region override StartUp
		public Process StartUp(string theApp2Watch)
		{
			/// Send the process a unique name
			Process p = StartUpProcess(theApp2Watch, "");
			
			// April 12, 05
			OnProcessStatusChangedEvent(this, new ProcessStatusEventArgs( theProcess, true) );

			return p;
		}
		#endregion

		#region override ShutDown
		public void ShutDown()
		{
			b_IsAlive = false;
			if(theProcess!=null)
			{
				if(GetProcessByID()!=null)
					theProcess.Kill();
				OnProcessStatusChangedEvent(this, new ProcessStatusEventArgs( null, false) );
			}
			else
				OnProcessStatusChangedEvent(this, new ProcessStatusEventArgs( theProcess, false) );
		}
		#endregion


		/// <summary>
		/// Is being use to destroy the hidden window in Spinning Engine
		/// </summary>
		/// <param name="hwnd"></param>
		/// <returns></returns>
		[DllImport("user32")] public static extern int SendMessage(int hwnd, int msg, int p1, int p2);
		
		/// <summary>
		/// Aug 27, 05: Bob
		/// </summary>
		protected int PID=-1; /// Process ID associated to this object
		
		protected Process theProcess=null;
		protected bool b_IsAlive=false;

		#region GetProcessByID
		/// <summary>
		/// Return the Process this object is manageing
		/// </summary>
		/// <returns>The process of this object PID</returns>
		protected Process GetProcessByID()
		{
			try
			{
				if(PID<0)
					return null;
				else
					return Process.GetProcessById(PID);
			}
			catch
			{
				return null;
			}
		}

		/// <summary>
		/// Set the PID for an object, It has been used in CCMUtil
		/// </summary>
		/// <param name="thPID"></param>
		public int ProcessID
		{
			get
			{
				return PID;
			}
			set
			{
				if(value<0)
					throw new Exception("Process ID cannot be negative.");
				PID = value;
			}
		}
		#endregion

		#region Process Status Event definitions
		public delegate void ProcessStatusEventHandler(object source, ProcessStatusEventArgs rea);
		public event ProcessStatusEventHandler ProcessStatusChangedEvent;
		protected void OnProcessStatusChangedEvent(object source, ProcessStatusEventArgs rea)
		{
			if(!rea.IsRunning)
			{
				b_IsAlive = false;
				if(theProcess!=null)
				{
					try
					{
						try
						{
							theProcess.Kill();
						}
						catch
						{
						}
					}
					finally
					{
						theProcess = null;
					}
				}
			}
			if(ProcessStatusChangedEvent!=null)
			{
				this.ProcessStatusChangedEvent(source, rea);
			}
		}

		#endregion


		#region IsAlive
		public bool IsAlive
		{
			get
			{
				return b_IsAlive;
			}
		}
		#endregion

		#region Dispose()
		public void Dispose()
		{
			if(theProcess!=null)
			{
				ShutDown();
			}
		}
		#endregion

		#region Process StartUpProcess
		protected Process StartUpProcess(string exe, string cmd)
		{
			try
			{
				if(!b_IsAlive)
				{
					theProcess = Process.Start(exe, cmd);
					PID = theProcess.Id;
					b_IsAlive = true;
				}
				// April 12, 05
				OnProcessStatusChangedEvent(this, new ProcessStatusEventArgs( theProcess, true) );
				return theProcess;
			}
			catch(Exception ex)
			{
				OnProcessStatusChangedEvent(this, new ProcessStatusEventArgs( theProcess, false) );
				Console.Write("CallbackMNethod.InitRemoting", "Cannot start process: "+exe+"\r\n\r\n"+ex.Message, 
					System.Diagnostics.EventLogEntryType.Error, 0);
				//MessageBox.Show ( "Cannot start process: "+exe+"\r\n\r\n"+ex.Message);
				return null;
			}
		}
		#endregion

		#region Initialize()
		public void Initialize(string theApp2Watch)
		{
			theProcess = FindProcess();
			if(theProcess==null)
			{
				theProcess = StartUp(theApp2Watch);
				if(theProcess==null)
					throw new Exception();
			}
		}
		#endregion

		
		public AppWrapper()
		{
			try
			{
				string AppPath = System.IO.Path.GetDirectoryName( System.Reflection.Assembly.GetExecutingAssembly().Location );
				//SAMShareIniFile = new Utils.IniFile(AppPath+@"\SAMShare.ini");
			}
			catch(Exception ex)
			{
				Console.Write("IPCParent", "Constructoe: "+ex.Message, 
					System.Diagnostics.EventLogEntryType.Error, 0);
			}
		}
	}
}