/*
 * Copyright 2012 LinkedIn Corp.
 *
 * Licensed 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 azkaban.execapp.metric;

import azkaban.event.Event;
import azkaban.event.Event.Type;
import azkaban.event.EventListener;
import azkaban.execapp.FlowRunner;
import azkaban.executor.Status;
import azkaban.metric.MetricException;
import azkaban.metric.MetricReportManager;
import azkaban.metric.TimeBasedReportingMetric;

/**
 * Metric to keep track of number of failed flows in between the tracking events
 */
public class NumFailedFlowMetric extends TimeBasedReportingMetric<Integer> implements EventListener {
  public static final String NUM_FAILED_FLOW_METRIC_NAME = "NumFailedFlowMetric";
  private static final String NUM_FAILED_FLOW_METRIC_TYPE = "uint16";

  public NumFailedFlowMetric(MetricReportManager manager, long interval) throws MetricException {
    super(NUM_FAILED_FLOW_METRIC_NAME, NUM_FAILED_FLOW_METRIC_TYPE, 0, manager, interval);
    logger.debug("Instantiated NumFailedJobMetric");
  }

  /**
  * Listen for events to maintain correct value of number of failed flows
  * {@inheritDoc}
  * @see azkaban.event.EventListener#handleEvent(azkaban.event.Event)
  */
  @Override
  public synchronized void handleEvent(Event event) {
    if (event.getType() == Type.FLOW_FINISHED) {
      FlowRunner runner = (FlowRunner) event.getRunner();
      if (runner != null && runner.getExecutableFlow().getStatus().equals(Status.FAILED)) {
        value = value + 1;
      }
    }
  }

  @Override
  protected void preTrackingEventMethod() {
    // Nothing to finalize before tracking event
  }

  @Override
  protected synchronized void postTrackingEventMethod() {
    value = 0;
  }

}