/// <summary>
/// Wrapper for handling replace task, but without adding to merge records.
/// </summary>
/// <param name="vote">The vote being modified.</param>
/// <param name="task">The new task to apply to the vote.</param>
/// <returns>Returns true if the task replacement was successfully completed.</returns>
private bool ReplaceTaskImplWrapper(VoteLineBlock vote, string task)
{
if (!VoteStorage.TryGetValue(vote, out var supporters))
{
return(false);
}
// Incoming parameter may be an entry in storage, or a copy of a vote.
// Adjust so that we're always pointing at an actual vote.
// If the vote isn't found in VoteStorage, just use the one provided.
vote = VoteStorage.GetVoteMatching(vote) ?? vote;
// Remove the version of the vote we're starting with.
VoteStorage.Remove(vote);
string originalTask = vote.Task;
vote.Task = task;
// If there's a conflict with the newly-tasked vote, we need to merge with the existing vote.
if (VoteStorage.ContainsKey(vote))
{
if (VoteStorage.TryGetValue(vote, out var toSupport))
{
foreach (var(supporterName, supporterVote) in supporters)
{
if (!toSupport.ContainsKey(supporterName))
{
supporterVote.Task = task;
toSupport.Add(supporterName, supporterVote);
}
}
}
else
{
// Undo the attempt if we couldn't get the conflicting vote data
vote.Task = originalTask;
VoteStorage.Add(vote, supporters);
return(false);
}
}
// If there's no conflict, update the tasks in the supporter votes and add the revised vote.
else
{
foreach (var(_, supporterVote) in supporters)
{
supporterVote.Task = task;
}
VoteStorage.Add(vote, supporters);
}
return(true);
}
public UndoAction(UndoActionType actionType, VoteStorage currentState,
VoteLineBlock?storageVote = null)
{
ActionType = actionType;
// Clone the current vote repository.
storage = new VoteStorage(currentState);
// Utilize a cloned storage vote if we need to track a changed VoteLineBlock
// that had internal properties changed. Otherwise those will be propogated
// to our storage collection.
if (storageVote != null)
{
var storedVote = storageVote.Clone();
storage.TryGetValue(storageVote, out var storedVoteSupporters);
storage.Remove(storageVote);
storage.Add(storedVote, storedVoteSupporters);
}
}
private bool SplitImplWrapper(VoteLineBlock fromVote, List <VoteLineBlock> toVotes)
{
if (!VoteStorage.TryGetValue(fromVote, out var fromSupport))
{
return(false);
}
foreach (var toVote in toVotes)
{
if (!VoteStorage.TryGetValue(toVote, out var toSupport))
{
return(false);
}
MergeImpl(fromVote, toVote, fromSupport, toSupport);
}
// But we still want to remove the from vote.
return(VoteStorage.Remove(fromVote));
}
/// <summary>
/// The wrapper handles the process of extracting the vote support from
/// the storage before passing the pieces on to the implementation.
/// </summary>
/// <param name="fromVote">The vote being merged.</param>
/// <param name="toVote">The vote being merged into.</param>
/// <returns>Returns true if there was a successful merge.</returns>
private bool MergeImplWrapper(VoteLineBlock fromVote, VoteLineBlock toVote)
{
if (fromVote == toVote)
{
return(false);
}
if (!VoteStorage.TryGetValue(fromVote, out var fromSupport))
{
return(false);
}
if (!VoteStorage.TryGetValue(toVote, out var toSupport))
{
return(false);
}
// Theoretically, all the supporters in the from vote could already
// be in the to vote, in which case no merging would happen.
MergeImpl(fromVote, toVote, fromSupport, toSupport);
// But we still want to remove the from vote.
return(VoteStorage.Remove(fromVote));
}
public bool Undo(IVoteCounter voteCounter)
{
if (undone)
{
return(false);
}
var currentVotes = voteCounter.VoteStorage;
// Remove pass - Remove all current votes or supporters that are not
// in the archived version of the vote repository.
HashSet <VoteLineBlock> voteRemovals = new HashSet <VoteLineBlock>();
foreach (var(currentVote, currentSupporters) in currentVotes)
{
if (!storage.TryGetValue(currentVote, out var storageSupporters))
{
voteRemovals.Add(currentVote);
}
else
{
HashSet <Origin> voterRemovals = new HashSet <Origin>();
foreach (var(currentSupporter, _) in currentSupporters)
{
if (!storageSupporters.ContainsKey(currentSupporter))
{
voterRemovals.Add(currentSupporter);
}
}
foreach (var removal in voterRemovals)
{
currentSupporters.Remove(removal);
}
}
}
foreach (var removal in voteRemovals)
{
currentVotes.Remove(removal);
}
// Replace pass - Add all archived votes or supporters that are not
// in the current version of the vote repository.
foreach (var(storageVote, storageSupporters) in storage)
{
if (!currentVotes.TryGetValue(storageVote, out var currentSupporters))
{
currentVotes.Add(storageVote, storageSupporters);
}
else
{
foreach (var(storageSupporter, storageSupporterVote) in storageSupporters)
{
if (!currentSupporters.ContainsKey(storageSupporter))
{
currentSupporters.Add(storageSupporter, storageSupporterVote);
}
}
}
}
return(undone = true);
}
