DateRangeUtil

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

namespace Common.Utilities
{
    [System.Diagnostics.DebuggerStepThrough()]
    public class DateRangeUtil
    {
        //public static Dictionary<int, DateRange> DefaultDateRanges { get; private set; }
        public static List<DateRange> DefaultDateRanges { get; private set; }

        static DateRangeUtil()
        {
            DefaultDateRanges = CreateDefaultDateRanges();
        }

        static List<DateRange> CreateDefaultDateRanges()
        {
            List<DateRange> list = new List<DateRange>();
            list.Add(new DateRange(DateRangeType.All, "All"));
            list.Add(new DateRange(DateRangeType.Today, "Today"));
            list.Add(new DateRange(DateRangeType.ThisWeek, "This Week"));
            list.Add(new DateRange(DateRangeType.ThisWeektodate, "This Week-to-date"));
            list.Add(new DateRange(DateRangeType.ThisMonth, "This Month"));
            list.Add(new DateRange(DateRangeType.ThisMonthtodate, "This Month-to-date"));
            list.Add(new DateRange(DateRangeType.ThisQuarter, "This Quarter"));
            list.Add(new DateRange(DateRangeType.ThisQuartertodate, "This Quarter-to-date"));
            list.Add(new DateRange(DateRangeType.ThisYear, "This Year"));
            list.Add(new DateRange(DateRangeType.ThisYeartodate, "This Year-to-date"));
            list.Add(new DateRange(DateRangeType.Yesterday, "Yesterday"));
            list.Add(new DateRange(DateRangeType.LastWeek, "Last Week"));
            list.Add(new DateRange(DateRangeType.LastMonth, "Last Month"));
            list.Add(new DateRange(DateRangeType.LastQuarter, "Last Quarter"));
            list.Add(new DateRange(DateRangeType.LastYear, "Last Year"));

            foreach (DateRange range in list)
                CalculateDateRange(range);

            return list;
        }

        public static void CalculateDateRange(DateRange range)
        {
            CalculateDateRange(range, DateTime.Today);
        }

        public static void CalculateDateRange(DateRange range, DateTime todayDate)
        {
            DateTime beginDt = DateTime.MinValue;
            DateTime endDt = DateTime.MinValue;
            if (GetDates(range.RangeType, todayDate, out beginDt, out endDt))
            {
                range.BeginDate = beginDt;
                range.EndDate = endDt;
            }
        }

        public static List<DateRange> GetDateRanges()
        {
            return GetDateRanges(DateTime.Today);
        }

        public static List<DateRange> GetDateRanges(DateTime todayDate)
        {
            List<DateRange> list = new List<DateRange>(DefaultDateRanges);
            foreach (DateRange range in DefaultDateRanges)
                CalculateDateRange(range, todayDate);
            return list;
        }

        public static bool GetDates(DateRangeType rangeType, out DateTime startDate, out DateTime stopDate)
        {
            return GetDates(rangeType, DateTime.Today, out startDate, out stopDate);
        }

        /// <summary>
        /// Based on iDateRangeName, returns 2 dates the are set to the correct start and stop dates.
        /// </summary>
        /// <param name="dateRangeName">
        /// Specifies the date range to set to the dates for. Must be one of the DateRangeNames elements.
        /// </param>
        /// <param name="startDate">
        /// On function return, set to the starting date based on dateRangeName.
        /// </param>
        /// <param name="stopDate">
        /// On function return, set to the stopping date based on dateRangeName.
        /// </param>
        public static bool GetDates(DateRangeType rangeType, DateTime todayDate, out DateTime startDate, out DateTime stopDate)
        {
            DateTime StartDate = todayDate;
            DateTime StopDate = todayDate;
            bool result = true;

            // All.
            if (rangeType == DateRangeType.All)
            {
                StartDate = new DateTime(1900, 1, 1);
                StopDate = new DateTime(2100, 12, 31);
            }

