public static List <ValidPrice> CalculateValidPrices(List <ProductAgreement> inputList)
{
inputList.Sort((x, y) => x.Order.CompareTo(y.Order));
List <ValidPrice> validPrices = new List <ValidPrice>();
foreach (ProductAgreement agreement in inputList)
{
ValidPrice newPrice = new ValidPrice();
newPrice.StartDate = agreement.StartDate;
newPrice.EndDate = agreement.EndDate;
newPrice.Price = agreement.Price;
UpdateValidPrices(validPrices, newPrice);
ConsolidateIntervals(validPrices);
}
return(validPrices);
}
public static void UpdateValidPrices(List <ValidPrice> validPrices, ValidPrice newItem)
{
// Premesis: The validPrices List is always sorted by StartDate.
// We control this by the inserting new items correctly.
var newItemIndex = 0;
// Find the interval that contains the new item's start date.
var intervalContainingNewStartDate = validPrices.Where(v => newItem.StartDate >= v.StartDate).LastOrDefault();
// Find the interval that contains the new item's end date.
var intervalContainingNewEndDate = validPrices.Where(v => newItem.EndDate <= v.EndDate).FirstOrDefault();
// Special case: new item lies in one single old interval.
if (intervalContainingNewStartDate != null && intervalContainingNewStartDate == intervalContainingNewEndDate)
{
// The new item is either splits the old period (or they are identical)
if (intervalContainingNewStartDate.StartDate == newItem.StartDate && intervalContainingNewStartDate.EndDate == newItem.EndDate)
{
// The timespans are identical. Simply update the price.
intervalContainingNewStartDate.Price = newItem.Price;
return;
}
else
{
// ToDo: Handle special case: StartDate or EndDate identical!
// ...
// ...
// Split old interval, insert newItem in between.
var secondPartOfOldInterval = new ValidPrice();
secondPartOfOldInterval.StartDate = newItem.EndDate.AddDays(1);
secondPartOfOldInterval.EndDate = intervalContainingNewEndDate.EndDate;
secondPartOfOldInterval.Price = intervalContainingNewEndDate.Price;
// Insert new item after first part of old interval.
newItemIndex = validPrices.IndexOf(intervalContainingNewStartDate) + 1;
intervalContainingNewStartDate.EndDate = newItem.StartDate.Subtract(new TimeSpan(1, 0, 0, 0));
validPrices.Insert(newItemIndex, newItem);
// Insert Second Part of old interval after newItem.
validPrices.Insert(newItemIndex + 1, secondPartOfOldInterval);
return;
}
}
// Default: update existing Start/End dates.
if (intervalContainingNewStartDate != null)
{
newItemIndex = validPrices.IndexOf(intervalContainingNewStartDate) + 1;
intervalContainingNewStartDate.EndDate = newItem.StartDate.Subtract(new TimeSpan(1, 0, 0, 0));
}
if (intervalContainingNewEndDate != null)
{
intervalContainingNewEndDate.StartDate = newItem.EndDate.AddDays(1);
}
// Insert new item
validPrices.Insert(newItemIndex, newItem);
}