using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;

namespace Infrastructure
{
	public class RetardedProfiler
	{
		public static void Reset()
		{
			foreach (var step in steps)
				step.Value.Stopwatch.Stop();

			steps.Clear();
		}

		public static IDisposable Step(string name)
		{
			InternalStep step;
			if (!steps.TryGetValue(name, out step))
			{
				step = new InternalStep(new Stopwatch());
				steps[name] = step;
			}

			step.Count++;
			step.Stopwatch.Start();
			return step;
		}

		public static string GetResults()
		{
			var sorted = steps.OrderByDescending(x => x.Value.Stopwatch.Elapsed)
				.ToList();
			var sb = new StringBuilder();
			sorted.ForEach(x => sb.AppendFormat("{0}: {1:.###} ({2}){3}", x.Key, x.Value.Stopwatch.Elapsed.TotalSeconds, x.Value.Count, Environment.NewLine));
			return sb.ToString();
		}

		private static readonly IDictionary<string, InternalStep> steps = new ConcurrentDictionary<string, InternalStep>();

		private class InternalStep : IDisposable
		{
			public int Count { get; set; }
			public Stopwatch Stopwatch { get; private set; }

			public InternalStep(Stopwatch sw)
			{
				Count = 0;
				Stopwatch = sw;
			}

			public void Dispose()
			{
				Stopwatch.Stop();
			}
		}
	}
}