            // Today.
            if (rangeType == DateRangeType.Today)
            {
                StartDate = DateTime.Today;
                StopDate = DateTime.Today.AddDays(1);
            }

            // This Week.
            if (rangeType == DateRangeType.ThisWeek)
            {
                // Set StartDate to most recent Sunday, first day of the current week.
                DateTime Dt = DateTime.Today;
                while (Dt.DayOfWeek != DayOfWeek.Sunday)
                    Dt = Dt.AddDays(-1);
                StartDate = Dt;

                // Set StopDate to the last day of this week, which is Saturday.
                Dt = DateTime.Today;
                while (Dt.DayOfWeek != DayOfWeek.Saturday)
                    Dt = Dt.AddDays(1);
                StopDate = Dt;
            }

            // This Week-to-date.
            if (rangeType == DateRangeType.ThisWeektodate)
            {
                // Set StartDate to most recent Sunday, first day of the current week.
                DateTime Dt = DateTime.Today;
                while (Dt.DayOfWeek != DayOfWeek.Sunday)
                    Dt = Dt.AddDays(-1);
                StartDate = Dt;

                // Set StopDate to today.
                StopDate = DateTime.Today;
            }

            // This Month.
            if (rangeType == DateRangeType.ThisMonth)
            {
                // Set StartDate to first of current month.
                StartDate = new DateTime(DateTime.Today.Year, DateTime.Today.Month, 1);

                // Set StopDate to last date of current month.
                DateTime Dt = new DateTime(DateTime.Today.Year, DateTime.Today.AddMonths(1).Month, 1).AddDays(-1);
                StopDate = new DateTime(DateTime.Today.Year, DateTime.Today.Month, Dt.Day);
            }

            // This Month-to-date.
            if (rangeType == DateRangeType.ThisMonthtodate)
            {
                // Set StartDate to first of current month.
                StartDate = new DateTime(DateTime.Today.Year, DateTime.Today.Month, 1);

                // Set StopDate to today.
                StopDate = DateTime.Today;
            }

            // This Quarter.
            if (rangeType == DateRangeType.ThisQuarter)
            {
                // Set StartDate to first day of the 1st month of this quarter.
                int CurrentMonth = DateTime.Today.Month;
                DateTime Dt = DateTime.Today;
                while ((CurrentMonth % 3) != 0)
                {
                    Dt = Dt.AddMonths(-1);
                    CurrentMonth--;
                }
                StartDate = new DateTime(Dt.Year, Dt.Month, 1);

                // Set StopDate to last date of current month.
                Dt = StartDate.AddMonths(4).AddDays(-1);
                StopDate = Dt;
            }

            // This Quarter-to-date.
            if (rangeType == DateRangeType.ThisQuartertodate)
            {
                // Set StartDate to first day of the 1st month of this quarter.
                int CurrentMonth = DateTime.Today.Month;
                DateTime Dt = DateTime.Today;
                while ((CurrentMonth % 3) != 0)
                {
                    Dt = Dt.AddMonths(-1);
                    CurrentMonth--;
                }
                StartDate = new DateTime(Dt.Year, Dt.Month, 1);

                // Set StopDate to today.
                StopDate = DateTime.Today;
            }

            // This Year.
            if (rangeType == DateRangeType.ThisYear)
            {
                // Set StartDate to first day of the year.
                StartDate = new DateTime(DateTime.Today.Year, 1, 1);

                // Set StopDate to last day of the year.
                StopDate = new DateTime(StartDate.AddYears(1).Year, 1, 1).AddDays(-1);
            }

            // This Year-to-date.
            if (rangeType == DateRangeType.ThisYeartodate)
            {
                // Set StartDate to first day of the year.
                StartDate = new DateTime(DateTime.Today.Year, 1, 1);

                // Set StopDate to today.
                StopDate = DateTime.Today;
            }

            // Yesterday.
            if (rangeType == DateRangeType.Yesterday)
            {
                // Set StartDate to yesterday.
                StartDate = DateTime.Today.AddDays(-1);

