/// <summary>
/// Explicit comparison of DateTimeRanges to be used as a delegate.
/// The result is the same as the DateTimeRange.CompareTo.
/// </summary>
/// <param name="x">The start date of the free busy</param>
/// <param name="y">The granularity of the free busy in minutes</param>
/// <returns>Negative, zero or possitive number if x is smaller, equal or bigger than y respectively</returns>
public static int CompareRangesByStartThenEnd(
DateTimeRange x,
DateTimeRange y)
{
if ((x == null) && (y == null))
{
// If x is null and y is null, they are equal.
return(0);
}
if (x == null)
{
// If x is null and y is not null, y is greater.
return(-1);
}
if (y == null)
{
// If x is not null and y is null, x is greater.
return(1);
}
int result = x.Start.CompareTo(y.Start);
if (result == 0)
{
result = x.End.CompareTo(y.End);
}
#if DEBUG
Debug.Assert((result == 0) == (x.CompareTo(y) == 0) &&
(result > 0) == (x.CompareTo(y) > 0));
#endif
return(result);
}
/// <summary>
/// Merges two sorted lists of ranges and condenses the resulting one
/// </summary>
/// <param name="left">List of ranges to merge</param>
/// <param name="right">List of ranges to merge</param>
/// <returns>The sorted and condensed union of the two lists</returns>
public static List <DateTimeRange> MergeFreeBusyLists(
List <DateTimeRange> left,
List <DateTimeRange> right)
{
IEnumerable <DateTimeRange> leftEnumerable = left as IEnumerable <DateTimeRange>;
IEnumerator <DateTimeRange> leftEnumerator = leftEnumerable.GetEnumerator();
bool moreLeft = leftEnumerator.MoveNext();
IEnumerable <DateTimeRange> rightEnumerable = right as IEnumerable <DateTimeRange>;
IEnumerator <DateTimeRange> rightEnumerator = rightEnumerable.GetEnumerator();
bool moreRight = rightEnumerator.MoveNext();
List <DateTimeRange> result = new List <DateTimeRange>(left.Capacity + right.Capacity);
while (moreLeft && moreRight)
{
DateTimeRange leftRange = leftEnumerator.Current;
DateTimeRange rightRange = rightEnumerator.Current;
DateTimeRange range = null;
if (leftRange.CompareTo(rightRange) < 0)
{
range = leftRange;
moreLeft = leftEnumerator.MoveNext();
}
else
{
range = rightRange;
moreRight = rightEnumerator.MoveNext();
}
result.Add(new DateTimeRange(range.Start, range.End));
}
while (moreLeft)
{
DateTimeRange range = leftEnumerator.Current;
result.Add(new DateTimeRange(range.Start, range.End));
moreLeft = leftEnumerator.MoveNext();
}
while (moreRight)
{
DateTimeRange range = rightEnumerator.Current;
result.Add(new DateTimeRange(range.Start, range.End));
moreRight = rightEnumerator.MoveNext();
}
log.DebugFormat("Merged {0} + {1} into {2} ranges",
left.Count,
right.Count,
result.Count);
CondenseFreeBusyTimes(result);
log.DebugFormat("Compressed {0} + {1} into {2} ranges",
left.Count,
right.Count,
result.Count);
return(result);
}