public HashSet <int> FavorHigherIndexOnStart(HashSet <int> splitIndices, SmartSplitType type)
{
var tracks = SmartSplitTestData.GetFavorHigherIndexOnStartTestTracks();
splitIndices.AdjustWithSmartSplit(tracks, type);
return(splitIndices);
}
private static HashSet <int> GetAvailableSplitIndices(Track[] tracks, SmartSplitType type)
{
var tracksLength = tracks.Count();
var availableSplitIndices = new HashSet <int>();
for (int i = 1; i < tracksLength; i++)
{
var currentValue = type == SmartSplitType.Albums ? tracks[i].AlbumId : tracks[i].ArtistId;
var previousValue = type == SmartSplitType.Albums ? tracks[i - 1].AlbumId : tracks[i - 1].ArtistId;
if (currentValue != previousValue)
{
availableSplitIndices.Add(i);
}
}
availableSplitIndices.Add(tracksLength);
return(availableSplitIndices);
}
public static void AdjustWithSmartSplit(this HashSet <int> splitIndices, IEnumerable <Track> tracks, SmartSplitType type)
{
var availableSplitIndices = GetAvailableSplitIndices(tracks.ToArray(), type);
var tempSplitIndices = new HashSet <int>(splitIndices);
var favorLowerIndex = false;
splitIndices.Clear();
foreach (var index in tempSplitIndices)
{
if (availableSplitIndices.Contains(index) == false || splitIndices.Contains(index))
{
var lowerIndex = availableSplitIndices.OrderBy(x => Math.Abs(x - index))
.Where(x => x < index && !splitIndices.Contains(x))
.FirstOrDefault();
var higherIndex = availableSplitIndices.OrderBy(x => Math.Abs(x - index))
.Where(x => x > index && !splitIndices.Contains(x))
.FirstOrDefault();
var chooseLowerIndex = (index - lowerIndex < higherIndex - index) || (index - lowerIndex == higherIndex - index && favorLowerIndex);
if (chooseLowerIndex && lowerIndex > 0)
{
splitIndices.Add(lowerIndex);
favorLowerIndex = true;
}
else if (higherIndex > 0)
{
splitIndices.Add(higherIndex);
favorLowerIndex = false;
}
}
else
{
splitIndices.Add(index);
}
}
}