support modify balance modification transaction

pkg/services/transactions.go

@@ -369,7 +369,7 @@ func (s *TransactionService) ModifyTransaction(transaction *models.Transaction)
 		sourceAccount := &models.Account{}
 		destinationAccount := &models.Account{}
 
-		if transaction.SourceAccountId != oldTransaction.SourceAccountId {
+		if transaction.SourceAccountId != oldTransaction.SourceAccountId || transaction.SourceAmount != oldTransaction.SourceAmount {
 			has, err := sess.ID(transaction.SourceAccountId).Where("uid=? AND deleted=?", transaction.Uid, false).Get(sourceAccount)
 
 			if err != nil {
@@ -377,23 +377,36 @@ func (s *TransactionService) ModifyTransaction(transaction *models.Transaction)
 			} else if !has {
 				return errs.ErrSourceAccountNotFound
 			}
+		}
 
+		if transaction.DestinationAccountId != oldTransaction.DestinationAccountId || transaction.DestinationAmount != oldTransaction.DestinationAmount {
+			if transaction.DestinationAccountId == transaction.SourceAccountId {
+				destinationAccount = sourceAccount
+			} else {
+				has, err := sess.ID(transaction.DestinationAccountId).Where("uid=? AND deleted=?", transaction.Uid, false).Get(destinationAccount)
+
+				if err != nil {
+					return err
+				} else if !has {
+					return errs.ErrDestinationAccountNotFound
+				}
+			}
+		}
+
+		if transaction.SourceAccountId != oldTransaction.SourceAccountId {
 			updateCols = append(updateCols, "source_account_id")
 		}
 
 		if transaction.DestinationAccountId != oldTransaction.DestinationAccountId {
-			has, err := sess.ID(transaction.DestinationAccountId).Where("uid=? AND deleted=?", transaction.Uid, false).Get(destinationAccount)
-
-			if err != nil {
-				return err
-			} else if !has {
-				return errs.ErrDestinationAccountNotFound
-			}
-
 			updateCols = append(updateCols, "destination_account_id")
 		}
 
 		if transaction.SourceAmount != oldTransaction.SourceAmount {
+			if oldTransaction.Type == models.TRANSACTION_TYPE_MODIFY_BALANCE {
+				originalBalance := sourceAccount.Balance - oldTransaction.DestinationAmount
+				transaction.DestinationAmount = transaction.SourceAmount - originalBalance
+			}
+
 			updateCols = append(updateCols, "source_amount")
 		}
 
@@ -419,10 +432,14 @@ func (s *TransactionService) ModifyTransaction(transaction *models.Transaction)
 			}
 
 			if transaction.SourceAmount != oldTransaction.SourceAmount {
-				transaction.DestinationAmount = transaction.SourceAmount - sourceAccount.Balance
+				sourceAccount.UpdatedUnixTime = time.Now().Unix()
+				updatedRows, err := sess.ID(sourceAccount.AccountId).SetExpr("balance", fmt.Sprintf("balance-(%d)+(%d)", oldTransaction.DestinationAmount, transaction.DestinationAmount)).Cols("updated_unix_time").Where("uid=? AND deleted=?", sourceAccount.Uid, false).Update(sourceAccount)
 
-				// TODO: implement
+				if err != nil {
-				return errs.ErrNotImplemented
+					return err
+				} else if updatedRows < 1 {
+					return errs.ErrDatabaseOperationFailed
+				}
 			}
 		} else if oldTransaction.Type == models.TRANSACTION_TYPE_INCOME {
 			if transaction.SourceAccountId != oldTransaction.SourceAccountId && transaction.DestinationAmount != oldTransaction.DestinationAmount {