ConflictResolution.cs

//Started along with sync initiation
public void StartConflictLiveQuery()
		{
			ConflictsLiveQuery = Database.CreateAllDocumentsQuery().ToLiveQuery();
			ConflictsLiveQuery.AllDocsMode = AllDocsMode.OnlyConflicts;
			ConflictsLiveQuery.Changed += HandleConflicts;
			ConflictsLiveQuery.Start();
		}
    
    private void HandleConflicts(object sender, QueryChangeEventArgs e)
		{
			var rows = ConflictsLiveQuery?.Rows;
			if (rows == null)
			{
				return;
			}

			foreach (var row in rows)
			{
				var conflicts = row.GetConflictingRevisions().ToArray();
				if (conflicts.Length > 1)
				{
					var defaultWinning = conflicts[0];
					var type = defaultWinning.GetProperty("type") as string ?? "";
					var id = defaultWinning.GetProperty("_id") as string ?? "";
					AppLog.WriteLogD(TAG + "ResolveConflicts", "Id: " + id);
					AppLog.WriteLogD(TAG + "ResolveConflicts", "Document Type: " + type);
					AppLog.WriteLogD(TAG + "ResolveConflicts", "ConflictsCount: " + conflicts.Length);
					switch (type)
					{
						// Automatic conflict resolution
						case "patient":
							var props = defaultWinning.UserProperties;
							ResolveConflicts(conflicts, props);
							break;
						// N-way merge conflict resolution
						case "user_info":
							var merged = NWayMergeConflicts(conflicts);
							ResolveConflicts(conflicts, merged);
							break;
						default:
							break;
					}
				}
			}
		}
    
    private void ResolveConflicts(SavedRevision[] revs, IDictionary<string, object> props)
		{
			Database.RunInTransaction(() =>
			{
				var i = 0;
				foreach (var rev in revs)
				{
					var newRev = rev.CreateRevision();
					if (i == 0)
					{ // Default winning revision
						newRev.SetUserProperties(props);
					}
					else
					{
						newRev.IsDeletion = true;
					}

					try
					{
						newRev.Save(true);
					}
					catch (Exception e)
					{
						AppLog.WriteLogD(TAG, $"Cannot resolve conflicts with error: {e}");
						return false;
					}

					i += 1;
				}

				return true;
			});
		}
    
    private IDictionary<string, object> NWayMergeConflicts(SavedRevision[] revs)
		{
			var parent = FindCommonParent(revs);
			if (parent == null)
			{
				var defaultWinning = revs[0];
				var props = defaultWinning.UserProperties;
				return props;
			}

			var mergedProps = parent.UserProperties ?? new Dictionary<string, object>();

			var gotDevToken = false;
			var gotSubCancelDate = false;
			var gotPlanId = false;
			var gotSubName = false;
			var gotCancelled = false;
			var gotHasCard = false;
			var gotSubscribed = false;
			var gotSubCreateDate = false;
			var gotExpireDate = false;
			var gotSubId = false;
			var gotSubStartDate = false;

			var gotPhoto = false;
			var gotPhotoName = false;

			foreach (var rev in revs)
			{
				var props = rev.UserProperties;
				if (props != null)
				{
					if (!gotDevToken)
					{
						var devToken = Lookup<string>(props, "device_token");
						if (devToken != Lookup<string>(mergedProps, "device_token"))
						{
							mergedProps["device_token"] = devToken;
							gotDevToken = true;
						}
					}

					if (!gotSubCancelDate)
					{
						var subCancelDate = Lookup<string>(props, "subscription_cancel_date");
						if (subCancelDate != Lookup<string>(mergedProps, "subscription_cancel_date"))
						{
							mergedProps["subscription_cancel_date"] = subCancelDate;
							gotSubCancelDate = true;
						}
					}

					if (!gotPlanId)
					{
						var planId = Lookup<string>(props, "current_planId");
						if (planId != Lookup<string>(mergedProps, "current_planId"))
						{
							mergedProps["current_planId"] = planId;
							gotPlanId = true;
						}
					}

					if (!gotSubName)
					{
						var currentSub = Lookup<string>(props, "current_subscription");
						if (currentSub != Lookup<string>(mergedProps, "current_subscription"))
						{
							mergedProps["current_subscription"] = currentSub;
							gotSubName = true;
						}
					}

					if (!gotCancelled)
					{
						var hasCancelled = LookupNullable<bool>(props, "has_cancelled_subscription");
						if (hasCancelled != LookupNullable<bool>(mergedProps, "has_cancelled_subscription"))
						{
							mergedProps["has_cancelled_subscription"] = hasCancelled;
							gotCancelled = true;
						}
					}

					if (!gotHasCard)
					{
						var hasCard = LookupNullable<bool>(props, "has_card");
						if (hasCard != LookupNullable<bool>(mergedProps, "has_card"))
						{
							mergedProps["has_card"] = hasCard;
							gotHasCard = true;
						}
					}

					if (!gotSubscribed)
					{
						var hasSubscribed = LookupNullable<bool>(props, "subscribed");
						if (hasSubscribed != LookupNullable<bool>(mergedProps, "subscribed"))
						{
							mergedProps["subscribed"] = hasSubscribed;
							gotSubscribed = true;
						}
					}

					if (!gotSubCreateDate)
					{
						var createDate = Lookup<string>(props, "subscription_created_at");
						if (createDate != Lookup<string>(mergedProps, "subscription_created_at"))
						{
							mergedProps["subscription_created_at"] = createDate;
							gotSubCreateDate = true;
						}
					}

					if (!gotExpireDate)
					{
						var expDate = Lookup<string>(props, "subscription_expire_at");
						if (expDate != Lookup<string>(mergedProps, "subscription_expire_at"))
						{
							mergedProps["subscription_expire_at"] = expDate;
							gotExpireDate = true;
						}
					}

					if (!gotSubId)
					{
						var subId = Lookup<string>(props, "subscription_id");
						if (subId != Lookup<string>(mergedProps, "subscription_id"))
						{
							mergedProps["subscription_id"] = subId;
							gotSubId = true;
						}
					}

					if (!gotSubStartDate)
					{
						var subStartDate = Lookup<string>(props, "subscription_start_date");
						if (subStartDate != Lookup<string>(mergedProps, "subscription_start_date"))
						{
							mergedProps["subscription_start_date"] = subStartDate;
							gotSubStartDate = true;
						}
					}

					if (!gotPhoto)
					{
						var photo = Lookup<string>(props, "photo");
						if (photo != Lookup<string>(mergedProps, "photo"))
						{
							mergedProps["photo"] = photo;
							gotPhoto = true;
						}
					}

					if (!gotPhotoName)
					{
						var photoName = Lookup<string>(props, "photo_name");
						if (photoName != Lookup<string>(mergedProps, "photo_name"))
						{
							mergedProps["photo_name"] = photoName;
							gotPhotoName = true;
						}
					}

					if (gotDevToken && gotSubCancelDate && gotPlanId && gotSubName && gotCancelled 
					    && gotHasCard && gotSubscribed && gotSubCreateDate && gotExpireDate && 
					    gotSubId && gotSubStartDate && gotPhoto && gotPhotoName)
					{
						break;
					}
				}
			}

			return mergedProps;
		}