/*
    * Copyright 2014 The Netty Project
    *
    * The Netty 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:
    *
    *   https://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 io.netty.handler.traffic;
  
  import static io.netty.util.internal.ObjectUtil.checkNotNullWithIAE;
  
  import io.netty.handler.traffic.GlobalChannelTrafficShapingHandler.PerChannel;
  
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.TimeUnit;
  
  /**
   * Version for {@link GlobalChannelTrafficShapingHandler}.
   * This TrafficCounter is the Global one, and its special property is to directly handle
   * other channel's TrafficCounters. In particular, there are no scheduler for those
   * channel's TrafficCounters because it is managed by this one.
   */
  public class GlobalChannelTrafficCounter extends TrafficCounter {
      /**
       * @param trafficShapingHandler the associated {@link GlobalChannelTrafficShapingHandler}.
       * @param executor the underlying executor service for scheduling checks (both Global and per Channel).
       * @param name the name given to this monitor.
       * @param checkInterval the checkInterval in millisecond between two computations.
       */
      public GlobalChannelTrafficCounter(GlobalChannelTrafficShapingHandler trafficShapingHandler,
              ScheduledExecutorService executor, String name, long checkInterval) {
          super(trafficShapingHandler, executor, name, checkInterval);
          checkNotNullWithIAE(executor, "executor");
      }
  
      /**
       * Class to implement monitoring at fix delay.
       * This version is Mixed in the way it mixes Global and Channel counters.
       */
      private static class MixedTrafficMonitoringTask implements Runnable {
          /**
           * The associated TrafficShapingHandler
           */
          private final GlobalChannelTrafficShapingHandler trafficShapingHandler1;
  
          /**
           * The associated TrafficCounter
           */
          private final TrafficCounter counter;
  
          /**
           * @param trafficShapingHandler The parent handler to which this task needs to callback to for accounting.
           * @param counter The parent TrafficCounter that we need to reset the statistics for.
           */
          MixedTrafficMonitoringTask(
                  GlobalChannelTrafficShapingHandler trafficShapingHandler,
                  TrafficCounter counter) {
              trafficShapingHandler1 = trafficShapingHandler;
              this.counter = counter;
          }
  
          @Override
          public void run() {
              if (!counter.monitorActive) {
                  return;
              }
              long newLastTime = milliSecondFromNano();
              counter.resetAccounting(newLastTime);
              for (PerChannel perChannel : trafficShapingHandler1.channelQueues.values()) {
                  perChannel.channelTrafficCounter.resetAccounting(newLastTime);
              }
              trafficShapingHandler1.doAccounting(counter);
          }
      }
  
      /**
       * Start the monitoring process.
       */
      @Override
      public synchronized void start() {
          if (monitorActive) {
              return;
          }
          lastTime.set(milliSecondFromNano());
          long localCheckInterval = checkInterval.get();
          if (localCheckInterval > 0) {
              monitorActive = true;
              monitor = new MixedTrafficMonitoringTask((GlobalChannelTrafficShapingHandler) trafficShapingHandler, this);
              scheduledFuture =
                  executor.scheduleAtFixedRate(monitor, 0, localCheckInterval, TimeUnit.MILLISECONDS);
          }
     }
 
     /**
      * Stop the monitoring process.
      */
     @Override
     public synchronized void stop() {
         if (!monitorActive) {
             return;
         }
         monitorActive = false;
         resetAccounting(milliSecondFromNano());
         trafficShapingHandler.doAccounting(this);
         if (scheduledFuture != null) {
             scheduledFuture.cancel(true);
         }
     }
 
     @Override
     public void resetCumulativeTime() {
         for (PerChannel perChannel :
             ((GlobalChannelTrafficShapingHandler) trafficShapingHandler).channelQueues.values()) {
             perChannel.channelTrafficCounter.resetCumulativeTime();
         }
         super.resetCumulativeTime();
     }
 
 }