                // Set StopDate to yesterday.
                StopDate = DateTime.Today.AddDays(-1);
            }

            // Last Week.
            if (rangeType == DateRangeType.LastWeek)
            {
                // Set StartDate to the first day of last week.
                StartDate = DateTime.Today.AddDays(-7);
                while (StartDate.DayOfWeek != System.DayOfWeek.Sunday)
                    StartDate = StartDate.AddDays(-1);

                // Set StopDate to the last day of last week, which was last Saturday.
                // If the current day is Saturday, then go to the previous Saturday.
                StopDate = DateTime.Today.AddDays(-1);
                while (StopDate.DayOfWeek != System.DayOfWeek.Saturday)
                    StopDate = StopDate.AddDays(-1);
            }

            // Last Month.
            if (rangeType == DateRangeType.LastMonth)
            {
                // Set StartDate to the first day of last month.
                StartDate = new DateTime(DateTime.Today.AddMonths(-1).Year, DateTime.Today.AddMonths(-1).Month, 1);

                // Set StopDate to the last day of last month.
                StopDate = new DateTime(DateTime.Today.Year, DateTime.Today.Month, 1).AddDays(-1);
            }

            // Last Quarter.
            if (rangeType == DateRangeType.LastQuarter)
            {
                // Set StartDate to the first day of the first month of the previous quarter.
                int CurrentMonth = DateTime.Today.Month;
                DateTime Dt = DateTime.Today;
                while ((CurrentMonth % 3) != 0)
                {
                    Dt = Dt.AddMonths(-1);
                    CurrentMonth--;
                }
                StartDate = Dt.AddMonths(-3);

                // Set StopDate to the last day of last month.
                StopDate = StartDate.AddMonths(4).AddDays(-1);
            }

            // Last Year.
            if (rangeType == DateRangeType.LastQuarter)
            {
                // Set StartDate to first day of the last year.
                StartDate = new DateTime(DateTime.Today.AddYears(-1).Year, 1, 1);

                // Set StopDate to the last day of the last year.
                StopDate = StartDate.AddYears(1).AddDays(-1);
            }

            //// Custom.
            //if (dateRangeName == DateRangeNames[15])
            //{
            //    // Don't return anything.
            //    result = false;
            //}

            startDate = StartDate;
            stopDate = StopDate;

            return result;
        }

        /// <summary>
        /// Returns a starting date based on today's date, for the dateRangeName.
        /// </summary>
        public static DateTime GetStartDate(DateRangeType rangeType)
        {
            DateTime StartDate;
            DateTime StopDate;
            GetDates(rangeType, out StartDate, out StopDate);

            return StartDate;
        }

        /// <summary>
        /// Returns a stopping date based on today's date, for the dateRangeName.
        /// </summary>
        public static DateTime GetStopDate(DateRangeType rangeType)
        {
            DateTime StartDate;
            DateTime StopDate;
            GetDates(rangeType, out StartDate, out StopDate);

            return StopDate;
        }
    }

    public class DateRange
    {
        public string Name { get; set; }
        public DateRangeType RangeType { get; set; }
        public DateTime? BeginDate { get; set; }
        public DateTime? EndDate { get; set; }

        public DateRange(DateRangeType rangeType, string name)
            : this(rangeType, name, null, null) { }

        public DateRange(DateRangeType rangeType, string name, DateTime? beginDt, DateTime? endDt)
        {
            this.RangeType = rangeType;
            this.Name = name;
            this.BeginDate = beginDt;
            this.EndDate = endDt;
        }
    }

    public enum DateRangeType
    {
        All = 0,
        Today = 1,
        ThisWeek = 2,
        ThisWeektodate = 3,
        ThisMonth = 4,
        ThisMonthtodate = 5,
        ThisQuarter = 6,
        ThisQuartertodate = 7,
        ThisYear = 8,
        ThisYeartodate = 9,
        Yesterday = 10,
        LastWeek = 11,
        LastMonth = 12,
        LastQuarter = 13,
        LastYear = 14,
    }
}