using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Threading;

namespace BenchmarkLab {
    class TimeMeasure : Benchmark {
        private static double initTime = getInitTime();
        private static double getInitTime() {
            Stopwatch sw = new Stopwatch();
            sw.Start();
                int x = 1;
                for (int i = 0; i < NumOfIterations; ++i) {
                    x = i;
                    x = i;
                    x = i;
                }
            sw.Stop();
            return sw.Elapsed.TotalMilliseconds;
        }

        private static bool isFirstMeasurement = true;
        public static double minExecTime { get; private set; } = 0;

        public TimeMeasure(Object t, List<Action> testsLs) {
            for(int i = 0; i < testsLs.Count; ++i) {
                //prevent the JIT Compiler from optimizing Fkt calls away
                long seed = Environment.TickCount;

                //use the second Core/Processor for the test
                Process.GetCurrentProcess().ProcessorAffinity = new IntPtr(2);

                //prevent "Normal" Processes from interrupting Threads
                Process.GetCurrentProcess().PriorityClass = ProcessPriorityClass.High;

                //prevent "Normal" Threads from interrupting this thread
                Thread.CurrentThread.Priority = ThreadPriority.Highest;

                // warming up
                testsLs[i]();

                // clean up
                GC.Collect();
                GC.WaitForPendingFinalizers();
                GC.Collect();

                Stopwatch sw = new Stopwatch();
                sw.Start();
                    testsLs[i]();
                sw.Stop();

                if (isFirstMeasurement == true || sw.Elapsed.TotalMilliseconds - initTime < minExecTime) {
                    minExecTime = sw.Elapsed.TotalMilliseconds - initTime;
                    isFirstMeasurement = false;
                }

                string operation = string.Empty;
                if (i == 0)
                    operation = " +=";
                else if (i == 1)
                    operation = " -=";
                else if (i == 2)
                    operation = " *=";
                else
                    operation = " /=";

                typeResults.Add(new DataRow { dataType = t.GetType().Name + operation, time = sw.Elapsed.TotalMilliseconds - initTime,
                                              opPerSec = getOpPerSec(sw.Elapsed.TotalMilliseconds - initTime) });
            }
        }

        public List<DataRow> typeResults { get; private set; } = new List<DataRow>();

        private double getOpPerSec(double execTime) {
            return NumOfIterations * 1e6 / execTime;
        }
    }
}