/*
 * Copyright 2010-2013 Ning, Inc.
 * Copyright 2014 Groupon, Inc
 * Copyright 2014 The Billing Project, LLC
 *
 * The Billing Project licenses this file to you under the Apache License, version 2.0
 * (the "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at:
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package org.killbill.billing.payment.api;

public enum TransactionStatus {
    /* Success! */
    SUCCESS,
    /* Initial status */
    UNKNOWN,
    /* The payment is asynchronous and final state will be updated later */
    PENDING,
    /* Plugin failed to make the payment */
    PAYMENT_FAILURE,
    /* Exception from plugin, state is unknown */
    PLUGIN_FAILURE,
    /* Payment Subsystem is off */
    PAYMENT_SYSTEM_OFF;
}

@@ -834,16 +834,80 @@
 l status
+ or plugin does not know (transaction may or not have happenend)
  */%0A    
@@ -1015,112 +1015,260 @@
  /* 
-Plugin failed to make the payment */%0A    PAYMENT_FAILURE,%0A    /* Exception from plugin, state is unknown
+Transaction went through, but came back with an error (for e.g : not enough funds) */%0A    PAYMENT_FAILURE,%0A    /* The transaction did not go through, and plugin knows for sure that operation was not even attenpted (for e.g: connection error to gateway)
  */%0A

Update comments (Review for TransactionStatus definitions)