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

namespace Benchmarking {
	/// <summary>
	/// Make sure you compile in Release with optimizations enabled, and Run the
	/// tests outside of Visual Studio (This part is important because the JIT
	/// stints its optimizations with a debugger attached, even in Release mode).
	/// </summary>
	static public class Profiler {
		static public double Profile(string desc, uint iterations, Action func) {
			//Run at highest priority to minimize fluctuations caused by others 
			Process.GetCurrentProcess().PriorityClass = ProcessPriorityClass.High;
			Thread.CurrentThread.Priority = ThreadPriority.Highest;

			// Warm up 
			func();

			// Clean up
			GC.Collect();
			GC.WaitForPendingFinalizers();
			GC.Collect();//To make sure the "finalized" objects are also collected.

			var watch = Stopwatch.StartNew();
			for (uint i = 0; i < iterations; i++) {
				func();
			}
			watch.Stop();
			double elapsedTime = watch.Elapsed.TotalMilliseconds;
			if (desc != null) Console.WriteLine("{0,-40}\t{1,15:n} ms", desc,
			elapsedTime);
			return elapsedTime;
		}

		static public double Profile(string desc, uint iterations, Action func,
				out int gcCount) {
			Process.GetCurrentProcess().PriorityClass = ProcessPriorityClass.High;
			Thread.CurrentThread.Priority = ThreadPriority.Highest;

			func();

			GC.Collect();
			GC.WaitForPendingFinalizers();
			GC.Collect();

			gcCount = GC.CollectionCount(0);
			var watch = Stopwatch.StartNew();
			for (uint i = 0; i < iterations; i++) {
				func();
			}
			watch.Stop();
			gcCount = GC.CollectionCount(0) - gcCount;
			double elapsedTime = watch.Elapsed.TotalMilliseconds;
			if (desc != null) Console.WriteLine("{0,-40}\t{1,15:n} ms",
			  desc, elapsedTime);
			return elapsedTime;
		}
	}
}