using System;
using System.Diagnostics;

namespace SemiColinGames {
  class Timer {

    private readonly Stopwatch stopwatch = new Stopwatch();
    private readonly double targetTime;
    private readonly string name;
    private double startTime = 0.0;
    private int[] histogram = new int[41];
    private int totalFrames = 0;

    public Timer(double targetTime, string name) {
      this.targetTime = targetTime;
      this.name = name;
    }

    public void Start() {
      startTime = stopwatch.Elapsed.TotalSeconds;
      stopwatch.Start();
    }

    public void Stop() {
      stopwatch.Stop();
      totalFrames++;
      double frameTime = stopwatch.Elapsed.TotalSeconds - startTime;
      int bucket = FMath.Clamp((int) (5.0f * frameTime / targetTime), 0, 40);
      histogram[bucket]++;
      if (totalFrames % 100 == 0) {
        DumpStats();
      }
    }

    public void DumpStats() {
      Debug.WriteLine(name + ".DumpStats():");
      for (int i = 0; i < histogram.Length - 1; i++) {
        int value = histogram[i];
        if (value > 0) {
          Debug.WriteLine($"{i * 5}-{(i + 1) * 5}%: {histogram[i]}");
        }
      }
      Debug.WriteLine($"200+%: {histogram[histogram.Length - 1]}");
    }
  }
}