public ProgramScheduleItem Peek(int offset)
{
if (offset == 0)
{
return(Current);
}
if ((State.Index + offset) % _scheduleItemsCount == 0)
{
IList <ProgramScheduleItem> shuffled;
ProgramScheduleItem tail = Current;
// clone the random
CloneableRandom randomCopy = _random.Clone();
do
{
int newSeed = randomCopy.Next();
randomCopy = new CloneableRandom(newSeed);
shuffled = Shuffle(_scheduleItems, randomCopy);
} while (_scheduleItems.Count > 1 && shuffled[0] == tail);
return(shuffled[0]);
}
return(_shuffled[(State.Index + offset) % _scheduleItemsCount]);
}
public Option <MediaItem> Peek(int offset)
{
if (offset == 0)
{
return(Current);
}
if ((State.Index + offset) % _mediaItemCount == 0)
{
IList <MediaItem> shuffled;
Option <MediaItem> tail = Current;
// clone the random
CloneableRandom randomCopy = _random.Clone();
do
{
int newSeed = randomCopy.Next();
randomCopy = new CloneableRandom(newSeed);
shuffled = Shuffle(_mediaItems, randomCopy);
} while (_mediaItems.Count > 1 && shuffled[0] == tail);
return(shuffled.Any() ? shuffled[0] : None);
}
return(_shuffled.Any() ? _shuffled[(State.Index + offset) % _mediaItemCount] : None);
}
public CloneableRandom Clone()
{
var clone = new CloneableRandom(_seed);
for (var i = 0; i < _count; i++)
{
clone.Next();
}
return(clone);
}
private IList <MediaItem> Shuffle(IEnumerable <GroupedMediaItem> list, CloneableRandom random)
{
GroupedMediaItem[] copy = list.ToArray();
int n = copy.Length;
while (n > 1)
{
n--;
int k = random.Next(n + 1);
(copy[k], copy[n]) = (copy[n], copy[k]);
}
return(GroupedMediaItem.FlattenGroups(copy, _mediaItemCount));
}
public void MoveNext()
{
if ((State.Index + 1) % _mediaItemCount == 0)
{
Option <MediaItem> tail = Current;
State.Index = 0;
do
{
State.Seed = _random.Next();
_random = new CloneableRandom(State.Seed);
_shuffled = Shuffle(_mediaItems, _random);
} while (_mediaItems.Count > 1 && Current == tail);
}
else
{
State.Index++;
}
State.Index %= _mediaItemCount;
}
public void MoveNext()
{
if ((State.Index + 1) % _scheduleItemsCount == 0)
{
ProgramScheduleItem tail = Current;
State.Index = 0;
do
{
State.Seed = _random.Next();
_random = new CloneableRandom(State.Seed);
_shuffled = Shuffle(_scheduleItems, _random);
} while (_scheduleItems.Count > 1 && Current == tail);
}
else
{
State.Index++;
}
State.Index %= _scheduleItemsCount;
}
public ShuffledMediaCollectionEnumerator(
IList <GroupedMediaItem> mediaItems,
CollectionEnumeratorState state)
{
_mediaItemCount = mediaItems.Sum(i => 1 + Optional(i.Additional).Flatten().Count());
_mediaItems = mediaItems;
if (state.Index >= _mediaItems.Count)
{
state.Index = 0;
state.Seed = new Random(state.Seed).Next();
}
_random = new CloneableRandom(state.Seed);
_shuffled = Shuffle(_mediaItems, _random);
State = new CollectionEnumeratorState {
Seed = state.Seed
};
while (State.Index < state.Index)
{
MoveNext();
}
}
public ShuffledScheduleItemsEnumerator(
IList <ProgramScheduleItem> scheduleItems,
CollectionEnumeratorState state)
{
_scheduleItemsCount = scheduleItems.Count;
_scheduleItems = scheduleItems;
if (state.Index >= _scheduleItems.Count)
{
state.Index = 0;
state.Seed = new Random(state.Seed).Next();
}
_random = new CloneableRandom(state.Seed);
_shuffled = Shuffle(_scheduleItems, _random);
State = new CollectionEnumeratorState {
Seed = state.Seed
};
while (State.Index < state.Index)
{
MoveNext();
}
}
private IList <ProgramScheduleItem> Shuffle(IEnumerable <ProgramScheduleItem> list, CloneableRandom random)
{
ProgramScheduleItem[] copy = list.ToArray();
int n = copy.Length;
while (n > 1)
{
n--;
int k = random.Next(n + 1);
(copy[k], copy[n]) = (copy[n], copy[k]);
}
return(copy);
}
