using System;

using System.Collections.Generic;



namespace MoreTerra.Utilities

{

	public class Profiler

	{

		private Dictionary<Int32, String> openIDs;

		private Dictionary<String, Dictionary<Int32, pTimeSpan>> profileList;

		private Int32 currentID;



		#region Helper Structures

		class pTimeSpan

		{

			public DateTime Start;

			public DateTime End;

			public String Note;



			public pTimeSpan(DateTime newDateTime, String newNote)

			{

				Start = newDateTime;

				End = new DateTime(0);



				if (String.IsNullOrEmpty(newNote))

					Note = newNote;

				else

					Note = "";

			}



			public TimeSpan Elapsed()

			{

				if (End.CompareTo(Start) < 0)

					return new TimeSpan(0);



				return End - Start;

			}

		}

		#endregion



		#region Constructors

		public Profiler()

		{

			openIDs = new Dictionary<Int32, String>();

			profileList = new Dictionary<String, Dictionary<Int32, pTimeSpan>>();

			currentID = 0;

		}

		#endregion



		public void Clear()

		{

			openIDs.Clear();

			profileList.Clear();

			currentID = 0;

		}



		public Int32 Start(String pName, String useNote = null)

		{

			pTimeSpan pts = new pTimeSpan(DateTime.Now, useNote);



			openIDs.Add(currentID, pName);



			if (profileList.ContainsKey(pName) == false)

				profileList[pName] = new Dictionary<Int32, pTimeSpan>();



			profileList[pName].Add(currentID, pts);



			return ++currentID;

		}



		public void Stop(Int32 id)

		{

			String pName;

			Dictionary<Int32, pTimeSpan> pList;



			if (openIDs.ContainsKey(id) == false)

				//              Throw exception.

				return;



			pName = openIDs[id];



			if (profileList.ContainsKey(pName) == false)

				//				Throw exception.

				return;



			pList = profileList[pName];



			if (pList.ContainsKey(id) == false)

				//				Throw exception.

				return;



			pList[id].End = DateTime.Now;



			openIDs.Remove(id);

		}



		public void Stop(String pName)

		{

			Int32 lastID = -1;



			// We really should walk the tree backwards.

			foreach (KeyValuePair<Int32, String> kvp in openIDs)

			{

				if (kvp.Value == pName)

					lastID = kvp.Key;

			}



			if (lastID == -1)

				// Throw Exception.

				return;





			Stop(lastID);

		}



		public TimeSpan Total(String pName)

		{

			TimeSpan t = new TimeSpan(0);

			Dictionary<Int32, pTimeSpan> pList;



			if (profileList.ContainsKey(pName) == false)

				// Throw exception.

				return t;



			pList = profileList[pName];



			foreach (KeyValuePair<Int32, pTimeSpan> kvp in pList)

			{

				t += kvp.Value.Elapsed();

			}



			return t;

		}



		#region Overrides

		public override string ToString()

		{

			String returnVal = "";



			foreach (KeyValuePair<String, Dictionary<Int32, pTimeSpan>> kvp in profileList)

			{

				returnVal = returnVal + kvp.Key + " : " + Total(kvp.Key).ToString() + Environment.NewLine;

			}



			return returnVal;

		}

		#endregion

	}

}