public static TPropertiesEnum DiffProperties <TPropertiesEnum, TDiffGram>(this ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> > self, ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> > other)
where TPropertiesEnum : struct
{
TPropertiesEnum changes = self.Value.DiffProperties(other.Value);
if ((self.Parent == null ^ other.Parent == null) || (self.Parent != null && other.Parent != null && self.Parent.Identity != other.Parent.Identity))
{
changes = self.Value.Union(changes, self.Value.ParentProperty);
}
else if (self.Value != other.Value && self.Parent != null && other.Parent != null)
{
var selfParentOrdered = self.Parent as IRecursiveParentWithOrderedChildren;
if (selfParentOrdered != null)
{
var selfParentSorted = selfParentOrdered as IRecursiveParentWithSortedChildren;
if (selfParentSorted != null)
{
if (selfParentSorted.Compare(self.Value, other.Value) != 0)
{
// Calculate where the node was, and where it would go in the old tree.
var otherParentSorted = (IRecursiveParentWithSortedChildren)other.Parent;
int beforeIndex = otherParentSorted.IndexOf(other.Value);
int afterIndex = ~otherParentSorted.IndexOf(self.Value);
// If the indices are the same, the new one would come "just before" the old one.
// If the new index is just 1 greater than the old index, the new one would come "just after" the old one.
// In either of these cases, since the old one will be gone in the new tree, the position hasn't changed.
if (afterIndex != beforeIndex && afterIndex != beforeIndex + 1)
{
changes = self.Value.Union(changes, self.Value.PositionUnderParentProperty);
}
}
}
else
{
// Calculate whether items were reordered without leveraging a sorting comparer.
var otherParentOrdered = (IRecursiveParentWithOrderedChildren)other.Parent;
int beforeIndex = otherParentOrdered.IndexOf(other.Value);
int afterIndex = selfParentOrdered.IndexOf(self.Value);
// TODO: review (and add tests for) cases where items are inserted/removed from the parent,
// causing all other items after it to apparently shift in position. We probably don't want
// to consider that a change in PositionUnderParent, since the removal or add will take care of it.
if (afterIndex != beforeIndex)
{
changes = self.Value.Union(changes, self.Value.PositionUnderParentProperty);
}
}
}
}
return(changes);
}
public int GetHashCode(ParentedRecursiveType <TRecursiveParent, TRecursiveType> obj)
{
return((int)obj.Value.Identity);
}
public static IReadOnlyList <TDiffGram> ChangesSince <TPropertiesEnum, TDiffGram>(this IRecursiveDiffingType <TPropertiesEnum, TDiffGram> current, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> priorVersion)
where TPropertiesEnum : struct
where TDiffGram : struct
{
Requires.NotNull(current, "current");
Requires.NotNull(priorVersion, "priorVersion");
if (current == priorVersion)
{
return(System.Collections.Immutable.ImmutableList.Create <TDiffGram>());
}
if (priorVersion.Identity != current.Identity)
{
throw new System.ArgumentException("Not another version of the same node.", nameof(priorVersion));
}
var currentAsParent = current as IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >;
var currentAsRecursiveType = (IRecursiveDiffingType <TPropertiesEnum, TDiffGram>)current;
var before = new HashSet <ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> > >(Comparers.Parented <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >());
var after = new HashSet <ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> > >(Comparers.Parented <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >());
var priorVersionAsParent = priorVersion as IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >;
if (priorVersionAsParent != null)
{
before.UnionWith(priorVersionAsParent.GetSelfAndDescendentsWithParents <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >());
}
else
{
before.Add(priorVersion.WithParent());
}
if (currentAsParent != null)
{
after.UnionWith(currentAsParent.GetSelfAndDescendentsWithParents <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >());
}
else
{
after.Add(current.WithParent());
}
var added = new HashSet <ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> > >(Comparers.Parented <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >());
var removed = new HashSet <ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> > >(Comparers.Parented <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >());
var changed = new Dictionary <ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> > >(Comparers.Parented <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >());
var descendentsOfAddOrRemove = new HashSet <IRecursiveType>(Comparers.Identity);
foreach (var fromBefore in before)
{
if (after.Contains(fromBefore))
{
ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> > fromAfter;
if (currentAsParent != null)
{
var parent = currentAsParent.GetParentedNode(fromBefore.Value.Identity);
fromAfter = new ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >(
(IRecursiveDiffingType <TPropertiesEnum, TDiffGram>)parent.Value,
(IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >)parent.Parent);
}
else
{
fromAfter = new ParentedRecursiveType <IRecursiveParent <IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >, IRecursiveDiffingType <TPropertiesEnum, TDiffGram> >(
fromBefore.Value.Identity == current.Identity ? (IRecursiveDiffingType <TPropertiesEnum, TDiffGram>)current : null);
}
if (!object.ReferenceEquals(fromBefore.Value, fromAfter.Value) || fromBefore.Parent.Identity != fromAfter.Parent.Identity)
{
changed.Add(fromBefore, fromAfter);
}
}
else
{
removed.Add(fromBefore);
}
}
foreach (var fromAfter in after)
{
if (!before.Contains(fromAfter))
{
added.Add(fromAfter);
}
}
foreach (var topLevelOperation in added.Concat(removed))
{
descendentsOfAddOrRemove.UnionWith(topLevelOperation.Value.GetSelfAndDescendents().Skip(1));
}
var history = new List <TDiffGram>();
history.AddRange(removed.Where(r => !descendentsOfAddOrRemove.Contains(r.Value)).Select(r => currentAsRecursiveType.Remove(r.Value)));
foreach (var changedNode in changed)
{
var oldNode = changedNode.Key;
var newNode = changedNode.Value;
var diff = newNode.DiffProperties(oldNode);
if (!currentAsRecursiveType.Equals(diff, default(TPropertiesEnum)))
{
history.Add(currentAsRecursiveType.Change(oldNode.Value, newNode.Value, diff));
}
}
history.AddRange(added.Where(a => !descendentsOfAddOrRemove.Contains(a.Value)).Select(a => currentAsRecursiveType.Add(a.Value)));
return(history);
}
public bool Equals(ParentedRecursiveType <TRecursiveParent, TRecursiveType> x, ParentedRecursiveType <TRecursiveParent, TRecursiveType> y)
{
return(x.Value.Identity == y.Value.Identity);
}
