/// <summary>
/// Normalizes the time range.
/// </summary>
/// <remarks>
/// Makes the startDate a left point of the time range, and makes the period positive.
/// </remarks>
public static void NormalizeTimeRange(ref DateTime startDate, ref int period,
RepPeriodUnit unit = RepPeriodUnit.Day)
{
startDate = startDate > DateTime.MinValue ? startDate.Date : DateTime.Today;
if (unit == RepPeriodUnit.Month)
{
if (period < 0)
{
startDate = startDate.AddMonths(period).Date;
period = -period;
}
}
else
{
// Examples:
// If the period is -1, 0 or 1, it means the single day, the startDate.
// If the period is 2, it means 2 days starting from the startDate.
// If the period is -2, it means 2 days ending with the startDate and including it.
if (period <= -2)
{
startDate = startDate.AddDays(period + 1).Date;
period = -period;
}
else if (period < 1)
{
period = 1;
}
}
}
/// <summary>
/// Normalizes the time range.
/// </summary>
public static void NormalizeTimeRange(ref DateTime startDate, ref DateTime endDate, ref int period,
RepPeriodUnit unit = RepPeriodUnit.Day)
{
bool periodInMonths = unit == RepPeriodUnit.Month;
if (startDate > DateTime.MinValue && endDate > DateTime.MinValue)
{
if (endDate < startDate)
{
endDate = startDate;
}
period = periodInMonths ?
((endDate.Year - startDate.Year) * 12) + endDate.Month - startDate.Month :
(int)(endDate - startDate).TotalDays + 1;
}
else if (startDate > DateTime.MinValue)
{
NormalizeTimeRange(ref startDate, ref period, unit);
endDate = periodInMonths ?
startDate.AddMonths(period) :
startDate.AddDays(period - 1);
}
else if (endDate > DateTime.MinValue)
{
period = Math.Abs(period);
NormalizeTimeRange(ref endDate, ref period, unit);
startDate = periodInMonths ?
endDate.AddMonths(-period) :
endDate.AddDays(-period + 1);
}
else
{
NormalizeTimeRange(ref startDate, ref period, unit);
endDate = periodInMonths ?
startDate.AddMonths(period) :
startDate.AddDays(period - 1);
}
}
