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

namespace WorktimeCollector
{
	class Program
	{
		static int days = 7;

		static int pause = 30;

		static void Main(string[] args)
		{
			if (args.Length > 0 && !string.IsNullOrEmpty(args[0]))
			{
				try
				{
					days = Convert.ToInt32(args[0]);
				}
				catch
				{
					PrintHelpText();
					return;
				}
			}

			Console.WriteLine("parsing Eventlogs...\n");
			var allDates = GetEventLogDatesFromLastNDays(days);
			var dates = new List<Day>();

			for (int i = 0; i < days - 1; i++)
			{
				var eventsOnDay = allDates.Where(x => x > DateTime.Today.AddDays(-i) && x < DateTime.Today.AddDays(-(i - 1)));
				if (eventsOnDay.FirstOrDefault() != default(DateTime))
				{
					dates.Add(new Day(eventsOnDay.Last(), eventsOnDay.First()));
				}
			}

			var currentWeek = new TimeSpan();
			var currentWeeksPause = new TimeSpan();
			for (int i = 0; i < dates.Count; i++)
			{
				var date = dates[i];
				if (date.Start.Date == DateTime.Today)
				{
					Console.WriteLine("Today Begin: " + date.StartString());
					Console.WriteLine("Today Time:  " +  TimeSpanToString(DateTime.Now.Subtract(date.Start)));
				}
				else
				{
					Console.WriteLine(date + " Begin: " + date.StartString());
					Console.WriteLine(date + " End:   " + date.EndString());
					Console.WriteLine(date + " Time:  " + date.TimeString());
				}

				currentWeek = currentWeek.Add(date.Time);
				currentWeeksPause = currentWeeksPause.Add(new TimeSpan(0, pause, 0));

				var weekNumber = WeekOfYear(date.Start);
				var nextWeekNumber = i + 1 < dates.Count ? WeekOfYear(dates[i + 1].Start) : weekNumber;
				if (weekNumber != nextWeekNumber)
				{
					Console.WriteLine();
					Console.WriteLine("Week " + weekNumber + " (" + GetWeekSpan(date.Start) + "): " + TimeSpanToString(currentWeek));
					Console.WriteLine("Week " + weekNumber + " - Pause " + TimeSpanToString(currentWeeksPause) + ":   " + TimeSpanToString(currentWeek.Subtract(currentWeeksPause)));
					currentWeek = new TimeSpan();
					currentWeeksPause = new TimeSpan();
				}

				Console.WriteLine();
			}
		}

		private static string GetWeekSpan(DateTime date)
		{
			return GetFirstDayOfWeek(date).ToString("dd.MM") + " - " + GetLastDayOfWeek(date).ToString("dd.MM");
		}

		private static DateTime GetFirstDayOfWeek(DateTime date)
		{
			var firstDayInWeek = date;
			while (WeekOfYear(firstDayInWeek) == WeekOfYear(date))
			{
				firstDayInWeek = firstDayInWeek.AddDays(-1);
			}
			return firstDayInWeek.AddDays(1);
		}

		private static DateTime GetLastDayOfWeek(DateTime date)
		{
			var LastDayInWeek = date;
			while (WeekOfYear(LastDayInWeek) == WeekOfYear(date))
			{
				LastDayInWeek = LastDayInWeek.AddDays(+1);
			}
			return LastDayInWeek.AddDays(-1);
		}

		private static string TimeSpanToString(TimeSpan span)
		{
			return string.Format("{0:00}:{1:00}", (int)span.TotalMinutes / 60, (int)span.TotalMinutes % 60);
		}

		private static int WeekOfYear(DateTime date)
		{
			return CultureInfo.InvariantCulture.Calendar.GetWeekOfYear(date, CalendarWeekRule.FirstDay, DayOfWeek.Monday);
		}

		private static List<DateTime> GetEventLogDatesFromLastNDays(int days)
		{
			var minDay = DateTime.Today.AddDays(-days).ToString(@"yyyy-MM-ddTHH\:mm\:ss");
			var times = new List<DateTime>();

			var proc = new Process
			{
				StartInfo = new ProcessStartInfo
				{
					FileName = "wevtutil.exe",
					Arguments = @"qe System /rd:true /f:text /q:""*[System[TimeCreated[@SystemTime >= '" + minDay + @"']]]""",
					UseShellExecute = false,
					RedirectStandardOutput = true,
					CreateNoWindow = true
				}
			};
			proc.Start();

			string time = string.Empty;
			while (!proc.StandardOutput.EndOfStream)
			{
				string line = proc.StandardOutput.ReadLine();
				if (line.StartsWith("  Date:"))
				{
					time = line.Substring(8);
					times.Add(DateTime.Parse(time));
				}
			}

			return times;
		}

		private static void PrintHelpText()
		{
			Console.WriteLine();
			Console.WriteLine("Usage Examples:");
			Console.WriteLine("    WorktimeCollector.exe     \t\t... Show Worktime for last " + days + " days");
			Console.WriteLine("    WorktimeCollector.exe 14  \t\t... Show Worktime for last 2 weeks");
			Console.WriteLine("    WorktimeCollector.exe 365 \t\t... Show Worktime for last year");
			Console.WriteLine();
			Console.WriteLine("How it work:");
			Console.WriteLine("    WorktimeCollector crunches the systems Eventlog entries and");
            Console.WriteLine("    looks for the first and last entry for each day. It then takes");
			Console.WriteLine("    the difference and prints them out.");
		}
	}
}








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

namespace WorktimeCollector
{
    public class Day
    {
        public DateTime Start { get; set; }

        public DateTime End { get; set; }

        public TimeSpan Time
        {
            get { return this.End.Subtract(this.Start); }

        }

        public Day(DateTime start, DateTime end)
        {
            this.Start = start;
            this.End = end;
        }

        public override string ToString()
        {
            return this.Start.ToString("dd.MM.yyyy");
        }

        public string StartString()
        {
            return this.Start.ToString("HH:mm");
        }

        public string EndString()
        {
            return this.End.ToString("HH:mm");
        }

        public string TimeString()
        {
            return new DateTime(this.Time.Ticks).ToString("HH:mm");
        }
    }
}