void ISearchValueVisitor.Visit(DateTimeSearchValue dateTime)
{
EnsureArg.IsNotNull(dateTime, nameof(dateTime));
if (_modifier != null)
{
ThrowModifierNotSupported();
}
// Based on spec here: http://hl7.org/fhir/STU3/search.html#prefix
switch (_comparator)
{
case SearchComparator.Eq:
_outputExpression = Expression.And(
Expression.GreaterThanOrEqual(FieldName.DateTimeStart, _componentIndex, dateTime.Start),
Expression.LessThanOrEqual(FieldName.DateTimeEnd, _componentIndex, dateTime.End));
break;
case SearchComparator.Ne:
_outputExpression = Expression.Or(
Expression.LessThan(FieldName.DateTimeStart, _componentIndex, dateTime.Start),
Expression.GreaterThan(FieldName.DateTimeEnd, _componentIndex, dateTime.End));
break;
case SearchComparator.Lt:
_outputExpression = Expression.LessThan(FieldName.DateTimeStart, _componentIndex, dateTime.Start);
break;
case SearchComparator.Gt:
_outputExpression = Expression.GreaterThan(FieldName.DateTimeEnd, _componentIndex, dateTime.End);
break;
case SearchComparator.Le:
_outputExpression = Expression.LessThanOrEqual(FieldName.DateTimeStart, _componentIndex, dateTime.End);
break;
case SearchComparator.Ge:
_outputExpression = Expression.GreaterThanOrEqual(FieldName.DateTimeEnd, _componentIndex, dateTime.Start);
break;
case SearchComparator.Sa:
_outputExpression = Expression.GreaterThan(FieldName.DateTimeStart, _componentIndex, dateTime.End);
break;
case SearchComparator.Eb:
_outputExpression = Expression.LessThan(FieldName.DateTimeEnd, _componentIndex, dateTime.Start);
break;
case SearchComparator.Ap:
var startTicks = dateTime.Start.UtcTicks;
var endTicks = dateTime.End.UtcTicks;
var differenceTicks = (long)((Clock.UtcNow.Ticks - Math.Max(startTicks, endTicks)) * ApproximateMultiplier);
var approximateStart = dateTime.Start.AddTicks(-differenceTicks);
var approximateEnd = dateTime.End.AddTicks(differenceTicks);
_outputExpression = Expression.And(
Expression.GreaterThanOrEqual(FieldName.DateTimeStart, _componentIndex, approximateStart),
Expression.LessThanOrEqual(FieldName.DateTimeEnd, _componentIndex, approximateEnd));
break;
default:
ThrowComparatorNotSupported();
break;
}
}
