private static IEnumerable <string> ResolveDateAgainstConstraint(TimexProperty timex, DateRange constraint)
{
if (timex.Month != null && timex.DayOfMonth != null)
{
var result = new List <string>();
for (var year = constraint.Start.Year; year <= constraint.End.Year; year++)
{
var t = timex.Clone();
t.Year = year;
result.AddRange(ResolveDefiniteAgainstConstraint(t, constraint));
}
return(result);
}
if (timex.DayOfWeek != null)
{
// convert between ISO day of week and .NET day of week
var day = timex.DayOfWeek == 7 ? DayOfWeek.Sunday : (DayOfWeek)timex.DayOfWeek;
var dates = TimexDateHelpers.DatesMatchingDay(day, constraint.Start, constraint.End);
var result = new List <string>();
foreach (var d in dates)
{
var t = timex.Clone();
t.DayOfWeek = null;
t.Year = d.Year;
t.Month = d.Month;
t.DayOfMonth = d.Day;
result.Add(t.TimexValue);
}
return(result);
}
if (timex.Hour != null)
{
var result = new List <string>();
DateTime day = constraint.Start;
while (day <= constraint.End)
{
var t = timex.Clone();
t.Year = day.Year;
t.Month = day.Month;
t.DayOfMonth = day.Day;
result.AddRange(ResolveDefiniteAgainstConstraint(t, constraint));
day = day.AddDays(1);
}
return(result);
}
return(Enumerable.Empty <string>());
}