/// <summary>
/// Evaluates the specified reference date.
/// </summary>
/// <param name="referenceDate">The reference date.</param>
/// <param name="periodStart">The period start.</param>
/// <param name="periodEnd">The period end.</param>
/// <param name="includeReferenceDateInResults">
/// if set to <c>true</c> [include reference date in results].
/// </param>
/// <returns></returns>
public override ISet <IPeriod> Evaluate(IDateTime referenceDate, DateTime periodStart, DateTime periodEnd, bool includeReferenceDateInResults)
{
// Ensure the reference date is associated with the time zone
if (referenceDate.AssociatedObject == null)
{
referenceDate.AssociatedObject = TimeZone;
}
var infos = new List <ITimeZoneInfo>(TimeZone.TimeZoneInfos);
// Evaluate extra time periods, without re-evaluating ones that were already evaluated
if ((EvaluationStartBounds == DateTime.MaxValue && EvaluationEndBounds == DateTime.MinValue) ||
(periodEnd.Equals(EvaluationStartBounds)) ||
(periodStart.Equals(EvaluationEndBounds)))
{
foreach (ITimeZoneInfo curr in infos)
{
var evaluator = curr.GetService(typeof(IEvaluator)) as IEvaluator;
Debug.Assert(curr.Start != null, "TimeZoneInfo.Start must not be null.");
Debug.Assert(curr.Start.TzId == null, "TimeZoneInfo.Start must not have a time zone reference.");
Debug.Assert(evaluator != null, "TimeZoneInfo.GetService(typeof(IEvaluator)) must not be null.");
// Time zones must include an effective start date/time
// and must provide an evaluator.
// Set the start bounds
if (EvaluationStartBounds > periodStart)
{
EvaluationStartBounds = periodStart;
}
// FIXME: 5 years is an arbitrary number, to eliminate the need
// to recalculate time zone information as much as possible.
DateTime offsetEnd = periodEnd.AddYears(5);
// Adjust our reference date to never fall out of bounds with
// the time zone information
IDateTime tziReferenceDate = referenceDate;
if (tziReferenceDate.LessThan(curr.Start))
{
tziReferenceDate = curr.Start;
}
// Determine the UTC occurrences of the Time Zone observances
ISet <IPeriod> periods = evaluator.Evaluate(
tziReferenceDate,
periodStart,
offsetEnd,
includeReferenceDateInResults);
foreach (IPeriod period in periods)
{
Periods.Add(period);
var o = new Occurrence(curr, period);
_occurancesLookup.Add(o);
}
if (EvaluationEndBounds == DateTime.MinValue || EvaluationEndBounds < offsetEnd)
{
EvaluationEndBounds = offsetEnd;
}
}
ProcessOccurrences(referenceDate);
}
else
{
if (EvaluationEndBounds != DateTime.MinValue && periodEnd > EvaluationEndBounds)
{
Evaluate(referenceDate, EvaluationEndBounds, periodEnd, includeReferenceDateInResults);
}
}
return(Periods);
}