public decimal GetBalanceFromDate(DateTime date)
{
FinancialDay closestDay = null;
TimeSpan? closestDistance = null;
// Find the closest day
foreach (var day in Calendar.Days)
{
TimeSpan distanceToDate;
// There is no "absolute value" function for TimeSpan, so we should handle negative numbers by avoiding them.
if (day.Date > date)
{
distanceToDate = day.Date - date;
}
else
{
distanceToDate = date - day.Date;
}
if (!closestDistance.HasValue || distanceToDate < closestDistance.Value)
{
closestDay = day;
closestDistance = distanceToDate;
}
}
if (closestDay == null)
{
return(0);
}
// If the day we found is after the date we wanted, we should extrapolate backwards using the starting balance.
// If the day we found is either exactly date we wanted or after it, we should use the ending balance as standard or to extrapolate forwards.
if (closestDay.Date > date)
{
return(GetDelta(closestDay.StartingBalance));
}
else
{
return(GetDelta(closestDay.EndingBalance));
}
}
private void InsertDay(int index, ref FinancialDay day)
{
if (index > 0)
{
var previous = DayCollection[index - 1];
previous.NextDay = day;
day.PreviousDay = previous;
}
if (index < DayCollection.Count)
{
var next = DayCollection[index];
next.PreviousDay = day;
day.NextDay = next;
}
DayCollection.Insert(index, day);
OnDayCollectionChanged();
}
public FinancialDay GetDayForDate(DateTime date)
{
FinancialDay returnDay;
lock (DayCollection)
{
var existing = FindDayForDate(date, out int index);
if (existing != null)
{
returnDay = existing;
}
else
{
returnDay = new FinancialDay(date);
InsertDay(index, ref returnDay);
}
}
return(returnDay);
}
