gistfile1.cs

            DuplicateContractCommand = new RelayCommand<ContractListItem>(c =>
                                                                      {
                                                                          if (CheckLocked()) return;

                                                                          SaveBeforeContinue();

                                                                          var copy = c.Contract.Copy();

                                                                          // Append (n) to the copys name. 
                                                                          // The algorithm will find the highest n in use for the common prefix of the property identifier.
                                                                          var regex = new Regex(@"\((?<index>\d+)\)$");
                                                                          var match = regex.Match(copy.PropertyIdentifier);
                                                                          var max = 0;
                                                                          if (match.Success)
                                                                          {
                                                                              max = int.Parse(match.Groups["index"].Captures[0].Value);
                                                                          }

                                                                          foreach (var contractListItem in ContractListItems)
                                                                          {
                                                                              // Strip any copy suffix and compare to make sure that we have a real collision
                                                                              var cleanName = regex.Replace(copy.PropertyIdentifier, "").ToLower().Trim();
                                                                              var currentItemCleanName = regex.Replace(contractListItem.Contract.PropertyIdentifier, "").ToLower().Trim();
                                                                              if (currentItemCleanName != cleanName)
                                                                                  continue;

                                                                              // Get "copy number" of this item and store it as max if it's higher than before
                                                                              var innerMatch = regex.Match(contractListItem.Contract.PropertyIdentifier);
                                                                              if (innerMatch.Success)
                                                                              {
                                                                                  var num = int.Parse(innerMatch.Groups["index"].Captures[0].Value);
                                                                                  if (num > max)
                                                                                      max = num;
                                                                              }
                                                                          }

                                                                          // Set new name to one above max
                                                                          if (match.Success)
                                                                              copy.PropertyIdentifier = regex.Replace(copy.PropertyIdentifier, "(" + ++max + ")");
                                                                          else
                                                                              copy.PropertyIdentifier = copy.PropertyIdentifier + " (" + ++max + ")";

                                                                          // Save to db
                                                                          _dataService.SaveContract(copy);

                                                                          // Create new list item
                                                                          var newContractListItem = new ContractListItem() { Contract = copy, TransactionId = copy.Id };
                                                                          ContractListItems.Add(newContractListItem);
                                                                          CurrentContractListItem = newContractListItem;
                                                                          RaisePropertyChanged(() => CurrentContractListItem);

                                                                      }, c => c != null);